From 04d8b8197cec9d5beade42759cef94900aa82a26 Mon Sep 17 00:00:00 2001 From: Richard Earnshaw Date: Mon, 4 Apr 2005 10:51:38 +0000 Subject: [PATCH] re PR target/14812 (ARM optimizer changes rsb/cmp to cmn, but condition codes different) PR target/14812 * arm.c (arm_select_cc_mode): Return CC_Zmode when comparing against a negated value. From-SVN: r97533 --- gcc/ChangeLog | 6 ++++++ gcc/config/arm/arm.c | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fe589da8458..dd8d0b7363a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-04-04 Richard Earnshaw + + PR target/14812 + * arm.c (arm_select_cc_mode): Return CC_Zmode when comparing against + a negated value. + 2005-04-04 Richard Henderson Jakub Jelinek diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 83c5b857ed9..bcf1904264b 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -6100,6 +6100,13 @@ arm_select_cc_mode (enum rtx_code op, rtx x, rtx y) || GET_CODE (x) == ROTATERT)) return CC_SWPmode; + /* This operation is performed swapped, but since we only rely on the Z + flag we don't need an additional mode. */ + if (GET_MODE (y) == SImode && REG_P (y) + && GET_CODE (x) == NEG + && (op == EQ || op == NE)) + return CC_Zmode; + /* This is a special case that is used by combine to allow a comparison of a shifted byte load to be split into a zero-extend followed by a comparison of the shifted integer (only valid for -- 2.30.2