From 233fcb0caa54073639f7e884b2544efb0d395b57 Mon Sep 17 00:00:00 2001
From: Ludwig Nussel <ludwig.nussel@suse.de>
Date: Wed, 2 Jun 2010 14:46:16 +0000
Subject: [PATCH] fix stack alignment dynamically for OP_BLOCK_COPY

---
 code/qcommon/vm_x86_64.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/code/qcommon/vm_x86_64.c b/code/qcommon/vm_x86_64.c
index 70ee7a29..2e23f4a9 100644
--- a/code/qcommon/vm_x86_64.c
+++ b/code/qcommon/vm_x86_64.c
@@ -757,13 +757,18 @@ emit_do_syscall:
 				emit("push %%r8");
 				emit("push %%r9");
 				emit("push %%r10");
-				emit("push %%r10");
+				emit("movq %%rsp, %%rbx"); // we need to align the stack pointer
+				emit("subq $8, %%rbx");    //   |
+				emit("andq $127, %%rbx");  //   |
+				emit("subq %%rbx, %%rsp"); // <-+
+				emit("push %%rbx");
 				emit("movl 4(%%rsi), %%edi");  // 1st argument dest
 				emit("movl 8(%%rsi), %%esi");  // 2nd argument src
 				emit("movl $%d, %%edx", iarg); // 3rd argument count
 				emit("movq $%"PRIu64", %%rax", (uint64_t)block_copy_vm);
 				emit("callq *%%rax");
-				emit("pop %%r10");
+				emit("pop %%rbx");
+				emit("addq %%rbx, %%rsp");
 				emit("pop %%r10");
 				emit("pop %%r9");
 				emit("pop %%r8");