fix(shader): repeat phi folding until no phi folds

core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp

@@ -1941,6 +1941,20 @@ void verifyDescriptorPhis() {
     sequential.context.memory = sequentialMemory.Regions();
     static_cast<void>(Recompile(sequential, *sequentialCapture));
 
+    const auto planRestoredSampler = [&](std::span<const std::uint32_t> code, const char* message) {
+        auto request = makeRequest(code);
+        const auto plan = GetResourcePlan(request);
+        require(plan->info.samplers.size() == 1u && plan->info.sampledPairs.size() == 1u, message);
+        AgcDriver::ShaderMemory memory({});
+        const auto capture = memory.Capture(request);
+        request.context.memory = memory.Regions();
+        static_cast<void>(Recompile(request, *capture));
+    };
+    std::vector<std::uint32_t> restoredSamplerCode{0xf40c0200u, 0xfa000000u, 0xf4080500u, 0xfa000020u, 0xf4080600u, 0xfa000040u, 0xbe930380u, 0xbf8cc07fu, 0xf09c0f08u, 0x00a20400u, 0xbe900380u, 0xbe910380u, 0xbe9c0414u, 0xbe9e0416u, 0xbf068011u, 0xbf850001u, 0x80128112u, 0xbe94041cu, 0xbe96041eu, 0x80118111u, 0xbf0a8211u, 0xbf85fff6u, 0xf09c0f08u, 0x00a20000u, 0x80108110u, 0xbf0a8210u, 0xbf85fff0u, 0x80138113u, 0xbf0a8213u, 0xbf85ffecu, 0xbf8c3f70u, 0xe0700000u, 0x80060000u, 0xe0700000u, 0x80060400u, 0x7d880090u, 0xbea23c6au, 0x4a020081u, 0xe0700000u, 0x80060100u, 0xbf810000u};
+    planRestoredSampler(restoredSamplerCode, "descriptor Phi: an S# copied out and back in three nested loops was planned as more than one sampler");
+    restoredSamplerCode.erase(restoredSamplerCode.end() - 6, restoredSamplerCode.end() - 1);
+    planRestoredSampler(restoredSamplerCode, "descriptor Phi: an S# copied out and back in three nested loops without a masked write was planned as more than one sampler");
+
     const auto entryWrites = [&](std::initializer_list<std::uint32_t> words) {
         auto code = loopCode;
         code.insert(code.begin() + 8, words);

core/shader/recompiler/Optimization/src/ConstantFolder.cpp

@@ -828,6 +828,23 @@ void ConstantFolder::Fold(IrProgram& program, std::span<IrBlock* const> blocks)
             const auto success = tryFoldValue(program, *inst);
         }
     }
+    std::vector<IrValue*> phis;
+    for (IrBlock* block : blocks) {
+        for (IrValue* inst : block->Instructions()) {
+            if (inst->Opcode() == IrOpcode::Phi) {
+                phis.push_back(inst);
+            }
+        }
+    }
+    bool folded = true;
+    while (folded) {
+        folded = false;
+        for (IrValue* phi : phis) {
+            if (phi->Opcode() == IrOpcode::Phi && foldPhi(*phi)) {
+                folded = true;
+            }
+        }
+    }
     std::vector<IrValue*> words;
     for (IrBlock* block : blocks) {
         for (IrValue* inst : block->Instructions()) {