[libcxx] r302731 - Don't interfere with the __builtin_foo namespace under MSVC
Eric Fiselier via cfe-commits
cfe-commits at lists.llvm.org
Wed May 10 14:30:04 PDT 2017
Author: ericwf
Date: Wed May 10 16:30:04 2017
New Revision: 302731
URL: http://llvm.org/viewvc/llvm-project?rev=302731&view=rev
Log:
Don't interfere with the __builtin_foo namespace under MSVC
This patch follows up on feedback received in the review for
D32988. Specifically that libc++ should not mess with the
__builtin namespace, and that libc++ should use __popcnt to implement
__pop_count under MSVC.
Removed:
libcxx/trunk/include/support/win32/msvc_builtin_support.h
Modified:
libcxx/trunk/include/algorithm
Modified: libcxx/trunk/include/algorithm
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/algorithm?rev=302731&r1=302730&r2=302731&view=diff
==============================================================================
--- libcxx/trunk/include/algorithm (original)
+++ libcxx/trunk/include/algorithm Wed May 10 16:30:04 2017
@@ -645,7 +645,7 @@ template <class BidirectionalIterator, c
#include "support/ibm/support.h"
#endif
#if defined(_LIBCPP_COMPILER_MSVC)
-#include "support/win32/msvc_builtin_support.h"
+#include <intrin.h>
#endif
#include <__undef_min_max>
@@ -783,51 +783,132 @@ struct __debug_less
// Precondition: __x != 0
inline _LIBCPP_INLINE_VISIBILITY
-unsigned
-__ctz(unsigned __x)
-{
+unsigned __ctz(unsigned __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned>(__builtin_ctz(__x));
+#else
+ static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
+ static_assert(sizeof(unsigned long) == 4, "");
+ unsigned long where;
+ // Search from LSB to MSB for first set bit.
+ // Returns zero if no set bit is found.
+ if (_BitScanForward(&where, mask))
+ return where;
+ return 32;
+#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long
-__ctz(unsigned long __x)
-{
+unsigned long __ctz(unsigned long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned long>(__builtin_ctzl(__x));
+#else
+ static_assert(sizeof(unsigned long) == sizeof(unsigned), "");
+ return __ctz(static_cast<unsigned>(__x));
+#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long long
-__ctz(unsigned long long __x)
-{
+unsigned long long __ctz(unsigned long long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned long long>(__builtin_ctzll(__x));
+#else
+ unsigned long where;
+// Search from LSB to MSB for first set bit.
+// Returns zero if no set bit is found.
+#if defined(_LIBCPP_HAS_BITSCAN64)
+ (defined(_M_AMD64) || defined(__x86_64__))
+ if (_BitScanForward64(&where, mask))
+ return static_cast<int>(where);
+#else
+ // Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
+ // Scan the Low Word.
+ if (_BitScanForward(&where, static_cast<unsigned long>(mask)))
+ return where;
+ // Scan the High Word.
+ if (_BitScanForward(&where, static_cast<unsigned long>(mask >> 32)))
+ return where + 32; // Create a bit offset from the LSB.
+#endif
+ return 64;
+#endif // _LIBCPP_COMPILER_MSVC
}
// Precondition: __x != 0
inline _LIBCPP_INLINE_VISIBILITY
-unsigned
-__clz(unsigned __x)
-{
+unsigned __clz(unsigned __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned>(__builtin_clz(__x));
+#else
+ static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
+ static_assert(sizeof(unsigned long) == 4, "");
+ unsigned long where;
+ // Search from LSB to MSB for first set bit.
+ // Returns zero if no set bit is found.
+ if (_BitScanReverse(&where, mask))
+ return 31 - where;
+ return 32; // Undefined Behavior.
