On December 13, 2019 12:54:08 AM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
wrote:
>On Thu, Dec 12, 2019 at 04:59:40PM +0100, Richard Biener wrote:
>> >If it starts being ambiguous somewhere, could we use some target
>macro
>> >or
>> >target hook to decide?
>>
>> Ambiguous IL is bad :/ IL semantics dependent on a target hook, too.
>Just look at SHIFT_COUNT_TRUNCATED...
>
>This is something I've also successfully bootstrapped/regtested on
>x86_64-linux and i686-linux:
Works for me.
I agree a rewrite isn't sth for stage 3/4 but we might want to revisit this
during next stage 1.
Richard.
>2019-12-11 Jakub Jelinek <ja...@redhat.com>
>
> PR target/92908
> * simplify-rtx.c (simplify_relational_operation): Punt for vector
> cmp_mode and scalar mode, if simplify_relational_operation returned
> const_true_rtx.
> (simplify_const_relational_operation): Change VOID_mode in function
> comment to VOIDmode.
>
> * gcc.target/i386/avx512bw-pr92908.c: New test.
>
>--- gcc/simplify-rtx.c.jj 2019-11-19 22:27:02.000058742 +0100
>+++ gcc/simplify-rtx.c 2019-12-11 13:31:57.197809704 +0100
>@@ -5037,6 +5037,15 @@ simplify_relational_operation (enum rtx_
> return NULL_RTX;
> #endif
> }
>+ /* For vector comparison with scalar int result, it is unknown
>+ if the target means here a comparison into an integral bitmask,
>+ or comparison where all comparisons true mean const_true_rtx
>+ whole result, or where any comparisons true mean const_true_rtx
>+ whole result. For const0_rtx all the cases are the same. */
>+ if (VECTOR_MODE_P (cmp_mode)
>+ && SCALAR_INT_MODE_P (mode)
>+ && tem == const_true_rtx)
>+ return NULL_RTX;
>
> return tem;
> }
>@@ -5383,7 +5392,7 @@ comparison_result (enum rtx_code code, i
> }
>
> /* Check if the given comparison (done in the given MODE) is actually
>- a tautology or a contradiction. If the mode is VOID_mode, the
>+ a tautology or a contradiction. If the mode is VOIDmode, the
> comparison is done in "infinite precision". If no simplification
> is possible, this function returns zero. Otherwise, it returns
> either const_true_rtx or const0_rtx. */
>--- gcc/testsuite/gcc.target/i386/avx512bw-pr92908.c.jj 2019-12-11
>14:24:12.083418762 +0100
>+++ gcc/testsuite/gcc.target/i386/avx512bw-pr92908.c 2019-12-11
>14:23:56.071665326 +0100
>@@ -0,0 +1,21 @@
>+/* PR target/92908 */
>+/* { dg-do run } */
>+/* { dg-options "-Og -fno-tree-fre -mavx512bw" } */
>+/* { dg-require-effective-target avx512bw } */
>+
>+#define AVX512BW
>+#include "avx512f-helper.h"
>+
>+typedef unsigned short V __attribute__ ((__vector_size__ (64)));
>+
>+V v;
>+
>+void
>+TEST (void)
>+{
>+ int i;
>+ v = (V) v == v;
>+ for (i = 0; i < 32; i++)
>+ if (v[i] != 0xffff)
>+ abort ();
>+}
>
>
> Jakub
