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gcc/0142-crc-loop-optimization-initial.patch
wangding16 40d16c6c94 [Sync] Sync patch from openeuler/gcc 
0142-crc-loop-optimization-initial.patch
2023-12-06 11:49:42 +08:00

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From 2716abb1a4de2a4edf06d2f1877d9b76a88e5807 Mon Sep 17 00:00:00 2001
From: bule <bule1@huawei.com>
Date: Thu, 15 Dec 2022 14:34:16 +0800
Subject: [PATCH 05/33] crc loop optimization initial
---
gcc/Makefile.in | 1 +
gcc/common.opt | 4 +
gcc/doc/invoke.texi | 6 +-
gcc/match.pd | 169 +++++
gcc/passes.def | 1 +
gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c | 85 +++
.../tree-ssa/loop-crc-1.c.042t.loop_crc | 90 +++
gcc/testsuite/gcc.dg/tree-ssa/loop-crc-2.c | 88 +++
gcc/testsuite/gcc.dg/tree-ssa/loop-crc-3.c | 85 +++
gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c | 89 +++
.../tree-ssa/loop-crc-4.c.042t.loop_crc | 0
.../loop-crc-calculation-check-fail.c | 156 +++++
...crc-calculation-check-fail.c.042t.loop_crc | 64 ++
.../loop-crc-calculation-check-fail.s | 329 +++++++++
.../gcc.dg/tree-ssa/loop-crc-loop-form-fail.c | 111 +++
.../gcc.dg/tree-ssa/loop-crc-sucess.c | 84 +++
.../tree-ssa/loop-crc-table-check-fail.c | 113 +++
gcc/timevar.def | 1 +
gcc/tree-pass.h | 1 +
gcc/tree-ssa-loop-crc.c | 644 ++++++++++++++++++
20 files changed, 2120 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c.042t.loop_crc
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-2.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-3.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c.042t.loop_crc
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c.042t.loop_crc
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.s
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-loop-form-fail.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-sucess.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loop-crc-table-check-fail.c
create mode 100644 gcc/tree-ssa-loop-crc.c
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 3f06b8907..2a59acfbe 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1592,6 +1592,7 @@ OBJS = \
tree-ssa-loop-manip.o \
tree-ssa-loop-niter.o \
tree-ssa-loop-array-widen-compare.o \
+ tree-ssa-loop-crc.o \
tree-ssa-loop-prefetch.o \
tree-ssa-loop-split.o \
tree-ssa-loop-unswitch.o \
diff --git a/gcc/common.opt b/gcc/common.opt
index 6f0ed7cea..a286a2628 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1065,6 +1065,10 @@ Common Report Var(flag_array_widen_compare) Optimization
Extends types for pointers to arrays to improve array comparsion performance.
In some extreme situations this may result in unsafe behavior.
+floop-crc
+Common Report Var(flag_loop_crc) Optimization
+do the loop crc conversion.
+
fauto-inc-dec
Common Report Var(flag_auto_inc_dec) Init(1) Optimization
Generate auto-inc/dec instructions.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7498758b0..52018617a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -460,7 +460,7 @@ Objective-C and Objective-C++ Dialects}.
-fno-allocation-dce -fallow-store-data-races @gol
-fassociative-math -fauto-profile -fauto-profile[=@var{path}] @gol
-farray-widen-compare -fauto-inc-dec -fbranch-probabilities @gol
--fcaller-saves @gol
+-fcaller-saves -floop-crc @gol
-fcombine-stack-adjustments -fconserve-stack @gol
-fcompare-elim -fcprop-registers -fcrossjumping @gol
-fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules @gol
@@ -9722,6 +9722,10 @@ extreme situations this may result in unsafe behavior.
This option may generate better or worse code; results are highly dependent
on the structure of loops within the source code.
+@item -floop-crc
+@opindex floop-crc
+Do the loop crc conversion
+
@item -fdce
@opindex fdce
Perform dead code elimination (DCE) on RTL@.
diff --git a/gcc/match.pd b/gcc/match.pd
index 01f81b063..87b316953 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3487,6 +3487,175 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
)
#endif
+
+#if GIMPLE
+(if (canonicalize_math_p ())
+/* These patterns are mostly used by PHIOPT to move some operations outside of
+ the if statements. They should be done late because it gives jump threading
+ and few other passes to reduce what is going on. */
+/* a ? x op POW2 : x -> x op (a ? POW2 : 0). */
+ (for op (plus minus bit_ior bit_xor lshift rshift lrotate rrotate)
+ (simplify
+ (cond @0 (op:s @1 INTEGER_CST@2) @1)
+ /* powerof2cst */
+ (if (INTEGRAL_TYPE_P (type) && integer_pow2p (@2))
+ (with {
+ tree shift = build_int_cst (integer_type_node, tree_log2 (@2));
+ }
+ (op @1 (lshift (convert (convert:boolean_type_node @0)) { shift; })))
+ )
+ )
+ )
+)
+#endif
+
+#if GIMPLE
+/* These patterns are mostly used by FORWPROP to move some operations outside of
+ the if statements. They should be done late because it gives jump threading
+ and few other passes to reduce what is going on. */
+/* Mul64 is defined as a multiplication algorithm which compute two 64-bit integers to one 128-bit integer
+ (i64 ResLo, i64 ResHi) = Mul64(i64 In0, i64 In1) {
+ In0Lo = In0(D) & 4294967295;
+ In0Hi = In0(D) >> 32;
+ In1Lo = In1(D) & 4294967295;
+ In1Hi = In1(D) >> 32;
+ Mull_01 = In0Hi * In1Lo;
+ Addc = In0Lo * In1Hi + Mull_01;
+ addc32 = Addc << 32;
+ ResLo = In0Lo * In1Lo + addc32;
+ ResHi = ((long unsigned int) (addc32 > ResLo)) +
+ (((long unsigned int) (Mull_01 > Addc)) << 32) + (Addc >> 32) + In0Hi * In1Hi;
+ } */
+ (simplify
+ (plus
+ (plus
+ (convert
+ (gt @10
+ (plus
+ (mult @4 @6)
