[gcc r17-3526] match: Use match to match mult for mul_ladder_sum1 [PR126954]

https://gcc.gnu.org/g:ac1c1f64e11b84ba6a5e8dbef4589f8369df7d08

commit r17-3526-gac1c1f64e11b84ba6a5e8dbef4589f8369df7d08
Author: Andrea Pinski <[email protected]>
Date:   Thu Aug 20 23:37:54 2026 -0700

    match: Use match to match mult for mul_ladder_sum1 [PR126954]
    
    While reading match patterns I noticed that currently
    mul_ladder_sum1 does this:
    ```
        @mul_hilo1)
      (with {
        tree_code mul_hilo_code = TREE_CODE (@mul_hilo1);
        tree_code rhs_code = ERROR_MARK;
        if (mul_hilo_code == SSA_NAME)
          {
            gimple *def = SSA_NAME_DEF_STMT (@mul_hilo1);
            if (def && gimple_code (def) == GIMPLE_ASSIGN)
              rhs_code = gimple_assign_rhs_code (def);
          } }
      (if (rhs_code == MULT_EXPR))))
    ```
    
    Which is exactly the same thing if the match pattern did:
        (mult@mul_hilo1 @2 @3)))
    
    Which is easier to understand and will use the valueizier if
    there is one instead of a straight walk backwards on the ssa names.
    
    I also checked the generated code from genmatch to see it was similar
    in what was done manually.
    
    Pushed as obvious after a bootstrap/test for x86_64-linux-gnu.
    
            PR tree-optimization/126954
    
    gcc/ChangeLog:
    
            * match.pd (mul_ladder_sum1): Change over to match syntax
            instead of doing it manually.
    
    Signed-off-by: Andrea Pinski <[email protected]>

Diff:
---
 gcc/match.pd | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index 51f825ec3279..4e28b5d9ded0 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -12916,17 +12916,7 @@ and,
     (plus:c
       (mul_lo @mul_hilo0 INTEGER_CST@0)
       (mul_hi (mul_lolo @op0 @op1 INTEGER_CST@0) INTEGER_CST@1))
-    @mul_hilo1)
-  (with {
-    tree_code mul_hilo_code = TREE_CODE (@mul_hilo1);
-    tree_code rhs_code = ERROR_MARK;
-    if (mul_hilo_code == SSA_NAME)
-      {
-	gimple *def = SSA_NAME_DEF_STMT (@mul_hilo1);
-	if (def && gimple_code (def) == GIMPLE_ASSIGN)
-	  rhs_code = gimple_assign_rhs_code (def);
-      } }
-  (if (rhs_code == MULT_EXPR))))
+    (mult@mul_hilo1 @2 @3)))
 /* Partial ladder sum: (xl*yl >> N) + hilo.  */
 (match (mul_ladder_part_sum @op0 @op1 @mul_hilo0 @0 @1)
   (plus:c