diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/simplify-rtx.c | 19 |
2 files changed, 24 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index db153d5..45c0a27 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2004-12-20 Zdenek Dvorak <dvorakz@suse.cz> + + PR rtl-optimization/18942 + * simplify-rtx.c (simplify_relational_operation_1): Simplify + x + cst1 == cst2 to x == cst2 - cst1. Made static. + 2004-12-20 Matt Austern <austern@apple.com> PR c++/19044 diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 5feeb65..8d7cb3f 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -2773,10 +2773,13 @@ simplify_relational_operation (enum rtx_code code, enum machine_mode mode, MODE is the mode of the result, while CMP_MODE specifies in which mode the comparison is done in, so it is the mode of the operands. */ -rtx + +static rtx simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode, enum machine_mode cmp_mode, rtx op0, rtx op1) { + enum rtx_code op0code = GET_CODE (op0); + if (GET_CODE (op1) == CONST_INT) { if (INTVAL (op1) == 0 && COMPARISON_P (op0)) @@ -2800,6 +2803,20 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode, } } + /* (eq/ne (plus x cst1) cst2) simplifies to (eq/ne x (cst2 - cst1)) */ + if ((code == EQ || code == NE) + && (op0code == PLUS || op0code == MINUS) + && CONSTANT_P (op1) + && CONSTANT_P (XEXP (op0, 1))) + { + rtx x = XEXP (op0, 0); + rtx c = XEXP (op0, 1); + + c = simplify_gen_binary (op0code == PLUS ? MINUS : PLUS, + cmp_mode, op1, c); + return simplify_gen_relational (code, mode, cmp_mode, x, c); + } + return NULL_RTX; } |