From f332643e7fef96f15db675dd50bf643199d8f6a5 Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Tue, 13 Dec 2011 18:26:56 -0800
Subject: [PATCH] rt: Use %ecx instead of %eax during the second half of
 __morestack

If Rust code made use of return values then using %eax here would clobber it
---
 src/rt/arch/i386/morestack.S | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/rt/arch/i386/morestack.S b/src/rt/arch/i386/morestack.S
index d1c255015c37..1a076b6a3ba8 100644
--- a/src/rt/arch/i386/morestack.S
+++ b/src/rt/arch/i386/morestack.S
@@ -122,11 +122,13 @@ MORESTACK:
 
 	subl $8, %esp // Alignment
 
+	// Now that we're on the return path we want to avoid
+	// stomping on %eax
 #ifdef __APPLE__
 	call 1f
-1:	popl %eax
-	movl L_upcall_del_stack$non_lazy_ptr-1b(%eax),%eax
-	pushl %eax
+1:	popl %ecx
+	movl L_upcall_del_stack$non_lazy_ptr-1b(%ecx),%ecx
+	pushl %ecx
 #else
 	pushl $UPCALL_DEL_STACK
 #endif