Clean up support/bits.h (#3177)

Use overloads instead of templates where applicable and change function names
from PascalCase to camelCase. Also puts the functions in the Bits namespace to
avoid naming conflicts.

1 files changed, 23 insertions, 24 deletions

diff --git a/src/support/bits.cpp b/src/support/bits.cpp
index e60f2365b..7e22466d8 100644
--- a/src/support/bits.cpp
+++ b/src/support/bits.cpp
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-#define wasm_support_bits_definitions
 #include "support/bits.h"
 #include "../compiler-support.h"
 #include "support/utilities.h"
@@ -25,7 +24,9 @@
 
 namespace wasm {
 
-template<> int PopCount<uint8_t>(uint8_t v) {
+namespace Bits {
+
+int popCount(uint8_t v) {
   // Small table lookup.
   static const uint8_t tbl[32] = {0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2,
                                   3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3,
@@ -33,15 +34,15 @@ template<> int PopCount<uint8_t>(uint8_t v) {
   return tbl[v & 0xf] + tbl[v >> 4];
 }
 
-template<> int PopCount<uint16_t>(uint16_t v) {
+int popCount(uint16_t v) {
 #if __has_builtin(__builtin_popcount) || defined(__GNUC__)
   return __builtin_popcount(v);
 #else
-  return PopCount((uint8_t)(v & 0xFF)) + PopCount((uint8_t)(v >> 8));
+  return popCount((uint8_t)(v & 0xFF)) + popCount((uint8_t)(v >> 8));
 #endif
 }
 
-template<> int PopCount<uint32_t>(uint32_t v) {
+int popCount(uint32_t v) {
 #if __has_builtin(__builtin_popcount) || defined(__GNUC__)
   return __builtin_popcount(v);
 #else
@@ -53,15 +54,15 @@ template<> int PopCount<uint32_t>(uint32_t v) {
 #endif
 }
 
-template<> int PopCount<uint64_t>(uint64_t v) {
+int popCount(uint64_t v) {
 #if __has_builtin(__builtin_popcount) || defined(__GNUC__)
   return __builtin_popcountll(v);
 #else
-  return PopCount((uint32_t)v) + PopCount((uint32_t)(v >> 32));
+  return popCount((uint32_t)v) + popCount((uint32_t)(v >> 32));
 #endif
 }
 
-template<> uint32_t BitReverse<uint32_t>(uint32_t v) {
+uint32_t bitReverse(uint32_t v) {
   // See Hacker's Delight, first edition, figure 7-1.
   v = ((v & 0x55555555) << 1) | ((v >> 1) & 0x55555555);
   v = ((v & 0x33333333) << 2) | ((v >> 2) & 0x33333333);
@@ -70,7 +71,7 @@ template<> uint32_t BitReverse<uint32_t>(uint32_t v) {
   return v;
 }
 
-template<> int CountTrailingZeroes<uint32_t>(uint32_t v) {
+int countTrailingZeroes(uint32_t v) {
   if (v == 0) {
     return 32;
   }
@@ -91,7 +92,7 @@ template<> int CountTrailingZeroes<uint32_t>(uint32_t v) {
 #endif
 }
 
-template<> int CountTrailingZeroes<uint64_t>(uint64_t v) {
+int countTrailingZeroes(uint64_t v) {
   if (v == 0) {
     return 64;
   }
@@ -102,12 +103,12 @@ template<> int CountTrailingZeroes<uint64_t>(uint64_t v) {
   _BitScanForward64(&count, v);
   return (int)count;
 #else
-  return (uint32_t)v ? CountTrailingZeroes((uint32_t)v)
-                     : 32 + CountTrailingZeroes((uint32_t)(v >> 32));
+  return (uint32_t)v ? countTrailingZeroes((uint32_t)v)
+                     : 32 + countTrailingZeroes((uint32_t)(v >> 32));
 #endif
 }
 
-template<> int CountLeadingZeroes<uint32_t>(uint32_t v) {
+int countLeadingZeroes(uint32_t v) {
   if (v == 0) {
     return 32;
   }
@@ -136,7 +137,7 @@ template<> int CountLeadingZeroes<uint32_t>(uint32_t v) {
 #endif
 }
 
-template<> int CountLeadingZeroes<uint64_t>(uint64_t v) {
+int countLeadingZeroes(uint64_t v) {
   if (v == 0) {
     return 64;
   }
@@ -147,20 +148,16 @@ template<> int CountLeadingZeroes<uint64_t>(uint64_t v) {
   _BitScanReverse64(&count, v);
   return 63 - int(count);
 #else
-  return v >> 32 ? CountLeadingZeroes((uint32_t)(v >> 32))
-                 : 32 + CountLeadingZeroes((uint32_t)v);
+  return v >> 32 ? countLeadingZeroes((uint32_t)(v >> 32))
+                 : 32 + countLeadingZeroes((uint32_t)v);
 #endif
 }
 
-template<> int CeilLog2<uint32_t>(uint32_t v) {
-  return 32 - CountLeadingZeroes(v - 1);
-}
+int ceilLog2(uint32_t v) { return 32 - countLeadingZeroes(v - 1); }
 
-template<> int CeilLog2<uint64_t>(uint64_t v) {
-  return 64 - CountLeadingZeroes(v - 1);
-}
+int ceilLog2(uint64_t v) { return 64 - countLeadingZeroes(v - 1); }
 
-uint32_t Log2(uint32_t v) {
+uint32_t log2(uint32_t v) {
   switch (v) {
     default:
       WASM_UNREACHABLE("invalid value");
@@ -179,6 +176,8 @@ uint32_t Log2(uint32_t v) {
   }
 }
 
-uint32_t Pow2(uint32_t v) { return 1 << v; }
+uint32_t pow2(uint32_t v) { return 1 << v; }
+
+} // namespace Bits
 
 } // namespace wasm