Merge pull request #1101 from Subv/ssy_stack

Shaders: Implemented a stack for the SSY/SYNC instructions.
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bunnei 2018-08-19 13:58:45 -04:00 committed by GitHub
commit 85da529f15
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@ -842,6 +842,33 @@ private:
shader.AddLine('}');
}
/*
* Emits code to push the input target address to the SSY address stack, incrementing the stack
* top.
*/
void EmitPushToSSYStack(u32 target) {
shader.AddLine('{');
++shader.scope;
shader.AddLine("ssy_stack[ssy_stack_top] = " + std::to_string(target) + "u;");
shader.AddLine("ssy_stack_top++;");
--shader.scope;
shader.AddLine('}');
}
/*
* Emits code to pop an address from the SSY address stack, setting the jump address to the
* popped address and decrementing the stack top.
*/
void EmitPopFromSSYStack() {
shader.AddLine('{');
++shader.scope;
shader.AddLine("ssy_stack_top--;");
shader.AddLine("jmp_to = ssy_stack[ssy_stack_top];");
shader.AddLine("break;");
--shader.scope;
shader.AddLine('}');
}
/**
* Compiles a single instruction from Tegra to GLSL.
* @param offset the offset of the Tegra shader instruction.
@ -1870,13 +1897,13 @@ private:
ASSERT_MSG(instr.bra.constant_buffer == 0, "Constant buffer SSY is not supported");
u32 target = offset + instr.bra.GetBranchTarget();
shader.AddLine("ssy_target = " + std::to_string(target) + "u;");
EmitPushToSSYStack(target);
break;
}
case OpCode::Id::SYNC: {
// The SYNC opcode jumps to the address previously set by the SSY opcode
ASSERT(instr.flow.cond == Tegra::Shader::FlowCondition::Always);
shader.AddLine("{ jmp_to = ssy_target; break; }");
EmitPopFromSSYStack();
break;
}
case OpCode::Id::DEPBAR: {
@ -1947,7 +1974,13 @@ private:
} else {
labels.insert(subroutine.begin);
shader.AddLine("uint jmp_to = " + std::to_string(subroutine.begin) + "u;");
shader.AddLine("uint ssy_target = 0u;");
// TODO(Subv): Figure out the actual depth of the SSY stack, for now it seems
// unlikely that shaders will use 20 nested SSYs.
constexpr u32 SSY_STACK_SIZE = 20;
shader.AddLine("uint ssy_stack[" + std::to_string(SSY_STACK_SIZE) + "];");
shader.AddLine("uint ssy_stack_top = 0u;");
shader.AddLine("while (true) {");
++shader.scope;