shader: Read branch conditions from an instruction

Fixes the identity removal pass.

7 files changed, 20 insertions, 5 deletions

diff --git a/src/shader_recompiler/backend/glasm/emit_glasm.cpp b/src/shader_recompiler/backend/glasm/emit_glasm.cpp
index d7a08e4b3..a893fa3fb 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm.cpp
+++ b/src/shader_recompiler/backend/glasm/emit_glasm.cpp
@@ -200,7 +200,7 @@ void Precolor(EmitContext& ctx, const IR::Program& program) {
             }
             // Add reference to the phi node on the phi predecessor to avoid overwritting it
             for (size_t i = 0; i < num_args; ++i) {
-                IR::IREmitter{*phi.PhiBlock(i)}.DummyReference(IR::Value{&phi});
+                IR::IREmitter{*phi.PhiBlock(i)}.Reference(IR::Value{&phi});
             }
         }
     }
diff --git a/src/shader_recompiler/backend/glasm/emit_glasm_bitwise_conversion.cpp b/src/shader_recompiler/backend/glasm/emit_glasm_bitwise_conversion.cpp
index cdbf6e93e..505378bfd 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm_bitwise_conversion.cpp
+++ b/src/shader_recompiler/backend/glasm/emit_glasm_bitwise_conversion.cpp
@@ -22,6 +22,10 @@ void EmitIdentity(EmitContext&, IR::Inst& inst, const IR::Value& value) {
     Alias(inst, value);
 }
 
+void EmitConditionRef(EmitContext&, IR::Inst& inst, const IR::Value& value) {
+    Alias(inst, value);
+}
+
 void EmitBitCastU16F16(EmitContext&, IR::Inst& inst, const IR::Value& value) {
     Alias(inst, value);
 }
diff --git a/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h b/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
index 54e7fab3c..df0933a3f 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
+++ b/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
@@ -22,7 +22,8 @@ class EmitContext;
 void EmitPhi(EmitContext& ctx, IR::Inst& inst);
 void EmitVoid(EmitContext& ctx);
 void EmitIdentity(EmitContext& ctx, IR::Inst& inst, const IR::Value& value);
-void EmitDummyReference(EmitContext&);
+void EmitConditionRef(EmitContext& ctx, IR::Inst& inst, const IR::Value& value);
+void EmitReference(EmitContext&);
 void EmitPhiMove(EmitContext& ctx, const IR::Value& phi, const IR::Value& value);
 void EmitJoin(EmitContext& ctx);
 void EmitDemoteToHelperInvocation(EmitContext& ctx);
diff --git a/src/shader_recompiler/backend/glasm/emit_glasm_not_implemented.cpp b/src/shader_recompiler/backend/glasm/emit_glasm_not_implemented.cpp
index a4c1ca481..015cb5576 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm_not_implemented.cpp
+++ b/src/shader_recompiler/backend/glasm/emit_glasm_not_implemented.cpp
@@ -21,7 +21,7 @@ void EmitPhi(EmitContext&, IR::Inst&) {}
 
 void EmitVoid(EmitContext&) {}
 
-void EmitDummyReference(EmitContext&) {}
+void EmitReference(EmitContext&) {}
 
 void EmitPhiMove(EmitContext& ctx, const IR::Value& phi, const IR::Value& value) {
     if (phi == value) {
diff --git a/src/shader_recompiler/backend/glasm/reg_alloc.cpp b/src/shader_recompiler/backend/glasm/reg_alloc.cpp
index 707b22247..1a88331b4 100644
--- a/src/shader_recompiler/backend/glasm/reg_alloc.cpp
+++ b/src/shader_recompiler/backend/glasm/reg_alloc.cpp
@@ -139,6 +139,7 @@ void RegAlloc::Free(Id id) {
 /*static*/ bool RegAlloc::IsAliased(const IR::Inst& inst) {
     switch (inst.GetOpcode()) {
     case IR::Opcode::Identity:
+    case IR::Opcode::ConditionRef:
     case IR::Opcode::BitCastU16F16:
     case IR::Opcode::BitCastU32F32:
     case IR::Opcode::BitCastU64F64:
diff --git a/src/shader_recompiler/backend/spirv/emit_spirv.cpp b/src/shader_recompiler/backend/spirv/emit_spirv.cpp
index 9ed2af991..3e20ac3b9 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv.cpp
+++ b/src/shader_recompiler/backend/spirv/emit_spirv.cpp
@@ -469,7 +469,15 @@ Id EmitIdentity(EmitContext& ctx, const IR::Value& value) {
     return id;
 }
 
-void EmitDummyReference(EmitContext&) {}
+Id EmitConditionRef(EmitContext& ctx, const IR::Value& value) {
+    const Id id{ctx.Def(value)};
+    if (!Sirit::ValidId(id)) {
+        throw NotImplementedException("Forward identity declaration");
+    }
+    return id;
+}
+
+void EmitReference(EmitContext&) {}
 
 void EmitPhiMove(EmitContext&) {
     throw LogicError("Unreachable instruction");
diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h b/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
index 22260d2a9..1181e7b4f 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_instructions.h
@@ -23,7 +23,8 @@ class EmitContext;
 Id EmitPhi(EmitContext& ctx, IR::Inst* inst);
 void EmitVoid(EmitContext& ctx);
 Id EmitIdentity(EmitContext& ctx, const IR::Value& value);
-void EmitDummyReference(EmitContext&);
+Id EmitConditionRef(EmitContext& ctx, const IR::Value& value);
+void EmitReference(EmitContext&);
 void EmitPhiMove(EmitContext&);
 void EmitJoin(EmitContext& ctx);
 void EmitDemoteToHelperInvocation(EmitContext& ctx);