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emit_arm64_saturation: Implement SignedSaturation

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Merry 2022-07-30 12:19:29 +01:00 committed by merry
parent e73c390927
commit ee2bc92993
1 changed files with 37 additions and 4 deletions
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41
src/dynarmic/backend/arm64/emit_arm64_saturation.cpp
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@ -100,10 +100,43 @@ void EmitIR<IR::Opcode::SignedSaturatedSub64>(oaknut::CodeGenerator& code, EmitC
template<>
void EmitIR<IR::Opcode::SignedSaturation>(oaknut::CodeGenerator& code, EmitContext& ctx, IR::Inst* inst) {
(void)code;
(void)ctx;
(void)inst;
ASSERT_FALSE("Unimplemented");
const auto overflow_inst = inst->GetAssociatedPseudoOperation(IR::Opcode::GetOverflowFromOp);
auto args = ctx.reg_alloc.GetArgumentInfo(inst);
const size_t N = args[1].GetImmediateU8();
ASSERT(N >= 1 && N <= 32);
if (N == 32) {
ctx.reg_alloc.DefineAsExisting(inst, args[0]);
if (overflow_inst) {
auto Woverflow = ctx.reg_alloc.WriteW(overflow_inst);
RegAlloc::Realize(Woverflow);
code.MOV(*Woverflow, WZR);
}
return;
}
const u32 positive_saturated_value = (1u << (N - 1)) - 1;
const u32 negative_saturated_value = ~u32{0} << (N - 1);
auto Woperand = ctx.reg_alloc.ReadW(args[0]);
auto Wresult = ctx.reg_alloc.WriteW(inst);
RegAlloc::Realize(Woperand, Wresult);
ctx.reg_alloc.SpillFlags();
code.MOV(Wscratch0, negative_saturated_value);
code.MOV(Wscratch1, positive_saturated_value);
code.CMP(*Woperand, Wscratch0);
code.CSEL(Wresult, Woperand, Wscratch0, GT);
code.CMP(*Woperand, Wscratch1);
code.CSEL(Wresult, Wresult, Wscratch1, LT);
if (overflow_inst) {
auto Woverflow = ctx.reg_alloc.WriteW(overflow_inst);
RegAlloc::Realize(Woverflow);
code.CMP(*Wresult, Woperand);
code.CSET(Woverflow, NE);
}
}
template<>