pcsx2/common/MathUtils.h

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/* PCSX2 - PS2 Emulator for PCs
* Copyright (C) 2014- PCSX2 Dev Team
*
* PCSX2 is free software: you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCSX2.
* If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
// Hopefully this file will be used for cross-source math utilities.
// Currently these are strewn across the code base. Please collect them all!
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#include "common/Pcsx2Defs.h"
// On GCC >= 4.7, this is equivalent to __builtin_clrsb(n);
inline u32 count_leading_sign_bits(s32 n)
{
Common: reformat (#4720) * common: format AlignedMalloc.cpp * common: format AppTrait.h * common: format Assertions.h * common: format CheckedStaticBox * common: format Console * common: format Dependencies.h * common: format EmbeddedImage * common: format EventSource * common: format Exceptions * common: format FastFormatString.cpp * common: format General.h * common: format InitInterface * common: format MathUtils.h * common: format MemsetFast/MemcpyFast * common: format Mutex.cpp * common: format PageFaultSource.h * common: format Path.h * common: format PathUtils.cpp * common: format Pcsx2Types.h * common: format Perf * common: format PersistentThread.h * common: format RwMutex * common: format SafeArray * common: format ScopedAlloc.h * common: format ScopedPtrMT.h * common: format Semaphore.cpp * common: format StringHelpers * common: format ThreadTools.cpp * common: format Threading.h * common: format ThreadingDialogs * common: format ThreadingInternal.h * common: format TraceLog.h * common: format VirtualMemory.cpp * common: format pxCheckBox * common: format pxEvents.h * common: format pxForwardDefs.h * common: format pxRadioPanel * common: format pxStaticText * common: format pxStreams * common: format pxTranslate.cpp * common: format pxWindowTextWriter.cpp * common: format wxAppWithHelpers * common: format wxBaseTools.h * common: format wxGuiTools * common: format wxHelpers.cpp * common: format Darwin directory * common: format Linux directory * common: format Windows directory * common: format LnxCpuDetect.cpp * common: format WinCpuDetect.cpp * common: format bmi.cpp * common: format cpudetect.cpp * common: format cpu_detect_internal.h * common: format fpu.cpp * common: format groups.cpp * common: format instructions.h * common: format internal.h * common: format jmp.cpp * common: format legacy.cpp * common: format legacy_instructions.h * common: format legacy_internal.h * common: format movs.cpp * common: format simd.cpp * common: format tools.h * common: format x86emitter.cpp * common: format x86types.h * common: format bmi.h * common: format dwshift.h * common: format group1.h group2.h group3.h * common: format incdec.h * common: format jmpcall.h * common: format movs.h * common: format simd_arithmetic.h * common: format simd_comparisons.h * common: format simd_helpers.h * common: format simd_moremovs.h * common: format simd_shufflepack.h * common: format simd_templated_helpers.h * common: format test.h
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// If the sign bit is 1, we invert the bits to 0 for count-leading-zero.
if (n < 0)
n = ~n;
Common: reformat (#4720) * common: format AlignedMalloc.cpp * common: format AppTrait.h * common: format Assertions.h * common: format CheckedStaticBox * common: format Console * common: format Dependencies.h * common: format EmbeddedImage * common: format EventSource * common: format Exceptions * common: format FastFormatString.cpp * common: format General.h * common: format InitInterface * common: format MathUtils.h * common: format MemsetFast/MemcpyFast * common: format Mutex.cpp * common: format PageFaultSource.h * common: format Path.h * common: format PathUtils.cpp * common: format Pcsx2Types.h * common: format Perf * common: format PersistentThread.h * common: format RwMutex * common: format SafeArray * common: format ScopedAlloc.h * common: format ScopedPtrMT.h * common: format Semaphore.cpp * common: format StringHelpers * common: format ThreadTools.cpp * common: format Threading.h * common: format ThreadingDialogs * common: format ThreadingInternal.h * common: format TraceLog.h * common: format VirtualMemory.cpp * common: format pxCheckBox * common: format pxEvents.h * common: format pxForwardDefs.h * common: format pxRadioPanel * common: format pxStaticText * common: format pxStreams * common: format pxTranslate.cpp * common: format pxWindowTextWriter.cpp * common: format wxAppWithHelpers * common: format wxBaseTools.h * common: format wxGuiTools * common: format wxHelpers.cpp * common: format Darwin directory * common: format Linux directory * common: format Windows directory * common: format LnxCpuDetect.cpp * common: format WinCpuDetect.cpp * common: format bmi.cpp * common: format cpudetect.cpp * common: format cpu_detect_internal.h * common: format fpu.cpp * common: format groups.cpp * common: format instructions.h * common: format internal.h * common: format jmp.cpp * common: format legacy.cpp * common: format legacy_instructions.h * common: format legacy_internal.h * common: format movs.cpp * common: format simd.cpp * common: format tools.h * common: format x86emitter.cpp * common: format x86types.h * common: format bmi.h * common: format dwshift.h * common: format group1.h group2.h group3.h * common: format incdec.h * common: format jmpcall.h * common: format movs.h * common: format simd_arithmetic.h * common: format simd_comparisons.h * common: format simd_helpers.h * common: format simd_moremovs.h * common: format simd_shufflepack.h * common: format simd_templated_helpers.h * common: format test.h
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// If BSR is used directly, it would have an undefined value for 0.
if (n == 0)
return 32;
// Perform our count leading zero.
