# HG changeset patch
# User David Anderson <dvander@alliedmods.net>
# Date 1376245639 25200
# Node ID 46f4122981c277f246f4b6c3dc8bad72d3a64db7
# Parent  be7835a7c28faffe6a0f8670ff0a031182fc8b93
Statically align the stack at function boundaries (bug 5842, r=ds).

diff -r be7835a7c28f -r 46f4122981c2 sourcepawn/jit/dll_exports.cpp
--- a/sourcepawn/jit/dll_exports.cpp	Sat Aug 10 21:23:02 2013 -0700
+++ b/sourcepawn/jit/dll_exports.cpp	Sun Aug 11 11:27:19 2013 -0700
@@ -146,6 +146,11 @@
 	return 1;
 }
 
+static cell_t DoNothing(IPluginContext *cx, const cell_t *params)
+{
+	return 1;
+}
+
 static void BindNative(IPluginRuntime *rt, const char *name, SPVM_NATIVE_FUNC fn)
 {
 	int err;
@@ -185,6 +190,7 @@
 	BindNative(rt, "printnum", PrintNum);
 	BindNative(rt, "printnums", PrintNums);
 	BindNative(rt, "printfloat", PrintFloat);
+	BindNative(rt, "donothing", DoNothing);
 
 	IPluginFunction *fun = rt->GetFunctionByName("main");
 	if (!fun)
diff -r be7835a7c28f -r 46f4122981c2 sourcepawn/jit/x86/jit_x86.cpp
--- a/sourcepawn/jit/x86/jit_x86.cpp	Sat Aug 10 21:23:02 2013 -0700
+++ b/sourcepawn/jit/x86/jit_x86.cpp	Sun Aug 11 11:27:19 2013 -0700
@@ -614,6 +614,9 @@
       __ movl(frm, stk);
       __ subl(tmp, dat);
       __ movl(Operand(info, AMX_INFO_FRAME), tmp);
+
+      // Align the stack to 16-bytes (each call adds 4 bytes).
+      __ subl(esp, 12);
       break;
 
     case OP_IDXADDR_B:
@@ -988,6 +991,7 @@
       // Remove parameters.
       __ movl(tmp, Operand(stk, 0));
       __ lea(stk, Operand(stk, tmp, ScaleFour, 4));
+      __ addl(esp, 12);
       __ ret();
       break;
     }
@@ -1585,12 +1589,6 @@
   // Save registers.
   __ push(edx);
 
-  // Align the stack to 16 bytes.
-  __ push(ebx);
-  __ movl(ebx, esp);
-  __ andl(esp, 0xfffffff0);
-  __ subl(esp, 4);
-
   // Push the parameters for the C++ function.
   __ push(stk);
   __ push(native_index);
@@ -1616,9 +1614,8 @@
   __ j(not_zero, &extern_error_);
   
   // Restore local state.
-  __ movl(esp, ebx);
-  __ pop(ebx);
   __ addl(stk, dat);
+  __ addl(esp, 12);
   __ pop(edx);
 
   if (op == OP_SYSREQ_N) {
@@ -1786,7 +1783,10 @@
   __ movl(ebx, edi);
   __ movl(Operand(esi, AMX_INFO_NSTACK), esp);
 
-  // Call into plugin.
+  // Align the stack.
+  __ andl(esp, 0xfffffff0);
+
+  // Call into plugin (align the stack first).
   __ call(ecx);
 
   __ movl(ecx, Operand(info, AMX_INFO_RETVAL));