mclow.lists created this revision.
mclow.lists added reviewers: ldionne, EricWF.
Still NFC here.
1. Take the 9 functions that each had an `#ifndef _LIBCPP_COMPILER_MSVC` ..
`#else` .. `endif` block in them and make just two blocks, each with 9
functions. Much easier to read, but makes for a terrible diff.
2. Change the return type of `__ctz` and `__clz` from the same type as the
parameter to `int`. I would have preferred `unsigned`, but that's not what
P0553 gave us. I reviewed all the call sites for these functions, and for
`__ctz` it was always immediately static_cast-ed to another type, and `__clz`
it made no difference either.
3. Change the name `__pop_count` to `__popcount` to match the name that we're
going to add from P0553.
4. Rename the local variable in the windows code from `where` to `__where`.
Shame on someone ;-)
https://reviews.llvm.org/D50876
Files:
include/__bit_reference
include/bit
Index: include/bit
===================================================================
--- include/bit
+++ include/bit
@@ -35,135 +35,134 @@
_LIBCPP_BEGIN_NAMESPACE_STD
+#ifndef _LIBCPP_COMPILER_MSVC
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __ctz(unsigned __x) { return __builtin_ctz(__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __ctz(unsigned long __x) { return __builtin_ctzl(__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __ctz(unsigned long long __x) { return __builtin_ctzll(__x); }
+
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __clz(unsigned __x) { return __builtin_clz(__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __clz(unsigned long __x) { return __builtin_clzl(__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __clz(unsigned long long __x) { return __builtin_clzll(__x); }
+
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __popcount(unsigned __x) { return __builtin_popcount (__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __popcount(unsigned long __x) { return __builtin_popcountl (__x); }
+
+inline _LIBCPP_INLINE_VISIBILITY
+int __popcount(unsigned long long __x) { return __builtin_popcountll(__x); }
+
+#else // _LIBCPP_COMPILER_MSVC
+
// Precondition: __x != 0
inline _LIBCPP_INLINE_VISIBILITY
-unsigned __ctz(unsigned __x) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return static_cast<unsigned>(__builtin_ctz(__x));
-#else
+int __ctz(unsigned __x) {
static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
static_assert(sizeof(unsigned long) == 4, "");
- unsigned long where;
+ unsigned long __where;
// Search from LSB to MSB for first set bit.
// Returns zero if no set bit is found.
- if (_BitScanForward(&where, __x))
- return where;
+ if (_BitScanForward(&__where, __x))
+ return static_cast<int>(__where);
return 32;
-#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long __ctz(unsigned long __x) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return static_cast<unsigned long>(__builtin_ctzl(__x));
-#else
+int __ctz(unsigned long __x) {
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) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return static_cast<unsigned long long>(__builtin_ctzll(__x));
-#else
- unsigned long where;
+int __ctz(unsigned long long __x) {
+ 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, __x))
- return static_cast<int>(where);
+ if (_BitScanForward64(&__where, __x))
+ 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>(__x)))
- return where;
+ if (_BitScanForward(&__where, static_cast<unsigned long>(__x)))
+ return __where;
// Scan the High Word.
- if (_BitScanForward(&where, static_cast<unsigned long>(__x >> 32)))
- return where + 32; // Create a bit offset from the LSB.
+ if (_BitScanForward(&__where, static_cast<unsigned long>(__x >> 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) {
-#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;
+ unsigned long __where;
// Search from LSB to MSB for first set bit.
// Returns zero if no set bit is found.
- if (_BitScanReverse(&where, __x))
- return 31 - where;
+ if (_BitScanReverse(&__where, __x))
+ return 31 - __where;
return 32; // Undefined Behavior.
-#endif
}
inline _LIBCPP_INLINE_VISIBILITY
-unsigned long __clz(unsigned long __x) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return static_cast<unsigned long>(__builtin_clzl (__x));
-#else
+int __clz(unsigned long __x) {
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) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return static_cast<unsigned long long>(__builtin_clzll(__x));
-#else
- unsigned long where;
+int __clz(unsigned long long __x) {
+ 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, __x))
- return static_cast<int>(63 - where);
+ if (_BitScanReverse64(&__where, __x))
+ return static_cast<int>(63 - __where);
#else
// Scan the high 32 bits.
- if (_BitScanReverse(&where, static_cast<unsigned long>(__x >> 32)))
- return 63 - (where + 32); // Create a bit offset from the MSB.
+ if (_BitScanReverse(&__where, static_cast<unsigned long>(__x >> 32)))
+ return 63 - (__where + 32); // Create a bit offset from the MSB.
// Scan the low 32 bits.
- if (_BitScanReverse(&where, static_cast<unsigned long>(__x)))
- return 63 - where;
+ if (_BitScanReverse(&__where, static_cast<unsigned long>(__x)))
+ 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
+inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned __x) {
static_assert(sizeof(unsigned) == 4, "");
return __popcnt(__x);
-#endif
}
-inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long __x) {
-#ifndef _LIBCPP_COMPILER_MSVC
- return __builtin_popcountl (__x);
-#else
+inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long __x) {
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
+inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long long __x) {
static_assert(sizeof(unsigned long long) == 8, "");
return __popcnt64(__x);
-#endif
}
+#endif // _LIBCPP_COMPILER_MSVC
+
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_BIT
Index: include/__bit_reference
===================================================================
--- include/__bit_reference
+++ include/__bit_reference
@@ -12,6 +12,7 @@
#define _LIBCPP___BIT_REFERENCE
#include <__config>
+#include <bit>
#include <algorithm>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -254,18 +255,18 @@
__storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
__storage_type __dn = _VSTD::min(__clz_f, __n);
__storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
- __r = _VSTD::__pop_count(*__first.__seg_ & __m);
+ __r = _VSTD::__popcount(*__first.__seg_ & __m);
__n -= __dn;
++__first.__seg_;
}
// do middle whole words
for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
- __r += _VSTD::__pop_count(*__first.__seg_);
+ __r += _VSTD::__popcount(*__first.__seg_);
// do last partial word
if (__n > 0)
{
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
- __r += _VSTD::__pop_count(*__first.__seg_ & __m);
+ __r += _VSTD::__popcount(*__first.__seg_ & __m);
}
return __r;
}
@@ -285,18 +286,18 @@
__storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
__storage_type __dn = _VSTD::min(__clz_f, __n);
__storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
- __r = _VSTD::__pop_count(~*__first.__seg_ & __m);
+ __r = _VSTD::__popcount(~*__first.__seg_ & __m);
__n -= __dn;
++__first.__seg_;
}
// do middle whole words
for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
- __r += _VSTD::__pop_count(~*__first.__seg_);
+ __r += _VSTD::__popcount(~*__first.__seg_);
// do last partial word
if (__n > 0)
{
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
- __r += _VSTD::__pop_count(~*__first.__seg_ & __m);
+ __r += _VSTD::__popcount(~*__first.__seg_ & __m);
}
return __r;
}
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