Shader_IR: Implement Fast BRX and allow multi-branches in the CFG.

5 files changed, 246 insertions, 130 deletions

diff --git a/src/video_core/shader/ast.cpp b/src/video_core/shader/ast.cpp
index e43aecc18..2fa3a3f7d 100644
--- a/src/video_core/shader/ast.cpp
+++ b/src/video_core/shader/ast.cpp
@@ -228,6 +228,10 @@ public:
         inner += expr.value ? "true" : "false";
     }
 
+    void operator()(ExprGprEqual const& expr) {
+        inner += "( gpr_" + std::to_string(expr.gpr) + " == " + std::to_string(expr.value) + ')';
+    }
+
     const std::string& GetResult() const {
         return inner;
     }
diff --git a/src/video_core/shader/control_flow.cpp b/src/video_core/shader/control_flow.cpp
index dac2e4272..d1c269ea7 100644
--- a/src/video_core/shader/control_flow.cpp
+++ b/src/video_core/shader/control_flow.cpp
@@ -35,14 +35,24 @@ struct BlockStack {
     std::stack<u32> pbk_stack{};
 };
 
-struct BlockBranchInfo {
-    Condition condition{};
-    s32 address{exit_branch};
-    bool kill{};
-    bool is_sync{};
-    bool is_brk{};
-    bool ignore{};
-};
+template <typename T, typename... Args>
+BlockBranchInfo MakeBranchInfo(Args&&... args) {
+    static_assert(std::is_convertible_v<T, BranchData>);
+    return std::make_shared<BranchData>(T(std::forward<Args>(args)...));
+}
+
+bool BlockBranchInfoAreEqual(BlockBranchInfo first, BlockBranchInfo second) {
+    return false; //(*first) == (*second);
+}
+
+bool BlockBranchIsIgnored(BlockBranchInfo first) {
+    bool ignore = false;
+    if (std::holds_alternative<SingleBranch>(*first)) {
+        auto branch = std::get_if<SingleBranch>(first.get());
+        ignore = branch->ignore;
+    }
+    return ignore;
+}
 
 struct BlockInfo {
     u32 start{};
@@ -234,6 +244,7 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
     u32 offset = static_cast<u32>(address);
     const u32 end_address = static_cast<u32>(state.program_size / sizeof(Instruction));
     ParseInfo parse_info{};
+    SingleBranch single_branch{};
 
     const auto insert_label = [](CFGRebuildState& state, u32 address) {
         const auto pair = state.labels.emplace(address);
@@ -246,13 +257,14 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
         if (offset >= end_address) {
             // ASSERT_OR_EXECUTE can't be used, as it ignores the break
             ASSERT_MSG(false, "Shader passed the current limit!");
-            parse_info.branch_info.address = exit_branch;
-            parse_info.branch_info.ignore = false;
+
+            single_branch.address = exit_branch;
+            single_branch.ignore = false;
             break;
         }
         if (state.registered.count(offset) != 0) {
-            parse_info.branch_info.address = offset;
-            parse_info.branch_info.ignore = true;
+            single_branch.address = offset;
+            single_branch.ignore = true;
             break;
         }
         if (IsSchedInstruction(offset, state.start)) {
@@ -269,24 +281,26 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
         switch (opcode->get().GetId()) {
         case OpCode::Id::EXIT: {
             const auto pred_index = static_cast<u32>(instr.pred.pred_index);
-            parse_info.branch_info.condition.predicate =
-                GetPredicate(pred_index, instr.negate_pred != 0);
-            if (parse_info.branch_info.condition.predicate == Pred::NeverExecute) {
+            single_branch.condition.predicate = GetPredicate(pred_index, instr.negate_pred != 0);
+            if (single_branch.condition.predicate == Pred::NeverExecute) {
                 offset++;
                 continue;
             }
             const ConditionCode cc = instr.flow_condition_code;
-            parse_info.branch_info.condition.cc = cc;
+            single_branch.condition.cc = cc;
             if (cc == ConditionCode::F) {
                 offset++;
                 continue;
             }
-            parse_info.branch_info.address = exit_branch;
-            parse_info.branch_info.kill = false;
-            parse_info.branch_info.is_sync = false;
-            parse_info.branch_info.is_brk = false;
-            parse_info.branch_info.ignore = false;
+            single_branch.address = exit_branch;
+            single_branch.kill = false;
+            single_branch.is_sync = false;
+            single_branch.is_brk = false;
+            single_branch.ignore = false;
             parse_info.end_address = offset;
+            parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+                single_branch.condition, single_branch.address, single_branch.kill,
+                single_branch.is_sync, single_branch.is_brk, single_branch.ignore);
 
