re PR rtl-optimization/89445 (_mm512_maskz_loadu_pd "forgets" to use the mask)

	PR rtl-optimization/89445
	* simplify-rtx.c (simplify_ternary_operation): Don't use
	simplify_merge_mask on operands that may trap.
	* rtlanal.c (may_trap_p_1): Use FLOAT_MODE_P instead of
	SCALAR_FLOAT_MODE_P checks.  For integral division by zero, if
	second operand is CONST_VECTOR, check if any element could be zero.
	Don't expect traps for VEC_{MERGE,SELECT,CONCAT,DUPLICATE} unless
	their operands can trap.

	* gcc.target/i386/avx512f-pr89445.c: New test.

From-SVN: r269176

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2be8a96355a671ad804b12ae78937c87d5f1f0eb..2185019488027af62741404f2f05f4bb4adc4697 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2019-02-24  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/89445
+       * simplify-rtx.c (simplify_ternary_operation): Don't use
+       simplify_merge_mask on operands that may trap.
+       * rtlanal.c (may_trap_p_1): Use FLOAT_MODE_P instead of
+       SCALAR_FLOAT_MODE_P checks.  For integral division by zero, if
+       second operand is CONST_VECTOR, check if any element could be zero.
+       Don't expect traps for VEC_{MERGE,SELECT,CONCAT,DUPLICATE} unless
+       their operands can trap.
+
 2019-02-23  Martin Sebor  <msebor@redhat.com>
 
        * gimple-ssa-sprintf.c (target_strtol): Rename...

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 345f13c6e9911aaa9217f8ac9f8c01b94bc96af9..3873b4098b0beba6ac60b034fbd83ca9799922ff 100644 (file)
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -2846,10 +2846,28 @@ may_trap_p_1 (const_rtx x, unsigned flags)
     case UMOD:
       if (HONOR_SNANS (x))
        return 1;
-      if (SCALAR_FLOAT_MODE_P (GET_MODE (x)))
+      if (FLOAT_MODE_P (GET_MODE (x)))
        return flag_trapping_math;
       if (!CONSTANT_P (XEXP (x, 1)) || (XEXP (x, 1) == const0_rtx))
        return 1;
+      if (GET_CODE (XEXP (x, 1)) == CONST_VECTOR)
+       {
+         /* For CONST_VECTOR, return 1 if any element is or might be zero.  */
+         unsigned int n_elts;
+         rtx op = XEXP (x, 1);
+         if (!GET_MODE_NUNITS (GET_MODE (op)).is_constant (&n_elts))
+           {
+             if (!CONST_VECTOR_DUPLICATE_P (op))
+               return 1;
+             for (unsigned i = 0; i < (unsigned int) XVECLEN (op, 0); i++)
+               if (CONST_VECTOR_ENCODED_ELT (op, i) == const0_rtx)
+                 return 1;
+           }
+         else
+           for (unsigned i = 0; i < n_elts; i++)
+             if (CONST_VECTOR_ELT (op, i) == const0_rtx)
+               return 1;
+       }
       break;
 
     case EXPR_LIST:
@@ -2898,12 +2916,16 @@ may_trap_p_1 (const_rtx x, unsigned flags)
     case NEG:
     case ABS:
     case SUBREG:
+    case VEC_MERGE:
+    case VEC_SELECT:
+    case VEC_CONCAT:
+    case VEC_DUPLICATE:
       /* These operations don't trap even with floating point.  */
       break;
 
     default:
       /* Any floating arithmetic may trap.  */
-      if (SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math)
+      if (FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math)
        return 1;
     }
 

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 83580a259f39776b14faf4ca4e73256c24797eda..89a46a933facaded1b23a84fa9a0924595b01e5a 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -6073,8 +6073,10 @@ simplify_ternary_operation (enum rtx_code code, machine_mode mode,
 
       if (!side_effects_p (op2))
        {
-         rtx top0 = simplify_merge_mask (op0, op2, 0);
-         rtx top1 = simplify_merge_mask (op1, op2, 1);
+         rtx top0
+           = may_trap_p (op0) ? NULL_RTX : simplify_merge_mask (op0, op2, 0);
+         rtx top1
+           = may_trap_p (op1) ? NULL_RTX : simplify_merge_mask (op1, op2, 1);
          if (top0 || top1)
            return simplify_gen_ternary (code, mode, mode,
                                         top0 ? top0 : op0,

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index dd9877efe5b2148e0023b7d74ba90b6542c08209..707c827621eceb062d81cbbbb34b78e28a926919 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-24  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/89445
+       * gcc.target/i386/avx512f-pr89445.c: New test.
+
 2019-02-23  Martin Sebor  <msebor@redhat.com>
 
        * gcc.dg/tree-ssa/builtin-sprintf-10.c: Cast remaining

diff --git a/gcc/testsuite/gcc.target/i386/avx512f-pr89445.c b/gcc/testsuite/gcc.target/i386/avx512f-pr89445.c
new file mode 100644 (file)
index 0000000..230c1d1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/avx512f-pr89445.c
@@ -0,0 +1,54 @@
+/* PR rtl-optimization/89445 */
+/* { dg-do run { target { avx512f && mmap } } } */
+/* { dg-options "-O2 -mavx512f" } */
+
+#include "avx512f-check.h"
+
+#include <sys/mman.h>
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+#ifndef MAP_ANON
+#define MAP_ANON 0
+#endif
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+__attribute__ ((noipa))
+void daxpy (unsigned long n, double a, double const *__restrict x,
+           double *__restrict y)
+{
+  const __m512d v_a = _mm512_broadcastsd_pd (_mm_set_sd (a));
+  const __mmask16 final = (1U << (n % 8u)) - 1;
+  __mmask16 mask = 65535u;
+  unsigned long i;
+  for (i = 0; i < n * sizeof (double); i += 8 * sizeof (double))
+    {
+      if (i + 8 * sizeof (double) > n * sizeof (double))
+       mask = final;
+      __m512d v_x = _mm512_maskz_loadu_pd (mask, (char const *) x + i);
+      __m512d v_y = _mm512_maskz_loadu_pd (mask, (char const *) y + i);
+      __m512d tmp = _mm512_fmadd_pd (v_x, v_a, v_y);
+      _mm512_mask_storeu_pd ((char *) y + i, mask, tmp);
+    }
+}
+
+static const double x[] = { 1, 2, 3, 4 };
+
+static void
+avx512f_test (void)
+{
+  char *ptr
+    = (char *) mmap (NULL, 2 * 4096, PROT_READ | PROT_WRITE,
+                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (ptr == MAP_FAILED)
+    return;
+
+  munmap (ptr + 4096, 4096);
+  double *y = (double *) (ptr + 4096 - sizeof (x));
+  __builtin_memcpy (y, x, sizeof (x));
+  daxpy (sizeof (x) / sizeof (x[0]), 1.0, x, y);
+  if (y[0] != 2.0 || y[1] != 4.0 || y[2] != 6.0 || y[3] != 8.0)
+    abort ();
+}