emit_x64_saturation: Use const on locals where applicable

Normalizes the use of const in the source file.
This commit is contained in:
Lioncash 2019-05-02 19:06:10 -04:00 committed by MerryMage
parent 7316fa47b3
commit cccbc7fd0e

View file

@ -214,27 +214,27 @@ void EmitX64::EmitSignedSaturation(EmitContext& ctx, IR::Inst* inst) {
auto overflow_inst = inst->GetAssociatedPseudoOperation(IR::Opcode::GetOverflowFromOp); auto overflow_inst = inst->GetAssociatedPseudoOperation(IR::Opcode::GetOverflowFromOp);
auto args = ctx.reg_alloc.GetArgumentInfo(inst); auto args = ctx.reg_alloc.GetArgumentInfo(inst);
size_t N = args[1].GetImmediateU8(); const size_t N = args[1].GetImmediateU8();
ASSERT(N >= 1 && N <= 32); ASSERT(N >= 1 && N <= 32);
if (N == 32) { if (N == 32) {
if (overflow_inst) { if (overflow_inst) {
auto no_overflow = IR::Value(false); const auto no_overflow = IR::Value(false);
overflow_inst->ReplaceUsesWith(no_overflow); overflow_inst->ReplaceUsesWith(no_overflow);
} }
ctx.reg_alloc.DefineValue(inst, args[0]); ctx.reg_alloc.DefineValue(inst, args[0]);
return; return;
} }
u32 mask = (1u << N) - 1; const u32 mask = (1u << N) - 1;
u32 positive_saturated_value = (1u << (N - 1)) - 1; const u32 positive_saturated_value = (1u << (N - 1)) - 1;
u32 negative_saturated_value = 1u << (N - 1); const u32 negative_saturated_value = 1u << (N - 1);
u32 sext_negative_satured_value = Common::SignExtend(N, negative_saturated_value); const u32 sext_negative_satured_value = Common::SignExtend(N, negative_saturated_value);
Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32(); const Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32();
Xbyak::Reg32 reg_a = ctx.reg_alloc.UseGpr(args[0]).cvt32(); const Xbyak::Reg32 reg_a = ctx.reg_alloc.UseGpr(args[0]).cvt32();
Xbyak::Reg32 overflow = ctx.reg_alloc.ScratchGpr().cvt32(); const Xbyak::Reg32 overflow = ctx.reg_alloc.ScratchGpr().cvt32();
Xbyak::Reg32 tmp = ctx.reg_alloc.ScratchGpr().cvt32(); const Xbyak::Reg32 tmp = ctx.reg_alloc.ScratchGpr().cvt32();
// overflow now contains a value between 0 and mask if it was originally between {negative,positive}_saturated_value. // overflow now contains a value between 0 and mask if it was originally between {negative,positive}_saturated_value.
code.lea(overflow, code.ptr[reg_a.cvt64() + negative_saturated_value]); code.lea(overflow, code.ptr[reg_a.cvt64() + negative_saturated_value]);
@ -295,14 +295,14 @@ void EmitX64::EmitUnsignedSaturation(EmitContext& ctx, IR::Inst* inst) {
auto overflow_inst = inst->GetAssociatedPseudoOperation(IR::Opcode::GetOverflowFromOp); auto overflow_inst = inst->GetAssociatedPseudoOperation(IR::Opcode::GetOverflowFromOp);
auto args = ctx.reg_alloc.GetArgumentInfo(inst); auto args = ctx.reg_alloc.GetArgumentInfo(inst);
size_t N = args[1].GetImmediateU8(); const size_t N = args[1].GetImmediateU8();
ASSERT(N <= 31); ASSERT(N <= 31);
u32 saturated_value = (1u << N) - 1; const u32 saturated_value = (1u << N) - 1;
Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32(); const Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32();
Xbyak::Reg32 reg_a = ctx.reg_alloc.UseGpr(args[0]).cvt32(); const Xbyak::Reg32 reg_a = ctx.reg_alloc.UseGpr(args[0]).cvt32();
Xbyak::Reg32 overflow = ctx.reg_alloc.ScratchGpr().cvt32(); const Xbyak::Reg32 overflow = ctx.reg_alloc.ScratchGpr().cvt32();
// Pseudocode: result = clamp(reg_a, 0, saturated_value); // Pseudocode: result = clamp(reg_a, 0, saturated_value);
code.xor_(overflow, overflow); code.xor_(overflow, overflow);