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Loops in shaders (no TDRs! woo!).

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This commit is contained in:
Ben Vanik 2015-12-07 13:03:57 -08:00
parent 367ca09f1d
commit ed0b97813a
2 changed files with 66 additions and 7 deletions
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73
src/xenia/gpu/glsl_shader_translator.cc
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@ -291,8 +291,11 @@ void main() {
EmitSource(" bool p0 = false;\n");
// Address register when using absolute addressing.
EmitSource(" int a0 = 0;\n");
// TODO(benvanik): remove when loops are implemented.
EmitSource(" int aL = 0;\n"); // Hack!
// Loop index stack - .x is the active loop, shifted right to yzw on push.
EmitSource(" ivec4 aL = ivec4(0);\n");
// Loop counter stack, .x is the active loop.
// Represents number of times remaining to loop.
EmitSource(" ivec4 loop_count = ivec4(0);\n");
// Temps for source register values.
EmitSource(" vec4 src0;\n");
EmitSource(" vec4 src1;\n");
@ -378,7 +381,32 @@ void GlslShaderTranslator::ProcessLoopStartInstruction(
EmitSource("// ");
instr.Disassemble(&source_);
EmitUnimplementedTranslationError();
// Setup counter.
EmitSourceDepth(
"loop_count = ivec4(state.loop_consts[%u].x & 0xFF, "
"loop_count.x, loop_count.y, loop_count.z);\n",
instr.loop_constant_index);
// Setup relative indexing.
if (instr.is_repeat) {
// Reuse the current loop index.
EmitSourceDepth("aL = ivec4(aL.x, aL.x, aL.y, aL.z);\n");
} else {
// Push new loop starting index.
EmitSourceDepth(
"aL = ivec4((state.loop_consts[%u] >> 8) & 0xFF, aL.x, aL.y, aL.z);\n",
instr.loop_constant_index);
}
// Quick skip loop if zero count.
EmitSourceDepth("if (loop_count.x == 0) {\n");
EmitSourceDepth(" pc = 0x%X; // Skip loop to L%d\n",
instr.loop_skip_address, instr.loop_skip_address);
EmitSourceDepth("} else {\n");
EmitSourceDepth(" pc = 0x%X; // Fallthrough to loop body L%d\n",
instr.dword_index + 1, instr.dword_index + 1);
EmitSourceDepth("}\n");
cf_wrote_pc_ = true;
}
void GlslShaderTranslator::ProcessLoopEndInstruction(
@ -386,7 +414,38 @@ void GlslShaderTranslator::ProcessLoopEndInstruction(
EmitSource("// ");
instr.Disassemble(&source_);
EmitUnimplementedTranslationError();
// Decrement loop counter, and if we are done break out.
EmitSourceDepth("if (--loop_count.x == 0");
if (instr.is_predicated_break) {
// If the predicate condition is met we 'break;' out of the loop.
// Need to restore stack and fall through to the next cf.
EmitSource(" || %cp0) {\n", instr.predicate_condition ? ' ' : '!');
} else {
EmitSource(") {\n");
}
Indent();
// Loop completed - pop and fall through to next cf.
EmitSourceDepth(
"loop_count = ivec4(loop_count.y, loop_count.z, loop_count.w, 0);\n");
EmitSourceDepth("aL = ivec4(aL.y, aL.z, aL.w, 0);\n");
uint32_t next_address = instr.dword_index + 1;
EmitSourceDepth("pc = 0x%X; // Exit loop to L%d\n", instr.dword_index + 1,
instr.dword_index + 1);
Unindent();
EmitSourceDepth("} else {\n");
Indent();
// Still looping. Adjust index and jump back to body.
EmitSourceDepth("aL.x += (state.loop_consts[%u] << 8) >> 24;\n",
instr.loop_constant_index);
EmitSourceDepth("pc = 0x%X; // Loop back to body L%d\n",
instr.loop_body_address, instr.loop_body_address);
Unindent();
EmitSourceDepth("}\n");
cf_wrote_pc_ = true;
}
void GlslShaderTranslator::ProcessCallInstruction(
@ -657,9 +716,9 @@ void GlslShaderTranslator::EmitLoadOperand(size_t i,
break;
case InstructionStorageAddressingMode::kAddressRelative:
if (storage_index_offset) {
EmitSource("[%d+%d+aL]", storage_index_offset, op.storage_index);
EmitSource("[%d+%d+aL.x]", storage_index_offset, op.storage_index);
} else {
EmitSource("[%d+aL]", op.storage_index);
EmitSource("[%d+aL.x]", op.storage_index);
}
break;
}
@ -736,7 +795,7 @@ void GlslShaderTranslator::EmitStoreResult(const InstructionResult& result,
EmitSource("[%d+a0]", result.storage_index);
break;
case InstructionStorageAddressingMode::kAddressRelative:
EmitSource("[%d+aL]", result.storage_index);
EmitSource("[%d+aL.x]", result.storage_index);
break;
}
}