On Tue, Aug 5, 2025 at 9:22 AM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> On Tue, Aug 5, 2025 at 3:32 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> >
> > commit 050b1708ea532ea4840e97d85fad4ca63d4cd631
> > Author: H.J. Lu <hjl.to...@gmail.com>
> > Date: Thu Jun 19 05:03:48 2025 +0800
> >
> > x86: Get the widest vector mode from MOVE_MAX
> >
> > gets the widest vector mode from MOVE_MAX. But for memset, it should
> > use STORE_MAX_PIECES.
> >
> > gcc/
> >
> > PR target/121410
> > * config/i386/i386-expand.cc (ix86_expand_set_or_cpymem): Use
> > STORE_MAX_PIECES to get the widest vector mode in vector loop
> > for memset.
> >
> > gcc/testsuite/
> >
> > PR target/121410
> > * gcc.target/i386/pr121410.c: New test.
>
> OK with a small cosmetic change suggested below.
>
> Thanks,
> Uros.
>
> >
> > Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
> > ---
> > gcc/config/i386/i386-expand.cc | 5 +++--
> > gcc/testsuite/gcc.target/i386/pr121410.c | 11 +++++++++++
> > 2 files changed, 14 insertions(+), 2 deletions(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/pr121410.c
> >
> > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
> > index 0e5af5319ff..a5527081d9e 100644
> > --- a/gcc/config/i386/i386-expand.cc
> > +++ b/gcc/config/i386/i386-expand.cc
> > @@ -9574,8 +9574,9 @@ ix86_expand_set_or_cpymem (rtx dst, rtx src, rtx
> > count_exp, rtx val_exp,
> > case vector_loop:
> > need_zero_guard = true;
> > unroll_factor = 4;
> > - /* Get the vector mode to move MOVE_MAX bytes. */
> > - nunits = MOVE_MAX / GET_MODE_SIZE (word_mode);
> > + /* Get the vector mode to move STORE_MAX_PIECES/MOVE_MAX bytes. */
> > + nunits = ((issetmem ? STORE_MAX_PIECES : MOVE_MAX)
>
> Please put the number of bytes into a temporary.
This is the patch I am checking in:
/* Get the vector mode to move STORE_MAX_PIECES/MOVE_MAX bytes. */
nunits = issetmem ? STORE_MAX_PIECES : MOVE_MAX;
nunits /= GET_MODE_SIZE (word_mode);
> > + / GET_MODE_SIZE (word_mode));
> > if (nunits > 1)
> > {
> > move_mode = mode_for_vector (word_mode, nunits).require ();
> > diff --git a/gcc/testsuite/gcc.target/i386/pr121410.c
> > b/gcc/testsuite/gcc.target/i386/pr121410.c
> > new file mode 100644
> > index 00000000000..04bab91e1b8
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr121410.c
> > @@ -0,0 +1,11 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -march=x86-64 -mavx512f -mstore-max=128" } */
> > +
> > +extern unsigned _BitInt(3719) a;
> > +extern _BitInt(465) g;
> > +void
> > +foo(void)
> > +{
> > + _BitInt(465) b = a >> 1860;
> > + g = b + b;
> > +}
> > --
> > 2.50.1
> >
--
H.J.
From 0f91925f628f36292a94688fdb68a343ae43af30 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 5 Aug 2025 06:27:15 -0700
Subject: [PATCH v2] x86: Get the widest vector mode from STORE_MAX_PIECES for
memset
commit 050b1708ea532ea4840e97d85fad4ca63d4cd631
Author: H.J. Lu <hjl.to...@gmail.com>
Date: Thu Jun 19 05:03:48 2025 +0800
x86: Get the widest vector mode from MOVE_MAX
gets the widest vector mode from MOVE_MAX. But for memset, it should
use STORE_MAX_PIECES.
gcc/
PR target/121410
* config/i386/i386-expand.cc (ix86_expand_set_or_cpymem): Use
STORE_MAX_PIECES to get the widest vector mode in vector loop
for memset.
gcc/testsuite/
PR target/121410
* gcc.target/i386/pr121410.c: New test.
Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
---
gcc/config/i386/i386-expand.cc | 5 +++--
gcc/testsuite/gcc.target/i386/pr121410.c | 11 +++++++++++
2 files changed, 14 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr121410.c
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 0e5af5319ff..911dd8e1e65 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -9574,8 +9574,9 @@ ix86_expand_set_or_cpymem (rtx dst, rtx src, rtx count_exp, rtx val_exp,
case vector_loop:
need_zero_guard = true;
unroll_factor = 4;
- /* Get the vector mode to move MOVE_MAX bytes. */
- nunits = MOVE_MAX / GET_MODE_SIZE (word_mode);
+ /* Get the vector mode to move STORE_MAX_PIECES/MOVE_MAX bytes. */
+ nunits = issetmem ? STORE_MAX_PIECES : MOVE_MAX;
+ nunits /= GET_MODE_SIZE (word_mode);
if (nunits > 1)
{
move_mode = mode_for_vector (word_mode, nunits).require ();
diff --git a/gcc/testsuite/gcc.target/i386/pr121410.c b/gcc/testsuite/gcc.target/i386/pr121410.c
new file mode 100644
index 00000000000..04bab91e1b8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121410.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=x86-64 -mavx512f -mstore-max=128" } */
+
+extern unsigned _BitInt(3719) a;
+extern _BitInt(465) g;
+void
+foo(void)
+{
+ _BitInt(465) b = a >> 1860;
+ g = b + b;
+}
--
2.50.1
