[gcc r12-6422] tree-optimization/103948 - detect vector vec_cmp in expand_vector_condition

[Uros Bizjak]

https://gcc.gnu.org/g:de0faa56a10406b50fba159957e3a3fd2f95c64b

commit r12-6422-gde0faa56a10406b50fba159957e3a3fd2f95c64b
Author: Uros Bizjak <ubizjak@gmail.com>
Date:   Mon Jan 10 20:39:35 2022 +0100

    tree-optimization/103948 - detect vector vec_cmp in expand_vector_condition
    
    Currently, expand_vector_condition detects only vcondMN and vconduMN
    named RTX patterns.  Teach it to also consider vec_cmpMN and vec_cmpuMN
    RTX patterns when all ones vector is returned for true and all zeros vector
    is returned for false.
    
    2022-01-10  Richard Biener  <rguenther@suse.de>
    
    gcc/ChangeLog:
    
            PR tree-optimization/103948
            * tree-vect-generic.c (expand_vector_condition): Return true if
            all ones vector is returned for true, all zeros vector for false
            and the target defines corresponding vec_cmp{,u}MN named RTX pattern.

Diff:
---
 gcc/tree-vect-generic.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/tree-vect-generic.c b/gcc/tree-vect-generic.c
index 6afb6999cd7..5814a71a5bb 100644
--- a/gcc/tree-vect-generic.c
+++ b/gcc/tree-vect-generic.c
@@ -1052,7 +1052,9 @@ expand_vector_condition (gimple_stmt_iterator *gsi, bitmap dce_ssa_names)
 	}
     }
 
-  if (expand_vec_cond_expr_p (type, TREE_TYPE (a1), code))
+  if (expand_vec_cond_expr_p (type, TREE_TYPE (a1), code)
+      || (integer_all_onesp (b) && integer_zerop (c)
+	  && expand_vec_cmp_expr_p (type, TREE_TYPE (a1), code)))
     {
       gcc_assert (TREE_CODE (a) == SSA_NAME || TREE_CODE (a) == VECTOR_CST);
       return true;