shader: bound material selectors by proven one-wave LDS append lists

src/graphics/shader/recompiler/ir/passes/SrtWalker.h

@@ -3,6 +3,7 @@
 
 #include "graphics/shader/recompiler/ir/ShaderIR.h"
 
+#include <algorithm>
 #include <span>
 
 namespace Libs::Graphics::ShaderRecompiler::IR {
@@ -49,6 +50,48 @@ void CompileSrtWalker(ResourcePlan& program);
 // Uses the strict reader for values that affect shader specialization.
 SrtRuntime CleanRuntime(SrtRuntime runtime);
 
+// Nonnegative affine coefficients: element zero is constant, remaining elements are
+// caller-selected leaves. Runtime range proofs must additionally exclude U32 wrap.
+template <size_t Size>
+std::optional<std::array<uint64_t, Size>> AffineIndex(
+    Value value, const auto& resolve, const auto& leaf, uint32_t depth = 0) {
+	value = resolve(value);
+	if (depth > 32u || value.GetType() != Type::U32) return {};
+	std::array<uint64_t, Size> result {};
+	if (value.IsImmediate()) {
+		result[0] = value.U32();
+		return result;
+	}
+	if (const auto index = leaf(value)) {
+		result[*index] = 1u;
+		return result;
+	}
+	const auto* inst = value.TryInstruction();
+	if (inst == nullptr) return {};
+	const auto op = inst->GetOpcode();
+	if (op != ValueOpcode::IAdd32 && op != ValueOpcode::IMul32 &&
+	    op != ValueOpcode::ShiftLeftLogical32) return {};
+	auto left = AffineIndex<Size>(inst->Arg(0), resolve, leaf, depth + 1u);
+	auto right = AffineIndex<Size>(inst->Arg(1), resolve, leaf, depth + 1u);
+	if (!left || !right) return {};
+	const auto constant = [](const auto& coefficients) {
+		return std::ranges::all_of(std::span(coefficients).subspan(1u),
+		                          [](uint64_t coefficient) { return coefficient == 0u; });
+	};
+	if (op == ValueOpcode::IMul32 && !constant(*right)) std::swap(left, right);
+	if (op != ValueOpcode::IAdd32 && !constant(*right)) return {};
+	if (op == ValueOpcode::ShiftLeftLogical32) {
+		if ((*right)[0] >= 32u) return {};
+		(*right)[0] = uint64_t {1} << (*right)[0];
+	}
+	for (size_t index = 0; index < Size; ++index) {
+		(*left)[index] = op == ValueOpcode::IAdd32
+		    ? (*left)[index] + (*right)[index] : (*left)[index] * (*right)[0];
+		if ((*left)[index] > UINT32_MAX) return {};
+	}
+	return left;
+}
+
 // One memoized evaluation session shared by the entire shader resource refresh.
 class SrtWalker {
 public: