On Thu, Jun 16, 2016 at 11:51:12AM +0200, Jakub Jelinek wrote:
> Here is what I've committed to the trunk and 6.2 after bootstrap/regtest on
> x86_64-linux and i686-linux.
> For 5/4.9, this doesn't apply cleanly, as http://gcc.gnu.org/r222592
> aka https://gcc.gnu.org/ml/gcc-patches/2015-04/msg01930.html
> has not been backported. Shall I backport that too, or just not apply to
> 5/4.9? I guess I should, because:
> int v;
> __attribute__ ((noinline, noclone)) void bar (void) { v++; }
> __attribute__ ((noinline, noclone)) void foo (unsigned int x) { signed int y
> = ((-__INT_MAX__ - 1) / 2), r; if (__builtin_mul_overflow (x, y, &r)) bar ();
> }
> int main () { foo (2); if (v) __builtin_abort (); return 0; }
> is miscompiled with -m32 -O2 in 5.x (though, 4.9 doesn't support
> __builtin_*_overflow, so maybe it is not an issue there).
Ok, I went ahead and committed following to 5.x branch
and the testcase also to trunk and 6.2.
What is your preference for 4.9? The testcase isn't applicable.
2016-06-16 Jakub Jelinek <ja...@redhat.com>
PR target/71554
* config/i386/i386.md (setcc + movzbl peephole2): Use reg_set_p.
(setcc + and peephole2): Likewise.
Backported from mainline
2015-04-29 Uros Bizjak <ubiz...@gmail.com>
* config/i386/i386.md (setcc+movzbl peephole2): Check also clobbered
reg.
(setcc+andl peephole2): Ditto.
2016-06-16 Jakub Jelinek <ja...@redhat.com>
PR target/71554
* gcc.c-torture/execute/pr71554.c: New test.
--- gcc/config/i386/i386.md (revision 237518)
+++ gcc/config/i386/i386.md (working copy)
@@ -11645,7 +11645,8 @@ (define_peephole2
(zero_extend (match_dup 1)))]
"(peep2_reg_dead_p (3, operands[1])
|| operands_match_p (operands[1], operands[3]))
- && ! reg_overlap_mentioned_p (operands[3], operands[0])"
+ && ! reg_overlap_mentioned_p (operands[3], operands[0])
+ && ! reg_set_p (operands[3], operands[4])"
[(parallel [(set (match_dup 5) (match_dup 0))
(match_dup 4)])
(set (strict_low_part (match_dup 6))
@@ -11688,7 +11689,8 @@ (define_peephole2
(clobber (reg:CC FLAGS_REG))])]
"(peep2_reg_dead_p (3, operands[1])
|| operands_match_p (operands[1], operands[3]))
- && ! reg_overlap_mentioned_p (operands[3], operands[0])"
+ && ! reg_overlap_mentioned_p (operands[3], operands[0])
+ && ! reg_set_p (operands[3], operands[4])"
[(parallel [(set (match_dup 5) (match_dup 0))
(match_dup 4)])
(set (strict_low_part (match_dup 6))
--- gcc/testsuite/gcc.c-torture/execute/pr71554.c (revision 0)
+++ gcc/testsuite/gcc.c-torture/execute/pr71554.c (working copy)
@@ -0,0 +1,28 @@
+/* PR target/71554 */
+
+int v;
+
+__attribute__ ((noinline, noclone)) void
+bar (void)
+{
+ v++;
+}
+
+__attribute__ ((noinline, noclone))
+void
+foo (unsigned int x)
+{
+ signed int y = ((-__INT_MAX__ - 1) / 2);
+ signed int r;
+ if (__builtin_mul_overflow (x, y, &r))
+ bar ();
+}
+
+int
+main ()
+{
+ foo (2);
+ if (v)
+ __builtin_abort ();
+ return 0;
+}
Jakub
