Skip to content

Commit

Permalink
Add MSVC intrinsics to ARM core, fix incorrect carry flag in fallback…
Browse files Browse the repository at this point in the history 
…s and replace unnecessary 64-bit math
  • Loading branch information
@calc84maniac
calc84maniac committed Sep 5, 2024
1 parent fdb2ed9 commit a3f1ce3
Showing 1 changed file with 100 additions and 30 deletions.
130 changes: 100 additions & 30 deletions core/arm/armcpu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,9 @@
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#if defined(_MSC_VER) && !defined(__clang__)
#include <intrin.h>
#endif

#ifndef __has_builtin
# define __has_builtin(builtin) 0
Expand All @@ -20,9 +23,15 @@
# define DEBUG_BREAK asm("int3")
#endif

#if (defined(__GNUC__) || defined(__clang__))
# define EXTENDED_ASM 1
#else
# define EXTENDED_ASM 0
#endif

#if defined(__GCC_ASM_FLAG_OUTPUTS__) && \
(defined(__i386) || defined(__x86_64__) || \
defined(_M_IX86) || defined(_M_IX64))
defined(_M_IX86) || defined(_M_X64))
# define FLAGS_FROM_EXTENDED_X86_ASM 1
#else
# define FLAGS_FROM_EXTENDED_X86_ASM 0
Expand All @@ -34,6 +43,12 @@
# define FLAGS_FROM_OVERFLOW_BUILTINS 0
#endif

#if _MSC_VER >= 1937 && !defined(__clang__) && (defined(_M_IX86) || defined(_M_X64))
# define FLAGS_FROM_MSVC_INTRINSICS 1
#else
# define FLAGS_FROM_MSVC_INTRINSICS 0
#endif

