From a0971b7c4be552e2664c6432887d0708db70006f Mon Sep 17 00:00:00 2001
From: David Nadlinger <code@klickverbot.at>
Date: Mon, 24 Dec 2012 02:04:18 +0100
Subject: [PATCH] Use more portable integer log from LLVM.

---
 gen/passes/GarbageCollect2Stack.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gen/passes/GarbageCollect2Stack.cpp b/gen/passes/GarbageCollect2Stack.cpp
index 0f08cbc7..acc26a21 100644
--- a/gen/passes/GarbageCollect2Stack.cpp
+++ b/gen/passes/GarbageCollect2Stack.cpp
@@ -46,6 +46,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtra.h"
 #include "llvm/Support/raw_ostream.h"
 
 #include <algorithm>
@@ -179,7 +180,7 @@ namespace {
             if (SizeLimit > 0)
             {
                 uint64_t ElemSize = A.TD.getTypeAllocSize(Ty);
-                unsigned BitsLimit = static_cast<unsigned>(log2(SizeLimit / ElemSize));
+                unsigned BitsLimit = Log2_64(SizeLimit / ElemSize));
 
                 // LLVM's alloca ueses an i32 for the number of elements.
                 BitsLimit = std::min(BitsLimit, 32U);