+ (lshift@10 @9 @3))))
+ (lshift
+ (convert
+ (gt @8 @9)) @3))
+ (plus@11
+ (rshift
+ (plus@9
+ (mult (bit_and@4 SSA_NAME@0 @2) @7)
+ (mult@8 @5 (bit_and@6 SSA_NAME@1 INTEGER_CST@2))) @3)
+ (mult (rshift@5 SSA_NAME@0 @3)
+ (rshift@7 SSA_NAME@1 INTEGER_CST@3))))
+ (if (INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (@0)) && types_match (@0, @1) &&
+ TYPE_PRECISION (type) == 64)
+ (with {
+ tree i128_type = build_nonstandard_integer_type (128, TYPE_UNSIGNED (type));
+ tree shift = build_int_cst (integer_type_node, 64);
+ //direct_internal_fn_supported_p (UMULH, type, OPTIMIZE_FOR_BOTH)
+ }
+ (convert:type (rshift
+ (mult (convert:i128_type @0) (convert:i128_type @1)) { shift; })))
+ )
+ )
+
+ /* (i64 ResLo, i64 ResHi) = Mul64(i64 In0, i64 In1) {
+ In0Lo = In0(D) & 4294967295;
+ In0Hi = In0(D) >> 32;
+ In1Lo = In1(D) & 4294967295;
+ In1Hi = In1(D) >> 32;
+ Mull_01 = In0Hi * In1Lo;
+ Addc = In0Lo * In1Hi + Mull_01;
+ addc32 = Addc << 32;
+ ResLo = In0(D) * In1(D);
+ ResHi = ((long unsigned int) (addc32 > ResLo)) +
+ (((long unsigned int) (Mull_01 > Addc)) << 32) + (Addc >> 32) + In0Hi * In1Hi;
+ } */
+ (simplify
+ (plus
+ (plus
+ (convert
+ (gt (lshift@10 @9 @3)
+ (mult @0 @1)))
+ (lshift
+ (convert
+ (gt @8 @9)) @3))
+ (plus@11
+ (rshift
+ (plus@9
+ (mult (bit_and@4 SSA_NAME@0 @2) @7)
+ (mult@8 @5 (bit_and@6 SSA_NAME@1 INTEGER_CST@2))) @3)
+ (mult (rshift@5 SSA_NAME@0 @3)
+ (rshift@7 SSA_NAME@1 INTEGER_CST@3))))
+ (if (INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (@0)) && types_match (@0, @1) &&
+ TYPE_PRECISION (type) == 64)
+ (with {
+ tree i128_type = build_nonstandard_integer_type (128, TYPE_UNSIGNED (type));
+ tree shift = build_int_cst (integer_type_node, 64);
+ //direct_internal_fn_supported_p (UMULH, type, OPTIMIZE_FOR_BOTH)
+ }
+ (convert:type (rshift
+ (mult (convert:i128_type @0) (convert:i128_type @1)) { shift; })))
+ )
+ )
+#endif
+
+#if GIMPLE
+/* These patterns are mostly used by FORWPROP to move some operations outside of
+ the if statements. They should be done late because it gives jump threading
+ and few other passes to reduce what is going on. */
+ /*
+ In0Lo = In0(D) & 4294967295;
+ In0Hi = In0(D) >> 32;
+ In1Lo = In1(D) & 4294967295;
+ In1Hi = In1(D) >> 32;
+ Addc = In0Lo * In1Hi + In0Hi * In1Lo;
+ addc32 = Addc << 32;
+ ResLo = In0Lo * In1Lo + addc32
+ */
+ (simplify
+ (plus (mult @4 @5)
+ (lshift
+ (plus
+ (mult (bit_and@4 SSA_NAME@0 @2) (rshift SSA_NAME@1 @3))
+ (mult (rshift SSA_NAME@0 @3) (bit_and@5 SSA_NAME@1 INTEGER_CST@2))) INTEGER_CST@3))
+ (if (INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (@0)) && types_match (@0, @1) &&
+ TYPE_PRECISION (type) == 64)
+ (with {
+ tree i128_type = build_nonstandard_integer_type (128, TYPE_UNSIGNED (type));
+ tree shift = build_int_cst (integer_type_node, 64);
+ //direct_internal_fn_supported_p (UMULH, type, OPTIMIZE_FOR_BOTH)
+ }
+ (mult (convert:type @0) (convert:type @1)))
+ )
+ )
+#endif
+
+
+#if GIMPLE
+/* Try to match */
+ /*
+_4 = (int) _3; //NOP_EXPR (SSA_NAME @2)
+_5 = _4 ^ c_10; //BIT_XOR_EXPR (SSA_NAME@1, SSA_NAME)
+_6 = _5 & 255; //BIT_XOR_EXPR (SSA_NAME, INTEGER_CST@3)
+ */
+(match (crc_match_index @1 @2 @3)
+ (bit_and (bit_xor (nop SSA_NAME@2) SSA_NAME@1) INTEGER_CST@3)
+ (if (INTEGRAL_TYPE_P (type) && tree_to_uhwi(@3) == 255))
+)
+
+#endif
+
+#if GIMPLE
+/* Try to match */
+ /*
+_8 = c_12 >> 8; // RSHIFT_EXPR (SSA_NAME @1, INTEGER_CST @2)
+c_19 = _7 ^ _8; // BIT_XOR_EXPR (SSA_NAME@3, SSA_NAME)
+ */
+(match (crc_match_res @1 @2 @3)
+ (bit_xor SSA_NAME@3 (rshift SSA_NAME@1 INTEGER_CST@2))
+ (if (INTEGRAL_TYPE_P (type) && tree_to_uhwi(@2) == 8))
+)
+
+#endif
+
/* Simplification moved from fold_cond_expr_with_comparison. It may also
be extended. */
/* This pattern implements two kinds simplification:
diff --git a/gcc/passes.def b/gcc/passes.def
index ea50db086..7abd946ce 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -92,6 +92,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_cd_dce);
NEXT_PASS (pass_phiopt, true /* early_p */);
NEXT_PASS (pass_array_widen_compare);
+ NEXT_PASS (pass_loop_crc);
NEXT_PASS (pass_tail_recursion);
NEXT_PASS (pass_convert_switch);
NEXT_PASS (pass_cleanup_eh);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c
new file mode 100644
index 000000000..07f9e01ec
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c
@@ -0,0 +1,85 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n);
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Processing loop" 1 "loop_crc"} } */
+/* { dg-final { scan-tree-dump-times "the loop can be optimized" 1 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c.042t.loop_crc b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c.042t.loop_crc
new file mode 100644
index 000000000..c726059f3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-1.c.042t.loop_crc
@@ -0,0 +1,90 @@
+
+;; Function updcrc (updcrc, funcdef_no=0, decl_uid=3687, cgraph_uid=1, symbol_order=1)
+
+;; 2 loops found
+;;
+;; Loop 0
+;; header 0, latch 1
+;; depth 0, outer -1
+;; nodes: 0 1 2 3 6 4 7 5
+;;
+;; Loop 1
+;; header 4, latch 7
+;; depth 1, outer 0
+;; nodes: 4 7
+;; 2 succs { 5 3 }
+;; 3 succs { 6 5 }
+;; 6 succs { 4 }
+;; 4 succs { 7 5 }
+;; 7 succs { 4 }
+;; 5 succs { 1 }
+
+Starting the loop_crc pass
+======================================
+Processing loop 1:
+======================================
+;;
+;; Loop 1
+;; header 4, latch 7
+;; depth 1, outer 0
+;; nodes: 4 7
+
+
+The 1th loop form is success matched,and the loop can be optimized.