#if __has_builtin(__builtin_constant_p) || __GNUC__ >= 3 // Not sure, so conservative
# define HAVE_BUILTIN_CONSTANT_P 1
#else
Expand All @@ -43,10 +58,21 @@
static uint8_t bitcount9(uint32_t x) {
#if __has_builtin(__builtin_popcount) || __GNUC__ >= 4
return __builtin_popcount(x & 0777);
#elif UINT32_MAX >= UINTPTR_MAX
uint32_t res = (x &= 0777), mask = UINT32_C(0x11111111);
res *= UINT32_C(0001001001001);
res >>= 3;
# if EXTENDED_ASM && (defined(__i386__) || defined(_M_IX86))
__asm__("andl\t%1, %0\nimull\t%1, %0" : "+r"(res) : "r"(mask) : "cc");
# else
res &= mask;
res *= mask;
#endif
return (res >> 28) + (x >> 8);
#else
uint64_t res = x & 0777, mask = UINT64_C(0x1111111111111111);
res *= UINT64_C(0001001001001);
# if defined(__x86_64__) || defined(_M_IX64)
# if EXTENDED_ASM && (defined(__x86_64__) || defined(_M_X64))
__asm__("andq\t%1, %0\nimulq\t%1, %0" : "+r"(res) : "r"(mask) : "cc");
# else
res &= mask;
Expand All @@ -60,17 +86,24 @@ static uint8_t lowestsetbit32(uint32_t x) {
assert(x && "invalid argument");
#if __has_builtin(__builtin_ctz) || __GNUC__ >= 4
return __builtin_ctz(x);
#elif defined(_MSC_VER) && !defined(__clang__)
unsigned long index;
_BitScanForward(&index, x);
return index;
#else
# if EXTENDED_ASM && \
(defined(__i386) || defined(__x86_64__) || \
defined(_M_IX86) || defined(_M_X64))
uint32_t res;
# if defined(__i386) || defined(__x86_64__) || \
defined(_M_IX86) || defined(_M_IX64)
__asm__("bsfl\t%1, %0" : "+r"(res) : "r"(x) : "cc");
# else
res = 0;
while (!(x & 1)) {
x >>= 1;
++res;
}
uint8_t res = 0;
x &= -x;
if (x & UINT32_C(0xAAAAAAAA)) res += 1;
if (x & UINT32_C(0xCCCCCCCC)) res += 2;
if (x & UINT32_C(0xF0F0F0F0)) res += 4;
if (x & UINT32_C(0xFF00FF00)) res += 8;
if (x & UINT32_C(0xFFFF0000)) res += 16;
# endif
return res;
#endif
Expand Down Expand Up @@ -209,13 +242,17 @@ static uint32_t arm_negs(arm_cpu_t *cpu, uint32_t x) {
#elif FLAGS_FROM_OVERFLOW_BUILTINS
int32_t res;
cpu->v = __builtin_sub_overflow(0, (int32_t)x, &res);
cpu->c = x;
return arm_movs(cpu, -x);
cpu->c = !res;
return arm_movs(cpu, res);
#elif FLAGS_FROM_MSVC_INTRINSICS
int32_t res;
cpu->v = _sub_overflow_i32(0, 0, x, &res);
cpu->c = !res;
return arm_movs(cpu, res);
#else
int64_t res = UINT64_C(0) - (int32_t)x;
cpu->v = res != (int32_t)res;
cpu->c = (uint32_t)res <= 0;
//cpu->c = 0 >= x;
uint32_t res = -x;
cpu->v = (x & res) >> 31;
cpu->c = !res;
return arm_movs(cpu, res);
#endif
}
Expand All @@ -229,10 +266,18 @@ static uint32_t arm_adds(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
cpu->v = __builtin_add_overflow((int32_t)x, (int32_t)y, &res);
cpu->c = __builtin_add_overflow(x, y, &x);
return arm_movs(cpu, x);
#elif FLAGS_FROM_MSVC_INTRINSICS
int32_t res;
cpu->v = _add_overflow_i32(0, x, y, &res);
cpu->c = _addcarry_u32(0, x, y, &x);
return arm_movs(cpu, x);
#else
int64_t res = (int64_t)(int32_t)x + (int32_t)y;
cpu->v = res != (int32_t)res;
cpu->c = (uint32_t)res < x;
uint32_t res = x + y;
flags->v = ((res ^ x) & (res ^ y)) >> 31;
flags->c = res < x;
//int64_t res = (int64_t)(int32_t)x + (int32_t)y;
//cpu->v = res != (int32_t)res;
//cpu->c = (uint32_t)res < x;
//cpu->c = x > ~y;
return arm_movs(cpu, res);
#endif
Expand All @@ -247,10 +292,18 @@ static uint32_t arm_subs(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
cpu->v = __builtin_sub_overflow((int32_t)x, (int32_t)y, &res);
cpu->c = !__builtin_sub_overflow(x, y, &x);
return arm_movs(cpu, x);
#elif FLAGS_FROM_MSVC_INTRINSICS
int32_t res;
cpu->v = _sub_overflow_i32(0, x, y, &res);
cpu->c = !_subborrow_u32(0, x, y, &x);
return arm_movs(cpu, x);
#else
int64_t res = (int64_t)(int32_t)x - (int32_t)y;
cpu->v = res != (int32_t)res;
cpu->c = (uint32_t)res <= x;
uint32_t res = x - y;
cpu->v = ((x ^ y) & (res ^ x)) >> 31;
cpu->c = res <= x;
//int64_t res = (int64_t)(int32_t)x - (int32_t)y;
//cpu->v = res != (int32_t)res;
//cpu->c = (uint32_t)res <= x;
//cpu->c = x >= y;
return arm_movs(cpu, res);
#endif
Expand All @@ -268,10 +321,20 @@ static uint32_t arm_adcs(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
cpu->c = __builtin_add_overflow(x, y, &x);
cpu->c |= __builtin_add_overflow(x, carry, &x);
return arm_movs(cpu, x);
#elif FLAGS_FROM_MSVC_INTRINSICS
bool carry = cpu->c;
int32_t res;
cpu->v = _add_overflow_i32(carry, x, y, &res);
cpu->c = _addcarry_u32(carry, x, y, &x);
return arm_movs(cpu, x);
#else
int64_t res = (uint64_t)(int32_t)x + (int32_t)y + cpu->c;
cpu->v = res != (int32_t)res;
cpu->c = ((uint64_t)x + y + cpu->c) >> 32;
uint32_t res = x + y + cpu->c;
uint32_t carries = (x | y) ^ ((x ^ y) & res);
cpu->c = carries >> 31;
cpu->v = cpu->c ^ (carries >> 30 & 1);
//int64_t res = (uint64_t)(int32_t)x + (int32_t)y + cpu->c;
//cpu->v = res != (int32_t)res;
//cpu->c = ((uint64_t)x + y + cpu->c) >> 32;
return arm_movs(cpu, res);
#endif
}
Expand All @@ -285,14 +348,21 @@ static uint32_t arm_sbcs(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
int32_t res;
cpu->v = __builtin_sub_overflow(x, y, &res);
cpu->v |= __builtin_sub_overflow(res, borrow, &res);
cpu->c = __builtin_sub_overflow(x, y, &x);
cpu->c |= __builtin_sub_overflow(x, borrow, &x);
cpu->c = !__builtin_sub_overflow(x, y, &x);
cpu->c &= !__builtin_sub_overflow(x, borrow, &x);
return arm_movs(cpu, x);
#elif FLAGS_FROM_MSVC_INTRINSICS
bool borrow = !cpu->c;
int32_t res;
cpu->v = _sub_overflow_i32(borrow, x, y, &res);
cpu->c = !_subborrow_u32(borrow, x, y, &x);
return arm_movs(cpu, x);
#else
int64_t res = (uint64_t)(int32_t)x - (int32_t)y - !cpu->c;
cpu->v = res != (int32_t)res;
cpu->c = ((uint64_t)x - y - !cpu->c) >> 32;
return arm_movs(cpu, res);
return arm_adcs(cpu, x, ~y);
//int64_t res = (uint64_t)(int32_t)x - (int32_t)y - !cpu->c;
//cpu->v = res != (int32_t)res;
//cpu->c = !(((uint64_t)x - y - !cpu->c) >> 32);
//return arm_movs(cpu, res);
#endif
}

Expand Down

0 comments on commit a3f1ce3

Please sign in to comment.