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

Sam Feifer sfeifer@redhat.com
Tue Jul 26 14:31:13 GMT 2022


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

After some research about mod with complex types, I found that the binary
mod operation does not work with complex types. If so, the complex test
case should not be simplified. Is this correct?

I should also note that the above function, f, causes a segmentation fault.
I can only get a function with complex types to compile by breaking up the
operations like I would in a forward propagation test case. When I do this,
it does not simplify into mod, which I think is right.

Thanks
-Sam


> 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
> >> >
> >>
>
>


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