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authorbunnei <bunneidev@gmail.com>2018-04-21 04:29:39 +0200
committerGitHub <noreply@github.com>2018-04-21 04:29:39 +0200
commit8ac3a3f45e2102da5cc3b56e4be9b5e766f72358 (patch)
treec74be88544f6465fe3afad898654dced8d51f006
parentMerge pull request #374 from lioncash/noexcept (diff)
parentShaderGen: Implemented the KIL instruction, which is equivalent to 'discard'. (diff)
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-rw-r--r--src/video_core/engines/shader_bytecode.h52
-rw-r--r--src/video_core/renderer_opengl/gl_shader_decompiler.cpp131
2 files changed, 179 insertions, 4 deletions
diff --git a/src/video_core/engines/shader_bytecode.h b/src/video_core/engines/shader_bytecode.h
index 7cd125f05..e6c2fd367 100644
--- a/src/video_core/engines/shader_bytecode.h
+++ b/src/video_core/engines/shader_bytecode.h
@@ -13,6 +13,9 @@ namespace Tegra {
namespace Shader {
struct Register {
+ // Register 255 is special cased to always be 0
+ static constexpr size_t ZeroIndex = 255;
+
constexpr Register() = default;
constexpr Register(u64 value) : value(value) {}
@@ -106,6 +109,8 @@ union OpCode {
FSETP_R = 0x5BB,
FSETP_C = 0x4BB,
+ FSETP_IMM = 0x36B,
+ FSETP_NEG_IMM = 0x37B,
EXIT = 0xE30,
KIL = 0xE33,
@@ -121,6 +126,7 @@ union OpCode {
Ffma,
Flow,
Memory,
+ FloatPredicate,
Unknown,
};
@@ -161,6 +167,9 @@ union OpCode {
case Id::FSETP_C:
case Id::KIL:
return op4;
+ case Id::FSETP_IMM:
+ case Id::FSETP_NEG_IMM:
+ return Id::FSETP_IMM;
}
switch (op5) {
@@ -238,8 +247,9 @@ union OpCode {
info_table[Id::FMUL_C] = {Type::Arithmetic, "fmul_c"};
info_table[Id::FMUL_IMM] = {Type::Arithmetic, "fmul_imm"};
info_table[Id::FMUL32_IMM] = {Type::Arithmetic, "fmul32_imm"};
- info_table[Id::FSETP_C] = {Type::Arithmetic, "fsetp_c"};
- info_table[Id::FSETP_R] = {Type::Arithmetic, "fsetp_r"};
+ info_table[Id::FSETP_C] = {Type::FloatPredicate, "fsetp_c"};
+ info_table[Id::FSETP_R] = {Type::FloatPredicate, "fsetp_r"};
+ info_table[Id::FSETP_IMM] = {Type::FloatPredicate, "fsetp_imm"};
info_table[Id::EXIT] = {Type::Trivial, "exit"};
info_table[Id::IPA] = {Type::Trivial, "ipa"};
info_table[Id::KIL] = {Type::Flow, "kil"};
@@ -283,7 +293,23 @@ namespace Shader {
enum class Pred : u64 {
UnusedIndex = 0x7,
- NeverExecute = 0xf,
+ NeverExecute = 0xF,
+};
+
+enum class PredCondition : u64 {
+ LessThan = 1,
+ Equal = 2,
+ LessEqual = 3,
+ GreaterThan = 4,
+ NotEqual = 5,
+ GreaterEqual = 6,
+ // TODO(Subv): Other condition types
+};
+
+enum class PredOperation : u64 {
+ And = 0,
+ Or = 1,
+ Xor = 2,
};
enum class SubOp : u64 {
@@ -305,7 +331,11 @@ union Instruction {
OpCode opcode;
BitField<0, 8, Register> gpr0;
BitField<8, 8, Register> gpr8;
- BitField<16, 4, Pred> pred;
+ union {
+ BitField<16, 4, Pred> full_pred;
+ BitField<16, 3, u64> pred_index;
+ } pred;
+ BitField<19, 1, u64> negate_pred;
BitField<20, 8, Register> gpr20;
BitField<20, 7, SubOp> sub_op;
BitField<28, 8, Register> gpr28;
@@ -343,6 +373,20 @@ union Instruction {
BitField<49, 1, u64> negate_c;
} ffma;
+ union {
+ BitField<0, 3, u64> pred0;
+ BitField<3, 3, u64> pred3;
+ BitField<7, 1, u64> abs_a;
+ BitField<39, 3, u64> pred39;
+ BitField<42, 1, u64> neg_pred;
+ BitField<43, 1, u64> neg_a;
+ BitField<44, 1, u64> abs_b;
+ BitField<45, 2, PredOperation> op;
+ BitField<47, 1, u64> ftz;
+ BitField<48, 4, PredCondition> cond;
+ BitField<56, 1, u64> neg_b;
+ } fsetp;
+
BitField<61, 1, u64> is_b_imm;
BitField<60, 1, u64> is_b_gpr;
BitField<59, 1, u64> is_c_gpr;
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index de137558d..2395945c3 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -220,6 +220,8 @@ private:
/// Generates code representing a temporary (GPR) register.
