[Scalar masks 2/x] Use bool masks in if-conversion

[Ilya Enkovich]

Hi,

This patch intoriduces a new vectorizer hook use_scalar_mask_p which affects 
code generated by if-conversion pass (and affects patterns in later patches).

Thanks,
Ilya
--
2015-08-17  Ilya Enkovich  <enkovich....@gmail.com>

        * doc/tm.texi (TARGET_VECTORIZE_USE_SCALAR_MASK_P): New.
        * doc/tm.texi.in: Regenerated.
        * target.def (use_scalar_mask_p): New.
        * tree-if-conv.c: Include target.h.
        (predicate_mem_writes): Don't convert boolean predicates into
        integer when scalar masks are used.


diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 2383fb9..a124489 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -4233,6 +4233,8 @@ address;  but often a machine-dependent strategy can 
generate better code.
 
 @hook TARGET_VECTORIZE_DESTROY_COST_DATA
 
+@hook TARGET_VECTORIZE_USE_SCALAR_MASK_P
+
 @hook TARGET_VECTORIZE_BUILTIN_TM_LOAD
 
 @hook TARGET_VECTORIZE_BUILTIN_TM_STORE
diff --git a/gcc/target.def b/gcc/target.def
index 4edc209..0975bf3 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1855,6 +1855,15 @@ DEFHOOK
  (void *data),
  default_destroy_cost_data)
 
+/* Target function to check scalar masks support.  */
+DEFHOOK
+(use_scalar_mask_p,
+ "This hook returns 1 if vectorizer should use scalar masks instead of "
+ "vector ones for MASK_LOAD, MASK_STORE and VEC_COND_EXPR.",
+ bool,
+ (void),
+ hook_bool_void_false)
+
 HOOK_VECTOR_END (vectorize)
 
 #undef HOOK_PREFIX
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index 291e602..73dcecd 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -122,6 +122,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "insn-codes.h"
 #include "optabs.h"
 #include "tree-hash-traits.h"
+#include "target.h"
 
 /* List of basic blocks in if-conversion-suitable order.  */
 static basic_block *ifc_bbs;
@@ -2082,15 +2083,24 @@ predicate_mem_writes (loop_p loop)
              mask = vect_masks[index];
            else
              {
-               masktype = build_nonstandard_integer_type (bitsize, 1);
-               mask_op0 = build_int_cst (masktype, swap ? 0 : -1);
-               mask_op1 = build_int_cst (masktype, swap ? -1 : 0);
-               cond = force_gimple_operand_gsi_1 (&gsi, unshare_expr (cond),
-                                                  is_gimple_condexpr,
-                                                  NULL_TREE,
-                                                  true, GSI_SAME_STMT);
-               mask = fold_build_cond_expr (masktype, unshare_expr (cond),
-                                            mask_op0, mask_op1);
+               if (targetm.vectorize.use_scalar_mask_p ())
+                 {
+                   masktype = boolean_type_node;
+                   mask = unshare_expr (cond);
+                 }
+               else
+                 {
+                   masktype = build_nonstandard_integer_type (bitsize, 1);
+                   mask_op0 = build_int_cst (masktype, swap ? 0 : -1);
+                   mask_op1 = build_int_cst (masktype, swap ? -1 : 0);
+                   cond = force_gimple_operand_gsi_1 (&gsi,
+                                                      unshare_expr (cond),
+                                                      is_gimple_condexpr,
+                                                      NULL_TREE,
+                                                      true, GSI_SAME_STMT);
+                   mask = fold_build_cond_expr (masktype, unshare_expr (cond),
+                                                mask_op0, mask_op1);
+                 }
                mask = ifc_temp_var (masktype, mask, &gsi);
                /* Save mask and its size for further use.  */
                vect_sizes.safe_push (bitsize);