From dbad5988402c39a712dc8798b066380e6b5b1116 Mon Sep 17 00:00:00 2001
From: Leon Sha <leon.sha@oracle.com>
Date: Fri, 14 Oct 2011 13:12:46 +0800
Subject: [PATCH] Bug 694256 - Build error: JS_FloorLog2 is missing. r=luke.

---
 js/public/Utility.h |  2 +-
 js/src/jslog2.cpp   | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/js/public/Utility.h b/js/public/Utility.h
index 0e44ccae802..1de9eb499a8 100644
--- a/js/public/Utility.h
+++ b/js/public/Utility.h
@@ -346,7 +346,7 @@ __BitScanReverse64(unsigned __int64 val)
 #  define js_FloorLog2wImpl(n)                                                \
     ((size_t)(JS_BITS_PER_WORD - 1 - js_bitscan_clz32(n)))
 # else
-#  define js_FloorLog2wImpl(n) ((size_t)JS_FloorLog2(n))
+extern size_t js_FloorLog2wImpl(size_t n);
 # endif
 #elif JS_BYTES_PER_WORD == 8
 # ifdef JS_HAS_BUILTIN_BITSCAN64
diff --git a/js/src/jslog2.cpp b/js/src/jslog2.cpp
index 39f30385686..2c6e5641c44 100644
--- a/js/src/jslog2.cpp
+++ b/js/src/jslog2.cpp
@@ -54,6 +54,17 @@ JS_STATIC_ASSERT_IF(JS_BYTES_PER_WORD == 8,
                     sizeof(unsigned long long) == sizeof(JSUword));
 #endif
 
+#if !defined(JS_HAS_BUILTIN_BITSCAN32) && JS_BYTES_PER_WORD == 4
+
+size_t
+js_FloorLog2wImpl(size_t n)
+{
+    size_t log2;
+
+    JS_FLOOR_LOG2(log2, n);
+    return log2;
+}
+#endif
 /*
  * js_FloorLog2wImpl has to be defined only for 64-bit non-GCC case.
  */