From 3245c24d1fd59c2d4a969570743f764022eb5033 Mon Sep 17 00:00:00 2001
From: Alon Zakai <alonzakai@gmail.com>
Date: Wed, 16 Mar 2016 17:46:46 -0700
Subject: add Log2 and Pow2 support methods

---
 src/support/bits.cpp | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

(limited to 'src/support/bits.cpp')

diff --git a/src/support/bits.cpp b/src/support/bits.cpp
index c1de4da8b..3d03b100c 100644
--- a/src/support/bits.cpp
+++ b/src/support/bits.cpp
@@ -15,6 +15,7 @@
  */
 
 #define wasm_support_bits_definitions
+#include "../compiler-support.h"
 #include "support/bits.h"
 
 namespace wasm {
@@ -99,4 +100,28 @@ int CountLeadingZeroes<uint64_t>(uint64_t v) {
                  : 32 + CountLeadingZeroes((uint32_t)v);
 }
 
+uint32_t Log2(uint32_t v) {
+  switch (v) {
+    default: WASM_UNREACHABLE();
+    case 1: return 0;
+    case 2: return 1;
+    case 4: return 2;
+    case 8: return 3;
+    case 16: return 4;
+    case 32: return 5;
+  }
+}
+
+uint32_t Pow2(uint32_t v) {
+  switch (v) {
+    default: WASM_UNREACHABLE();
+    case 0: return 1;
+    case 1: return 2;
+    case 2: return 4;
+    case 3: return 8;
+    case 4: return 16;
+    case 5: return 32;
+  }
+}
+
 } // namespace wasm
-- 
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