From 921c44189aae73ef85ea7ac4712e54f667fdd4f6 Mon Sep 17 00:00:00 2001 From: Rask Ingemann Lambertsen Date: Sun, 9 Sep 2007 21:21:59 +0200 Subject: [PATCH] re PR target/30315 (optimize unsigned-add overflow test on x86 to use cpu flags from addl) PR target/30315 * config/i386/i386.h (CANONICALIZE_COMPARISON): Delete. * simplify-rtx.c (simplify_relational_operation_1): Add the canonicalization from i386.h. * doc/md.texi (Canonicalization of Instructions): Document it. From-SVN: r128305 --- gcc/ChangeLog | 8 ++++++++ gcc/config/i386/i386.h | 10 ---------- gcc/doc/md.texi | 7 ++++++- gcc/simplify-rtx.c | 6 ++++++ 4 files changed, 20 insertions(+), 11 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d748be2aa93..4c58b2865f5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2007-09-09 Rask Ingemann Lambertsen + + PR target/30315 + * config/i386/i386.h (CANONICALIZE_COMPARISON): Delete. + * simplify-rtx.c (simplify_relational_operation_1): Add the + canonicalization from i386.h. + * doc/md.texi (Canonicalization of Instructions): Document it. + 2007-09-09 Jan Hubicka Dwarakanath Rajagopal diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index 06e90f4b600..4f8a531ed6f 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -2070,16 +2070,6 @@ do { \ #define SELECT_CC_MODE(OP, X, Y) ix86_cc_mode ((OP), (X), (Y)) -/* Canonicalize overflow checks to save on the insn patterns. We change - "a + b < b" into "a + b < a" and "a + b >= b" into "a + b >= a". */ -#define CANONICALIZE_COMPARISON(code, op0, op1) \ -{ \ - if ((code == LTU || code == GEU) \ - && GET_CODE (op0) == PLUS \ - && rtx_equal_p (op1, XEXP (op0, 1))) \ - op1 = XEXP (op0, 0); \ -} - /* Return nonzero if MODE implies a floating point inequality can be reversed. */ diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 1b0d766f736..c75b9838af1 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -1,5 +1,5 @@ @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1996, 1998, 1999, 2000, 2001, -@c 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. +@c 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @@ -5513,6 +5513,11 @@ An operand of @code{neg}, @code{not}, @code{mult}, @code{plus}, or @code{minus} is made the first operand under the same conditions as above. +@item +@code{(ltu (plus @var{a} @var{b}) @var{b})} is converted to +@code{(ltu (plus @var{a} @var{b}) @var{a})}. Likewise with @code{geu} instead +of @code{ltu}. + @item @code{(minus @var{x} (const_int @var{n}))} is converted to @code{(plus @var{x} (const_int @var{-n}))}. diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index ac91f2fc92a..02f9e2b4c36 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -3813,6 +3813,12 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode, } } + /* Canonicalize (LTU/GEU (PLUS a b) b) as (LTU/GEU (PLUS a b) a). */ + if ((code == LTU || code == GEU) + && GET_CODE (op0) == PLUS + && rtx_equal_p (op1, XEXP (op0, 1))) + return simplify_gen_relational (code, mode, cmp_mode, op0, XEXP (op0, 0)); + if (op1 == const0_rtx) { /* Canonicalize (GTU x 0) as (NE x 0). */