On Thu, Jun 02, 2022 at 08:36:42AM +0000, Richard Biener wrote:
> > --- gcc/match.pd.jj 2022-06-01 13:54:32.000654151 +0200
> > +++ gcc/match.pd 2022-06-01 15:13:35.473084402 +0200
> > @@ -5969,6 +5969,17 @@ (define_operator_list SYNC_FETCH_AND_AND
> > && (!TYPE_UNSIGNED (TREE_TYPE (@2)) || TYPE_UNSIGNED (TREE_TYPE
> > (@0))))
> > (ovf @1 @0))))
> >
> > +/* Optimize __builtin_mul_overflow_p (x, cst, (utype) 0) if all 3 types
> > + are unsigned to x > (umax / cst). */
> > +(simplify
> > + (imagpart (IFN_MUL_OVERFLOW:cs@2 @0 integer_nonzerop@1))
>
> does :c work here? I think it is at least ignored, possibly diagnostic
> in genmatch is missing ...
I saw it used in another pattern, so thought it will work fine:
(cmp:c (realpart (IFN_ADD_OVERFLOW:c@2 @0 @1)) @0)
And looking at the generated source, I think it does work:
case CFN_MUL_OVERFLOW:
if (gimple_call_num_args (_c1) == 2)
{
tree _q20 = gimple_call_arg (_c1, 0);
_q20 = do_valueize (valueize, _q20);
tree _q21 = gimple_call_arg (_c1, 1);
_q21 = do_valueize (valueize, _q21);
if (integer_nonzerop (_q21))
{
{
/* #line 5976 "../../gcc/match.pd" */
tree captures[3] ATTRIBUTE_UNUSED = { _p0, _q20, _q21
};
if (gimple_simplify_256 (res_op, seq, valueize, type,
captures))
return true;
}
}
if (integer_nonzerop (_q20))
{
{
/* #line 5976 "../../gcc/match.pd" */
tree captures[3] ATTRIBUTE_UNUSED = { _p0, _q21, _q20
};
if (gimple_simplify_256 (res_op, seq, valueize, type,
captures))
return true;
}
}
}
Though, sure, I should test it in the testcase too.
Here is what I've committed as obvious after testing on x86_64-linux
-m32/-m64:
2022-06-02 Jakub Jelinek <ja...@redhat.com>
PR middle-end/30314
* gcc.dg/tree-ssa/pr30314.c: Add tests with swapped arguments.
--- gcc/testsuite/gcc.dg/tree-ssa/pr30314.c.jj 2022-06-01 17:54:30.000000000
+0200
+++ gcc/testsuite/gcc.dg/tree-ssa/pr30314.c 2022-06-02 11:01:27.818987766
+0200
@@ -4,6 +4,8 @@
/* { dg-final { scan-tree-dump-not "\.MUL_OVERFLOW " "optimized" } } */
/* { dg-final { scan-tree-dump " > 122713351" "optimized" { target int32 } } }
*/
/* { dg-final { scan-tree-dump " > 527049830677415760" "optimized" { target
lp64 } } } */
+/* { dg-final { scan-tree-dump " > 102261126" "optimized" { target int32 } } }
*/
+/* { dg-final { scan-tree-dump " > 439208192231179800" "optimized" { target
lp64 } } } */
int
foo (unsigned int x)
@@ -16,3 +18,15 @@ bar (unsigned long int x)
{
return __builtin_mul_overflow_p (x, 35UL, 0UL);
}
+
+int
+baz (unsigned int x)
+{
+ return __builtin_mul_overflow_p (42, x, 0U);
+}
+
+int
+qux (unsigned long int x)
+{
+ return __builtin_mul_overflow_p (42, x, 0UL);
+}
Jakub
