[ir] resolve conditional Phi inputs when tracking bindless texture handles

src/shader_recompiler/frontend/ir/breadth_first_search.h

@@ -1,8 +1,12 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <functional>
 #include <optional>
 #include <type_traits>
 #include <queue>
@@ -13,9 +17,10 @@
 
 namespace Shader::IR {
 
-template <typename Pred>
-auto BreadthFirstSearch(const Value& value, Pred&& pred)
+template <typename Pred, typename Resolve = std::identity>
+auto BreadthFirstSearch(Value value, Pred&& pred, Resolve&& resolve = {})
     -> std::invoke_result_t<Pred, const Inst*> {
+    value = resolve(value);
     if (value.IsImmediate()) {
         // Nothing to do with immediates
         return std::nullopt;
@@ -36,7 +41,7 @@ auto BreadthFirstSearch(const Value& value, Pred&& pred)
         }
         // Visit the right most arguments first
         for (size_t arg = inst->NumArgs(); arg--;) {
-            const Value arg_value{inst->Arg(arg)};
+            const Value arg_value{resolve(inst->Arg(arg))};
             if (arg_value.IsImmediate()) {
                 continue;
             }

src/shader_recompiler/ir_opt/texture_pass.cpp

@@ -31,6 +31,60 @@ struct TextureInst {
 
 using TextureInstVector = boost::container::small_vector<TextureInst, 24>;
 
+const IR::Block* ConditionalHeader(const IR::Block* body) {
+    const auto predecessors{body->ImmPredecessors()};
+    const auto successors{body->ImmSuccessors()};
+    if (predecessors.size() != 1 || successors.size() != 1) return nullptr;
+    const IR::Block* const header{predecessors[0]};
+    const auto targets{header->ImmSuccessors()};
+    if (targets.size() != 2 || targets[0] != body || targets[1] != successors[0] ||
+        targets[1]->ImmPredecessors().size() != 2 || header->empty() ||
+        header->back().GetOpcode() != IR::Opcode::ConditionRef) {
+        return nullptr;
+    }
+    return header;
+}
+
+std::pair<IR::Value, bool> Condition(IR::Value value) {
+    bool negated{};
+    while (const IR::Inst* inst = value.TryInstRecursive()) {
+        if (inst->GetOpcode() == IR::Opcode::LogicalNot) negated = !negated;
+        else if (inst->GetOpcode() != IR::Opcode::ConditionRef) break;
+        value = inst->Arg(0);
+    }
+    return {value.Resolve(), negated};
+}
+
+IR::Value ResolveConditionalPhi(IR::Value value, const IR::Block* block) {
+    if (!value.Resolve().IsPhi() || !(block = ConditionalHeader(block))) return value;
+    const auto [condition, negated]{Condition(block->back().Arg(0))};
+    boost::container::small_vector<const IR::Block*, 16> visited;
+    while (value.Resolve().IsPhi() && std::ranges::find(visited, block) == visited.end()) {
+        visited.push_back(block);
+        const IR::Inst* const phi{value.InstRecursive()};
+        const auto predecessors{block->ImmPredecessors()};
+        if (predecessors.size() == 1) {
+            block = predecessors[0];
+            continue;
+        }
+        if (predecessors.size() != 2 || phi->NumArgs() != 2) break;
+        const IR::Block* body{predecessors[0]};
+        const IR::Block* header{ConditionalHeader(body)};
+        if (header != predecessors[1]) {
+            body = predecessors[1];
+            header = ConditionalHeader(body);
+            if (header != predecessors[0]) break;
+        }
+        const auto [other_condition, other_negated]{Condition(header->back().Arg(0))};
+        if (condition == other_condition && (phi->PhiBlock(0) == header || phi->PhiBlock(0) == body)) {
+            const IR::Block* const incoming{negated == other_negated ? body : header};
+            value = phi->Arg(phi->PhiBlock(0) == incoming ? 0 : 1);
+        }
+        block = header;
+    }
+    return value;
+}
+
 constexpr u32 DESCRIPTOR_SIZE = 8;
 constexpr u32 DESCRIPTOR_SIZE_SHIFT = u32(std::countr_zero(DESCRIPTOR_SIZE));
 constexpr u32 DESCRIPTOR_MAX_COUNT = 1024;
@@ -299,23 +353,23 @@ static inline bool IsTexturePixelFormatIntegerCached(Environment& env,
 }
 
