From: Austin Clements <austin@google.com>
Date: Wed, 5 Nov 2014 20:36:47 +0000 (-0500)
Subject: [dev.power64] 6g: don't create variables for indirect addresses
X-Git-Tag: go1.5beta1~2684^2~11^2~10
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4f81684f8640e81b1c337a6b88488a888d13abea;p=gostls13.git

[dev.power64] 6g: don't create variables for indirect addresses

Previously, mkvar treated, for example, 0(AX) the same as AX.
As a result, a move to an indirect address would be marked as
*setting* the register, rather than just using it, resulting
in unnecessary register moves.  Fix this by not producing
variables for indirect addresses.

LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/164610043
---

diff --git a/src/cmd/6g/reg.c b/src/cmd/6g/reg.c
index 8d600d6433..afd3f1056e 100644
--- a/src/cmd/6g/reg.c
+++ b/src/cmd/6g/reg.c
@@ -621,6 +621,9 @@ mkvar(Reg *r, Adr *a)
 	if(r != R)
 		r->use1.b[0] |= doregbits(a->index);
 
+	if(t >= D_INDIR && t < 2*D_INDIR)
+		goto none;
+
 	switch(t) {
 	default:
 		regu = doregbits(t);