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Shaders: Corrected the 'abs' and 'neg' bit usage in the float arithmetic instructions.

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We should definitely audit our shader generator for more errors like this.
This commit is contained in:
Subv 2018-08-16 09:05:16 -05:00
parent 24a759de4a
commit 2e95ba2e9c
2 changed files with 38 additions and 16 deletions
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4
src/video_core/engines/shader_bytecode.h
View File

@ -282,6 +282,10 @@ union Instruction {
}
} alu;
union {
BitField<48, 1, u64> negate_b;
} fmul;
union {
BitField<48, 1, u64> is_signed;
} shift;

50
src/video_core/renderer_opengl/gl_shader_decompiler.cpp
View File

@ -741,6 +741,30 @@ private:
return op->second;
}
/**
* Transforms the input string GLSL operand into one that applies the abs() function and negates
* the output if necessary. When both abs and neg are true, the negation will be applied after
* taking the absolute value.
* @param operand The input operand to take the abs() of, negate, or both.
* @param abs Whether to apply the abs() function to the input operand.
* @param neg Whether to negate the input operand.
* @returns String corresponding to the operand after being transformed by the abs() and
* negation operations.
*/
static std::string GetOperandAbsNeg(const std::string& operand, bool abs, bool neg) {
std::string result = operand;
if (abs) {
result = "abs(" + result + ')';
}
if (neg) {
result = "-(" + result + ')';
}
return result;
}
/*
* Returns whether the instruction at the specified offset is a 'sched' instruction.
* Sched instructions always appear before a sequence of 3 instructions.
@ -857,13 +881,6 @@ private:
switch (opcode->GetType()) {
case OpCode::Type::Arithmetic: {
std::string op_a = regs.GetRegisterAsFloat(instr.gpr8);
if (instr.alu.abs_a) {
op_a = "abs(" + op_a + ')';
}
if (instr.alu.negate_a) {
op_a = "-(" + op_a + ')';
}
std::string op_b;
@ -878,17 +895,10 @@ private:
}
}
if (instr.alu.abs_b) {
op_b = "abs(" + op_b + ')';
}
if (instr.alu.negate_b) {
op_b = "-(" + op_b + ')';
}
switch (opcode->GetId()) {
case OpCode::Id::MOV_C:
case OpCode::Id::MOV_R: {
// MOV does not have neither 'abs' nor 'neg' bits.
regs.SetRegisterToFloat(instr.gpr0, 0, op_b, 1, 1);
break;
}
@ -896,6 +906,8 @@ private:
case OpCode::Id::FMUL_C:
case OpCode::Id::FMUL_R:
case OpCode::Id::FMUL_IMM: {
// FMUL does not have 'abs' bits and only the second operand has a 'neg' bit.
op_b = GetOperandAbsNeg(op_b, false, instr.fmul.negate_b);
regs.SetRegisterToFloat(instr.gpr0, 0, op_a + " * " + op_b, 1, 1,
instr.alu.saturate_d);
break;
@ -903,11 +915,14 @@ private:
case OpCode::Id::FADD_C:
case OpCode::Id::FADD_R:
case OpCode::Id::FADD_IMM: {
op_a = GetOperandAbsNeg(op_a, instr.alu.abs_a, instr.alu.negate_a);
op_b = GetOperandAbsNeg(op_b, instr.alu.abs_b, instr.alu.negate_b);
regs.SetRegisterToFloat(instr.gpr0, 0, op_a + " + " + op_b, 1, 1,
instr.alu.saturate_d);
break;
}
case OpCode::Id::MUFU: {
op_a = GetOperandAbsNeg(op_a, instr.alu.abs_a, instr.alu.negate_a);
switch (instr.sub_op) {
case SubOp::Cos:
regs.SetRegisterToFloat(instr.gpr0, 0, "cos(" + op_a + ')', 1, 1,
@ -947,6 +962,9 @@ private:
case OpCode::Id::FMNMX_C:
case OpCode::Id::FMNMX_R:
case OpCode::Id::FMNMX_IMM: {
op_a = GetOperandAbsNeg(op_a, instr.alu.abs_a, instr.alu.negate_a);
op_b = GetOperandAbsNeg(op_b, instr.alu.abs_b, instr.alu.negate_b);
std::string condition =
GetPredicateCondition(instr.alu.fmnmx.pred, instr.alu.fmnmx.negate_pred != 0);
std::string parameters = op_a + ',' + op_b;
@ -960,7 +978,7 @@ private:
case OpCode::Id::RRO_R:
case OpCode::Id::RRO_IMM: {
// Currently RRO is only implemented as a register move.
// Usage of `abs_b` and `negate_b` here should also be correct.
op_b = GetOperandAbsNeg(op_b, instr.alu.abs_b, instr.alu.negate_b);
regs.SetRegisterToFloat(instr.gpr0, 0, op_b, 1, 1);
LOG_WARNING(HW_GPU, "RRO instruction is incomplete");
break;