[Bug tree-optimization/126954] New: mul_ladder_sum1 match pattern can be simplified

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126954

            Bug ID: 126954
           Summary: mul_ladder_sum1 match pattern can be simplified
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: internal-improvement
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: pinskia at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

/* Second variant: @mul_hilo1 is the outermost addend and could match
   anything, so guard that its definition is a MULT_EXPR.  */
(match (mul_ladder_sum1 @op0 @op1 @mul_hilo0 @mul_hilo1 @0 @1)
  (plus:c
    (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))))


Just to:
/* Second variant: @mul_hilo1 is the outermost addend and could match
   anything, so guard that its definition is a MULT_EXPR.  */
(match (mul_ladder_sum1 @op0 @op1 @mul_hilo0 @mul_hilo1 @0 @1)
  (plus:c
    (plus:c
      (mul_lo @mul_hilo0 INTEGER_CST@0)
      (mul_hi (mul_lolo @op0 @op1 INTEGER_CST@0) INTEGER_CST@1))
    (mult@mul_hilo1 @2 @3)))