shader: FMUL switch to using LUT (#3441)

* shader: add FmulPostFactor LUT table

* shader: FMUL apply LUT

* Update src/video_core/engines/shader_bytecode.h

Co-Authored-By: Mat M. <mathew1800@gmail.com>

* nit: mistype

* clang-format & add missing import

* shader: remove post factor LUT.

* shader: move post factor LUT to function and fix incorrect order.

* clang-format

* shader: FMUL: add static to post factor LUT

* nit: typo

Co-authored-by: Mat M. <mathew1800@gmail.com>
This commit is contained in:
Nguyen Dac Nam 2020-02-27 23:14:25 +07:00 committed by GitHub
parent 1f57f679a4
commit db2f547434
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1 changed files with 14 additions and 19 deletions

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@ -53,28 +53,23 @@ u32 ShaderIR::DecodeArithmetic(NodeBlock& bb, u32 pc) {
op_b = GetOperandAbsNegFloat(op_b, false, instr.fmul.negate_b);
// TODO(Rodrigo): Should precise be used when there's a postfactor?
Node value = Operation(OperationCode::FMul, PRECISE, op_a, op_b);
static constexpr std::array FmulPostFactor = {
1.000f, // None
0.500f, // Divide 2
0.250f, // Divide 4
0.125f, // Divide 8
8.000f, // Mul 8
4.000f, // Mul 4
2.000f, // Mul 2
};
if (instr.fmul.postfactor != 0) {
auto postfactor = static_cast<s32>(instr.fmul.postfactor);
// Postfactor encoded as 3-bit 1's complement in instruction, interpreted with below
// logic.
if (postfactor >= 4) {
postfactor = 7 - postfactor;
} else {
postfactor = 0 - postfactor;
op_a = Operation(OperationCode::FMul, NO_PRECISE, op_a,
Immediate(FmulPostFactor[instr.fmul.postfactor]));
}
if (postfactor > 0) {
value = Operation(OperationCode::FMul, NO_PRECISE, value,
Immediate(static_cast<f32>(1 << postfactor)));
} else {
value = Operation(OperationCode::FDiv, NO_PRECISE, value,
Immediate(static_cast<f32>(1 << -postfactor)));
}
}
// TODO(Rodrigo): Should precise be used when there's a postfactor?
Node value = Operation(OperationCode::FMul, PRECISE, op_a, op_b);
value = GetSaturatedFloat(value, instr.alu.saturate_d);