 
-std::optional<ConstBufferAddr> Track(const IR::Value& value, Environment& env, const HostTranslateInfo& host_info);
-static inline std::optional<ConstBufferAddr> TrackCached(const IR::Value& v, Environment& env, const HostTranslateInfo& host_info) {
-    if (const IR::Inst* key = v.InstRecursive()) {
+std::optional<ConstBufferAddr> Track(const IR::Value& value, Environment& env, const HostTranslateInfo& host_info, const IR::Block* block);
+static inline std::optional<ConstBufferAddr> TrackCached(const IR::Value& v, Environment& env, const HostTranslateInfo& host_info, const IR::Block* block) {
+    if (const IR::Inst* key = v.TryInstRecursive()) {
         if (auto it = env.track_cache.find(key); it != env.track_cache.end()) return it->second;
-        auto found = Track(v, env, host_info);
+        auto found = Track(v, env, host_info, block);
         if (found) env.track_cache.emplace(key, *found);
         return found;
     }
-    return Track(v, env, host_info);
+    return Track(v, env, host_info, block);
 }
 
-std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environment& env, const HostTranslateInfo& host_info);
+std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environment& env, const HostTranslateInfo& host_info, const IR::Block* block);
 
-std::optional<ConstBufferAddr> Track(const IR::Value& value, Environment& env, const HostTranslateInfo& host_info) {
-    return IR::BreadthFirstSearch(value, [&env, &host_info](const IR::Inst* inst) {
-        return TryGetConstBuffer(inst, env, host_info);
-    });
+std::optional<ConstBufferAddr> Track(const IR::Value& value, Environment& env, const HostTranslateInfo& host_info, const IR::Block* block) {
+    return IR::BreadthFirstSearch(value, [&env, &host_info, block](const IR::Inst* inst) {
+        return TryGetConstBuffer(inst, env, host_info, block);
+    }, [&](IR::Value operand) { return ResolveConditionalPhi(operand, block); });
 }
 
 std::optional<u32> TryGetConstant(IR::Value& value, Environment& env) {
@@ -339,13 +393,13 @@ std::optional<u32> TryGetConstant(IR::Value& value, Environment& env) {
     return ReadCbufCached(env, index_number, offset_number);
 }
 
-std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environment& env, const HostTranslateInfo& host_info) {
+std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environment& env, const HostTranslateInfo& host_info, const IR::Block* block) {
     switch (inst->GetOpcode()) {
     default:
         return std::nullopt;
     case IR::Opcode::BitwiseOr32: {
-        std::optional lhs{TrackCached(inst->Arg(0), env, host_info)};
-        std::optional rhs{TrackCached(inst->Arg(1), env, host_info)};
+        std::optional lhs{TrackCached(inst->Arg(0), env, host_info, block)};
+        std::optional rhs{TrackCached(inst->Arg(1), env, host_info, block)};
         if (!lhs || !rhs) {
             return std::nullopt;
         }
@@ -375,7 +429,7 @@ std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environme
         if (!shift.IsImmediate()) {
             return std::nullopt;
         }
-        std::optional lhs{TrackCached(inst->Arg(0), env, host_info)};
+        std::optional lhs{TrackCached(inst->Arg(0), env, host_info, block)};
         if (lhs) {
             lhs->shift_left = shift.U32();
         }
@@ -403,7 +457,7 @@ std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environme
                 return std::nullopt;
             } while (false);
         }
-        std::optional lhs{TrackCached(op1, env, host_info)};
+        std::optional lhs{TrackCached(op1, env, host_info, block)};
         if (lhs) {
             lhs->shift_left = static_cast<u32>(std::countr_zero(op2.U32()));
         }
@@ -469,7 +523,7 @@ std::optional<ConstBufferAddr> TryGetConstBuffer(const IR::Inst* inst, Environme
 TextureInst MakeInst(Environment& env, IR::Block* block, IR::Inst& inst, const HostTranslateInfo& host_info) {
     ConstBufferAddr addr;
     if (IsBindless(inst)) {
-        const std::optional<ConstBufferAddr> track_addr{TrackCached(inst.Arg(0), env, host_info)};
+        const std::optional<ConstBufferAddr> track_addr{TrackCached(inst.Arg(0), env, host_info, block)};
 
         if (!track_addr) {
             throw NotImplementedException("Failed to track bindless texture constant buffer");
@@ -671,6 +725,7 @@ void TexturePass(Environment& env, IR::Program& program, const HostTranslateInfo
     env.track_cache.clear();
     TextureInstVector to_replace;
     for (IR::Block* const block : program.post_order_blocks) {
+        env.track_cache.clear();
         for (IR::Inst& inst : block->Instructions()) {
             if (!IsTextureInstruction(inst)) {
                 continue;