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x86-specific FADD implementation

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This commit is contained in:
Cacodemon345
2025-06-30 01:10:58 +06:00
parent 15211f3021
commit 96734590ca
1 changed files with 54 additions and 5 deletions
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59
src/cpu/x87_ops_arith.h
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@@ -1,3 +1,56 @@
#ifdef X87_INLINE_ASM
static inline double float_add(double src, double val, int round)
{
int orig_round, new_round;
__asm volatile(""
:
:
: "memory");
asm (
"fnstcw %0\n" : "=m"(orig_round)
);
new_round = orig_round & ~(3 << 10);
new_round |= (round << 10);
__asm volatile(""
:
:
: "memory");
asm (
"fldl %0\n"
"fldcw %1\n"
"faddl %2\n"
"fstl %0\n"
"fldcw %3\n"
: "=m"(src)
: "m"(new_round), "m"(val), "m"(orig_round)
);
return src;
}
#define DO_FADD(use_var) \
do \
{ \
ST(0) = float_add(ST(0), use_var, (cpu_state.npxc >> 10) & 3); \
} \
while (0)
#else
#define DO_FADD(use_var) \
do \
{ \
if ((cpu_state.npxc >> 10) & 3) \
fesetround(rounding_modes[(cpu_state.npxc >> 10) & 3]); \
ST(0) += use_var; \
if ((cpu_state.npxc >> 10) & 3) \
fesetround(FE_TONEAREST); \
} \
while (0)
#endif
#define opFPU(name, optype, a_size, load_var, get, use_var, cycle_postfix) \
static int opFADD##name##_a##a_size(UNUSED(uint32_t fetchdat)) \
{ \
@@ -8,11 +61,7 @@
load_var = get(); \
if (cpu_state.abrt) \
return 1; \
if ((cpu_state.npxc >> 10) & 3) \
fesetround(rounding_modes[(cpu_state.npxc >> 10) & 3]); \
ST(0) += use_var; \
if ((cpu_state.npxc >> 10) & 3) \
fesetround(FE_TONEAREST); \
DO_FADD(use_var); \
FP_TAG_VALID; \
CLOCK_CYCLES_FPU((fpu_type >= FPU_487SX) ? (x87_timings.fadd##cycle_postfix) : ((x87_timings.fadd##cycle_postfix) * cpu_multi)); \
CONCURRENCY_CYCLES((fpu_type >= FPU_487SX) ? (x87_concurrency.fadd##cycle_postfix) : ((x87_concurrency.fadd##cycle_postfix) * cpu_multi)); \