X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=ArmPkg%2FLibrary%2FCompilerIntrinsicsLib%2FArm%2Fclzsi2.c;h=5c2a3ea2b4282a317e7e9fb1057c768d48b5fc3b;hb=3402aac7d985bf8a9f9d3c639f3fe93609380513;hp=c7b4607ca49e442967d9f061452a682c8edade8d;hpb=2ef2b01e07c02db339f34004445734a2dbdd80e1;p=mirror_edk2.git diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.c b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.c index c7b4607ca4..5c2a3ea2b4 100644 --- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.c +++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.c @@ -1,96 +1,96 @@ -/** @file - Compiler intrinsic to return the number of leading zeros, ported from LLVM code. - - Copyright (c) 2008-2009, Apple Inc. All rights reserved. - - All rights reserved. This program and the accompanying materials - are licensed and made available under the terms and conditions of the BSD License - which accompanies this distribution. The full text of the license may be found at - http://opensource.org/licenses/bsd-license.php - - THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, - WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. - -**/ -/** - University of Illinois/NCSA - Open Source License - - Copyright (c) 2003-2008 University of Illinois at Urbana-Champaign. - All rights reserved. - - Developed by: - - LLVM Team - - University of Illinois at Urbana-Champaign - - http://llvm.org - - Permission is hereby granted, free of charge, to any person obtaining a copy of - this software and associated documentation files (the "Software"), to deal with - the Software without restriction, including without limitation the rights to - use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies - of the Software, and to permit persons to whom the Software is furnished to do - so, subject to the following conditions: - - * Redistributions of source code must retain the above copyright notice, - this list of conditions and the following disclaimers. - - * Redistributions in binary form must reproduce the above copyright notice, - this list of conditions and the following disclaimers in the - documentation and/or other materials provided with the distribution. - - * Neither the names of the LLVM Team, University of Illinois at - Urbana-Champaign, nor the names of its contributors may be used to - endorse or promote products derived from this Software without specific - prior written permission. - - THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS - FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE - SOFTWARE. -**/ - - -#include "Llvm_int_lib.h" - -// Returns: the number of leading 0-bits - -// Precondition: a != 0 - -INT32 -__clzsi2(INT32 a) -{ - UINT32 x = (UINT32)a; - INT32 t = ((x & 0xFFFF0000) == 0) << 4; // if (x is small) t = 16 else 0 - x >>= 16 - t; // x = [0 - 0xFFFF] - UINT32 r = t; // r = [0, 16] - // return r + clz(x) - t = ((x & 0xFF00) == 0) << 3; - x >>= 8 - t; // x = [0 - 0xFF] - r += t; // r = [0, 8, 16, 24] - // return r + clz(x) - t = ((x & 0xF0) == 0) << 2; - x >>= 4 - t; // x = [0 - 0xF] - r += t; // r = [0, 4, 8, 12, 16, 20, 24, 28] - // return r + clz(x) - t = ((x & 0xC) == 0) << 1; - x >>= 2 - t; // x = [0 - 3] - r += t; // r = [0 - 30] and is even - // return r + clz(x) -// switch (x) -// { -// case 0: -// return r + 2; -// case 1: -// return r + 1; -// case 2: -// case 3: -// return r; -// } - return r + ((2 - x) & -((x & 2) == 0)); -} +/** @file + Compiler intrinsic to return the number of leading zeros, ported from LLVM code. + + Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
+ + This program and the accompanying materials + are licensed and made available under the terms and conditions of the BSD License + which accompanies this distribution. The full text of the license may be found at + http://opensource.org/licenses/bsd-license.php + + THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, + WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. + +**/ +/** + University of Illinois/NCSA + Open Source License + + Copyright (c) 2003-2008 University of Illinois at Urbana-Champaign. + All rights reserved. + + Developed by: + + LLVM Team + + University of Illinois at Urbana-Champaign + + http://llvm.org + + Permission is hereby granted, free of charge, to any person obtaining a copy of + this software and associated documentation files (the "Software"), to deal with + the Software without restriction, including without limitation the rights to + use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies + of the Software, and to permit persons to whom the Software is furnished to do + so, subject to the following conditions: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimers. + + * Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimers in the + documentation and/or other materials provided with the distribution. + + * Neither the names of the LLVM Team, University of Illinois at + Urbana-Champaign, nor the names of its contributors may be used to + endorse or promote products derived from this Software without specific + prior written permission. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS + FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE + SOFTWARE. +**/ + + +#include "Llvm_int_lib.h" + +// Returns: the number of leading 0-bits + +// Precondition: a != 0 + +INT32 +__clzsi2(INT32 a) +{ + UINT32 x = (UINT32)a; + INT32 t = ((x & 0xFFFF0000) == 0) << 4; // if (x is small) t = 16 else 0 + x >>= 16 - t; // x = [0 - 0xFFFF] + UINT32 r = t; // r = [0, 16] + // return r + clz(x) + t = ((x & 0xFF00) == 0) << 3; + x >>= 8 - t; // x = [0 - 0xFF] + r += t; // r = [0, 8, 16, 24] + // return r + clz(x) + t = ((x & 0xF0) == 0) << 2; + x >>= 4 - t; // x = [0 - 0xF] + r += t; // r = [0, 4, 8, 12, 16, 20, 24, 28] + // return r + clz(x) + t = ((x & 0xC) == 0) << 1; + x >>= 2 - t; // x = [0 - 3] + r += t; // r = [0 - 30] and is even + // return r + clz(x) +// switch (x) +// { +// case 0: +// return r + 2; +// case 1: +// return r + 1; +// case 2: +// case 3: +// return r; +// } + return r + ((2 - x) & -((x & 2) == 0)); +}