Fixes: ef85d150b5963 ("RISC-V: Enable TARGET_SUPPORTS_WIDE_INT")
(gcc-13 regression)
DF +0.0 is bitwise all zeros so int x0 store to mem can be used to optimize it.
void zd(double *) { *d = 0.0; }
currently:
| fmv.d.x fa5,zero
| fsd fa5,0(a0)
| ret
With patch
| sd zero,0(a0)
| ret
This came to light when testing the in-flight f-m-o patch where an ICE
was getting triggered due to lack of this pattern but turns out this
is an independent optimization of its own [1]
[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624857.html
Ran thru full multilib testsuite, there was 1 false failure due to
random string "lw" appearing in lto build assembler output, which is
also fixed in the patch.
gcc/Changelog:
PR target/110748
* config/riscv/predicates.md (const_0_operand): Add back
const_double.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/pr110748-1.c: New Test.
* gcc.target/riscv/xtheadfmv-fmv.c: Add '\t' around test
patterns to avoid random string matches.
Signed-off-by: Vineet Gupta <vine...@rivosinc.com>
---
Changes since v1:
- No code changes
- Updated commitlog: typo, "Fixes:" tag, mention PR in Changelog entry
---
gcc/config/riscv/predicates.md | 2 +-
gcc/testsuite/gcc.target/riscv/pr110748-1.c | 10 ++++++++++
gcc/testsuite/gcc.target/riscv/xtheadfmv-fmv.c | 8 ++++----
3 files changed, 15 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/riscv/pr110748-1.c
diff --git a/gcc/config/riscv/predicates.md b/gcc/config/riscv/predicates.md
index 5a22c77f0cd0..9db28c2def7e 100644
--- a/gcc/config/riscv/predicates.md
+++ b/gcc/config/riscv/predicates.md
@@ -58,7 +58,7 @@
(match_test "INTVAL (op) + 1 != 0")))
(define_predicate "const_0_operand"
- (and (match_code "const_int,const_wide_int,const_vector")
+ (and (match_code "const_int,const_wide_int,const_double,const_vector")
(match_test "op == CONST0_RTX (GET_MODE (op))")))
(define_predicate "const_1_operand"
diff --git a/gcc/testsuite/gcc.target/riscv/pr110748-1.c
b/gcc/testsuite/gcc.target/riscv/pr110748-1.c
new file mode 100644
index 000000000000..2f5bc08aae72
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr110748-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target hard_float } */
+/* { dg-options "-march=rv64g -mabi=lp64d -O2" } */
+
+
+void zd(double *d) { *d = 0.0; }
+void zf(float *f) { *f = 0.0; }
+
+/* { dg-final { scan-assembler-not "\tfmv\\.d\\.x\t" } } */
+/* { dg-final { scan-assembler-not "\tfmv\\.s\\.x\t" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/xtheadfmv-fmv.c
b/gcc/testsuite/gcc.target/riscv/xtheadfmv-fmv.c
index 1036044291e7..89eb48bed1b9 100644
--- a/gcc/testsuite/gcc.target/riscv/xtheadfmv-fmv.c
+++ b/gcc/testsuite/gcc.target/riscv/xtheadfmv-fmv.c
@@ -18,7 +18,7 @@ d2ll (double d)
/* { dg-final { scan-assembler "th.fmv.hw.x" } } */
/* { dg-final { scan-assembler "fmv.x.w" } } */
/* { dg-final { scan-assembler "th.fmv.x.hw" } } */
-/* { dg-final { scan-assembler-not "sw" } } */
-/* { dg-final { scan-assembler-not "fld" } } */
-/* { dg-final { scan-assembler-not "fsd" } } */
-/* { dg-final { scan-assembler-not "lw" } } */
+/* { dg-final { scan-assembler-not "\tsw\t" } } */
+/* { dg-final { scan-assembler-not "\tfld\t" } } */
+/* { dg-final { scan-assembler-not "\tfsd\t" } } */
+/* { dg-final { scan-assembler-not "\tlw\t" } } */
--
2.34.1