+#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long
-__clz(unsigned long __x)
-{
+unsigned long __clz(unsigned long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned long>(__builtin_clzl (__x));
+#else
+ static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
+ return __clz(static_cast<unsigned>(__x));
+#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long long
-__clz(unsigned long long __x)
-{
+unsigned long long __clz(unsigned long long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
return static_cast<unsigned long long>(__builtin_clzll(__x));
+#else
+ unsigned long where;
+// BitScanReverse scans from MSB to LSB for first set bit.
+// Returns 0 if no set bit is found.
+#if defined(_LIBCPP_HAS_BITSCAN64)
+ if (_BitScanReverse64(&where, mask))
+ return static_cast<int>(63 - where);
+#else
+ // Scan the high 32 bits.
+ if (_BitScanReverse(&where, static_cast<unsigned long>(mask >> 32)))
+ return 63 - (where + 32); // Create a bit offset from the MSB.
+ // Scan the low 32 bits.
+ if (_BitScanReverse(&where, static_cast<unsigned long>(mask)))
+ return 63 - where;
+#endif
+ return 64; // Undefined Behavior.
+#endif // _LIBCPP_COMPILER_MSVC
+}
+
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
+ return __builtin_popcount (__x);
+#else
+ static_assert(sizeof(unsigned) == 4, "");
+ return __popcnt(__x);
+#endif
}
-inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned __x) {return __builtin_popcount (__x);}
-inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long __x) {return __builtin_popcountl (__x);}
-inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long long __x) {return __builtin_popcountll(__x);}
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
+ return __builtin_popcountl (__x);
+#else
+ static_assert(sizeof(unsigned long) == 4, "");
+ return __popcnt(__x);
+#endif
+}
+
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long long __x) {
+#ifndef _LIBCPP_COMPILER_MSVC
+ return __builtin_popcountll(__x);
+#else
+ static_assert(sizeof(unsigned long long) == 8, "");
+ return __popcnt64(__x);
+#endif
+}
// all_of
Removed: libcxx/trunk/include/support/win32/msvc_builtin_support.h
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/support/win32/msvc_builtin_support.h?rev=302730&view=auto
==============================================================================
--- libcxx/trunk/include/support/win32/msvc_builtin_support.h (original)
+++ libcxx/trunk/include/support/win32/msvc_builtin_support.h (removed)
@@ -1,156 +0,0 @@
-// -*- C++ -*-
-//===----------------------- support/win32/support.h ----------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H
-#define _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H
-
-#ifndef _LIBCPP_COMPILER_MSVC
-#error "This header can only be included when using Microsoft's C1XX frontend"
-#endif
-
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif
-
-// "builtins" not implemented here for Clang or GCC as they provide
-// implementations. Assuming required for elsewhere else, certainly MSVC.
-#include <intrin.h>
-
-// Bit builtin's make these assumptions when calling _BitScanForward/Reverse
-// etc. These assumptions are expected to be true for Win32/Win64 which this
-// file supports.
-static_assert(sizeof(unsigned long long) == 8, "");
-static_assert(sizeof(unsigned long) == 4, "");
-static_assert(sizeof(unsigned int) == 4, "");
-
-_LIBCPP_ALWAYS_INLINE int __builtin_popcount(unsigned int x)
-{
- // Binary: 0101...
- static const unsigned int m1 = 0x55555555;
- // Binary: 00110011..
- static const unsigned int m2 = 0x33333333;
- // Binary: 4 zeros, 4 ones ...
- static const unsigned int m4 = 0x0f0f0f0f;
- // The sum of 256 to the power of 0,1,2,3...
- static const unsigned int h01 = 0x01010101;
- // Put count of each 2 bits into those 2 bits.
- x -= (x >> 1) & m1;
- // Put count of each 4 bits into those 4 bits.
- x = (x & m2) + ((x >> 2) & m2);
- // Put count of each 8 bits into those 8 bits.
- x = (x + (x >> 4)) & m4;
- // Returns left 8 bits of x + (x<<8) + (x<<16) + (x<<24).