#ifdef _MSC_VER
Common: reformat (#4720) * common: format AlignedMalloc.cpp * common: format AppTrait.h * common: format Assertions.h * common: format CheckedStaticBox * common: format Console * common: format Dependencies.h * common: format EmbeddedImage * common: format EventSource * common: format Exceptions * common: format FastFormatString.cpp * common: format General.h * common: format InitInterface * common: format MathUtils.h * common: format MemsetFast/MemcpyFast * common: format Mutex.cpp * common: format PageFaultSource.h * common: format Path.h * common: format PathUtils.cpp * common: format Pcsx2Types.h * common: format Perf * common: format PersistentThread.h * common: format RwMutex * common: format SafeArray * common: format ScopedAlloc.h * common: format ScopedPtrMT.h * common: format Semaphore.cpp * common: format StringHelpers * common: format ThreadTools.cpp * common: format Threading.h * common: format ThreadingDialogs * common: format ThreadingInternal.h * common: format TraceLog.h * common: format VirtualMemory.cpp * common: format pxCheckBox * common: format pxEvents.h * common: format pxForwardDefs.h * common: format pxRadioPanel * common: format pxStaticText * common: format pxStreams * common: format pxTranslate.cpp * common: format pxWindowTextWriter.cpp * common: format wxAppWithHelpers * common: format wxBaseTools.h * common: format wxGuiTools * common: format wxHelpers.cpp * common: format Darwin directory * common: format Linux directory * common: format Windows directory * common: format LnxCpuDetect.cpp * common: format WinCpuDetect.cpp * common: format bmi.cpp * common: format cpudetect.cpp * common: format cpu_detect_internal.h * common: format fpu.cpp * common: format groups.cpp * common: format instructions.h * common: format internal.h * common: format jmp.cpp * common: format legacy.cpp * common: format legacy_instructions.h * common: format legacy_internal.h * common: format movs.cpp * common: format simd.cpp * common: format tools.h * common: format x86emitter.cpp * common: format x86types.h * common: format bmi.h * common: format dwshift.h * common: format group1.h group2.h group3.h * common: format incdec.h * common: format jmpcall.h * common: format movs.h * common: format simd_arithmetic.h * common: format simd_comparisons.h * common: format simd_helpers.h * common: format simd_moremovs.h * common: format simd_shufflepack.h * common: format simd_templated_helpers.h * common: format test.h
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unsigned long ret;
_BitScanReverse(&ret, n);
return 31 - (u32)ret;
#else
Common: reformat (#4720) * common: format AlignedMalloc.cpp * common: format AppTrait.h * common: format Assertions.h * common: format CheckedStaticBox * common: format Console * common: format Dependencies.h * common: format EmbeddedImage * common: format EventSource * common: format Exceptions * common: format FastFormatString.cpp * common: format General.h * common: format InitInterface * common: format MathUtils.h * common: format MemsetFast/MemcpyFast * common: format Mutex.cpp * common: format PageFaultSource.h * common: format Path.h * common: format PathUtils.cpp * common: format Pcsx2Types.h * common: format Perf * common: format PersistentThread.h * common: format RwMutex * common: format SafeArray * common: format ScopedAlloc.h * common: format ScopedPtrMT.h * common: format Semaphore.cpp * common: format StringHelpers * common: format ThreadTools.cpp * common: format Threading.h * common: format ThreadingDialogs * common: format ThreadingInternal.h * common: format TraceLog.h * common: format VirtualMemory.cpp * common: format pxCheckBox * common: format pxEvents.h * common: format pxForwardDefs.h * common: format pxRadioPanel * common: format pxStaticText * common: format pxStreams * common: format pxTranslate.cpp * common: format pxWindowTextWriter.cpp * common: format wxAppWithHelpers * common: format wxBaseTools.h * common: format wxGuiTools * common: format wxHelpers.cpp * common: format Darwin directory * common: format Linux directory * common: format Windows directory * common: format LnxCpuDetect.cpp * common: format WinCpuDetect.cpp * common: format bmi.cpp * common: format cpudetect.cpp * common: format cpu_detect_internal.h * common: format fpu.cpp * common: format groups.cpp * common: format instructions.h * common: format internal.h * common: format jmp.cpp * common: format legacy.cpp * common: format legacy_instructions.h * common: format legacy_internal.h * common: format movs.cpp * common: format simd.cpp * common: format tools.h * common: format x86emitter.cpp * common: format x86types.h * common: format bmi.h * common: format dwshift.h * common: format group1.h group2.h group3.h * common: format incdec.h * common: format jmpcall.h * common: format movs.h * common: format simd_arithmetic.h * common: format simd_comparisons.h * common: format simd_helpers.h * common: format simd_moremovs.h * common: format simd_shufflepack.h * common: format simd_templated_helpers.h * common: format test.h
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return __builtin_clz(n);
#endif
}