From d2cb78ca7b60bd3c3e4b7febdae2ee3f0c9ea70d Mon Sep 17 00:00:00 2001 From: bernds Date: Tue, 31 Mar 2009 15:19:33 +0000 Subject: [PATCH] * simplify-rtx.c (simplify_relational_operation_1): Simplify (LTU (PLUS a C) C) or (LTU (PLUS a C) a) to (GEU a -C); likewise with GEU/LTU reversed. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@145353 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 4 ++++ gcc/simplify-rtx.c | 14 ++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d4686fd651be..9aeafa9eae20 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -15,6 +15,10 @@ and keep using them to simplify new expressions, while applying the same substitutions to them as to the expression. + * simplify-rtx.c (simplify_relational_operation_1): Simplify + (LTU (PLUS a C) C) or (LTU (PLUS a C) a) to (GEU a -C); likewise with + GEU/LTU reversed. + 2009-03-31 Ramana Radhakrishnan PR target/27237 diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 6fe480f5dc7e..b8b6ad81763a 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -3856,6 +3856,20 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode, } } + /* (LTU/GEU (PLUS a C) C), where C is constant, can be simplified to + (GEU/LTU a -C). Likewise for (LTU/GEU (PLUS a C) a). */ + if ((code == LTU || code == GEU) + && GET_CODE (op0) == PLUS + && GET_CODE (XEXP (op0, 1)) == CONST_INT + && (rtx_equal_p (op1, XEXP (op0, 0)) + || rtx_equal_p (op1, XEXP (op0, 1)))) + { + rtx new_cmp + = simplify_gen_unary (NEG, cmp_mode, XEXP (op0, 1), cmp_mode); + return simplify_gen_relational ((code == LTU ? GEU : LTU), mode, + cmp_mode, XEXP (op0, 0), new_cmp); + } + /* Canonicalize (LTU/GEU (PLUS a b) b) as (LTU/GEU (PLUS a b) a). */ if ((code == LTU || code == GEU) && GET_CODE (op0) == PLUS -- 2.11.4.GIT