diff options
Diffstat (limited to 'open-vm-tools/lib/include/vm_basic_asm_x86_64.h')
| -rw-r--r-- | open-vm-tools/lib/include/vm_basic_asm_x86_64.h | 178 |
1 files changed, 109 insertions, 69 deletions
diff --git a/open-vm-tools/lib/include/vm_basic_asm_x86_64.h b/open-vm-tools/lib/include/vm_basic_asm_x86_64.h index 4cd6aebe..ecb4189f 100644 --- a/open-vm-tools/lib/include/vm_basic_asm_x86_64.h +++ b/open-vm-tools/lib/include/vm_basic_asm_x86_64.h @@ -1,5 +1,5 @@ /********************************************************* - * Copyright (C) 1998-2004 VMware, Inc. All rights reserved. + * Copyright (C) 1998-2015 VMware, Inc. All rights reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published @@ -53,14 +53,14 @@ #error "This file is x86-64 only!" #endif -#ifdef _MSC_VER +#if defined(_MSC_VER) && !defined(BORA_NO_WIN32_INTRINS) #ifdef __cplusplus extern "C" { #endif -uint64 _umul128(uint64 multiplier, uint64 multiplicand, +uint64 _umul128(uint64 multiplier, uint64 multiplicand, uint64 *highProduct); -int64 _mul128(int64 multiplier, int64 multiplicand, +int64 _mul128(int64 multiplier, int64 multiplicand, int64 *highProduct); uint64 __shiftright128(uint64 lowPart, uint64 highPart, uint8 shift); #ifdef __cplusplus @@ -323,55 +323,81 @@ xtest(void) * * Mul64x6464 -- * - * Unsigned integer by fixed point multiplication: - * result = multiplicand * multiplier >> shift + * Unsigned integer by fixed point multiplication, with rounding: + * result = floor(multiplicand * multiplier * 2**(-shift) + 0.5) * * Unsigned 64-bit integer multiplicand. * Unsigned 64-bit fixed point multiplier, represented as - * multiplier >> shift, where shift < 64. - * Unsigned 64-bit integer product. - * - * Implementation: - * Multiply 64x64 bits to yield a full 128-bit product. - * Shift result in RDX:RAX right by "shift". - * Return the low-order 64 bits of the above. + * (multiplier, shift), where shift < 64. * * Result: - * Product + * Unsigned 64-bit integer product. * *----------------------------------------------------------------------------- */ -#if defined(__GNUC__) +#if defined(__GNUC__) && !defined(MUL64_NO_ASM) static INLINE uint64 Mul64x6464(uint64 multiplicand, uint64 multiplier, uint32 shift) { + /* + * Implementation: + * Multiply 64x64 bits to yield a full 128-bit product. + * Clear the carry bit (needed for the shift == 0 case). + * Shift result in RDX:RAX right by "shift". + * Add the carry bit. (If shift > 0, this is the highest order bit + * that was discarded by the shift; else it is 0.) + * Return the low-order 64 bits of the above. + * + */ uint64 result, dummy; - __asm__("mulq %3 \n\t" + __asm__("mulq %3 \n\t" + "clc \n\t" "shrdq %b4, %1, %0 \n\t" + "adc $0, %0 \n\t" : "=a" (result), "=d" (dummy) : "0" (multiplier), "rm" (multiplicand), - "c" (shift) + "c" (shift) : "cc"); return result; } -#elif defined(_MSC_VER) +#elif defined(_MSC_VER) && !defined(MUL64_NO_ASM) static INLINE uint64 -Mul64x6464(uint64 multiplicand, uint64 multiplier, uint32 shift) +Mul64x6464(uint64 multiplicand, + uint64 multiplier, + uint32 shift) { + /* + * Unfortunately, MSVC intrinsics don't give us access to the carry + * flag after a 128-bit shift, so the implementation is more + * awkward: + * Multiply 64x64 bits to yield a full 128-bit product. + * Shift result right by "shift". + * If shift != 0, extract and add in highest order bit that was + * discarded by the shift. + * Return the low-order 64 bits of the above. + */ uint64 tmplo, tmphi; tmplo = _umul128(multiplicand, multiplier, &tmphi); - return __shiftright128(tmplo, tmphi, (uint8) shift); + if (shift == 0) { + return tmplo; + } else { + return __shiftright128(tmplo, tmphi, (uint8) shift) + + ((tmplo >> (shift - 1)) & 1); + } } +#else +#define MUL64_NO_ASM 1 +#include "mul64.h" #endif /* @@ -379,80 +405,100 @@ Mul64x6464(uint64 multiplicand, uint64 multiplier, uint32 shift) * * Muls64x64s64 -- * - * Signed integer by fixed point multiplication: - * result = multiplicand * multiplier >> shift + * Signed integer by fixed point multiplication, with rounding: + * result = floor(multiplicand * multiplier * 2**(-shift) + 0.5) * * Signed 64-bit integer multiplicand. * Unsigned 64-bit fixed point multiplier, represented as - * multiplier >> shift, where shift < 64. - * Signed 64-bit integer product. - * - * Implementation: - * Multiply 64x64 bits to yield a full 128-bit product. - * Shift result in RDX:RAX right by "shift". - * Return the low-order 64 bits of the above. - * - * Note: using an unsigned