[PATCH] Avoid integer vector used as a vector mask

[Ilya Enkovich <enkovich.gnu@gmail.com>]

Hi,

Currently when MASK_LOAD and MASK_STORE is vectorized we check
scalar type of a mask but don't check its vector mask.  It means
we may vectorize it when mask was just loaded from an array of
booleans.  This happens e.g. for following test:

SUBROUTINE TEST (x, y, z, mask, ims, ime)
  IMPLICIT NONE
  INTEGER ims, ime, i
  LOGICAL mask (ims:ime)
  REAL x(ims:ime), y(ims:ime), z(ims:ime)

  DO 812 i=ims,ime
     IF (mask(i)) x(i) = y(i) - z(i)
812  CONTINUE
  END

Produced GIMPLE:

  vect__15.30_76 = MEM[base: _91, offset: 0B];
  vect__17.32_80 = MASK_LOAD (vectp_y.33_78, 4B, vect__15.30_76);
  vect__19.35_83 = MASK_LOAD (vectp_z.36_81, 4B, vect__15.30_76);
  vect__20.38_84 = vect__17.32_80 - vect__19.35_83;
  MASK_STORE (vectp_x.39_85, 4B, vect__15.30_76, vect__20.38_84);

Loaded values don't have required all 0s and all 1s values and
shouldn't be used as a mask.  This patch checks vector type of
a mask used for MASK_LOAD and MASK_STORE.  Bootstrapped and
regtested for x86_64-pc-linux-gnu.  OK for trunk?

Thanks,
Ilya
--
gcc/

2015-12-11  Ilya Enkovich  <enkovich.gnu@gmail.com>

	* tree-vect-stmts.c (vectorizable_mask_load_store): Check
	mask vectype.


diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 5377d15..abcd9a4 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -1780,7 +1780,7 @@ vectorizable_mask_load_store (gimple *stmt, gimple_stmt_iterator *gsi,
   if (!mask_vectype)
     mask_vectype = get_mask_type_for_scalar_type (TREE_TYPE (vectype));
 
-  if (!mask_vectype)
+  if (!mask_vectype || !VECTOR_BOOLEAN_TYPE_P (mask_vectype))
     return false;
 
   if (is_store)