https://gcc.gnu.org/g:ab2da8fb67b1aa0557a16b62689a888730dba610
commit r14-9494-gab2da8fb67b1aa0557a16b62689a888730dba610
Author: Jakub Jelinek <ja...@redhat.com>
Date: Fri Mar 15 10:46:47 2024 +0100
i386: Fix a pasto in ix86_expand_int_sse_cmp [PR114339]
In r13-3803-gfa271afb58 I've added an optimization for LE/LEU/GE/GEU
comparison against CONST_VECTOR. As the comments say:
/* x <= cst can be handled as x < cst + 1 unless there is
wrap around in cst + 1. */
...
/* For LE punt if some element is signed maximum. */
...
/* For LEU punt if some element is unsigned maximum. */
and
/* x >= cst can be handled as x > cst - 1 unless there is
wrap around in cst - 1. */
...
/* For GE punt if some element is signed minimum. */
...
/* For GEU punt if some element is zero. */
Apparently I wrote the GE/GEU (second case) first and then
copied/adjusted it for LE/LEU, most of the adjustments look correct, but
I've left if (code == GE) comparison when testing if it should punt for
signed maximum. That condition is never true, because this is in
switch (code) { ... case LE: case LEU: block and we really meant to
be what the comment says, for LE punt if some element is signed maximum,
as then cst + 1 wraps around.
The following patch fixes the pasto.
2024-03-15 Jakub Jelinek <ja...@redhat.com>
PR target/114339
* config/i386/i386-expand.cc (ix86_expand_int_sse_cmp) <case LE>:
Fix
a pasto, compare code against LE rather than GE.
* gcc.target/i386/pr114339.c: New test.
Diff:
---
gcc/config/i386/i386-expand.cc | 2 +-
gcc/testsuite/gcc.target/i386/pr114339.c | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 2210e6f7cc8..8bb8f21e686 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -4690,7 +4690,7 @@ ix86_expand_int_sse_cmp (rtx dest, enum rtx_code code,
rtx cop0, rtx cop1,
rtx elt = CONST_VECTOR_ELT (cop1, i);
if (!CONST_INT_P (elt))
break;
- if (code == GE)
+ if (code == LE)
{
/* For LE punt if some element is signed maximum. */
if ((INTVAL (elt) & (GET_MODE_MASK (eltmode) >> 1))
diff --git a/gcc/testsuite/gcc.target/i386/pr114339.c
b/gcc/testsuite/gcc.target/i386/pr114339.c
new file mode 100644
index 00000000000..8fba3747cf1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr114339.c
@@ -0,0 +1,20 @@
+/* PR target/114339 */
+/* { dg-do run } */
+/* { dg-options "-O2 -Wno-psabi" } */
+/* { dg-additional-options "-mavx" { target avx_runtime } } */
+
+typedef long long V __attribute__((vector_size (16)));
+
+__attribute__((noipa)) V
+foo (V a)
+{
+ return a <= (V) {0, __LONG_LONG_MAX__ };
+}
+
+int
+main ()
+{
+ V t = foo ((V) { 0, 0 });
+ if (t[0] != -1LL || t[1] != -1LL)
+ __builtin_abort ();
+}