+updcrc (uch * s, unsigned int n)
+{
+ static ulg crc = 4294967295;
+ register ulg c;
+ unsigned char _2;
+ long unsigned int _3;
+ long unsigned int _4;
+ long unsigned int _5;
+ long unsigned int _6;
+ long unsigned int _7;
+ ulg _21;
+
+ <bb 2> :
+ if (s_12(D) == 0B)
+ goto <bb 5>; [INV]
+ else
+ goto <bb 3>; [INV]
+
+ <bb 3> :
+ c_14 = crc;
+ if (n_15(D) != 0)
+ goto <bb 6>; [INV]
+ else
+ goto <bb 5>; [INV]
+
+ <bb 6> :
+
+ <bb 4> :
+ # s_8 = PHI <s_12(D)(6), s_16(7)>
+ # n_9 = PHI <n_15(D)(6), n_18(7)>
+ # c_10 = PHI <c_14(6), c_17(7)>
+ s_16 = s_8 + 1;
+ _2 = *s_8;
+ _3 = (long unsigned int) _2;
+ _4 = _3 ^ c_10;
+ _5 = _4 & 255;
+ _6 = crc_32_tab[_5];
+ _7 = c_10 >> 8;
+ c_17 = _6 ^ _7;
+ n_18 = n_9 + 4294967295;
+ if (n_18 != 0)
+ goto <bb 7>; [INV]
+ else
+ goto <bb 5>; [INV]
+
+ <bb 7> :
+ goto <bb 4>; [100.00%]
+
+ <bb 5> :
+ # c_11 = PHI <4294967295(2), c_14(3), c_17(4)>
+ crc = c_11;
+ _21 = c_11 ^ 4294967295;
+ return _21;
+
+}
+
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-2.c
new file mode 100644
index 000000000..f73c4d550
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-2.c
@@ -0,0 +1,88 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ for (int i = 0; i < 5; i++) {
+ c++;
+ }
+
+ } while (--n);
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Wrong loop form for crc matching." 1 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-3.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-3.c
new file mode 100644
index 000000000..70eb1b814
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-3.c
@@ -0,0 +1,85 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n || c != 0) ;
+ }
+ crc = c;
+exit1:
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Wrong loop form for crc matching." 1 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c
new file mode 100644
index 000000000..1d7e0a319
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c
@@ -0,0 +1,89 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+int test[5] = {0};
+
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8) * test[c%5];
+ } while (--n) ;
+ }
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ test[c%5] = c;
+ } while (--n) ;
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Table check fail. not only single array is read." 2 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c.042t.loop_crc b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-4.c.042t.loop_crc
new file mode 100644
index 000000000..e69de29bb
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c
new file mode 100644
index 000000000..71b25f537
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c
@@ -0,0 +1,156 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+int test[5] = {0};
+
+ulg updcrc(s, n)
+ uch *s;
+ unsigned n;
+{
+ register ulg c;
+
+ static ulg crc = (ulg)0xffffffffL;
+ int a = 0;
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ a++;
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8) ;
+ } while (--n) ;
+ }
+ crc = c;
+ return c ^ 0xffffffffL*a;
+}
+
+ulg updcrc1(s, n)
+ uch *s;
+ unsigned n;
+{
+ register ulg c;
+
+ static ulg crc = (ulg)0xffffffffL;
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ unsigned n_back = n;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8) ;
+ n = n - 2;
+ } while (n != 0) ;
+ }
+
+ crc = c;
+ return c ^ 0xffffffffL;
+}
+
+ulg updcrc2(s, n)
+ uch *s;
+ unsigned n;
+{
+ register ulg c;
+
+ static ulg crc = (ulg)0xffffffffL;
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ unsigned n_back = n;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8) + 1;
+ } while (--n) ;
+ }
+
+ crc = c;
+ return c ^ 0xffffffffL;
+}
+/*
+ulg updcrc3(s, n)
+ uch *s;
+ int n;
+{
+ register ulg c;
+
+ static ulg crc = (ulg)0xffffffffL;
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ --n;
+ } while (n ) ;
+ }
+
+ crc = c;
+ return c ^ 0xffffffffL;
+}*/
+/* { dg-final { scan-tree-dump-times "num of phi noeds check failed." 1 "loop_crc"} } */
+/* { dg-final { scan-tree-dump-times "evolution pattern check failed." 1 "loop_crc"} } */
+/* { dg-final { scan-tree-dump-times "calculation pattern check failed." 1 "loop_crc"} } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c.042t.loop_crc b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c.042t.loop_crc
new file mode 100644
index 000000000..6d52a8684
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.c.042t.loop_crc
@@ -0,0 +1,64 @@
+
+;; Function updcrc3 (updcrc3, funcdef_no=0, decl_uid=3687, cgraph_uid=1, symbol_order=1)
+
+;; 2 loops found
+;;
+;; Loop 0
+;; header 0, latch 1
+;; depth 0, outer -1
+;; nodes: 0 1 2 3 4 5
+;;
+;; Loop 1
+;; header 4, latch 4
+;; depth 1, outer 0
+;; nodes: 4
+;; 2 succs { 5 3 }
+;; 3 succs { 4 5 }
+;; 4 succs { 4 }
+;; 5 succs { 1 }
+
+Starting the loop_crc pass
+======================================
+Processing loop 1:
+======================================
+;;
+;; Loop 1
+;; header 4, latch 4
+;; depth 1, outer 0
+;; nodes: 4
+
+
+
+Wrong loop form for crc matching.
