diff options
Diffstat (limited to 'absl/base/internal/bits.h')
| -rw-r--r-- | absl/base/internal/bits.h | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/absl/base/internal/bits.h b/absl/base/internal/bits.h index 8b03453c..81648e2c 100644 --- a/absl/base/internal/bits.h +++ b/absl/base/internal/bits.h @@ -24,7 +24,7 @@ // Clang on Windows has __builtin_clzll; otherwise we need to use the // windows intrinsic functions. -#if defined(_MSC_VER) +#if defined(_MSC_VER) && !defined(__clang__) #include <intrin.h> #if defined(_M_X64) #pragma intrinsic(_BitScanReverse64) @@ -36,7 +36,7 @@ #include "absl/base/attributes.h" -#if defined(_MSC_VER) +#if defined(_MSC_VER) && !defined(__clang__) // We can achieve something similar to attribute((always_inline)) with MSVC by // using the __forceinline keyword, however this is not perfect. MSVC is // much less aggressive about inlining, and even with the __forceinline keyword. @@ -73,24 +73,25 @@ ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64Slow(uint64_t n) { } ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64(uint64_t n) { -#if defined(_MSC_VER) && defined(_M_X64) +#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64) // MSVC does not have __buitin_clzll. Use _BitScanReverse64. unsigned long result = 0; // NOLINT(runtime/int) if (_BitScanReverse64(&result, n)) { return 63 - result; } return 64; -#elif defined(_MSC_VER) +#elif defined(_MSC_VER) && !defined(__clang__) // MSVC does not have __buitin_clzll. Compose two calls to _BitScanReverse unsigned long result = 0; // NOLINT(runtime/int) - if ((n >> 32) && _BitScanReverse(&result, n >> 32)) { + if ((n >> 32) && + _BitScanReverse(&result, static_cast<unsigned long>(n >> 32))) { return 31 - result; } - if (_BitScanReverse(&result, n)) { + if (_BitScanReverse(&result, static_cast<unsigned long>(n))) { return 63 - result; } return 64; -#elif defined(__GNUC__) +#elif defined(__GNUC__) || defined(__clang__) // Use __builtin_clzll, which uses the following instructions: // x86: bsr // ARM64: clz @@ -126,13 +127,13 @@ ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32Slow(uint64_t n) { } ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32(uint32_t n) { -#if defined(_MSC_VER) +#if defined(_MSC_VER) && !defined(__clang__) unsigned long result = 0; // NOLINT(runtime/int) if (_BitScanReverse(&result, n)) { return 31 - result; } return 32; -#elif defined(__GNUC__) +#elif defined(__GNUC__) || defined(__clang__) // Use __builtin_clz, which uses the following instructions: // x86: bsr // ARM64: clz @@ -163,19 +164,19 @@ ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64Slow(uint64_t n) { } ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64(uint64_t n) { -#if defined(_MSC_VER) && defined(_M_X64) +#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64) unsigned long result = 0; // NOLINT(runtime/int) _BitScanForward64(&result, n); return result; -#elif defined(_MSC_VER) +#elif defined(_MSC_VER) && !defined(__clang__) unsigned long result = 0; // NOLINT(runtime/int) if (static_cast<uint32_t>(n) == 0) { - _BitScanForward(&result, n >> 32); + _BitScanForward(&result, static_cast<unsigned long>(n >> 32)); return result + 32; } - _BitScanForward(&result, n); + _BitScanForward(&result, static_cast<unsigned long>(n)); return result; -#elif defined(__GNUC__) +#elif defined(__GNUC__) || defined(__clang__) static_assert(sizeof(unsigned long long) == sizeof(n), // NOLINT(runtime/int) "__builtin_ctzll does not take 64-bit arg"); return __builtin_ctzll(n); @@ -196,11 +197,11 @@ ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32Slow(uint32_t n) { } ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32(uint32_t n) { -#if defined(_MSC_VER) +#if defined(_MSC_VER) && !defined(__clang__) unsigned long result = 0; // NOLINT(runtime/int) _BitScanForward(&result, n); return result; -#elif defined(__GNUC__) +#elif defined(__GNUC__) || defined(__clang__) static_assert(sizeof(int) == sizeof(n), "__builtin_ctz does not take 32-bit arg"); return __builtin_ctz(n); |