diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2020-05-08 10:03:56 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-05-08 10:03:56 +0200 |
| commit | a229f9b3737062c6e853879be6683f3f3e4a6661 (patch) | |
| tree | 31fa0f21442170ed14bc6e3f755c2f0a08010653 /gcc/testsuite | |
| parent | a139bc2b492de8a761890a5d299951dede3d8f7b (diff) | |
ix86: Add peephole2 for *add<mode>3_cc_overflow_1 followed by matching memory store [PR94857]
The following peephole2 changes:
- addl (%rdi), %esi
+ xorl %eax, %eax
+ addl %esi, (%rdi)
setc %al
- movl %esi, (%rdi)
- movzbl %al, %eax
ret
on the testcase. *add<mode>3_cc_overflow_1, being an add{l,q} insn, is
commutative, so if TARGET_READ_MODIFY_WRITE we can replace
addl (%rdi), %esi; movl %esi, (%rdi)
with
addl %esi, (%rdi)
if %esi is dead after those two insns.
2020-05-08 Jakub Jelinek <jakub@redhat.com>
PR target/94857
* config/i386/i386.md (peephole2 after *add<mode>3_cc_overflow_1): New
define_peephole2.
* gcc.target/i386/pr94857.c: New test.
Diffstat (limited to 'gcc/testsuite')
| -rw-r--r-- | gcc/testsuite/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/i386/pr94857.c | 13 |
2 files changed, 16 insertions, 0 deletions
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 174198fdbe4..db0a837829f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,8 @@ 2020-05-08 Jakub Jelinek <jakub@redhat.com> + PR target/94857 + * gcc.target/i386/pr94857.c: New test. + PR tree-optimization/94783 * gcc.dg/tree-ssa/pr94783.c: New test. diff --git a/gcc/testsuite/gcc.target/i386/pr94857.c b/gcc/testsuite/gcc.target/i386/pr94857.c new file mode 100644 index 00000000000..f84ee22b922 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr94857.c @@ -0,0 +1,13 @@ +/* PR target/94857 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -mtune=skylake -masm=att" } */ +/* { dg-additional-options "-mregparm=2" { target ia32 } } */ +/* { dg-final { scan-assembler "\taddl\t%\[a-z0-9]\*, \\\(" } } */ + +int +foo (unsigned *p, unsigned x) +{ + unsigned u = *p; + *p += x; + return u > *p; +} |