+updcrc3 (uch * s, unsigned int n)
+{
+ unsigned int n_back;
+ static ulg crc = 4294967295;
+ register ulg c;
+ ulg _22;
+
+ <bb 2> :
+ if (s_12(D) == 0B)
+ goto <bb 5>; [INV]
+ else
+ goto <bb 3>; [INV]
+
+ <bb 3> :
+ c_14 = crc;
+ if (n_15(D) != 0)
+ goto <bb 4>; [INV]
+ else
+ goto <bb 5>; [INV]
+
+ <bb 4> :
+ goto <bb 4>; [100.00%]
+
+ <bb 5> :
+ # c_11 = PHI <4294967295(2), c_14(3)>
+ crc = c_11;
+ _22 = c_11 ^ 4294967295;
+ return _22;
+
+}
+
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.s b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.s
new file mode 100644
index 000000000..cae934bfe
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-calculation-check-fail.s
@@ -0,0 +1,329 @@
+ .arch armv8-a
+ .file "loop-crc-calculation-check-fail.c"
+ .text
+ .section .rodata
+ .align 3
+ .type crc_32_tab, %object
+ .size crc_32_tab, 2048
+crc_32_tab:
+ .xword 0
+ .xword 1996959894
+ .xword 3993919788
+ .xword 2567524794
+ .xword 124634137
+ .xword 1886057615
+ .xword 3915621685
+ .xword 2657392035
+ .xword 249268274
+ .xword 2044508324
+ .xword 3772115230
+ .xword 2547177864
+ .xword 162941995
+ .xword 2125561021
+ .xword 3887607047
+ .xword 2428444049
+ .xword 498536548
+ .xword 1789927666
+ .xword 4089016648
+ .xword 2227061214
+ .xword 450548861
+ .xword 1843258603
+ .xword 4107580753
+ .xword 2211677639
+ .xword 325883990
+ .xword 1684777152
+ .xword 4251122042
+ .xword 2321926636
+ .xword 335633487
+ .xword 1661365465
+ .xword 4195302755
+ .xword 2366115317
+ .xword 997073096
+ .xword 1281953886
+ .xword 3579855332
+ .xword 2724688242
+ .xword 1006888145
+ .xword 1258607687
+ .xword 3524101629
+ .xword 2768942443
+ .xword 901097722
+ .xword 1119000684
+ .xword 3686517206
+ .xword 2898065728
+ .xword 853044451
+ .xword 1172266101
+ .xword 3705015759
+ .xword 2882616665
+ .xword 651767980
+ .xword 1373503546
+ .xword 3369554304
+ .xword 3218104598
+ .xword 565507253
+ .xword 1454621731
+ .xword 3485111705
+ .xword 3099436303
+ .xword 671266974
+ .xword 1594198024
+ .xword 3322730930
+ .xword 2970347812
+ .xword 795835527
+ .xword 1483230225
+ .xword 3244367275
+ .xword 3060149565
+ .xword 1994146192
+ .xword 31158534
+ .xword 2563907772
+ .xword 4023717930
+ .xword 1907459465
+ .xword 112637215
+ .xword 2680153253
+ .xword 3904427059
+ .xword 2013776290
+ .xword 251722036
+ .xword 2517215374
+ .xword 3775830040
+ .xword 2137656763
+ .xword 141376813
+ .xword 2439277719
+ .xword 3865271297
+ .xword 1802195444
+ .xword 476864866
+ .xword 2238001368
+ .xword 4066508878
+ .xword 1812370925
+ .xword 453092731
+ .xword 2181625025
+ .xword 4111451223
+ .xword 1706088902
+ .xword 314042704
+ .xword 2344532202
+ .xword 4240017532
+ .xword 1658658271
+ .xword 366619977
+ .xword 2362670323
+ .xword 4224994405
+ .xword 1303535960
+ .xword 984961486
+ .xword 2747007092
+ .xword 3569037538
+ .xword 1256170817
+ .xword 1037604311
+ .xword 2765210733
+ .xword 3554079995
+ .xword 1131014506
+ .xword 879679996
+ .xword 2909243462
+ .xword 3663771856
+ .xword 1141124467
+ .xword 855842277
+ .xword 2852801631
+ .xword 3708648649
+ .xword 1342533948
+ .xword 654459306
+ .xword 3188396048
+ .xword 3373015174
+ .xword 1466479909
+ .xword 544179635
+ .xword 3110523913
+ .xword 3462522015
+ .xword 1591671054
+ .xword 702138776
+ .xword 2966460450
+ .xword 3352799412
+ .xword 1504918807
+ .xword 783551873
+ .xword 3082640443
+ .xword 3233442989
+ .xword 3988292384
+ .xword 2596254646
+ .xword 62317068
+ .xword 1957810842
+ .xword 3939845945
+ .xword 2647816111
+ .xword 81470997
+ .xword 1943803523
+ .xword 3814918930
+ .xword 2489596804
+ .xword 225274430
+ .xword 2053790376
+ .xword 3826175755
+ .xword 2466906013
+ .xword 167816743
+ .xword 2097651377
+ .xword 4027552580
+ .xword 2265490386
+ .xword 503444072
+ .xword 1762050814
+ .xword 4150417245
+ .xword 2154129355
+ .xword 426522225
+ .xword 1852507879
+ .xword 4275313526
+ .xword 2312317920
+ .xword 282753626
+ .xword 1742555852
+ .xword 4189708143
+ .xword 2394877945
+ .xword 397917763
+ .xword 1622183637
+ .xword 3604390888
+ .xword 2714866558
+ .xword 953729732
+ .xword 1340076626
+ .xword 3518719985
+ .xword 2797360999
+ .xword 1068828381
+ .xword 1219638859
+ .xword 3624741850
+ .xword 2936675148
+ .xword 906185462
+ .xword 1090812512
+ .xword 3747672003
+ .xword 2825379669
+ .xword 829329135
+ .xword 1181335161
+ .xword 3412177804
+ .xword 3160834842
+ .xword 628085408
+ .xword 1382605366
+ .xword 3423369109
+ .xword 3138078467
+ .xword 570562233
+ .xword 1426400815
+ .xword 3317316542
+ .xword 2998733608
+ .xword 733239954
+ .xword 1555261956
+ .xword 3268935591
+ .xword 3050360625
+ .xword 752459403
+ .xword 1541320221
+ .xword 2607071920
+ .xword 3965973030
+ .xword 1969922972
+ .xword 40735498
+ .xword 2617837225
+ .xword 3943577151
+ .xword 1913087877
+ .xword 83908371
+ .xword 2512341634
+ .xword 3803740692
+ .xword 2075208622
+ .xword 213261112
+ .xword 2463272603
+ .xword 3855990285
+ .xword 2094854071
+ .xword 198958881
+ .xword 2262029012
+ .xword 4057260610
+ .xword 1759359992
+ .xword 534414190
+ .xword 2176718541
+ .xword 4139329115
+ .xword 1873836001
+ .xword 414664567
+ .xword 2282248934
+ .xword 4279200368
+ .xword 1711684554
+ .xword 285281116
+ .xword 2405801727
+ .xword 4167216745
+ .xword 1634467795
+ .xword 376229701
+ .xword 2685067896
+ .xword 3608007406
+ .xword 1308918612
+ .xword 956543938
+ .xword 2808555105
+ .xword 3495958263
+ .xword 1231636301
+ .xword 1047427035
+ .xword 2932959818
+ .xword 3654703836
+ .xword 1088359270
+ .xword 936918000
+ .xword 2847714899
+ .xword 3736837829
+ .xword 1202900863
+ .xword 817233897
+ .xword 3183342108
+ .xword 3401237130
+ .xword 1404277552
+ .xword 615818150
+ .xword 3134207493
+ .xword 3453421203
+ .xword 1423857449
+ .xword 601450431
+ .xword 3009837614
+ .xword 3294710456
+ .xword 1567103746
+ .xword 711928724
+ .xword 3020668471
+ .xword 3272380065
+ .xword 1510334235
+ .xword 755167117
+ .text
+ .align 2
+ .global updcrc3
+ .type updcrc3, %function
+updcrc3:
+.LFB0:
+ .cfi_startproc
+ str x19, [sp, -48]!
