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cpu/drcbex86.cpp: Fixed flags for 64-bit multiply instructions.

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This commit is contained in:
Vas Crabb 2025-04-10 07:00:50 +10:00
parent f0b88787fb
commit 1c8234fb80
1 changed files with 22 additions and 24 deletions
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46
src/devices/cpu/drcbex86.cpp
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@ -262,27 +262,24 @@ int dmulu(uint64_t &dstlo, uint64_t &dsthi, uint64_t src1, uint64_t src2, bool f
return 0;
}
// fetch source values
uint64_t a = src1;
uint64_t b = src2;
if (a == 0 || b == 0)
if (!src1 || !src2)
{
dsthi = dstlo = 0;
return FLAG_Z;
}
// compute high and low parts first
uint64_t lo = uint64_t(uint32_t(a >> 0)) * uint64_t(uint32_t(b >> 0));
uint64_t hi = uint64_t(uint32_t(a >> 32)) * uint64_t(uint32_t(b >> 32));
uint64_t lo = uint64_t(uint32_t(src1 >> 0)) * uint64_t(uint32_t(src2 >> 0));
uint64_t hi = uint64_t(uint32_t(src1 >> 32)) * uint64_t(uint32_t(src2 >> 32));
// compute middle parts
uint64_t prevlo = lo;
uint64_t temp = uint64_t(uint32_t(a >> 32)) * uint64_t(uint32_t(b >> 0));
uint64_t temp = uint64_t(uint32_t(src1 >> 32)) * uint64_t(uint32_t(src2 >> 0));
lo += temp << 32;
hi += (temp >> 32) + (lo < prevlo);
prevlo = lo;
temp = uint64_t(uint32_t(a >> 0)) * uint64_t(uint32_t(b >> 32));
temp = uint64_t(uint32_t(src1 >> 0)) * uint64_t(uint32_t(src2 >> 32));
lo += temp << 32;
hi += (temp >> 32) + (lo < prevlo);
@ -291,9 +288,9 @@ int dmulu(uint64_t &dstlo, uint64_t &dsthi, uint64_t src1, uint64_t src2, bool f
dstlo = lo;
if (halfmul_flags)
return ((lo >> 60) & FLAG_S) | ((hi != 0) << 1) | ((dstlo == 0) << 2);
return ((hi >> 60) & FLAG_S) | ((hi != 0) << 1) | ((dsthi == 0 && dstlo == 0) << 2);
return ((lo >> 60) & FLAG_S) | (hi ? FLAG_V : 0) | (!lo ? FLAG_Z : 0);
else
return ((hi >> 60) & FLAG_S) | (hi ? FLAG_V : 0) | ((!hi && !lo) ? FLAG_Z : 0);
}
@ -313,15 +310,16 @@ int dmuls(uint64_t &dstlo, uint64_t &dsthi, int64_t src1, int64_t src2, bool fla
return 0;
}
// fetch absolute source values
a = src1; if (int64_t(a) < 0) a = -a;
b = src2; if (int64_t(b) < 0) b = -b;
if (a == 0 || b == 0)
if (!src1 || !src2)
{
dsthi = dstlo = 0;
return FLAG_Z;
}
// fetch absolute source values
a = src1; if (int64_t(a) < 0) a = -a;
b = src2; if (int64_t(b) < 0) b = -b;
// compute high and low parts first
lo = uint64_t(uint32_t(a >> 0)) * uint64_t(uint32_t(b >> 0));
hi = uint64_t(uint32_t(a >> 32)) * uint64_t(uint32_t(b >> 32));
@ -349,9 +347,9 @@ int dmuls(uint64_t &dstlo, uint64_t &dsthi, int64_t src1, int64_t src2, bool fla
dstlo = lo;
if (halfmul_flags)
return ((lo >> 60) & FLAG_S) | ((hi != (int64_t(lo) >> 63)) << 1) | ((dstlo == 0) << 2);
return ((hi >> 60) & FLAG_S) | ((hi != (int64_t(lo) >> 63)) << 1) | ((dsthi == 0 && dstlo == 0) << 2);
