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| author | Richard Biener <rguenther@suse.de> | 2022-03-23 14:53:49 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-03-23 15:57:33 +0100 |
| commit | d9792f8d227cdd409c2b082ef0685b47ccfaa334 (patch) | |
| tree | 5856fa65491d4df41a0f442c6974442497b15607 /gcc | |
| parent | 1daa198aafd72925ca8dd8616385f523ff180d4a (diff) | |
| download | gcc-d9792f8d227cdd409c2b082ef0685b47ccfaa334.zip gcc-d9792f8d227cdd409c2b082ef0685b47ccfaa334.tar.gz gcc-d9792f8d227cdd409c2b082ef0685b47ccfaa334.tar.bz2 | |
target/102125 - alternative memcpy folding improvement
The following extends the heuristical memcpy folding path with the
ability to use misaligned accesses on strict-alignment targets just
like the size-based path does. That avoids regressing the following
testcase on arm
uint64_t bar64(const uint8_t *rData1)
{
uint64_t buffer;
memcpy(&buffer, rData1, sizeof(buffer));
return buffer;
}
when r12-3482-g5f6a6c91d7c592 is reverted.
2022-03-23 Richard Biener <rguenther@suse.de>
PR target/102125
* gimple-fold.cc (gimple_fold_builtin_memory_op): Allow the
use of movmisalign when either the source or destination
decl is properly aligned.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimple-fold.cc | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc index c9179ab..5eff7d6 100644 --- a/gcc/gimple-fold.cc +++ b/gcc/gimple-fold.cc @@ -1254,7 +1254,11 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, srcvar = fold_build2 (MEM_REF, desttype, src, off0); else { - if (STRICT_ALIGNMENT) + enum machine_mode mode = TYPE_MODE (desttype); + if ((mode == BLKmode && STRICT_ALIGNMENT) + || (targetm.slow_unaligned_access (mode, src_align) + && (optab_handler (movmisalign_optab, mode) + == CODE_FOR_nothing))) return false; srctype = build_aligned_type (TYPE_MAIN_VARIANT (desttype), src_align); @@ -1267,7 +1271,11 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, destvar = fold_build2 (MEM_REF, srctype, dest, off0); else { - if (STRICT_ALIGNMENT) + enum machine_mode mode = TYPE_MODE (srctype); + if ((mode == BLKmode && STRICT_ALIGNMENT) + || (targetm.slow_unaligned_access (mode, dest_align) + && (optab_handler (movmisalign_optab, mode) + == CODE_FOR_nothing))) return false; desttype = build_aligned_type (TYPE_MAIN_VARIANT (srctype), dest_align); |