https://gcc.gnu.org/g:04918a2d3f20b02ac3efad1096c33894d57789a0
commit r15-9316-g04918a2d3f20b02ac3efad1096c33894d57789a0
Author: Jakub Jelinek <ja...@redhat.com>
Date: Tue Apr 8 15:14:58 2025 +0200
simplify-rtx: Fix up POPCOUNT optimization [PR119672]
The gcc.dg/vect/pr113281-1.c test and many others ICE on riscv since
presumably the r15-9238 change which allowed more cases of vector modes
in simplify_const_relational_operation.
In the testcase it is EQ of
(popcount:SI (unspec:RVVMF32BI [
(and:RVVMF32BI (const_vector:RVVMF32BI repeat [
(const_int 1 [0x1])
])
(reg:RVVMF32BI 147 [ mask__6.8_35 ]))
(reg:SI 143 [ _41 ])
(const_int 0 [0])
(reg:SI 66 vl)
(reg:SI 67 vtype)
] UNSPEC_VPREDICATE))
and
(const_int 0 [0])
which it tries to fold as EQ comparison of
(unspec:RVVMF32BI [
(and:RVVMF32BI (const_vector:RVVMF32BI repeat [
(const_int 1 [0x1])
])
(reg:RVVMF32BI 147 [ mask__6.8_35 ]))
(reg:SI 143 [ _41 ])
(const_int 0 [0])
(reg:SI 66 vl)
(reg:SI 67 vtype)
] UNSPEC_VPREDICATE)
with
(const_int 0 [0])
which ICEs because const0_rtx isn't a vector.
Fixed by using CONST0_RTX, so that we pass
(const_vector:RVVMF32BI repeat [
(const_int 0 [0])
])
instead.
2025-04-08 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/119672
* simplify-rtx.cc
(simplify_context::simplify_relational_operation_1):
For POPCOUNT == 0 or != 0 optimizations use
CONST0_RTX (GET_MODE (XEXP (op0, 0))) rather than const0_rtx.
Diff:
---
gcc/simplify-rtx.cc | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index 6f969effdf99..88d31a71c05a 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -6465,14 +6465,16 @@ simplify_context::simplify_relational_operation_1
(rtx_code code,
case LEU:
/* (eq (popcount x) (const_int 0)) -> (eq x (const_int 0)). */
return simplify_gen_relational (EQ, mode, GET_MODE (XEXP (op0, 0)),
- XEXP (op0, 0), const0_rtx);
+ XEXP (op0, 0),
+ CONST0_RTX (GET_MODE (XEXP (op0, 0))));
case NE:
case GT:
case GTU:
/* (ne (popcount x) (const_int 0)) -> (ne x (const_int 0)). */
return simplify_gen_relational (NE, mode, GET_MODE (XEXP (op0, 0)),
- XEXP (op0, 0), const0_rtx);
+ XEXP (op0, 0),
+ CONST0_RTX (GET_MODE (XEXP (op0, 0))));
default:
break;