return ((lo >> 60) & FLAG_S) | ((hi != (int64_t(lo) >> 63)) ? FLAG_V : 0) | (!lo ? FLAG_Z : 0);
else
return ((hi >> 60) & FLAG_S) | ((hi != (int64_t(lo) >> 63)) ? FLAG_V : 0) | ((!hi && !lo) ? FLAG_Z : 0);
}
@ -5057,7 +5055,7 @@ void drcbe_x86::op_mulu(Assembler &a, const instruction &inst)
be_parameter src1p(*this, inst.param(2), PTYPE_MRI);
be_parameter src2p(*this, inst.param(3), PTYPE_MRI);
normalize_commutative(src1p, src2p);
bool compute_hi = (dstp != edstp);
const bool compute_hi = (dstp != edstp);
// 32-bit form
if (inst.size() == 4)
@ -5102,7 +5100,7 @@ void drcbe_x86::op_mulu(Assembler &a, const instruction &inst)
{
// general case
a.mov(dword_ptr(esp, 28), 0); // mov [esp+28],0 (calculate flags as 64x64=128)
a.mov(dword_ptr(esp, 24), inst.flags()); // mov [esp+24],flags
a.mov(dword_ptr(esp, 24), inst.flags() ? 1 : 0); // mov [esp+24],flags
emit_mov_m64_p64(a, qword_ptr(esp, 16), src2p); // mov [esp+16],src2p
emit_mov_m64_p64(a, qword_ptr(esp, 8), src1p); // mov [esp+8],src1p
if (!compute_hi)
@ -5178,7 +5176,7 @@ void drcbe_x86::op_mululw(Assembler &a, const instruction &inst)
{
// general case
a.mov(dword_ptr(esp, 28), 1); // mov [esp+28],1 (calculate flags as 64x64=64)
a.mov(dword_ptr(esp, 24), inst.flags()); // mov [esp+24],flags
a.mov(dword_ptr(esp, 24), inst.flags() ? 1 : 0); // mov [esp+24],flags
emit_mov_m64_p64(a, qword_ptr(esp, 16), src2p); // mov [esp+16],src2p
emit_mov_m64_p64(a, qword_ptr(esp, 8), src1p); // mov [esp+8],src1p
a.mov(dword_ptr(esp, 4), imm(&m_reslo)); // mov [esp+4],&reslo
@ -5213,7 +5211,7 @@ void drcbe_x86::op_muls(Assembler &a, const instruction &inst)
be_parameter src1p(*this, inst.param(2), PTYPE_MRI);
be_parameter src2p(*this, inst.param(3), PTYPE_MRI);
normalize_commutative(src1p, src2p);
bool compute_hi = (dstp != edstp);
const bool compute_hi = (dstp != edstp);
// 32-bit form
if (inst.size() == 4)
@ -5257,7 +5255,7 @@ void drcbe_x86::op_muls(Assembler &a, const instruction &inst)
{
// general case
a.mov(dword_ptr(esp, 28), 0); // mov [esp+28],0 (calculate flags as 64x64=128)
a.mov(dword_ptr(esp, 24), inst.flags()); // mov [esp+24],flags
a.mov(dword_ptr(esp, 24), inst.flags() ? 1 : 0); // mov [esp+24],flags
emit_mov_m64_p64(a, qword_ptr(esp, 16), src2p); // mov [esp+16],src2p
emit_mov_m64_p64(a, qword_ptr(esp, 8), src1p); // mov [esp+8],src1p
if (!compute_hi)
@ -5334,7 +5332,7 @@ void drcbe_x86::op_mulslw(Assembler &a, const instruction &inst)
{
// general case
a.mov(dword_ptr(esp, 28), 1); // mov [esp+28],1 (calculate flags as 64x64=64)
a.mov(dword_ptr(esp, 24), inst.flags()); // mov [esp+24],flags
a.mov(dword_ptr(esp, 24), inst.flags() ? 1 : 0); // mov [esp+24],flags
emit_mov_m64_p64(a, qword_ptr(esp, 16), src2p); // mov [esp+16],src2p
emit_mov_m64_p64(a, qword_ptr(esp, 8), src1p); // mov [esp+8],src1p
a.mov(dword_ptr(esp, 4), imm(&m_reslo)); // mov [esp+4],&reslo