- return (x * h01) >> 24;
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_popcountl(unsigned long x)
-{
- return __builtin_popcount(static_cast<int>(x));
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_popcountll(unsigned long long x)
-{
- // Binary: 0101...
- static const unsigned long long m1 = 0x5555555555555555;
- // Binary: 00110011..
- static const unsigned long long m2 = 0x3333333333333333;
- // Binary: 4 zeros, 4 ones ...
- static const unsigned long long m4 = 0x0f0f0f0f0f0f0f0f;
- // The sum of 256 to the power of 0,1,2,3...
- static const unsigned long long h01 = 0x0101010101010101;
- // Put count of each 2 bits into those 2 bits.
- x -= (x >> 1) & m1;
- // Put count of each 4 bits into those 4 bits.
- x = (x & m2) + ((x >> 2) & m2);
- // Put count of each 8 bits into those 8 bits.
- x = (x + (x >> 4)) & m4;
- // Returns left 8 bits of x + (x<<8) + (x<<16) + (x<<24) + ...
- return static_cast<int>((x * h01) >> 56);
-}
-
-// Returns the number of trailing 0-bits in x, starting at the least significant
-// bit position. If x is 0, the result is undefined.
-_LIBCPP_ALWAYS_INLINE int __builtin_ctzll(unsigned long long mask)
-{
- unsigned long where;
-// Search from LSB to MSB for first set bit.
-// Returns zero if no set bit is found.
-#if defined(_LIBCPP_HAS_BITSCAN64)
- (defined(_M_AMD64) || defined(__x86_64__))
- if (_BitScanForward64(&where, mask))
- return static_cast<int>(where);
-#else
- // Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
- // Scan the Low Word.
- if (_BitScanForward(&where, static_cast<unsigned long>(mask)))
- return static_cast<int>(where);
- // Scan the High Word.
- if (_BitScanForward(&where, static_cast<unsigned long>(mask >> 32)))
- return static_cast<int>(where + 32); // Create a bit offset from the LSB.
-#endif
- return 64;
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_ctzl(unsigned long mask)
-{
- unsigned long where;
- // Search from LSB to MSB for first set bit.
- // Returns zero if no set bit is found.
- if (_BitScanForward(&where, mask))
- return static_cast<int>(where);
- return 32;
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_ctz(unsigned int mask)
-{
- // Win32 and Win64 expectations.
- static_assert(sizeof(mask) == 4, "");
- static_assert(sizeof(unsigned long) == 4, "");
- return __builtin_ctzl(static_cast<unsigned long>(mask));
-}
-
-// Returns the number of leading 0-bits in x, starting at the most significant
-// bit position. If x is 0, the result is undefined.
-_LIBCPP_ALWAYS_INLINE int __builtin_clzll(unsigned long long mask)
-{
- unsigned long where;
-// BitScanReverse scans from MSB to LSB for first set bit.
-// Returns 0 if no set bit is found.
-#if defined(_LIBCPP_HAS_BITSCAN64)
- if (_BitScanReverse64(&where, mask))
- return static_cast<int>(63 - where);
-#else
- // Scan the high 32 bits.
- if (_BitScanReverse(&where, static_cast<unsigned long>(mask >> 32)))
- return static_cast<int>(63 -
- (where + 32)); // Create a bit offset from the MSB.
- // Scan the low 32 bits.
- if (_BitScanReverse(&where, static_cast<unsigned long>(mask)))
- return static_cast<int>(63 - where);
-#endif
- return 64; // Undefined Behavior.
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_clzl(unsigned long mask)
-{
- unsigned long where;
- // Search from LSB to MSB for first set bit.
- // Returns zero if no set bit is found.
- if (_BitScanReverse(&where, mask))
- return static_cast<int>(31 - where);
- return 32; // Undefined Behavior.
-}
-
-_LIBCPP_ALWAYS_INLINE int __builtin_clz(unsigned int x)
-{
- return __builtin_clzl(x);
-}
-
-#endif // _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H
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