+ .cfi_def_cfa_offset 48
+ .cfi_offset 19, -48
+ str x0, [sp, 24]
+ str w1, [sp, 20]
+ ldr x0, [sp, 24]
+ cmp x0, 0
+ bne .L2
+ mov x19, 4294967295
+ b .L3
+.L2:
+ adrp x0, crc.0
+ add x0, x0, :lo12:crc.0
+ ldr x19, [x0]
+ ldr w0, [sp, 20]
+ str w0, [sp, 44]
+ ldr w0, [sp, 20]
+ cmp w0, 0
+ beq .L3
+.L4:
+ ldr x0, [sp, 24]
+ add x1, x0, 1
+ str x1, [sp, 24]
+ ldrb w0, [x0]
+ and x0, x0, 255
+ eor x0, x19, x0
+ and x1, x0, 255
+ adrp x0, crc_32_tab
+ add x0, x0, :lo12:crc_32_tab
+ ldr x1, [x0, x1, lsl 3]
+ lsr x0, x19, 8
+ eor x19, x1, x0
+ ldr w0, [sp, 20]
+ sub w0, w0, #1
+ str w0, [sp, 20]
+ ldr w0, [sp, 20]
+ cmp w0, 999
+ bls .L4
+.L3:
+ adrp x0, crc.0
+ add x0, x0, :lo12:crc.0
+ str x19, [x0]
+ eor x0, x19, 4294967295
+ ldr x19, [sp], 48
+ .cfi_restore 19
+ .cfi_def_cfa_offset 0
+ ret
+ .cfi_endproc
+.LFE0:
+ .size updcrc3, .-updcrc3
+ .data
+ .align 3
+ .type crc.0, %object
+ .size crc.0, 8
+crc.0:
+ .xword 4294967295
+ .ident "GCC: (Kunpeng gcc 10.3.1-2.3.0.b006) 10.3.1"
+ .section .note.GNU-stack,"",@progbits
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-loop-form-fail.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-loop-form-fail.c
new file mode 100644
index 000000000..b59704e31
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-loop-form-fail.c
@@ -0,0 +1,111 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+/* check when the loop have a innor loop, should fail. */
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ for (int i = 0; i < 5; i++) {
+ c++;
+ }
+
+ } while (--n);
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+
+/* check when the loop have a second backedge, should fail. */
+ulg updcrc1(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n || c != 0) ;
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Wrong loop form for crc matching." 2 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-sucess.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-sucess.c
new file mode 100644
index 000000000..e1e16eaf2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-sucess.c
@@ -0,0 +1,84 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n);
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "the loop can be optimized" 1 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-table-check-fail.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-table-check-fail.c
new file mode 100644
index 000000000..f03a4fa82
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-crc-table-check-fail.c
@@ -0,0 +1,113 @@
+/* { dg-do compile { target {{ aarch64*-*-linux* } && lp64 } } } */
+/* { dg-options "-O3 -mabi=lp64 -floop-crc -fdump-tree-loop_crc-details" } */
+
+#include <stdint.h>
+#include <stddef.h>
+typedef unsigned long ulg;
+typedef unsigned char uch;
+
+static const ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf1L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+int test[5] = {0};
+
+/* check when the loop is doing more then 1 array read or writing an array, both should fail. */
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8) * test[c%5];
+ } while (--n) ;
+ }
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ test[c%5] = c;
+ } while (--n) ;
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+
+/* check when the loop is not working on a correct crc_table. should fail. */
+ulg updcrc1(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n)
+ do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n) ;
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+/* { dg-final { scan-tree-dump-times "Table check fail. not only single array is read." 2 "loop_crc"} } */
+/* { dg-final { scan-tree-dump-times "Table check fail. Table not matching." 1 "loop_crc"} } */
\ No newline at end of file
diff --git a/gcc/timevar.def b/gcc/timevar.def
index 2814b14f2..ba86a1b7b 100644
--- a/gcc/timevar.def
+++ b/gcc/timevar.def
@@ -215,6 +215,7 @@ DEFTIMEVAR (TV_TREE_COPY_RENAME , "tree rename SSA copies")
DEFTIMEVAR (TV_TREE_SSA_VERIFY , "tree SSA verifier")
DEFTIMEVAR (TV_TREE_STMT_VERIFY , "tree STMT verifier")
DEFTIMEVAR (TV_TREE_ARRAY_WIDEN_COMPARE, "tree array widen compare")
+DEFTIMEVAR (TV_TREE_LOOP_CRC, "tree loop crc")
DEFTIMEVAR (TV_TREE_SWITCH_CONVERSION, "tree switch conversion")
DEFTIMEVAR (TV_TREE_SWITCH_LOWERING, "tree switch lowering")
DEFTIMEVAR (TV_TREE_RECIP , "gimple CSE reciprocals")
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 3cdc12466..027f8992d 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -437,6 +437,7 @@ extern gimple_opt_pass *make_pass_phiopt (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_forwprop (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_phiprop (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_array_widen_compare (gcc::context *ctxt);
+extern gimple_opt_pass *make_pass_loop_crc (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_tree_ifcombine (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_dse (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_nrv (gcc::context *ctxt);
diff --git a/gcc/tree-ssa-loop-crc.c b/gcc/tree-ssa-loop-crc.c
new file mode 100644
index 000000000..4982384c6
--- /dev/null
+++ b/gcc/tree-ssa-loop-crc.c
@@ -0,0 +1,644 @@
+/* Array widen compare.
