From: Christoph Mallon <christoph.mallon@gmx.de>
Date: Wed, 17 Oct 2007 12:07:06 +0000 (+0000)
Subject: In the RA constraint handler insert no copy when an operand is used more than once... 
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=87555a6159756a518614c43a91f3f8250fee128c;p=libfirm

In the RA constraint handler insert no copy when an operand is used more than once with constraints, but the constraints are equal (this is not optimal, but better than before and solves the test x, x case on x86).

[r16244]
---

diff --git a/ir/be/bechordal.c b/ir/be/bechordal.c
index 3246d434c..6df799992 100644
--- a/ir/be/bechordal.c
+++ b/ir/be/bechordal.c
@@ -293,6 +293,11 @@ static ir_node *prepare_constr_insn(be_chordal_env_t *env, ir_node *irn)
 			if(a_op->carrier != op->carrier || !a_op->has_constraints)
 				continue;
 
+			/* if the constraint is the same, no copy is necessary
+			 * TODO generalise unequal but overlapping constraints */
+			if (a_op->req == op->req)
+				continue;
+
 			if (be_is_Copy(get_irn_n(insn->irn, a_op->pos)))
 				continue;