Re: [PATCH] match.pd: Add new division pattern [PR104992]

[Andrew Pinski <pinskia@gmail.com>]

On Mon, Jul 25, 2022 at 1:59 PM Sam Feifer <sfeifer@redhat.com> wrote:
>
>
>> I suspect for eq and mult you might want to add :c to them even though
>> in your testcase you don't need them, you might be able to get it via
>> using different statements and looking at the forwprop gimple dump.
>> Also, did you send the wrong patch as it looks like the function call
>> to build_zero_cst has been eaten ... (or is it just because TREE_TYPE
>> has parentheses inside the macro and it just accidently works :)).
>
>
> I got lucky and it works without parentheses :). I just added them in for readability.
>
>> You might also want to make sure it does the right thing for vector
>> types and complex types (yes both are valid for trunc_div still).
>>
>
> I made a vector test case, but it's giving me errors when using " == " between two vectors. I'm running it with the C++ front end and it's saying the return value cannot be converted. Any tips for this?
>
> I'm not sure exactly what you mean by "complex types" in terms of testing this patch. Could I get an example?

int f(_Complex int x, _Complex int y)
{
  return x == x / y * y;
}

For vector try (which works for both the C and C++ front-end):
#define vector __attribute__((vector_size(4*sizeof(int)) ))
vector int f(vector int x, vector int y)
{
  return x == x / y * y;
}

That is for the vector case, == still returns a vector type.

Thanks,
Andrew Pinski

>
> Thanks
> -Sam
>
>> Thanks,
>> Andrew Pinski
>>
>> > diff --git a/gcc/testsuite/gcc.dg/pr104992-1.c b/gcc/testsuite/gcc.dg/pr104992-1.c
>> > new file mode 100644
>> > index 00000000000..a80e5e180ce
>> > --- /dev/null
>> > +++ b/gcc/testsuite/gcc.dg/pr104992-1.c
>> > @@ -0,0 +1,30 @@
>> > +/* PR tree-optimization/104992 */
>> > +/* { dg-do run } */
>> > +/* { dg-options "-O2"} */
>> > +
>> > +#include "pr104992.c"
>> > +
>> > +int main () {
>> > +
>> > +    /* Should be true.  */
>> > +    if (!foo(6, 3)
>> > +        || !bar(12, 2)
>> > +        || !baz(34, 17)
>> > +        || !qux(50, 10)
>> > +        || !fred(16, 8)
>> > +        || !baz(-9, 3)
>> > +        || !baz(9, -3)
>> > +        || !baz(-9, -3)
>> > +        ) {
>> > +            __builtin_abort();
>> > +         }
>> > +
>> > +    /* Should be false.  */
>> > +    if (foo(5, 30)
>> > +        || bar(72, 27)
>> > +        || baz(42, 15)) {
>> > +            __builtin_abort();
>> > +        }
>> > +
>> > +    return 0;
>> > +}
>> > diff --git a/gcc/testsuite/gcc.dg/pr104992.c b/gcc/testsuite/gcc.dg/pr104992.c
>> > new file mode 100644
>> > index 00000000000..b4b0ca53118
>> > --- /dev/null
>> > +++ b/gcc/testsuite/gcc.dg/pr104992.c
>> > @@ -0,0 +1,35 @@
>> > +/* PR tree-optimization/104992 */
>> > +/* { dg-do compile } */
>> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
>> > +
>> > +/* Form from PR.  */
>> > +__attribute__((noipa)) unsigned foo(unsigned x, unsigned y)
>> > +{
>> > +    return x / y * y == x;
>> > +}
>> > +
>> > +__attribute__((noipa)) unsigned bar(unsigned x, unsigned y) {
>> > +    return x == x / y * y;
>> > +}
>> > +
>> > +/* Signed test case.  */
>> > +__attribute__((noipa)) unsigned baz (int x, int y) {
>> > +    return x / y * y == x;
>> > +}
>> > +
>> > +/* Changed order.  */
>> > +__attribute__((noipa)) unsigned qux (unsigned x, unsigned y) {
>> > +    return y * (x / y) == x;
>> > +}
>> > +
>> > +/* Wrong order.  */
>> > +__attribute__((noipa)) unsigned fred (unsigned x, unsigned y) {
>> > +    return y * x / y == x;
>> > +}
>> > +
>> > +/* Wrong pattern.  */
>> > +__attribute__((noipa)) unsigned waldo (unsigned x, unsigned y, unsigned z) {
>> > +    return x / y * z == x;
>> > +}
>> > +
>> > +/* { dg-final {scan-tree-dump-times " % " 4 "optimized" } } */
>> >
>> > base-commit: 633e9920589ddfaf2d6da1c24ce99b18a2638db4
>> > --
>> > 2.31.1
>> >
>>