+ Copyright (C) 2022-2022 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "target.h"
+#include "tree.h"
+#include "gimple.h"
+#include "tree-pass.h"
+#include "gimple-ssa.h"
+#include "tree-pretty-print.h"
+#include "fold-const.h"
+#include "gimplify.h"
+#include "gimple-iterator.h"
+#include "tree-ssa-loop-manip.h"
+#include "tree-ssa-loop.h"
+#include "ssa.h"
+#include "tree-into-ssa.h"
+#include "cfganal.h"
+#include "cfgloop.h"
+#include "gimple-pretty-print.h"
+#include "tree-cfg.h"
+#include "cgraph.h"
+#include "print-tree.h"
+#include "cfghooks.h"
+#include "gimple-fold.h"
+
+/* Match.pd function to match the ctz expression. */
+extern bool gimple_crc_match_index (tree, tree *, tree (*)(tree));
+extern bool gimple_crc_match_res (tree, tree *, tree (*)(tree));
+
+static gimple *crc_table_read_stmt = NULL;
+
+
+/* The loop form check will check the entire loop control flow
+ It should be a loop that:
+ 1. a do-while loop with header and latch only with no other control flow inside the loop
+ 2. have only one exiting edge
+ 3. have only one back edge and one entry edge
+*/
+static bool
+crc_loop_form_check (class loop *loop)
+{
+ if (loop->num_nodes > 2 || loop->inner)
+ return false;
+ // should only have 1 exit edge
+ vec<edge> edges;
+ edges = get_loop_exit_edges (loop);
+ if (edges.length() != 1)
+ return false;
+
+ // The header should have only 2 incoming edges
+ // One of them is the preheader edge and the other is the backedge from the latch
+ if (EDGE_COUNT (loop->header->preds) != 2)
+ return false;
+ edge e1 = EDGE_PRED (loop->header, 0);
+ edge e2 = EDGE_PRED (loop->header, 1);
+
+ if ((e1->src == loop->latch && e2->src->loop_father != loop)
+ || (e2->src == loop->latch && e1->src->loop_father != loop))
+ return true;
+
+ return false;
+}
+
+/* Check there is only one array is read in the loop.
+ Return the only array as crc_table. */
+static bool
+only_one_array_read (class loop *loop, tree &crc_table)
+{
+ gimple_stmt_iterator gsi;
+ gimple *stmt;
+ bool res = false;
+ for (gsi = gsi_start_bb (loop->header); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ stmt = gsi_stmt (gsi);
+ if (stmt == NULL)
+ return false;
+
+ if (gimple_code (stmt) == GIMPLE_ASSIGN &&
+ TREE_CODE(gimple_assign_lhs (stmt)) == ARRAY_REF )
+ return false;
+
+ if (gimple_code (stmt) == GIMPLE_ASSIGN &&
+ TREE_CODE(gimple_assign_rhs1 (stmt)) == ARRAY_REF)
+ {
+ if (crc_table == NULL)
+ {
+ crc_table = gimple_assign_rhs1 (stmt);
+ crc_table_read_stmt = stmt;
+ res = true;
+ }
+ else
+ return false;
+ }
+ }
+ return res;
+}
+
+static const unsigned HOST_WIDE_INT crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+
+/* Check the content of the array. */
+static bool
+match_crc_table (tree crc_table)
+{
+ unsigned HOST_WIDE_INT lb = tree_to_uhwi (array_ref_low_bound (crc_table));
+ unsigned HOST_WIDE_INT ub = tree_to_uhwi (array_ref_up_bound (crc_table));
+ unsigned HOST_WIDE_INT es = tree_to_uhwi (array_ref_element_size (crc_table));
+ if (lb != 0 || ub != 255 || es != 8)
+ return false;
+
+ tree decl = TREE_OPERAND (crc_table, 0);
+ tree ctor = ctor_for_folding(decl);
+ for (int i = 0; i < 255; i++) {
+ unsigned HOST_WIDE_INT val = tree_to_uhwi (CONSTRUCTOR_ELT (ctor,i)->value);
+ if (crc_32_tab[i] != val)
+ return false;
+ }
+ return true;
+}
+
+
+/* Check the crc table. The loop should have only one data reference.
+ And match the data reference with the predefined array. */
+static bool
+crc_table_check (class loop *loop)
+{
+ tree crc_table = NULL;
+ if (!only_one_array_read (loop, crc_table))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nTable check fail. not only single array is read.\n");
+ return false;
+ }
+ if (!match_crc_table (crc_table))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nTable check fail. Table not matching.\n");
+ return false;
+ }
+ return true;
+}
+
+/* check whether the evolution pattern of phi is phi = SSA_NAME + target*/
+static bool
+evolution_pattern_plus_with_p (class loop* loop, gphi *phi, unsigned HOST_WIDE_INT target)
+{
+ edge backedge = find_edge (loop->latch, loop->header);
+ if (backedge == NULL)
+ return false;
+ tree evolution_node = PHI_ARG_DEF_FROM_EDGE (phi, backedge);
+ gimple *evolution_expr = SSA_NAME_DEF_STMT (evolution_node);
+
+ if (evolution_expr && (gimple_assign_rhs_code (evolution_expr) == PLUS_EXPR ||
+ gimple_assign_rhs_code (evolution_expr) == POINTER_PLUS_EXPR))
+ {
+ tree rhs1 = gimple_assign_rhs1 (evolution_expr);
+ tree rhs2 = gimple_assign_rhs2 (evolution_expr);
+ if (TREE_CODE (rhs1) == SSA_NAME && TREE_CODE (rhs2) == INTEGER_CST
+ && tree_to_uhwi (rhs2) == target)
+ return true;
+ }
+ return false;
+}
+
+/* Check whether there are only 3 phi nodes in the header block.
+ Return 3 phi nodes in the capture. */
+static bool
+check_num_of_phi (basic_block header, gphi *capture[])
+{
+ gphi *phi;
+ gphi_iterator gsi;
+ int num_of_phi = 0;
+
+ for (gsi = gsi_start_phis (header); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ phi = gsi.phi();
+ if (phi) num_of_phi++;
+ if (num_of_phi > 3)
+ return false;
+ capture[num_of_phi - 1] = phi;
+ }
+ /* phi node should be exactly 3. */
+ return num_of_phi == 3;
+}
+
+/* Check the evolution pattern of three phi nodes.
