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shader_jit: Fix/optimize conditional evaluation (#234)

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* shader_jit: Add conditional unit-tests

Tests all permutations of X, Y, AND, OR with each possible input value.

* video_core: Fix shader-interpreter conditional-code initialization

Rather than reserving the incoming state of the conditional codes, the
shader-interpreter was setting them both to false. In pretty much all
cases, the initial state of a shaderunit can be zero-initialized
statically. Just running the interpreter shouldn't necessarily reset the
conditional codes though.  The JIT loads incoming conditional codes
while the shader-interpreter resets them to false. This makes the
interpreter match the behavior of the shader-jit.

* shader_jit_a64: Fix/optimize conditional evaluation

Fix some of the regressions introduced by the previous optimization.
EOR does not support a constant of `0` in its immediate. In these cases
the COND{0,1} registers can be utilized immediately.

* shader_jit_x64: Fix conditional evaluation extended-bit hazard

The unit test seems to have identified a bug in the x64 jit too. The x64
jit was doing 32-bit comparisons despite the condition flags being 8-bit
values and is sensitive to garbage being in the upper 24 bits of the
register. This is fixed by using the proper 8-bit register types rather
than the 32-bit ones(`eax,`ebx` -> `al`, `bl`).

* shader_jit_x64: Zero-extend conditional-code bytes

`mov` was doing a partial update of bits within the register, allowing
garbage to be introduced in the upper bits of the register.
This commit is contained in:
Wunk 2024-08-20 01:19:04 -07:00 • committed by GitHub
parent f248fefe06
commit 52f06f757f
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6 changed files with 144 additions and 40 deletions
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88
src/tests/video_core/shader.cpp
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@ -674,6 +674,94 @@ TEMPLATE_TEST_CASE("Nested Loop", "[video_core][shader]", ShaderJitTest) {
}
}
SHADER_TEST_CASE("Conditional", "[video_core][shader]") {
const auto sh_input = SourceRegister::MakeInput(0);
const auto sh_temp = SourceRegister::MakeTemporary(0);
const auto sh_output = DestRegister::MakeOutput(0);
const std::initializer_list<nihstro::InlineAsm> assembly_template = {
// IFC configured later
{OpCode::Id::NOP},
// True
{OpCode::Id::MOV, sh_output, sh_input},
{OpCode::Id::END},
// False
{OpCode::Id::MOV, sh_output, sh_temp},
{OpCode::Id::END},
};
const bool ref_x = GENERATE(0, 1);
const bool cmp_x = GENERATE(0, 1);
const bool result_x = (cmp_x == ref_x);
const bool ref_y = GENERATE(0, 1);
const bool cmp_y = GENERATE(0, 1);
const bool result_y = (cmp_y == ref_y);
nihstro::Instruction IFC = {};
IFC.opcode = nihstro::OpCode::Id::IFC;
IFC.flow_control.num_instructions = 2;
IFC.flow_control.dest_offset = 3;
IFC.flow_control.refx = ref_x;
IFC.flow_control.refy = ref_y;
Pica::ShaderUnit shader_unit;
shader_unit.conditional_code[0] = cmp_x;
shader_unit.conditional_code[1] = cmp_y;
// JustX
{
auto shader_setup = CompileShaderSetup(assembly_template);
IFC.flow_control.op = nihstro::Instruction::FlowControlType::Op::JustX;
shader_setup->program_code[0] = IFC.hex;
const float result = result_x ? 1.0f : 0.0f;
auto shader_test = TestType(std::move(shader_setup));
shader_test.Run(shader_unit, 1.0f);
REQUIRE(shader_unit.output[0].x.ToFloat32() == result);
}
// JustY
{
auto shader_setup = CompileShaderSetup(assembly_template);
IFC.flow_control.op = nihstro::Instruction::FlowControlType::Op::JustY;
shader_setup->program_code[0] = IFC.hex;
const float result = result_y ? 1.0f : 0.0f;
auto shader_test = TestType(std::move(shader_setup));
shader_test.Run(shader_unit, 1.0f);
REQUIRE(shader_unit.output[0].x.ToFloat32() == result);
}
// OR
{
auto shader_setup = CompileShaderSetup(assembly_template);
IFC.flow_control.op = nihstro::Instruction::FlowControlType::Op::Or;
shader_setup->program_code[0] = IFC.hex;
const float result = (result_x || result_y) ? 1.0f : 0.0f;
auto shader_test = TestType(std::move(shader_setup));
shader_test.Run(shader_unit, 1.0f);
REQUIRE(shader_unit.output[0].x.ToFloat32() == result);
}
// AND
{
auto shader_setup = CompileShaderSetup(assembly_template);
IFC.flow_control.op = nihstro::Instruction::FlowControlType::Op::And;
shader_setup->program_code[0] = IFC.hex;
const float result = (result_x && result_y) ? 1.0f : 0.0f;
auto shader_test = TestType(std::move(shader_setup));
shader_test.Run(shader_unit, 1.0f);
REQUIRE(shader_unit.output[0].x.ToFloat32() == result);
}
}
SHADER_TEST_CASE("Source Swizzle", "[video_core][shader]") {
const auto sh_input = SourceRegister::MakeInput(0);
const auto sh_output = DestRegister::MakeOutput(0);