             return {ParseResult::ControlCaught, parse_info};
         }
@@ -295,99 +309,107 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
                 return {ParseResult::AbnormalFlow, parse_info};
             }
             const auto pred_index = static_cast<u32>(instr.pred.pred_index);
-            parse_info.branch_info.condition.predicate =
-                GetPredicate(pred_index, instr.negate_pred != 0);
-            if (parse_info.branch_info.condition.predicate == Pred::NeverExecute) {
+            single_branch.condition.predicate = GetPredicate(pred_index, instr.negate_pred != 0);
+            if (single_branch.condition.predicate == Pred::NeverExecute) {
                 offset++;
                 continue;
             }
             const ConditionCode cc = instr.flow_condition_code;
-            parse_info.branch_info.condition.cc = cc;
+            single_branch.condition.cc = cc;
             if (cc == ConditionCode::F) {
                 offset++;
                 continue;
             }
             const u32 branch_offset = offset + instr.bra.GetBranchTarget();
             if (branch_offset == 0) {
-                parse_info.branch_info.address = exit_branch;
+                single_branch.address = exit_branch;
             } else {
-                parse_info.branch_info.address = branch_offset;
+                single_branch.address = branch_offset;
             }
             insert_label(state, branch_offset);
-            parse_info.branch_info.kill = false;
-            parse_info.branch_info.is_sync = false;
-            parse_info.branch_info.is_brk = false;
-            parse_info.branch_info.ignore = false;
+            single_branch.kill = false;
+            single_branch.is_sync = false;
+            single_branch.is_brk = false;
+            single_branch.ignore = false;
             parse_info.end_address = offset;
+            parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+                single_branch.condition, single_branch.address, single_branch.kill,
+                single_branch.is_sync, single_branch.is_brk, single_branch.ignore);
 
             return {ParseResult::ControlCaught, parse_info};
         }
         case OpCode::Id::SYNC: {
             const auto pred_index = static_cast<u32>(instr.pred.pred_index);
-            parse_info.branch_info.condition.predicate =
-                GetPredicate(pred_index, instr.negate_pred != 0);
-            if (parse_info.branch_info.condition.predicate == Pred::NeverExecute) {
+            single_branch.condition.predicate = GetPredicate(pred_index, instr.negate_pred != 0);
+            if (single_branch.condition.predicate == Pred::NeverExecute) {
                 offset++;
                 continue;
             }
             const ConditionCode cc = instr.flow_condition_code;
-            parse_info.branch_info.condition.cc = cc;
+            single_branch.condition.cc = cc;
             if (cc == ConditionCode::F) {
                 offset++;
                 continue;
             }
-            parse_info.branch_info.address = unassigned_branch;
-            parse_info.branch_info.kill = false;
-            parse_info.branch_info.is_sync = true;
-            parse_info.branch_info.is_brk = false;
-            parse_info.branch_info.ignore = false;
+            single_branch.address = unassigned_branch;
+            single_branch.kill = false;
+            single_branch.is_sync = true;
+            single_branch.is_brk = false;
+            single_branch.ignore = false;
             parse_info.end_address = offset;
+            parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+                single_branch.condition, single_branch.address, single_branch.kill,
+                single_branch.is_sync, single_branch.is_brk, single_branch.ignore);
 
             return {ParseResult::ControlCaught, parse_info};
         }
         case OpCode::Id::BRK: {
             const auto pred_index = static_cast<u32>(instr.pred.pred_index);
-            parse_info.branch_info.condition.predicate =
-                GetPredicate(pred_index, instr.negate_pred != 0);
-            if (parse_info.branch_info.condition.predicate == Pred::NeverExecute) {
+            single_branch.condition.predicate = GetPredicate(pred_index, instr.negate_pred != 0);
+            if (single_branch.condition.predicate == Pred::NeverExecute) {
                 offset++;
                 continue;
             }
             const ConditionCode cc = instr.flow_condition_code;
-            parse_info.branch_info.condition.cc = cc;
+            single_branch.condition.cc = cc;
             if (cc == ConditionCode::F) {
                 offset++;
                 continue;
             }
-            parse_info.branch_info.address = unassigned_branch;
-            parse_info.branch_info.kill = false;
-            parse_info.branch_info.is_sync = false;
-            parse_info.branch_info.is_brk = true;
-            parse_info.branch_info.ignore = false;
+            single_branch.address = unassigned_branch;
+            single_branch.kill = false;
+            single_branch.is_sync = false;
+            single_branch.is_brk = true;
+            single_branch.ignore = false;
             parse_info.end_address = offset;
+            parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+                single_branch.condition, single_branch.address, single_branch.kill,
+                single_branch.is_sync, single_branch.is_brk, single_branch.ignore);
 
