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Fix CNTLZ (I think) 

SAR alt. instruction
This commit is contained in:
Dr. Chat 2015-05-05 08:23:24 -05:00
parent 649eb1cf8e
commit 0e836f2eec
1 changed files with 56 additions and 45 deletions
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89
src/xenia/cpu/backend/x64/x64_sequences.cc
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@ -4612,6 +4612,7 @@ void EmitSarXX(X64Emitter& e, const ARGS& i) {
SEQ::EmitAssociativeBinaryOp(
e, i,
[](X64Emitter& e, const REG& dest_src, const Reg8& src) {
if (e.cpu()->has(Xbyak::util::Cpu::tBMI2)) {
if (dest_src.getBit() == 64) {
e.sarx(dest_src.cvt64(), dest_src.cvt64(), src.cvt64());
} else if (dest_src.getBit() == 32) {
@ -4620,6 +4621,15 @@ void EmitSarXX(X64Emitter& e, const ARGS& i) {
e.movsx(dest_src.cvt32(), dest_src);
e.sarx(dest_src.cvt32(), dest_src.cvt32(), src.cvt32());
}
} else {
// back up ecx...
e.mov(e.al, e.cl);
e.mov(e.cl, src);
e.sar(dest_src, e.cl);
e.mov(e.cl, e.al);
}
}, [](X64Emitter& e, const REG& dest_src, int8_t constant) {
e.sar(dest_src, constant);
});
@ -5200,6 +5210,7 @@ EMITTER_OPCODE_TABLE(
// ============================================================================
// OPCODE_CNTLZ
// Count leading zeroes
// ============================================================================
EMITTER(CNTLZ_I8, MATCH(I<OPCODE_CNTLZ, I8<>, I8<>>)) {
static void Emit(X64Emitter& e, const EmitArgType& i) {
@ -5211,21 +5222,21 @@ EMITTER(CNTLZ_I8, MATCH(I<OPCODE_CNTLZ, I8<>, I8<>>)) {
} else {
e.inLocalLabel();
e.cmp(i.src1, 0); // Special case if number is 0
e.jne(".la"); // not 0, use bsr
e.mov(i.src1, 8); // If it's 0, the result should be 8
e.jmp(".lb");
// BSR: searches $2 until MSB 1 found, stores idx (from bit 0) in $1
// if input is 0, results are undefined
e.L(".la");
e.bsr(e.ebx, i.src1);
// if input is 0, results are undefined (and ZF is set)
e.bsr(i.dest, i.src1);
e.jz(".la"); // Jump if zero
// sub: $1 = $1 - $2
// sub 7 from e.eax
e.mov(e.eax, 7);
e.sub(e.eax, e.ebx);
e.sub(e.eax, i.dest);
e.mov(i.dest, e.eax);
e.jmp(".lb"); // Jmp to end
// src1 was zero, so write 8 to the dest reg
e.L(".la");
e.mov(i.dest, 8);
e.L(".lb");
e.outLocalLabel();
@ -5240,21 +5251,21 @@ EMITTER(CNTLZ_I16, MATCH(I<OPCODE_CNTLZ, I8<>, I16<>>)) {
} else {
e.inLocalLabel();
e.cmp(i.src1, 0); // Special case if number is 0
e.jne(".la"); // not 0, use bsr
e.mov(i.src1, 16); // If it's 0, the result should be 16
e.jmp(".lb");
// BSR: searches $2 until MSB 1 found, stores idx (from bit 0) in $1
// if input is 0, results are undefined
e.L(".la");
e.bsr(e.ebx, i.src1);
// if input is 0, results are undefined (and ZF is set)
e.bsr(i.dest, i.src1);
e.jz(".la"); // Jump if zero
// sub: $1 = $1 - $2
// sub 16 from e.eax
// sub 15 from e.eax
e.mov(e.eax, 15);
e.sub(e.eax, e.ebx);
e.sub(e.eax, i.dest);
e.mov(i.dest, e.eax);
e.jmp(".lb"); // Jmp to end
// src1 was zero, so write 16 to the dest reg
e.L(".la");
e.mov(i.dest, 16);
e.L(".lb");
e.outLocalLabel();
@ -5268,21 +5279,21 @@ EMITTER(CNTLZ_I32, MATCH(I<OPCODE_CNTLZ, I8<>, I32<>>)) {
} else {
e.inLocalLabel();
e.cmp(i.src1, 0); // Special case if number is 0
e.jne(".la"); // not 0, use bsr
e.mov(i.src1, 32); // If it's 0, the result should be 32
e.jmp(".lb");
// BSR: searches $2 until MSB 1 found, stores idx (from bit 0) in $1
// if input is 0, results are undefined
e.L(".la");
e.bsr(e.ebx, i.src1);
// if input is 0, results are undefined (and ZF is set)
e.bsr(i.dest, i.src1);
e.jz(".la"); // Jump if zero
// sub: $1 = $1 - $2
// sub 32 from e.eax
// sub 31 from e.eax
e.mov(e.eax, 31);
e.sub(e.eax, e.ebx);
e.sub(e.eax, i.dest);
e.mov(i.dest, e.eax);
e.jmp(".lb"); // Jmp to end
// src1 was zero, so write 32 to the dest reg
e.L(".la");
e.mov(i.dest, 32);
e.L(".lb");
e.outLocalLabel();
@ -5296,21 +5307,21 @@ EMITTER(CNTLZ_I64, MATCH(I<OPCODE_CNTLZ, I8<>, I64<>>)) {
} else {
e.inLocalLabel();
e.cmp(i.src1, 0); // Special case if number is 0
e.jne(".la"); // not 0, use bsr
e.mov(i.src1, 64); // If it's 0, the result should be 64
e.jmp(".lb");
// BSR: searches $2 until MSB 1 found, stores idx (from bit 0) in $1
// if input is 0, results are undefined
e.L(".la");
e.bsr(e.rbx, i.src1);
// if input is 0, results are undefined (and ZF is set)
e.bsr(i.dest, i.src1);
e.jz(".la"); // Jump if zero
// sub: $1 = $1 - $2
// sub 64 from e.rax
// sub 63 from e.rax
e.mov(e.rax, 63);
e.sub(e.rax, e.ebx);
e.sub(e.rax, i.dest);
e.mov(i.dest, e.rax);
e.jmp(".lb"); // Jmp to end
// src1 was zero, so write 64 to the dest reg
e.L(".la");
e.mov(i.dest, 64);
e.L(".lb");
e.outLocalLabel();