std::string GetRegister(const Register& reg, unsigned elem = 0) {
+ if (reg == Register::ZeroIndex)
+ return "0";
if (stage == Maxwell3D::Regs::ShaderStage::Fragment && reg < 4) {
// GPRs 0-3 are output color for the fragment shader
return std::string{"color."} + "rgba"[(reg + elem) & 3];
@@ -276,6 +278,52 @@ private:
shader.AddLine(dest + " = " + src + ";");
}
+ /*
+ * Writes code that assigns a predicate boolean variable.
+ * @param pred The id of the predicate to write to.
+ * @param value The expression value to assign to the predicate.
+ */
+ void SetPredicate(u64 pred, const std::string& value) {
+ using Tegra::Shader::Pred;
+ // Can't assign to the constant predicate.
+ ASSERT(pred != static_cast<u64>(Pred::UnusedIndex));
+
+ std::string variable = 'p' + std::to_string(pred);
+ shader.AddLine(variable + " = " + value + ';');
+ declr_predicates.insert(std::move(variable));
+ }
+
+ /*
+ * Returns the condition to use in the 'if' for a predicated instruction.
+ * @param instr Instruction to generate the if condition for.
+ * @returns string containing the predicate condition.
+ */
+ std::string GetPredicateCondition(Instruction instr) const {
+ using Tegra::Shader::Pred;
+ ASSERT(instr.pred.pred_index != static_cast<u64>(Pred::UnusedIndex));
+
+ std::string variable =
+ 'p' + std::to_string(static_cast<u64>(instr.pred.pred_index.Value()));
+
+ if (instr.negate_pred) {
+ return "!(" + variable + ')';
+ }
+
+ return variable;
+ }
+
+ /*
+ * Returns whether the instruction at the specified offset is a 'sched' instruction.
+ * Sched instructions always appear before a sequence of 3 instructions.
+ */
+ bool IsSchedInstruction(u32 offset) const {
+ // sched instructions appear once every 4 instructions.
+ static constexpr size_t SchedPeriod = 4;
+ u32 absolute_offset = offset - main_offset;
+
+ return (absolute_offset % SchedPeriod) == 0;
+ }
+
/**
* Compiles a single instruction from Tegra to GLSL.
* @param offset the offset of the Tegra shader instruction.
@@ -283,10 +331,24 @@ private:
* + 1. If the current instruction always terminates the program, returns PROGRAM_END.
*/
u32 CompileInstr(u32 offset) {
+ // Ignore sched instructions when generating code.