+ Should be one of the node +1 every time (s), one of the node -1
+ every time (n), and a 3rd one neither (c). Return 3 phi nodes in
+ the capture with the order of s,n,c.*/
+static bool
+check_evolution_pattern (class loop* loop, gphi *capture[])
+{
+ gphi *s=NULL;
+ gphi *n=NULL;
+ gphi *c=NULL;
+
+ for (int i = 0; i < 3; i++)
+ {
+ if (evolution_pattern_plus_with_p(loop, capture[i], 1))
+ {
+ if (s != NULL)
+ return false;
+ s = capture[i];
+ }
+ else if (evolution_pattern_plus_with_p(loop, capture[i], 4294967295))
+ {
+ if (n != NULL)
+ return false;
+ n = capture[i];
+ }
+ else
+ {
+ if (c != NULL)
+ return false;
+ c = capture[i];
+ }
+ }
+
+ // some envolution pattern cannot find
+ if (!n || !s || !c)
+ return false;
+
+ capture[0] = s;
+ capture[1] = n;
+ capture[2] = c;
+ return true;
+}
+/* check the calculation pattern before and after the crc_table array read stmt.
+ _7 = crc_32_tab[_6];
+ The caculation of index _6 should be the result of a sequency of calculation by the s and c
+ The result of the array read _7 should be used to calculate the new c. */
+static bool
+check_calculation_pattern (class loop* loop, gphi *capture[])
+{
+ gphi *s=capture[0];
+ gphi *c=capture[2];
+ tree res_ops[3];
+ tree index = TREE_OPERAND (gimple_assign_rhs1 (crc_table_read_stmt), 1);
+
+ /* Try to match
+ _4 = (int) _3; //NOP_EXPR (SSA_NAME @2)
+ _5 = _4 ^ c_10; //BIT_XOR_EXPR (SSA_NAME, PHI @1)
+ _6 = _5 & 255; //BIT_XOR_EXPR (SSA_NAME, INTEGER_CST@3)
+ */
+
+ if (!gimple_crc_match_index(index, res_ops, NULL))
+ return false;
+ gimple *s_res_stmt = SSA_NAME_DEF_STMT(res_ops[1]);
+ tree s_res = TREE_OPERAND(gimple_assign_rhs1(s_res_stmt),0);
+ if (res_ops[0] != gimple_phi_result (c) ||
+ s_res != gimple_phi_result (s))
+ return false;
+
+ /* Try to match
+ _8 = c_12 >> 8; // RSHIFT_EXPR (SSA_NAME @1, INTEGER_CST @2)
+ c_19 = _7 ^ _8; // BIT_XOR_EXPR (SSA_NAME@3, SSA_NAME)
+ */
+ edge backedge = find_edge(loop->latch, loop->header);
+ tree updated_c = PHI_ARG_DEF_FROM_EDGE (c, backedge);
+ if (!gimple_crc_match_res(updated_c, res_ops, NULL))
+ return false;
+ if (res_ops[0] != gimple_phi_result (c)
+ || res_ops[2] != gimple_assign_lhs(crc_table_read_stmt))
+ return false;
+
+ return true;
+}
+
+/* check the exit condition is n != 0. */
+static bool
+check_exit_condition (class loop* loop, gphi *n)
+{
+ edge backedge = find_edge(loop->latch, loop->header);
+ gimple *cond_stmt = gsi_stmt (gsi_last_bb (loop->header));
+ if (!cond_stmt || gimple_code (cond_stmt) != GIMPLE_COND || gimple_cond_code (cond_stmt) != NE_EXPR
+ || gimple_cond_lhs (cond_stmt) != PHI_ARG_DEF_FROM_EDGE (n, backedge)
+ || tree_to_uhwi(gimple_cond_rhs (cond_stmt)) != 0)
+ return false;
+
+ return true;
+}
+
+/* Check the loop body. The loop body we are trying to match is
+
+# s_10 = PHI <s_14(D)(6), s_18(7)>
+# n_11 = PHI <n_17(D)(6), n_20(7)>
+# c_12 = PHI <c_16(6), c_19(7)>
+_1 = (int) c_12;
+s_18 = s_10 + 1;
+_3 = *s_10;
+_4 = (int) _3;
+_5 = _1 ^ _4;
+_6 = _5 & 255;
+_7 = crc_32_tab[_6];
+_8 = c_12 >> 8;
+c_19 = _7 ^ _8;
+n_20 = n_11 + 4294967295;
+if (n_20 != 0)
+ goto <bb 7>; [INV]
+else
+ goto <bb 5>; [INV]
+
+which is doing a very simple calculation
+do {
+ c = crc_32_tab[(c ^ (*s++)) & 0xff] ^ (c >> 8);
+} while (--n);
+
+In this case ,we don't want this loop to have any other operation inside.
+so the matching condition is
+1. There are only 3 loop variant during each itoration, namely s,c,n,
+ which is limited by the condition that the loop have exactly 3 phi nodes.
+2. The 3 loop variants should have evolution pattern as 1 of the 3 nodes is
+ increased by 1 every itoration, 1 of the 3 nodes is decreased by 1 every itor
+ and the 3rd one is neither. These three tree node SSA value will be captured for
+ the later arithmatic pattern matching
+3. Pattern matching for the index of crc_table
+4. pattern matching for the result of c calcuation after read from crc_table
+5. The exit condition matching.
