[gcc r15-863] vect: Use vect representative statement instead of original in patch recog [PR115060]

[Feng Xue via Gcc-cvs]

https://gcc.gnu.org/g:a3aeff4ce95bd616a2108dc2363d9cbaba53b170

commit r15-863-ga3aeff4ce95bd616a2108dc2363d9cbaba53b170
Author: Feng Xue <f...@os.amperecomputing.com>
Date:   Thu May 23 15:25:53 2024 +0800

    vect: Use vect representative statement instead of original in patch recog 
[PR115060]
    
    Some utility functions (such as vect_look_through_possible_promotion) that 
are
    to find out certain kind of direct or indirect definition SSA for a value, 
may
    return the original one of the SSA, not its pattern representative SSA, even
    pattern is involved. For example,
    
       a = (T1) patt_b;
       patt_b = (T2) c;        // b = ...
       patt_c = not-a-cast;    // c = ...
    
    Given 'a', the mentioned function will return 'c', instead of 'patt_c'. This
    subtlety would make some pattern recog code that is unaware of it mis-use 
the
    original instead of the new pattern statement, which is inconsistent wth
    processing logic of the pattern formation pass. This patch corrects the 
issue
    by forcing another utility function (vect_get_internal_def) return the 
pattern
    statement information to caller by default.
    
    2024-05-23 Feng Xue <f...@os.amperecomputing.com>
    
    gcc/
            PR tree-optimization/115060
            * tree-vect-patterns.cc (vect_get_internal_def): Return statement 
for
            vectorization.
            (vect_widened_op_tree): Call vect_get_internal_def instead of 
look_def
            to get statement information.
            (vect_recog_widen_abd_pattern): No need to call 
vect_stmt_to_vectorize.

Diff:
---
 gcc/tree-vect-patterns.cc | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index a313dc64643..8929e5aa7f3 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -266,7 +266,7 @@ vect_get_internal_def (vec_info *vinfo, tree op)
   stmt_vec_info def_stmt_info = vinfo->lookup_def (op);
   if (def_stmt_info
       && STMT_VINFO_DEF_TYPE (def_stmt_info) == vect_internal_def)
-    return def_stmt_info;
+    return vect_stmt_to_vectorize (def_stmt_info);
   return NULL;
 }
 
@@ -655,7 +655,8 @@ vect_widened_op_tree (vec_info *vinfo, stmt_vec_info 
stmt_info, tree_code code,
 
              /* Recursively process the definition of the operand.  */
              stmt_vec_info def_stmt_info
-               = vinfo->lookup_def (this_unprom->op);
+               = vect_get_internal_def (vinfo, this_unprom->op);
+
              nops = vect_widened_op_tree (vinfo, def_stmt_info, code,
                                           widened_code, shift_p, max_nops,
                                           this_unprom, common_type,
@@ -1739,7 +1740,6 @@ vect_recog_widen_abd_pattern (vec_info *vinfo, 
stmt_vec_info stmt_vinfo,
   if (!abd_pattern_vinfo)
     return NULL;
 
-  abd_pattern_vinfo = vect_stmt_to_vectorize (abd_pattern_vinfo);
   gcall *abd_stmt = dyn_cast <gcall *> (STMT_VINFO_STMT (abd_pattern_vinfo));
   if (!abd_stmt
       || !gimple_call_internal_p (abd_stmt)