| Index: runtime/platform/utils_macos.h
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| diff --git a/runtime/platform/utils_macos.h b/runtime/platform/utils_macos.h
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| index d0e068644eb226ab5be4ff150f11709682fa6c13..6d8a4a59e54b5884ec14335367fae5ed4a475c63 100644
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| --- a/runtime/platform/utils_macos.h
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| +++ b/runtime/platform/utils_macos.h
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| @@ -7,12 +7,14 @@
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|  
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|  namespace dart {
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|  
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| -inline int Utils::CountTrailingZeros(uint32_t x) {
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| +inline int Utils::CountTrailingZeros(uword x) {
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| +#if defined(ARCH_IS_32_BIT)
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|    return __builtin_ctzl(x);
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| -};
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| -
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| -inline int Utils::CountTrailingZeros(uint64_t x) {
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| +#elif defined(ARCH_IS_64_BIT)
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|    return __builtin_ctzll(x);
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| +#else
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| +#error Architecture is not 32-bit or 64-bit.
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| +#endif
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|  };
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|  
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|  }  // namespace dart
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| 
 |