cross-platform clz

src/core/math.h

@@ -1,6 +1,8 @@
 #ifndef DREAVM_MATH_H
 #define DREAVM_MATH_H
 
+#include "core/platform.h"
+
 namespace dreavm {
 namespace core {
 
@@ -8,6 +10,27 @@ template <typename T>
 T align(T v, T alignment) {
   return (v + alignment - 1) & -alignment;
 }
+
+#if defined(PLATFORM_LINUX) || defined(PLATFORM_DARWIN)
+inline int clz(uint32_t v) {
+  return __builtin_clz(v);
+}
+inline int clz(uint64_t v) {
+  return __builtin_clzll(v);
+}
+#else
+inline int clz(uint32_t v) {
+  unsigned long r = 0;
+  _BitScanReverse(&r, v);
+  return 31 - r;
+}
+inline int clz(uint64_t v) {
+  unsigned long r = 0;
+  _BitScanReverse64(&r, v);
+  return 63 - r;
+}
+#endif
+
 }
 }
 

src/cpu/backend/x64/x64_emitter.cc

@@ -65,7 +65,7 @@ X64Fn X64Emitter::Emit(IRBuilder &builder) {
   // TODO align each local
   int stack_size = 16 + builder.locals_size();
   // add 8 for function return value which will be pushed when this is called
-  stack_size = align(stack_size, 16) + 8;
+  stack_size = core::align(stack_size, 16) + 8;
   assert((stack_size + 8) % 16 == 0);
 
   // emit prolog

src/cpu/sh4.cc

@@ -390,7 +390,7 @@ void SH4::CheckPendingInterrupts() {
   }
 
   // process the highest priority in the pending vector
-  int n = 63 - __builtin_clzll(pending_interrupts_);
+  int n = 63 - core::clz(pending_interrupts_);
   Interrupt intr = sorted_interrupts_[n];
   InterruptInfo &int_info = interrupts[intr];
 

src/emu/memory.h

@@ -87,7 +87,7 @@ class PageTable {
       return;
     }
 
-    int n = 31 - __builtin_clz(mirror_mask);
+    int n = 31 - core::clz(mirror_mask);
     uint32_t next_mask = mirror_mask & ~(1 << n);
 
     start |= mirror_mask;