diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 41 |
1 files changed, 41 insertions, 0 deletions
@@ -8133,6 +8133,47 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode, return REDUCE_BIT_FIELD (simplify_gen_binary (PLUS, mode, op0, op1)); case MINUS_EXPR: + /* Check if this is a case for multiplication and subtraction. */ + if (TREE_CODE (type) == INTEGER_TYPE + && TREE_CODE (TREE_OPERAND (exp, 1)) == MULT_EXPR) + { + tree subsubexp0, subsubexp1; + enum tree_code code0, code1; + + subexp1 = TREE_OPERAND (exp, 1); + subsubexp0 = TREE_OPERAND (subexp1, 0); + subsubexp1 = TREE_OPERAND (subexp1, 1); + code0 = TREE_CODE (subsubexp0); + code1 = TREE_CODE (subsubexp1); + if (code0 == NOP_EXPR && code1 == NOP_EXPR + && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (subsubexp0, 0))) + < TYPE_PRECISION (TREE_TYPE (subsubexp0))) + && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (subsubexp0, 0))) + == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (subsubexp1, 0)))) + && (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (subsubexp0, 0))) + == TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (subsubexp1, 0))))) + { + tree op0type = TREE_TYPE (TREE_OPERAND (subsubexp0, 0)); + enum machine_mode innermode = TYPE_MODE (op0type); + bool zextend_p = TYPE_UNSIGNED (op0type); + this_optab = zextend_p ? umsub_widen_optab : smsub_widen_optab; + if (mode == GET_MODE_2XWIDER_MODE (innermode) + && (this_optab->handlers[(int) mode].insn_code + != CODE_FOR_nothing)) + { + expand_operands (TREE_OPERAND (subsubexp0, 0), + TREE_OPERAND (subsubexp1, 0), + NULL_RTX, &op0, &op1, EXPAND_NORMAL); + op2 = expand_expr (TREE_OPERAND (exp, 0), subtarget, + VOIDmode, 0); + temp = expand_ternary_op (mode, this_optab, op0, op1, op2, + target, unsignedp); + gcc_assert (temp); + return REDUCE_BIT_FIELD (temp); + } + } + } + /* For initializers, we are allowed to return a MINUS of two symbolic constants. Here we handle all cases when both operands are constant. */ |