             return {ParseResult::ControlCaught, parse_info};
         }
         case OpCode::Id::KIL: {
             const auto pred_index = static_cast<u32>(instr.pred.pred_index);
-            parse_info.branch_info.condition.predicate =
-                GetPredicate(pred_index, instr.negate_pred != 0);
-            if (parse_info.branch_info.condition.predicate == Pred::NeverExecute) {
+            single_branch.condition.predicate = GetPredicate(pred_index, instr.negate_pred != 0);
+            if (single_branch.condition.predicate == Pred::NeverExecute) {
                 offset++;
                 continue;
             }
             const ConditionCode cc = instr.flow_condition_code;
-            parse_info.branch_info.condition.cc = cc;
+            single_branch.condition.cc = cc;
             if (cc == ConditionCode::F) {
                 offset++;
                 continue;
             }
-            parse_info.branch_info.address = exit_branch;
-            parse_info.branch_info.kill = true;
-            parse_info.branch_info.is_sync = false;
-            parse_info.branch_info.is_brk = false;
-            parse_info.branch_info.ignore = false;
+            single_branch.address = exit_branch;
+            single_branch.kill = true;
+            single_branch.is_sync = false;
+            single_branch.is_brk = false;
+            single_branch.ignore = false;
             parse_info.end_address = offset;
+            parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+                single_branch.condition, single_branch.address, single_branch.kill,
+                single_branch.is_sync, single_branch.is_brk, single_branch.ignore);
 
             return {ParseResult::ControlCaught, parse_info};
         }
@@ -407,16 +429,25 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
             auto tmp = TrackBranchIndirectInfo(state, address, offset);
             if (tmp) {
                 auto result = *tmp;
-                std::string entries{};
+                std::vector<CaseBranch> branches{};
+                s32 pc_target = offset + result.relative_position;
                 for (u32 i = 0; i < result.entries; i++) {
-                    auto k = locker.ObtainKey(result.buffer, result.offset + i * 4);
-                    entries = entries + std::to_string(*k) + '\n';
+                    auto k = state.locker.ObtainKey(result.buffer, result.offset + i * 4);
+                    if (!k) {
+                        return {ParseResult::AbnormalFlow, parse_info};
+                    }
+                    u32 value = *k;
+                    u32 target = static_cast<u32>((value >> 3) + pc_target);
+                    insert_label(state, target);
+                    branches.emplace_back(value, target);
                 }
-                LOG_CRITICAL(HW_GPU,
-                             "Track Successful, BRX: buffer:{}, offset:{}, entries:{}, inner:\n{}",
-                             result.buffer, result.offset, result.entries, entries);
+                parse_info.end_address = offset;
+                parse_info.branch_info =
+                    MakeBranchInfo<MultiBranch>(static_cast<u32>(instr.gpr8.Value()), branches);
+
+                return {ParseResult::ControlCaught, parse_info};
             } else {
-                LOG_CRITICAL(HW_GPU, "Track Unsuccesful");
+                LOG_WARNING(HW_GPU, "BRX Track Unsuccesful");
             }
             return {ParseResult::AbnormalFlow, parse_info};
         }
@@ -426,10 +457,13 @@ std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address)
 
         offset++;
     }
-    parse_info.branch_info.kill = false;
-    parse_info.branch_info.is_sync = false;
-    parse_info.branch_info.is_brk = false;
+    single_branch.kill = false;
+    single_branch.is_sync = false;
+    single_branch.is_brk = false;
     parse_info.end_address = offset - 1;
+    parse_info.branch_info = MakeBranchInfo<SingleBranch>(
+        single_branch.condition, single_branch.address, single_branch.kill, single_branch.is_sync,
+        single_branch.is_brk, single_branch.ignore);
     return {ParseResult::BlockEnd, parse_info};
 }
 
