On Mon, Sep 6, 2021 at 6:03 PM Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Mon, 6 Sep 2021, liuhongt wrote:
>
> > Hi:
> > For the conversion from _Float16 to int, if the corresponding optab
> > does not exist, the compiler will try the wider mode (SFmode here),
> > but when floatsfsi exists but FAIL, FROM will be rewritten, which
> > leads to a PR runtime error.
> >
> > Boostrapped and regtested on x86_64-linux-gnu{-m32,}.
> > Ok for trunk?
> >
> > gcc/ChangeLog:
> >
> > PR middle-end/102182
> > * optabs.c (expand_fix): Add from1 to avoid from being
> > overwritten.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR middle-end/102182
> > *gcc.target/i386/pr101282.c: New test.
> > ---
> > gcc/optabs.c | 10 +++++++---
> > gcc/testsuite/gcc.target/i386/pr101282.c | 18 ++++++++++++++++++
> > 2 files changed, 25 insertions(+), 3 deletions(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/pr101282.c
> >
> > diff --git a/gcc/optabs.c b/gcc/optabs.c
> > index ebed78fda3f..6af67d05253 100644
> > --- a/gcc/optabs.c
> > +++ b/gcc/optabs.c
> > @@ -5480,6 +5480,7 @@ expand_fix (rtx to, rtx from, int unsignedp)
> > FOR_EACH_MODE_FROM (imode, GET_MODE (to))
> > {
> > int doing_unsigned = unsignedp;
> > + rtx from1 = NULL_RTX;
> >
> > icode = can_fix_p (imode, fmode, unsignedp, &must_trunc);
> > if (icode == CODE_FOR_nothing && imode != GET_MODE (to) && unsignedp)
> > @@ -5489,19 +5490,22 @@ expand_fix (rtx to, rtx from, int unsignedp)
> > {
> > rtx_insn *last = get_last_insn ();
>
> better declare from1 here
Changed.
>
> > if (fmode != GET_MODE (from))
> > - from = convert_to_mode (fmode, from, 0);
> > + from1 = convert_to_mode (fmode, from, 0);
> >
> > if (must_trunc)
> > {
> > rtx temp = gen_reg_rtx (GET_MODE (from));
> > - from = expand_unop (GET_MODE (from), ftrunc_optab, from,
> > + from1 = expand_unop (GET_MODE (from), ftrunc_optab, from,
>
> this must use from1 as well?
Oh, yes!
>
> > temp, 0);
> > }
> >
> > if (imode != GET_MODE (to))
> > target = gen_reg_rtx (imode);
> >
> > - if (maybe_emit_unop_insn (icode, target, from,
> > + if (!from1)
> > + from1 = from;
>
> so move this up.
>
> > + if (maybe_emit_unop_insn (icode, target, from1,
> > doing_unsigned ? UNSIGNED_FIX : FIX))
> > {
> > if (target != to)
> > diff --git a/gcc/testsuite/gcc.target/i386/pr101282.c
> > b/gcc/testsuite/gcc.target/i386/pr101282.c
> > new file mode 100644
> > index 00000000000..2148b9294ef
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr101282.c
> > @@ -0,0 +1,18 @@
> > +/* { dg-do run { target { ia32 } } } */
> > +/* { dg-options "-Os -march=i686 -mfpmath=sse -msse2" } */
> > +
> > +#include<stdlib.h>
> > +int
> > +main (void)
> > +{
> > + static volatile unsigned int ivin, ivout;
> > + static volatile _Float16 fv1, fv2;
> > + ivin = ((unsigned int)1);
> > + fv1 = ((unsigned int)1);
> > + fv2 = ivin;
> > + ivout = fv2;
> > + if (ivout != ((unsigned int)1))
> > + abort ();
> > +
> > + exit (0);
> > +}
> >
>
> --
> Richard Biener <rguent...@suse.de>
> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
> Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
Here is the update patch.
--
BR,
Hongtao
From 4d94a88a28e9b73885851c167f724ac60a2f70ec Mon Sep 17 00:00:00 2001
From: liuhongt <hongtao....@intel.com>
Date: Mon, 6 Sep 2021 17:09:38 +0800
Subject: [PATCH v2] Avoid FROM being overwritten in expand_fix.
For the conversion from _Float16 to int, if the corresponding optab
does not exist, the compiler will try the wider mode (SFmode here),
but when floatsfsi exists but FAIL, FROM will be rewritten, which
leads to a PR runtime error.
gcc/ChangeLog:
PR middle-end/102182
* optabs.c (expand_fix): Add from1 to avoid from being
overwritten.
gcc/testsuite/ChangeLog:
PR middle-end/102182
*gcc.target/i386/pr101282.c: New test.
---
gcc/optabs.c | 11 ++++++-----
gcc/testsuite/gcc.target/i386/pr101282.c | 18 ++++++++++++++++++
2 files changed, 24 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr101282.c
diff --git a/gcc/optabs.c b/gcc/optabs.c
index ebed78fda3f..019bbb62882 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -5488,20 +5488,21 @@ expand_fix (rtx to, rtx from, int unsignedp)
if (icode != CODE_FOR_nothing)
{
rtx_insn *last = get_last_insn ();
+ rtx from1 = from;
if (fmode != GET_MODE (from))
- from = convert_to_mode (fmode, from, 0);
+ from1 = convert_to_mode (fmode, from, 0);
if (must_trunc)
{
- rtx temp = gen_reg_rtx (GET_MODE (from));
- from = expand_unop (GET_MODE (from), ftrunc_optab, from,
- temp, 0);
+ rtx temp = gen_reg_rtx (GET_MODE (from1));
+ from1 = expand_unop (GET_MODE (from1), ftrunc_optab, from1,
+ temp, 0);
}
if (imode != GET_MODE (to))
target = gen_reg_rtx (imode);
- if (maybe_emit_unop_insn (icode, target, from,
+ if (maybe_emit_unop_insn (icode, target, from1,
doing_unsigned ? UNSIGNED_FIX : FIX))
{
if (target != to)
diff --git a/gcc/testsuite/gcc.target/i386/pr101282.c b/gcc/testsuite/gcc.target/i386/pr101282.c
new file mode 100644
index 00000000000..2148b9294ef
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr101282.c
@@ -0,0 +1,18 @@
+/* { dg-do run { target { ia32 } } } */
+/* { dg-options "-Os -march=i686 -mfpmath=sse -msse2" } */
+
+#include<stdlib.h>
+int
+main (void)
+{
+ static volatile unsigned int ivin, ivout;
+ static volatile _Float16 fv1, fv2;
+ ivin = ((unsigned int)1);
+ fv1 = ((unsigned int)1);
+ fv2 = ivin;
+ ivout = fv2;
+ if (ivout != ((unsigned int)1))
+ abort ();
+
+ exit (0);
+}
--
2.27.0
