From be2ad1d7f587a235fc69b80f280f5e3702647434 Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Sun, 24 Aug 2014 19:07:27 -0700
Subject: [PATCH] cmd/5g, cmd/6g, cmd/8g: clear Addr node when registerizing

Update #8525

Some temporary variables that were fully registerized nevertheless had stack space allocated for them because the Addrs were still marked as having associated nodes.

Distribution of stack space reserved for temporary variables while running make.bash (6g):

BEFORE

40.89%  7026 allocauto: 0 to 0
 7.83%  1346 allocauto: 0 to 24
 7.22%  1241 allocauto: 0 to 8
 6.30%  1082 allocauto: 0 to 16
 4.96%   853 allocauto: 0 to 56
 4.59%   789 allocauto: 0 to 32
 2.97%   510 allocauto: 0 to 40
 2.32%   399 allocauto: 0 to 48
 2.10%   360 allocauto: 0 to 64
 1.91%   328 allocauto: 0 to 72

AFTER

48.49%  8332 allocauto: 0 to 0
 9.52%  1635 allocauto: 0 to 16
 5.28%   908 allocauto: 0 to 48
 4.80%   824 allocauto: 0 to 32
 4.73%   812 allocauto: 0 to 8
 3.38%   581 allocauto: 0 to 24
 2.35%   404 allocauto: 0 to 40
 2.32%   399 allocauto: 0 to 64
 1.65%   284 allocauto: 0 to 56
 1.34%   230 allocauto: 0 to 72

LGTM=rsc
R=rsc
CC=dave, dvyukov, golang-codereviews, minux
https://golang.org/cl/126160043
---
 src/cmd/5g/reg.c | 1 +
 src/cmd/6g/reg.c | 1 +
 src/cmd/8g/reg.c | 1 +
 3 files changed, 3 insertions(+)

diff --git a/src/cmd/5g/reg.c b/src/cmd/5g/reg.c
index d259a232e60a41..8e49a2d9c83b79 100644
--- a/src/cmd/5g/reg.c
+++ b/src/cmd/5g/reg.c
@@ -1315,6 +1315,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->name = D_NONE;
 	a->type = D_REG;
 	a->reg = rn;
diff --git a/src/cmd/6g/reg.c b/src/cmd/6g/reg.c
index 5e3a1981861760..1f757e1972057f 100644
--- a/src/cmd/6g/reg.c
+++ b/src/cmd/6g/reg.c
@@ -1191,6 +1191,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->offset = 0;
 	a->type = rn;
 
diff --git a/src/cmd/8g/reg.c b/src/cmd/8g/reg.c
index a69d124db80cb8..302b273a1b4f5f 100644
--- a/src/cmd/8g/reg.c
+++ b/src/cmd/8g/reg.c
@@ -1168,6 +1168,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->offset = 0;
 	a->type = rn;