@@ -453,9 +487,10 @@ bool TryInspectAddress(CFGRebuildState& state) {
         BlockInfo& current_block = state.block_info[block_index];
         current_block.end = address - 1;
         new_block.branch = current_block.branch;
-        BlockBranchInfo forward_branch{};
-        forward_branch.address = address;
-        forward_branch.ignore = true;
+        BlockBranchInfo forward_branch = MakeBranchInfo<SingleBranch>();
+        auto branch = std::get_if<SingleBranch>(forward_branch.get());
+        branch->address = address;
+        branch->ignore = true;
         current_block.branch = forward_branch;
         return true;
     }
@@ -470,12 +505,15 @@ bool TryInspectAddress(CFGRebuildState& state) {
 
     BlockInfo& block_info = CreateBlockInfo(state, address, parse_info.end_address);
     block_info.branch = parse_info.branch_info;
-    if (parse_info.branch_info.condition.IsUnconditional()) {
+    if (std::holds_alternative<SingleBranch>(*block_info.branch)) {
+        auto branch = std::get_if<SingleBranch>(block_info.branch.get());
+        if (branch->condition.IsUnconditional()) {
+            return true;
+        }
+        const u32 fallthrough_address = parse_info.end_address + 1;
+        state.inspect_queries.push_front(fallthrough_address);
         return true;
     }
-
-    const u32 fallthrough_address = parse_info.end_address + 1;
-    state.inspect_queries.push_front(fallthrough_address);
     return true;
 }
 
@@ -513,31 +551,41 @@ bool TryQuery(CFGRebuildState& state) {
     state.queries.pop_front();
     gather_labels(q2.ssy_stack, state.ssy_labels, block);
     gather_labels(q2.pbk_stack, state.pbk_labels, block);
-    if (!block.branch.condition.IsUnconditional()) {
-        q2.address = block.end + 1;
-        state.queries.push_back(q2);
-    }
+    if (std::holds_alternative<SingleBranch>(*block.branch)) {
+        auto branch = std::get_if<SingleBranch>(block.branch.get());
+        if (!branch->condition.IsUnconditional()) {
+            q2.address = block.end + 1;
+            state.queries.push_back(q2);
+        }
 
-    Query conditional_query{q2};
-    if (block.branch.is_sync) {
-        if (block.branch.address == unassigned_branch) {
-            block.branch.address = conditional_query.ssy_stack.top();
+        Query conditional_query{q2};
+        if (branch->is_sync) {
+            if (branch->address == unassigned_branch) {
+                branch->address = conditional_query.ssy_stack.top();
+            }
+            conditional_query.ssy_stack.pop();
         }
-        conditional_query.ssy_stack.pop();
-    }
-    if (block.branch.is_brk) {
-        if (block.branch.address == unassigned_branch) {
-            block.branch.address = conditional_query.pbk_stack.top();
+        if (branch->is_brk) {
+            if (branch->address == unassigned_branch) {
+                branch->address = conditional_query.pbk_stack.top();
+            }
+            conditional_query.pbk_stack.pop();
         }
-        conditional_query.pbk_stack.pop();
+        conditional_query.address = branch->address;
+        state.queries.push_back(std::move(conditional_query));
+        return true;
+    }
+    auto multi_branch = std::get_if<MultiBranch>(block.branch.get());
+    for (auto& branch_case : multi_branch->branches) {
+        Query conditional_query{q2};
+        conditional_query.address = branch_case.address;
+        state.queries.push_back(std::move(conditional_query));
     }
-    conditional_query.address = block.branch.address;
-    state.queries.push_back(std::move(conditional_query));
     return true;
 }
 } // Anonymous namespace
 
-void InsertBranch(ASTManager& mm, const BlockBranchInfo& branch) {
+void InsertBranch(ASTManager& mm, const BlockBranchInfo& branch_info) {
     const auto get_expr = ([&](const Condition& cond) -> Expr {
         Expr result{};
         if (cond.cc != ConditionCode::T) {
@@ -564,15 +612,24 @@ void InsertBranch(ASTManager& mm, const BlockBranchInfo& branch) {
         }
         return MakeExpr<ExprBoolean>(true);
     });
-    if (branch.address < 0) {
-        if (branch.kill) {
-            mm.InsertReturn(get_expr(branch.condition), true);
+    if (std::holds_alternative<SingleBranch>(*branch_info)) {
+        auto branch = std::get_if<SingleBranch>(branch_info.get());
+        if (branch->address < 0) {
+            if (branch->kill) {
+                mm.InsertReturn(get_expr(branch->condition), true);
+                return;
+            }
+            mm.InsertReturn(get_expr(branch->condition), false);
             return;
         }
-        mm.InsertReturn(get_expr(branch.condition), false);
+        mm.InsertGoto(get_expr(branch->condition), branch->address);
         return;
     }
-    mm.InsertGoto(get_expr(branch.condition), branch.address);
+    auto multi_branch = std::get_if<MultiBranch>(branch_info.get());
+    for (auto& branch_case : multi_branch->branches) {
+        mm.InsertGoto(MakeExpr<ExprGprEqual>(multi_branch->gpr, branch_case.cmp_value),
+                      branch_case.address);
+    }
 }
 
