[PATCH] Fix PR80457

[Bill Schmidt]

Hi,

While investigating a performance issue, I happened to notice that vectorized
COND_EXPRs were not contributing to the vectorizer cost model.  This patch
addresses that.

Bootstrapped and tested on powerpc64le-unknown-linux-gnu.  Is this ok for
trunk, or should it wait for GCC 8?

Thanks,
Bill


[gcc]

2017-04-18  Bill Schmidt  <wschm...@linux.vnet.ibm.com>

        PR tree-optimization/80457
        * tree-vect-stmts.c (vectorizable_condition): Update the cost
        model when vectorizing a COND_EXPR.

[gcc/testsuite]

2017-04-18  Bill Schmidt  <wschm...@linux.vnet.ibm.com>

        PR tree-optimization/80457
        * gcc.target/powerpc/pr78604.c: Verify that vectorized COND_EXPRs
        call vect_model_simple_cost.


Index: gcc/testsuite/gcc.target/powerpc/pr78604.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pr78604.c  (revision 246948)
+++ gcc/testsuite/gcc.target/powerpc/pr78604.c  (working copy)
@@ -2,7 +2,7 @@
 /* { dg-skip-if "" { powerpc*-*-darwin* } { "*" } { "" } } */
 /* { dg-require-effective-target powerpc_p8vector_ok } */
 /* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { 
"-mcpu=power8" } } */
-/* { dg-options "-mcpu=power8 -O2 -ftree-vectorize" } */
+/* { dg-options "-mcpu=power8 -O2 -ftree-vectorize -fdump-tree-vect-details" } 
*/
 
 #ifndef SIZE
 #define SIZE 1024
@@ -110,3 +110,4 @@ uns_gte (UNS_TYPE val1, UNS_TYPE val2)
 /* { dg-final { scan-assembler-times {\mvcmpgtsd\M} 4 } } */
 /* { dg-final { scan-assembler-times {\mvcmpgtud\M} 4 } } */
 /* { dg-final { scan-assembler-not   {\mvcmpequd\M} } } */
+/* { dg-final { scan-tree-dump-times "vect_model_simple_cost" 8 "vect" } } */
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c       (revision 246948)
+++ gcc/tree-vect-stmts.c       (working copy)
@@ -7746,7 +7746,7 @@ vectorizable_condition (gimple *stmt, gimple_stmt_
   tree vec_compare;
   tree new_temp;
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
-  enum vect_def_type dt, dts[4];
+  enum vect_def_type dt[2], dts[4];
   int ncopies;
   enum tree_code code, cond_code, bitop1 = NOP_EXPR, bitop2 = NOP_EXPR;
   stmt_vec_info prev_stmt_info = NULL;
@@ -7813,10 +7813,10 @@ vectorizable_condition (gimple *stmt, gimple_stmt_
     return false;
 
   gimple *def_stmt;
-  if (!vect_is_simple_use (then_clause, stmt_info->vinfo, &def_stmt, &dt,
+  if (!vect_is_simple_use (then_clause, stmt_info->vinfo, &def_stmt, &dt[0],
                           &vectype1))
     return false;
-  if (!vect_is_simple_use (else_clause, stmt_info->vinfo, &def_stmt, &dt,
+  if (!vect_is_simple_use (else_clause, stmt_info->vinfo, &def_stmt, &dt[1],
                           &vectype2))
     return false;
 
@@ -7900,8 +7900,12 @@ vectorizable_condition (gimple *stmt, gimple_stmt_
                return false;
            }
        }
-      return expand_vec_cond_expr_p (vectype, comp_vectype,
-                                    cond_code);
+      if (expand_vec_cond_expr_p (vectype, comp_vectype, cond_code))
+       {
+         vect_model_simple_cost (stmt_info, ncopies, dt, NULL, NULL);
+         return true;
+       }
+      return false;
     }
 
   /* Transform.  */