+ */
+static bool
+crc_loop_body_check (class loop *loop)
+{
+ basic_block header = loop->header;
+ gphi *capture[3];
+ if (!check_num_of_phi(header, capture))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n num of phi noeds check failed.\n");
+ return false;
+ }
+ if (!check_evolution_pattern(loop, capture))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n evolution pattern check failed.\n");
+ return false;
+ }
+ if (!check_calculation_pattern(loop, capture))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n calculation pattern check failed.\n");
+ return false;
+ }
+ if (!check_exit_condition(loop, capture[1] /* n*/))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n exit condition check failed.\n");
+ return false;
+ }
+ return true;
+/* gphi *phi;
+ gphi_iterator gsi;
+ int num_of_phi = 0;
+ //s, n, c;
+ //only 3 phi nodes are there, every one of the phi nodes comming from 2 edge only, one from preheader, one from latch
+ // s increase by 1 every itoration
+ // n decrease by 1 every itoration
+ // The final one is c, which is the result, should be used for the start of the later pattern matching
+ for (gsi = gsi_start_phis(loop->header); !gsi_end_p(gsi); gsi_next(&gsi))
+ {
+ phi = gsi.phi();
+
+ if (phi) num_of_phi++;
+ if (num_of_phi > 3) return false; // more then 3 phi node
+ if (gimple_phi_num_args(phi) > 2) // more than 2 edges other then one backedge and one preheader edge
+ return false;
+ //capture[num_of_phi - 1] = gimple_phi_result(phi);
+ capture[num_of_phi - 1] = phi;
+ }
+ if (num_of_phi != 3) return false; // phi node should be 3 */
+ // Find the envolution pattern for s and n, try to match the identity of these variable
+/* gphi *s=NULL;
+ gphi *n=NULL;
+ gphi *c=NULL;
+
+ for (int i = 0; i < 3; i++)
+ {
+ if (evolution_pattern_plus_with_p(loop, capture[i], 1))
+ {
+ if(s != NULL)
+ return false;
+ s = capture[i];
+ }
+ else if (evolution_pattern_plus_with_p(loop, capture[i], 4294967295))
+ {
+ if(n != NULL)
+ return false;
+ n = capture[i];
+ }
+ else
+ {
+ if(c != NULL)
+ return false;
+ c = capture[i];
+ }
+ }
+
+ // some envolution pattern cannot find
+ if (!n || !s || !c)
+ return false;
+ gphi *s=capture[0];
+ gphi *n=capture[1];
+ gphi *c=capture[2];
+ tree res_ops[3];
+ tree index = TREE_OPERAND (gimple_assign_rhs1 (crc_table_read_stmt), 1);
+
+ /* Try to match
+ _1 = (int) c_12; //NOP_EXPR (SSA_NAME @1)
+ _4 = (int) _3; //NOP_EXPR (SSA_NAME @2)
+ _5 = _1 ^ _4; //BIT_XOR_EXPR (SSA_NAME, SSA_NAME)
+ _6 = _5 & 255; //BIT_XOR_EXPR (SSA_NAME, INTEGER_CST@3)
+
+
+ if (!gimple_crc_match_index(index, res_ops, NULL))
+ return false;
+ gimple *s_res_stmt = SSA_NAME_DEF_STMT(res_ops[1]);
+ tree s_res = TREE_OPERAND(gimple_assign_rhs1(s_res_stmt),0);
+ if (res_ops[0] != gimple_phi_result (c) ||
+ s_res != gimple_phi_result (s))
+ return false;
+
+ /*
+_8 = c_12 >> 8; // RSHIFT_EXPR (SSA_NAME @1, INTEGER_CST @2)
+c_19 = _7 ^ _8; // BIT_XOR_EXPR (SSA_NAME@3, SSA_NAME)
+
+ edge backedge = find_edge(loop->latch, loop->header);
+ tree updated_c = PHI_ARG_DEF_FROM_EDGE (c, backedge);
+ if (!gimple_crc_match_res(updated_c, res_ops, NULL))
+ return false;
+ if (res_ops[0] != gimple_phi_result (c)
+ || res_ops[2] != gimple_assign_lhs(crc_table_read_stmt))
+ return false;
+
+ // try match n as the induction variable
+ // The proceed condition for back edge is n != 0
+ gimple *cond_stmt = gsi_stmt (gsi_last_bb (loop->header));
+ if (!cond_stmt || gimple_code (cond_stmt) != GIMPLE_COND || gimple_cond_code (cond_stmt) != NE_EXPR
+ || gimple_cond_lhs (cond_stmt) != PHI_ARG_DEF_FROM_EDGE (n, backedge)
+ || tree_to_uhwi(gimple_cond_rhs (cond_stmt)) != 0)
+ return false;
+
+ return true;
+ */
+}
+
+
+static bool
+match_crc_loop (class loop *loop)
+{
+ if (!crc_loop_form_check(loop))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nWrong loop form for crc matching.\n");
+ return false;
+ }
+ if (!crc_table_check(loop))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nWrong crc table for crc matching.\n");
+ return false;
+ }
+ if (!crc_loop_body_check(loop))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nWrong loop body for crc matching.\n");
+ return false;
+ }
+ return true;
+}
+
+/* The main entry of loop crc optimizes. */
+static unsigned int
+tree_ssa_loop_crc ()
+{
+ unsigned int todo = 0;
+ class loop *loop;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ flow_loops_dump (dump_file, NULL, 1);
+ fprintf (dump_file, "\nStarting the loop_crc pass\n");
+ }
+
+ FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "======================================\n");
+ fprintf (dump_file, "Processing loop %d:\n", loop->num);
+ fprintf (dump_file, "======================================\n");
+ flow_loop_dump (loop, dump_file, NULL, 1);
+ fprintf (dump_file, "\n\n");
+ }
+
+ if (match_crc_loop (loop))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "The %dth loop form is success matched,"
+ "and the loop can be optimized.\n",
+ loop->num);
+ }
+
+ convert_to_new_loop (loop);
+ }
+ }
+
+ todo |= (TODO_update_ssa);
+ return todo;
+}
+
+/* Loop crc. */
+
+namespace {
+
+const pass_data pass_data_tree_loop_crc =
+{
+ GIMPLE_PASS,
+ "loop_crc",
+ OPTGROUP_LOOP,
+ TV_TREE_LOOP_CRC,
+ (PROP_cfg | PROP_ssa),
+ 0,
+ 0,
+ 0,
+ (TODO_update_ssa | TODO_verify_all)
+};
+
+class pass_loop_crc : public gimple_opt_pass
+{
+public:
+ pass_loop_crc (gcc::context *ctxt)
+ : gimple_opt_pass (pass_data_tree_loop_crc, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *);
+ virtual unsigned int execute (function *);
+
+}; // class pass_loop_crc
+
+bool
+pass_loop_crc::gate (function *)
+{
+ return (flag_loop_crc > 0 && optimize >= 3);
+}
+
+unsigned int
+pass_loop_crc::execute (function *fun)
+{
+ if (number_of_loops (fun) <= 1)
+ return 0;
+
+ /* Only supports LP64 data mode. */
+ if (TYPE_PRECISION (long_integer_type_node) != 64
+ || POINTER_SIZE != 64 || TYPE_PRECISION (integer_type_node) != 32)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "The current data mode is not supported,"
+ "only the LP64 date mode is supported.\n");
+ return 0;
+ }
+
+ return tree_ssa_loop_crc ();
+}
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_loop_crc (gcc::context *ctxt)
+{
+ return new pass_loop_crc (ctxt);
+}
\ No newline at end of file
--
2.33.0
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