shift instruction is correct because - * shift < 64 and we return only the low 64 bits of the shifted - * result. + * (multiplier, shift), where shift < 64. * * Result: - * Product + * Signed 64-bit integer product. * *----------------------------------------------------------------------------- */ -#if defined(__GNUC__) +#if defined(__GNUC__) && !defined(MUL64_NO_ASM) static inline int64 -Muls64x64s64(int64 multiplicand, int64 multiplier, uint32 shift) +Muls64x64s64(int64 multiplicand, + int64 multiplier, + uint32 shift) { int64 result, dummy; - __asm__("imulq %3 \n\t" - "shrdq %b4, %1, %0 \n\t" - : "=a" (result), - "=d" (dummy) - : "0" (multiplier), - "rm" (multiplicand), - "c" (shift) - : "cc"); + /* Implementation: + * Multiply 64x64 bits to yield a full 128-bit product. + * Clear the carry bit (needed for the shift == 0 case). + * Shift result in RDX:RAX right by "shift". + * Add the carry bit. (If shift > 0, this is the highest order bit + * that was discarded by the shift; else it is 0.) + * Return the low-order 64 bits of the above. + * + * Note: using the unsigned shrd instruction is correct because + * shift < 64 and we return only the low 64 bits of the shifted + * result. + */ + __asm__("imulq %3 \n\t" + "clc \n\t" + "shrdq %b4, %1, %0 \n\t" + "adc $0, %0 \n\t" + : "=a" (result), + "=d" (dummy) + : "0" (multiplier), + "rm" (multiplicand), + "c" (shift) + : "cc"); return result; } -#elif defined(_MSC_VER) +#elif defined(_MSC_VER) && !defined(MUL64_NO_ASM) static INLINE int64 -Muls64x64s64(int64 multiplicand, int64 multiplier, uint32 shift) +Muls64x64s64(int64 multiplicand, + int64 multiplier, + uint32 shift) { + /* + * Unfortunately, MSVC intrinsics don't give us access to the carry + * flag after a 128-bit shift, so the implementation is more + * awkward: + * Multiply 64x64 bits to yield a full 128-bit product. + * Shift result right by "shift". + * If shift != 0, extract and add in highest order bit that was + * discarded by the shift. + * Return the low-order 64 bits of the above. + * + * Note: using an unsigned shift is correct because shift < 64 and + * we return only the low 64 bits of the shifted result. + */ int64 tmplo, tmphi; - tmplo = _mul128(multiplicand, multiplier, &tmphi); - return __shiftright128(tmplo, tmphi, (uint8) shift); + if (shift == 0) { + return tmplo; + } else { + return __shiftright128(tmplo, tmphi, (uint8) shift) + + ((tmplo >> (shift - 1)) & 1); + } } #endif +#ifndef MUL64_NO_ASM /* *----------------------------------------------------------------------------- * * Mul64x3264 -- * - * Unsigned integer by fixed point multiplication: - * result = multiplicand * multiplier >> shift + * Unsigned integer by fixed point multiplication, with rounding: + * result = floor(multiplicand * multiplier * 2**(-shift) + 0.5) * * Unsigned 64-bit integer multiplicand. * Unsigned 32-bit fixed point multiplier, represented as - * multiplier >> shift, where shift < 64. - * Unsigned 64-bit integer product. - * - * Implementation: - * Multiply 64x64 bits to yield a full 128-bit product. - * Shift result in RDX:RAX right by "shift". - * Return the low-order 64 bits of the above. + * (multiplier, shift), where shift < 64. * * Result: - * Return the low-order 64 bits of ((multiplicand * multiplier) >> shift) + * Unsigned 64-bit integer product. * *----------------------------------------------------------------------------- */ @@ -468,21 +514,15 @@ Mul64x3264(uint64 multiplicand, uint32 multiplier, uint32 shift) * * Muls64x32s64 -- * - * Signed integer by fixed point multiplication: - * result = (multiplicand * multiplier) >> shift + * Signed integer by fixed point multiplication, with rounding: + * result = floor(multiplicand * multiplier * 2**(-shift) + 0.5) * * Signed 64-bit integer multiplicand. * Unsigned 32-bit fixed point multiplier, represented as - * multiplier >> shift, where shift < 64. - * Signed 64-bit integer product. - * - * Implementation: - * Multiply 64x64 bits to yield a full 128-bit product. - * Shift result in RDX:RAX right by "shift". - * Return the low-order 64 bits of the above. + * (multiplier, shift), where shift < 64. * * Result: - * Return the low-order 64 bits of ((multiplicand * multiplier) >> shift) + * Signed 64-bit integer product. * *----------------------------------------------------------------------------- */ @@ -492,7 +532,7 @@ Muls64x32s64(int64 multiplicand, uint32 multiplier, uint32 shift) { return Muls64x64s64(multiplicand, multiplier, shift); } - +#endif #if defined(__GNUC__) |