 void DecompileShader(CFGRebuildState& state) {
@@ -584,9 +641,10 @@ void DecompileShader(CFGRebuildState& state) {
         if (state.labels.count(block.start) != 0) {
             state.manager->InsertLabel(block.start);
         }
-        u32 end = block.branch.ignore ? block.end + 1 : block.end;
+        const bool ignore = BlockBranchIsIgnored(block.branch);
+        u32 end = ignore ? block.end + 1 : block.end;
         state.manager->InsertBlock(block.start, end);
-        if (!block.branch.ignore) {
+        if (!ignore) {
             InsertBranch(*state.manager, block.branch);
         }
     }
@@ -668,11 +726,9 @@ std::unique_ptr<ShaderCharacteristics> ScanFlow(const ProgramCode& program_code,
         ShaderBlock new_block{};
         new_block.start = block.start;
         new_block.end = block.end;
-        new_block.ignore_branch = block.branch.ignore;
+        new_block.ignore_branch = BlockBranchIsIgnored(block.branch);
         if (!new_block.ignore_branch) {
-            new_block.branch.cond = block.branch.condition;
-            new_block.branch.kills = block.branch.kill;
-            new_block.branch.address = block.branch.address;
+            new_block.branch = block.branch;
         }
         result_out->end = std::max(result_out->end, block.end);
         result_out->blocks.push_back(new_block);
diff --git a/src/video_core/shader/control_flow.h b/src/video_core/shader/control_flow.h
index 6d0e50d7c..369ca255b 100644
--- a/src/video_core/shader/control_flow.h
+++ b/src/video_core/shader/control_flow.h
@@ -7,6 +7,7 @@
 #include <list>
 #include <optional>
 #include <set>
+#include <variant>
 
 #include "video_core/engines/shader_bytecode.h"
 #include "video_core/shader/ast.h"
@@ -37,29 +38,57 @@ struct Condition {
     }
 };
 
-struct ShaderBlock {
-    struct Branch {
-        Condition cond{};
-        bool kills{};
-        s32 address{};
+class SingleBranch {
+public:
+    SingleBranch() = default;
+    SingleBranch(Condition condition, s32 address, bool kill, bool is_sync, bool is_brk,
+                 bool ignore)
+        : condition{condition}, address{address}, kill{kill}, is_sync{is_sync}, is_brk{is_brk},
+          ignore{ignore} {}
+
+    bool operator==(const SingleBranch& b) const {
+        return std::tie(condition, address, kill, is_sync, is_brk, ignore) ==
+               std::tie(b.condition, b.address, b.kill, b.is_sync, b.is_brk, b.ignore);
+    }
+
+    Condition condition{};
+    s32 address{exit_branch};
+    bool kill{};
+    bool is_sync{};
+    bool is_brk{};
+    bool ignore{};
+};
+
+struct CaseBranch {
+    CaseBranch(u32 cmp_value, u32 address) : cmp_value{cmp_value}, address{address} {}
+    u32 cmp_value;
+    u32 address;
+};
+
+class MultiBranch {
+public:
+    MultiBranch(u32 gpr, std::vector<CaseBranch>& branches)
+        : gpr{gpr}, branches{std::move(branches)} {}
 
-        bool operator==(const Branch& b) const {
-            return std::tie(cond, kills, address) == std::tie(b.cond, b.kills, b.address);
-        }
+    u32 gpr{};
+    std::vector<CaseBranch> branches{};
+};
 
-        bool operator!=(const Branch& b) const {
-            return !operator==(b);
-        }
-    };
+using BranchData = std::variant<SingleBranch, MultiBranch>;
+using BlockBranchInfo = std::shared_ptr<BranchData>;
 
