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Merge pull request #118 from CarterLi/master
Emulate _BitScanForward64 on WIN32
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commit
810c734c3f
13
format.h
13
format.h
@ -56,15 +56,22 @@ inline uint32_t clz(uint32_t x) {
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return 31 - r;
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}
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# define FMT_BUILTIN_CLZ(n) fmt::internal::clz(n)
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# ifdef _WIN64
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# pragma intrinsic(_BitScanReverse64)
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inline uint32_t clzll(uint64_t n) {
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unsigned long r = 0;
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# ifdef _WIN64
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# pragma intrinsic(_BitScanReverse64)
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_BitScanReverse64(&r, x);
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# else
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// Scan the high 32 bits.
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if (_BitScanReverse(&r, static_cast<uint32_t>(n >> 32)))
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return 63 - (r + 32);
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// Scan the low 32 bits.
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_BitScanReverse(&r, static_cast<uint32_t>(n));
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# endif
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return 63 - r;
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}
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# define FMT_BUILTIN_CLZLL(n) fmt::internal::clzll(n)
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# endif
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}
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}
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#endif
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