8#ifndef BOTAN_UTIL_MUL128_H_
9#define BOTAN_UTIL_MUL128_H_
11#include <botan/types.h>
17#if defined(__SIZEOF_INT128__) && defined(BOTAN_TARGET_CPU_HAS_NATIVE_64BIT)
18 #define BOTAN_TARGET_HAS_NATIVE_UINT128
22 typedef unsigned int uint128_t __attribute__((mode(TI)));
24 typedef unsigned __int128 uint128_t;
30#if defined(BOTAN_TARGET_HAS_NATIVE_UINT128)
32#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) \
34 const uint128_t r = static_cast<uint128_t>(a) * b; \
35 *hi = (r >> 64) & 0xFFFFFFFFFFFFFFFF; \
36 *lo = (r ) & 0xFFFFFFFFFFFFFFFF; \
39#elif defined(BOTAN_BUILD_COMPILER_IS_MSVC) && defined(BOTAN_TARGET_CPU_HAS_NATIVE_64BIT)
42#pragma intrinsic(_umul128)
44#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) \
45 do { *lo = _umul128(a, b, hi); } while(0)
47#elif defined(BOTAN_USE_GCC_INLINE_ASM)
49#if defined(BOTAN_TARGET_ARCH_IS_X86_64)
51#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) do { \
52 asm("mulq %3" : "=d" (*hi), "=a" (*lo) : "a" (a), "rm" (b) : "cc"); \
55#elif defined(BOTAN_TARGET_ARCH_IS_ALPHA)
57#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) do { \
58 asm("umulh %1,%2,%0" : "=r" (*hi) : "r" (a), "r" (b)); \
62#elif defined(BOTAN_TARGET_ARCH_IS_IA64)
64#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) do { \
65 asm("xmpy.hu %0=%1,%2" : "=f" (*hi) : "f" (a), "f" (b)); \
69#elif defined(BOTAN_TARGET_ARCH_IS_PPC64)
71#define BOTAN_FAST_64X64_MUL(a,b,lo,hi) do { \
72 asm("mulhdu %0,%1,%2" : "=r" (*hi) : "r" (a), "r" (b) : "cc"); \
85inline void mul64x64_128(uint64_t a, uint64_t b, uint64_t* lo, uint64_t* hi)
87#if defined(BOTAN_FAST_64X64_MUL)
88 BOTAN_FAST_64X64_MUL(a, b, lo, hi);
96 const size_t HWORD_BITS = 32;
97 const uint32_t HWORD_MASK = 0xFFFFFFFF;
99 const uint32_t a_hi = (a >> HWORD_BITS);
100 const uint32_t a_lo = (a & HWORD_MASK);
101 const uint32_t b_hi = (b >> HWORD_BITS);
102 const uint32_t b_lo = (b & HWORD_MASK);
104 uint64_t x0 =
static_cast<uint64_t
>(a_hi) * b_hi;
105 uint64_t x1 =
static_cast<uint64_t
>(a_lo) * b_hi;
106 uint64_t x2 =
static_cast<uint64_t
>(a_hi) * b_lo;
107 uint64_t x3 =
static_cast<uint64_t
>(a_lo) * b_lo;
110 x2 += x3 >> HWORD_BITS;
116 x0 +=
static_cast<uint64_t
>(
static_cast<bool>(x2 < x1)) << HWORD_BITS;
118 *hi = x0 + (x2 >> HWORD_BITS);
119 *lo = ((x2 & HWORD_MASK) << HWORD_BITS) + (x3 & HWORD_MASK);
#define BOTAN_FUTURE_INTERNAL_HEADER(hdr)
void mul64x64_128(uint64_t a, uint64_t b, uint64_t *lo, uint64_t *hi)