From: Cerion Armour-Brown <cerion@valgrind.org>
Date: Wed, 23 Feb 2005 11:20:53 +0000 (+0000)
Subject: Fix to run_translation: need to save LR on _caller's_ stack, and leave a hole for... 
X-Git-Tag: svn/VALGRIND_3_0_1^2~384
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10387d61099f87a6fcf52c754a5c67456604bd0e;p=thirdparty%2Fvalgrind.git

Fix to run_translation: need to save LR on _caller's_ stack, and leave a hole for a callee to do the same on our stack.

git-svn-id: svn://svn.valgrind.org/vex/trunk@950
---

diff --git a/VEX/switchback/switchback.c b/VEX/switchback/switchback.c
index de68c70150..25a89497f9 100644
--- a/VEX/switchback/switchback.c
+++ b/VEX/switchback/switchback.c
@@ -390,7 +390,12 @@ asm(
 
 // save LR
 "   mflr %r0\n"
-"   stw  %r0,  4(%r1)\n"
+"   stw  %r0,260(%r1)\n"
+
+// leave hole @ 4(%r1) for a caller to save it's LR
+// no params
+// no local vars
+// no need to save non-volatile CR fields
 
 // store registers to stack: just the callee-saved regs
 "   stw %r13,  8(%r1)\n"
@@ -427,10 +432,6 @@ asm(
 "   lis %r5,res@ha\n"
 "   stw %r3,res@l(%r5)\n"
 
-// restore LR
-"   lwz  %r0,  4(%r1)\n"
-"   mtlr %r0\n"
-
 // reload registers from stack
 "   lwz %r13,  8(%r1)\n"
 "   lwz %r14, 12(%r1)\n"
@@ -452,10 +453,14 @@ asm(
 "   lwz %r30, 76(%r1)\n"
 "   lwz %r31, 80(%r1)\n"
 
-// restore stack pointer
-"   lwz %r1,0(%r1)\n"
+// restore LR
+"   lwz  %r0,260(%r1)\n"
+"   mtlr %r0\n"
+
+// restore previous stack pointer
+"   addi %r1,%r1,256\n"
 
-// return in usual way
+// return
 "   blr"
 );