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| author | Andrew Pinski <apinski@marvell.com> | 2021-08-31 04:41:14 +0000 |
|---|---|---|
| committer | Andrew Pinski <apinski@marvell.com> | 2021-09-01 20:58:00 +0000 |
| commit | a45786e9a31f995087d8cb42bc3a4fe06911e588 (patch) | |
| tree | 0e7553eb6a7b0825a66344ab1fbe69cde71d27de /gcc | |
| parent | c4d6dcacfca1b804504515496e6d9de176d7f51e (diff) | |
| download | gcc-a45786e9a31f995087d8cb42bc3a4fe06911e588.zip gcc-a45786e9a31f995087d8cb42bc3a4fe06911e588.tar.gz gcc-a45786e9a31f995087d8cb42bc3a4fe06911e588.tar.bz2 | |
Fix target/101934: aarch64 memset code creates unaligned stores for -mstrict-align
The problem here is the aarch64_expand_setmem code did not check
STRICT_ALIGNMENT if it is creating an overlapping store.
This patch adds that check and the testcase works.
gcc/ChangeLog:
PR target/101934
* config/aarch64/aarch64.c (aarch64_expand_setmem):
Check STRICT_ALIGNMENT before creating an overlapping
store.
gcc/testsuite/ChangeLog:
PR target/101934
* gcc.target/aarch64/memset-strict-align-1.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/aarch64/aarch64.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/aarch64/memset-strict-align-1.c | 28 |
2 files changed, 30 insertions, 2 deletions
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index 3213585..26d59ba 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -23566,8 +23566,8 @@ aarch64_expand_setmem (rtx *operands) /* Do certain trailing copies as overlapping if it's going to be cheaper. i.e. less instructions to do so. For instance doing a 15 byte copy it's more efficient to do two overlapping 8 byte copies than - 8 + 4 + 2 + 1. */ - if (n > 0 && n < copy_limit / 2) + 8 + 4 + 2 + 1. Only do this when -mstrict-align is not supplied. */ + if (n > 0 && n < copy_limit / 2 && !STRICT_ALIGNMENT) { next_mode = smallest_mode_for_size (n, MODE_INT); int n_bits = GET_MODE_BITSIZE (next_mode).to_constant (); diff --git a/gcc/testsuite/gcc.target/aarch64/memset-strict-align-1.c b/gcc/testsuite/gcc.target/aarch64/memset-strict-align-1.c new file mode 100644 index 0000000..5cdc8a4 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/memset-strict-align-1.c @@ -0,0 +1,28 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -mstrict-align" } */ + +struct s { char x[95]; }; +void foo (struct s *); +void bar (void) { struct s s1 = {}; foo (&s1); } + +/* memset (s1 = {}, sizeof = 95) should be expanded out + such that there are no overlap stores when -mstrict-align + is in use. + so 2 pair 16 bytes stores (64 bytes). + 1 16 byte stores + 1 8 byte store + 1 4 byte store + 1 2 byte store + 1 1 byte store + */ + +/* { dg-final { scan-assembler-times "stp\tq" 2 } } */ +/* { dg-final { scan-assembler-times "str\tq" 1 } } */ +/* { dg-final { scan-assembler-times "str\txzr" 1 } } */ +/* { dg-final { scan-assembler-times "str\twzr" 1 } } */ +/* { dg-final { scan-assembler-times "strh\twzr" 1 } } */ +/* { dg-final { scan-assembler-times "strb\twzr" 1 } } */ + +/* Also one store pair for the frame-pointer and the LR. */ +/* { dg-final { scan-assembler-times "stp\tx" 1 } } */ + |