https://gcc.gnu.org/g:19e565ed13972410451091a789fe58638d03b795
commit r15-2842-g19e565ed13972410451091a789fe58638d03b795
Author: Kyrylo Tkachov <ktkac...@nvidia.com>
Date: Mon Aug 5 10:47:33 2024 -0700
aarch64: Check CONSTM1_RTX in definition of Dm constraint
The constraint Dm is intended to match vectors of minus 1, but actually
checks for CONST1_RTX. This doesn't have a bad effect in practice as its
only use in the aarch64_wrffr pattern for the setffr instruction which
is a VNx16BI operation and -1 and 1 are the same there. That pattern
can only be currently generated through intrinsics anyway that create it
with a CONSTM1_RTX constant.
Fix the constraint definition so that it doesn't become a footgun if its
used in some other pattern.
Bootstrapped and tested on aarch64-none-linux-gnu.
Signed-off-by: Kyrylo Tkachov <ktkac...@nvidia.com>
gcc/ChangeLog:
* config/aarch64/constraints.md (Dm): Match CONSTM1_RTX rather
CONST1_RTX.
Diff:
---
gcc/config/aarch64/constraints.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/aarch64/constraints.md
b/gcc/config/aarch64/constraints.md
index 0c81fb28f7e5..a2878f580d90 100644
--- a/gcc/config/aarch64/constraints.md
+++ b/gcc/config/aarch64/constraints.md
@@ -556,7 +556,7 @@
"@internal
A constraint that matches a vector of immediate minus one."
(and (match_code "const,const_vector")
- (match_test "op == CONST1_RTX (GET_MODE (op))")))
+ (match_test "op == CONSTM1_RTX (GET_MODE (op))")))
(define_constraint "Dd"
"@internal