+ if (IsSchedInstruction(offset))
+ return offset + 1;
+
const Instruction instr = {program_code[offset]};
shader.AddLine("// " + std::to_string(offset) + ": " + OpCode::GetInfo(instr.opcode).name);
+ using Tegra::Shader::Pred;
+ ASSERT_MSG(instr.pred.full_pred != Pred::NeverExecute,
+ "NeverExecute predicate not implemented");
+
+ if (instr.pred.pred_index != static_cast<u64>(Pred::UnusedIndex)) {
+ shader.AddLine("if (" + GetPredicateCondition(instr) + ')');
+ shader.AddLine('{');
+ ++shader.scope;
+ }
+
switch (OpCode::GetInfo(instr.opcode).type) {
case OpCode::Type::Arithmetic: {
std::string dest = GetRegister(instr.gpr0);
@@ -450,14 +512,70 @@ private:
}
break;
}
+ case OpCode::Type::FloatPredicate: {
+ std::string op_a = instr.fsetp.neg_a ? "-" : "";
+ op_a += GetRegister(instr.gpr8);
+
+ if (instr.fsetp.abs_a) {
+ op_a = "abs(" + op_a + ')';
+ }
+
+ std::string op_b{};
+
+ if (instr.is_b_imm) {
+ if (instr.fsetp.neg_b) {
+ // Only the immediate version of fsetp has a neg_b bit.
+ op_b += '-';
+ }
+ op_b += '(' + GetImmediate19(instr) + ')';
+ } else {
+ if (instr.is_b_gpr) {
+ op_b += GetRegister(instr.gpr20);
+ } else {
+ op_b += GetUniform(instr.uniform);
+ }
+ }
+ if (instr.fsetp.abs_b) {
+ op_b = "abs(" + op_b + ')';
+ }
+
+ using Tegra::Shader::Pred;
+ ASSERT_MSG(instr.fsetp.pred0 == static_cast<u64>(Pred::UnusedIndex) &&
+ instr.fsetp.pred39 == static_cast<u64>(Pred::UnusedIndex),
+ "Compound predicates are not implemented");
+
+ // We can't use the constant predicate as destination.
+ ASSERT(instr.fsetp.pred3 != static_cast<u64>(Pred::UnusedIndex));
+
+ using Tegra::Shader::PredCondition;
+ switch (instr.fsetp.cond) {
+ case PredCondition::LessThan:
+ SetPredicate(instr.fsetp.pred3, '(' + op_a + ") < (" + op_b + ')');
+ break;
+ case PredCondition::Equal:
+ SetPredicate(instr.fsetp.pred3, '(' + op_a + ") == (" + op_b + ')');
+ break;
+ default:
+ NGLOG_CRITICAL(HW_GPU, "Unhandled predicate condition: {} (a: {}, b: {})",
+ static_cast<unsigned>(instr.fsetp.cond.Value()), op_a, op_b);
+ UNREACHABLE();
+ }
+ break;
+ }
default: {
switch (instr.opcode.EffectiveOpCode()) {
case OpCode::Id::EXIT: {
+ ASSERT_MSG(instr.pred.pred_index == static_cast<u64>(Pred::UnusedIndex),
+ "Predicated exits not implemented");
shader.AddLine("return true;");
offset = PROGRAM_END - 1;
break;
}
+ case OpCode::Id::KIL: {
+ shader.AddLine("discard;");
+ break;
+ }
case OpCode::Id::IPA: {
const auto& attribute = instr.attribute.fmt28;
std::string dest = GetRegister(instr.gpr0);
@@ -476,6 +594,12 @@ private:
}
}
+ // Close the predicate condition scope.
+ if (instr.pred.pred_index != static_cast<u64>(Pred::UnusedIndex)) {
+ --shader.scope;
+ shader.AddLine('}');
+ }
+
return offset + 1;
}
@@ -605,6 +729,12 @@ private:
declarations.AddNewLine();
++const_buffer_layout;
}
+
+ declarations.AddNewLine();
+ for (const auto& pred : declr_predicates) {
+ declarations.AddLine("bool " + pred + " = false;");
+ }
+ declarations.AddNewLine();
}
private:
@@ -618,6 +748,7 @@ private:
// Declarations
std::set<std::string> declr_register;
+ std::set<std::string> declr_predicates;
std::set<Attribute::Index> declr_input_attribute;
std::set<Attribute::Index> declr_output_attribute;
std::array<ConstBufferEntry, Maxwell3D::Regs::MaxConstBuffers> declr_const_buffers;