commit 944b60fb75b8f7894e76f012f06d208cb63a1918
author Corentin Wallez <cwallez@chromium.org> Mon May 29 11:33:33 2017 -0700
committer Corentin Wallez <corentin@wallez.net> Tue May 30 10:48:32 2017 -0700
tree acd5ff15499990af9c1e24e2cd0328c15662f0ed
parent 583e9a8f3cdf1a9d734b8a8bbcb8944f39cfd333

Fix compilation on Windows

There are still a bunch of warning that we should remove.

src/backend/common/Math.cpp

diff --git a/src/backend/common/Math.cpp b/src/backend/common/Math.cpp
index 483f524..41af98f 100644
--- a/src/backend/common/Math.cpp
+++ b/src/backend/common/Math.cpp
@@ -14,23 +14,34 @@
 
 #include "Math.h"
 
+#include <intrin.h>
+
 #include "Forward.h"
 
 namespace backend {
 
-    unsigned long ScanForward(unsigned long bits) {
+    uint32_t ScanForward(uint32_t bits) {
         ASSERT(bits != 0);
-        // TODO(cwallez@chromium.org): handle non-posix platforms
-        // unsigned long firstBitIndex = 0ul;
-        // unsigned char ret = _BitScanForward(&firstBitIndex, bits);
-        // ASSERT(ret != 0);
-        // return firstBitIndex;
-        return static_cast<unsigned long>(__builtin_ctzl(bits));
+        #if defined(_WIN32) || defined(_WIN64)
+            unsigned long firstBitIndex = 0ul;
+            unsigned char ret = _BitScanForward(&firstBitIndex, bits);
+            ASSERT(ret != 0);
+            return firstBitIndex;
+        #else
+            return static_cast<unsigned long>(__builtin_ctz(bits));
+        #endif
     }
 
     uint32_t Log2(uint32_t value) {
         ASSERT(value != 0);
-        return 31 - __builtin_clz(value);
+        #if defined(_WIN32) || defined(_WIN64)
+            unsigned long firstBitIndex = 0ul;
+            unsigned char ret = _BitScanReverse(&firstBitIndex, value);
+            ASSERT(ret != 0);
+            return firstBitIndex;
+        #else
+            return 31 - __builtin_clz(value);
+        #endif
     }
 
     bool IsPowerOfTwo(size_t n) {