+bool BlockBranchInfoAreEqual(BlockBranchInfo first, BlockBranchInfo second);
+
+struct ShaderBlock {
     u32 start{};
     u32 end{};
     bool ignore_branch{};
-    Branch branch{};
+    BlockBranchInfo branch{};
 
     bool operator==(const ShaderBlock& sb) const {
-        return std::tie(start, end, ignore_branch, branch) ==
-               std::tie(sb.start, sb.end, sb.ignore_branch, sb.branch);
+        return std::tie(start, end, ignore_branch) ==
+                   std::tie(sb.start, sb.end, sb.ignore_branch) &&
+               BlockBranchInfoAreEqual(branch, sb.branch);
     }
 
     bool operator!=(const ShaderBlock& sb) const {
diff --git a/src/video_core/shader/decode.cpp b/src/video_core/shader/decode.cpp
index 3f87b87ca..053241128 100644
--- a/src/video_core/shader/decode.cpp
+++ b/src/video_core/shader/decode.cpp
@@ -198,24 +198,38 @@ void ShaderIR::InsertControlFlow(NodeBlock& bb, const ShaderBlock& block) {
         }
         return result;
     };
-    if (block.branch.address < 0) {
-        if (block.branch.kills) {
-            Node n = Operation(OperationCode::Discard);
-            n = apply_conditions(block.branch.cond, n);
+    if (std::holds_alternative<SingleBranch>(*block.branch)) {
+        auto branch = std::get_if<SingleBranch>(block.branch.get());
+        if (branch->address < 0) {
+            if (branch->kill) {
+                Node n = Operation(OperationCode::Discard);
+                n = apply_conditions(branch->condition, n);
+                bb.push_back(n);
+                global_code.push_back(n);
+                return;
+            }
+            Node n = Operation(OperationCode::Exit);
+            n = apply_conditions(branch->condition, n);
             bb.push_back(n);
             global_code.push_back(n);
             return;
         }
-        Node n = Operation(OperationCode::Exit);
-        n = apply_conditions(block.branch.cond, n);
+        Node n = Operation(OperationCode::Branch, Immediate(branch->address));
+        n = apply_conditions(branch->condition, n);
         bb.push_back(n);
         global_code.push_back(n);
         return;
     }
-    Node n = Operation(OperationCode::Branch, Immediate(block.branch.address));
-    n = apply_conditions(block.branch.cond, n);
-    bb.push_back(n);
-    global_code.push_back(n);
+    auto multi_branch = std::get_if<MultiBranch>(block.branch.get());
+    Node op_a = GetRegister(multi_branch->gpr);
+    for (auto& branch_case : multi_branch->branches) {
+        Node n = Operation(OperationCode::Branch, Immediate(branch_case.address));
+        Node op_b = Immediate(branch_case.cmp_value);
+        Node condition = GetPredicateComparisonInteger(Tegra::Shader::PredCondition::Equal, false, op_a, op_b);
+        auto result = Conditional(condition, {n});
+        bb.push_back(result);
+        global_code.push_back(result);
+    }
 }
 
 u32 ShaderIR::DecodeInstr(NodeBlock& bb, u32 pc) {
diff --git a/src/video_core/shader/expr.h b/src/video_core/shader/expr.h
index d3dcd00ec..e41d23e93 100644
--- a/src/video_core/shader/expr.h
+++ b/src/video_core/shader/expr.h
@@ -17,13 +17,14 @@ using Tegra::Shader::Pred;
 class ExprAnd;
 class ExprBoolean;
 class ExprCondCode;
+class ExprGprEqual;
 class ExprNot;
 class ExprOr;
 class ExprPredicate;
 class ExprVar;
 
-using ExprData =
-    std::variant<ExprVar, ExprCondCode, ExprPredicate, ExprNot, ExprOr, ExprAnd, ExprBoolean>;
+using ExprData = std::variant<ExprVar, ExprCondCode, ExprPredicate, ExprNot, ExprOr, ExprAnd,
+                              ExprBoolean, ExprGprEqual>;
 using Expr = std::shared_ptr<ExprData>;
 
 class ExprAnd final {
@@ -118,6 +119,18 @@ public:
     bool value;
 };
 
+class ExprGprEqual final {
+public:
+    ExprGprEqual(u32 gpr, u32 value) : gpr{gpr}, value{value} {}
+
+    bool operator==(const ExprGprEqual& b) const {
+        return gpr == b.gpr && value == b.value;
+    }
+
+    u32 gpr;
+    u32 value;
+};
+
 template <typename T, typename... Args>
 Expr MakeExpr(Args&&... args) {
     static_assert(std::is_convertible_v<T, ExprData>);