From: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
To: gcc Patches <gcc-patches@gcc.gnu.org>,
Richard Sandiford <richard.sandiford@arm.com>
Subject: [SVE][match.pd] Fix ICE observed in PR110280
Date: Tue, 20 Jun 2023 15:24:58 +0530 [thread overview]
Message-ID: <CAAgBjMnXn5ArbP9zg2Pwu-_CWb=E4f5_dx95T+bSPCb0HsnE7A@mail.gmail.com> (raw)
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Hi Richard,
For the following reduced test-case taken from PR:
#include "arm_sve.h"
svuint32_t l() {
alignas(16) const unsigned int lanes[4] = {0, 0, 0, 0};
return svld1rq_u32(svptrue_b8(), lanes);
}
compiling with -O3 -mcpu=generic+sve results in following ICE:
during GIMPLE pass: fre
pr110280.c: In function 'l':
pr110280.c:5:1: internal compiler error: in eliminate_stmt, at
tree-ssa-sccvn.cc:6890
5 | }
| ^
0x865fb1 eliminate_dom_walker::eliminate_stmt(basic_block_def*,
gimple_stmt_iterator*)
../../gcc/gcc/tree-ssa-sccvn.cc:6890
0x120bf4d eliminate_dom_walker::before_dom_children(basic_block_def*)
../../gcc/gcc/tree-ssa-sccvn.cc:7324
0x120bf4d eliminate_dom_walker::before_dom_children(basic_block_def*)
../../gcc/gcc/tree-ssa-sccvn.cc:7257
0x1aeec77 dom_walker::walk(basic_block_def*)
../../gcc/gcc/domwalk.cc:311
0x11fd924 eliminate_with_rpo_vn(bitmap_head*)
../../gcc/gcc/tree-ssa-sccvn.cc:7504
0x1214664 do_rpo_vn_1
../../gcc/gcc/tree-ssa-sccvn.cc:8616
0x1215ba5 execute
../../gcc/gcc/tree-ssa-sccvn.cc:8702
cc1 simplifies:
lanes[0] = 0;
lanes[1] = 0;
lanes[2] = 0;
lanes[3] = 0;
_1 = { -1, ... };
_7 = svld1rq_u32 (_1, &lanes);
to:
_9 = MEM <vector(4) unsigned int> [(unsigned int * {ref-all})&lanes];
_7 = VEC_PERM_EXPR <_9, _9, { 0, 1, 2, 3, ... }>;
and then fre1 dump shows:
Applying pattern match.pd:8675, generic-match-5.cc:9025
Match-and-simplified VEC_PERM_EXPR <_9, _9, { 0, 1, 2, 3, ... }> to {
0, 0, 0, 0 }
RHS VEC_PERM_EXPR <_9, _9, { 0, 1, 2, 3, ... }> simplified to { 0, 0, 0, 0 }
The issue seems to be with the following pattern:
(simplify
(vec_perm vec_same_elem_p@0 @0 @1)
@0)
which simplifies above VEC_PERM_EXPR to:
_7 = {0, 0, 0, 0}
which is incorrect since _9 and mask have different vector lengths.
The attached patch amends the pattern to simplify above VEC_PERM_EXPR
only if operand and mask have same number of elements, which seems to fix
the issue, and we're left with the following in .optimized dump:
<bb 2> [local count: 1073741824]:
_2 = VEC_PERM_EXPR <{ 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 1, 2, 3, ... }>;
return _2;
code-gen:
l:
mov z0.b, #0
ret
Patch is bootstrapped+tested on aarch64-linux-gnu.
OK to commit ?
Thanks,
Prathamesh
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[SVE][match.pd] Fix ICE observed in PR110280.
gcc/ChangeLog:
PR tree-optimization/110280
* match.pd (vec_perm_expr(v, v, mask) -> v): Simplify the pattern
only if operand and mask of VEC_PERM_EXPR have same number of
elements.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/sve/pr110280.c: New test.
diff --git a/gcc/match.pd b/gcc/match.pd
index 2dd23826034..0eb5f8f0af6 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -8669,10 +8669,11 @@ and,
@0
(if (uniform_vector_p (@0))))
-
(simplify
(vec_perm vec_same_elem_p@0 @0 @1)
- @0)
+ (if (known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (@0)),
+ TYPE_VECTOR_SUBPARTS (TREE_TYPE (@1))))
+ @0))
/* Push VEC_PERM earlier if that may help FMA perception (PR101895). */
(simplify
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr110280.c b/gcc/testsuite/gcc.target/aarch64/sve/pr110280.c
new file mode 100644
index 00000000000..453c9cbcf9e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/pr110280.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+#include "arm_sve.h"
+
+svuint32_t l()
+{
+ _Alignas(16) const unsigned int lanes[4] = {0, 0, 0, 0};
+ return svld1rq_u32(svptrue_b8(), lanes);
+}
next reply other threads:[~2023-06-20 9:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 9:54 Prathamesh Kulkarni [this message]
2023-06-20 11:15 ` Richard Biener
2023-06-22 9:07 ` Prathamesh Kulkarni
2023-06-22 12:33 ` Richard Biener
2023-06-23 9:09 ` Prathamesh Kulkarni
2023-06-23 9:28 ` Richard Biener
2023-06-23 10:03 ` Prathamesh Kulkarni
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