gl_shader_decompiler: Implement IADD instruction.

src/video_core/engines/shader_bytecode.h

@@ -264,7 +264,7 @@ union Instruction {
         BitField<39, 5, u64> shift_amount;
         BitField<48, 1, u64> negate_b;
         BitField<49, 1, u64> negate_a;
-    } iscadd;
+    } alu_integer;
 
     union {
         BitField<20, 8, u64> shift_position;
@@ -434,6 +434,9 @@ public:
         FMUL_R,
         FMUL_IMM,
         FMUL32_IMM,
+        IADD_C,
+        IADD_R,
+        IADD_IMM,
         ISCADD_C, // Scale and Add
         ISCADD_R,
         ISCADD_IMM,
@@ -489,10 +492,10 @@ public:
     enum class Type {
         Trivial,
         Arithmetic,
+        ArithmeticInteger,
         Bfe,
         Logic,
         Shift,
-        ScaledAdd,
         Ffma,
         Flow,
         Memory,
@@ -617,9 +620,12 @@ private:
             INST("0101110001101---", Id::FMUL_R, Type::Arithmetic, "FMUL_R"),
             INST("0011100-01101---", Id::FMUL_IMM, Type::Arithmetic, "FMUL_IMM"),
             INST("00011110--------", Id::FMUL32_IMM, Type::Arithmetic, "FMUL32_IMM"),
-            INST("0100110000011---", Id::ISCADD_C, Type::ScaledAdd, "ISCADD_C"),
-            INST("0101110000011---", Id::ISCADD_R, Type::ScaledAdd, "ISCADD_R"),
-            INST("0011100-00011---", Id::ISCADD_IMM, Type::ScaledAdd, "ISCADD_IMM"),
+            INST("0100110000010---", Id::IADD_C, Type::ArithmeticInteger, "IADD_C"),
+            INST("0101110000010---", Id::IADD_R, Type::ArithmeticInteger, "IADD_R"),
+            INST("0011100-00010---", Id::IADD_IMM, Type::ArithmeticInteger, "IADD_IMM"),
+            INST("0100110000011---", Id::ISCADD_C, Type::ArithmeticInteger, "ISCADD_C"),
+            INST("0101110000011---", Id::ISCADD_R, Type::ArithmeticInteger, "ISCADD_R"),
+            INST("0011100-00011---", Id::ISCADD_IMM, Type::ArithmeticInteger, "ISCADD_IMM"),
             INST("0101000010000---", Id::MUFU, Type::Arithmetic, "MUFU"),
             INST("0100110010010---", Id::RRO_C, Type::Arithmetic, "RRO_C"),
             INST("0101110010010---", Id::RRO_R, Type::Arithmetic, "RRO_R"),

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -992,13 +992,13 @@ private:
             break;
         }
 
-        case OpCode::Type::ScaledAdd: {
+        case OpCode::Type::ArithmeticInteger: {
             std::string op_a = regs.GetRegisterAsInteger(instr.gpr8);
 
-            if (instr.iscadd.negate_a)
+            if (instr.alu_integer.negate_a)
                 op_a = '-' + op_a;
 
-            std::string op_b = instr.iscadd.negate_b ? "-" : "";
+            std::string op_b = instr.alu_integer.negate_b ? "-" : "";
 
             if (instr.is_b_imm) {
                 op_b += '(' + std::to_string(instr.alu.GetSignedImm20_20()) + ')';
@@ -1011,10 +1011,30 @@ private:
                 }
             }
 
-            std::string shift = std::to_string(instr.iscadd.shift_amount.Value());
+            switch (opcode->GetId()) {
+            case OpCode::Id::IADD_C:
+            case OpCode::Id::IADD_R:
+            case OpCode::Id::IADD_IMM: {
+                ASSERT_MSG(!instr.saturate_a, "Unimplemented");
+                regs.SetRegisterToInteger(instr.gpr0, true, 0, op_a + " + " + op_b, 1, 1);
+                break;
+            }
+            case OpCode::Id::ISCADD_C:
+            case OpCode::Id::ISCADD_R:
+            case OpCode::Id::ISCADD_IMM: {
+                std::string shift = std::to_string(instr.alu_integer.shift_amount.Value());
+
+                regs.SetRegisterToInteger(instr.gpr0, true, 0,
+                                          "((" + op_a + " << " + shift + ") + " + op_b + ')', 1, 1);
+                break;
+            }
+            default: {
+                NGLOG_CRITICAL(HW_GPU, "Unhandled ArithmeticInteger instruction: {}",
+                               opcode->GetName());
+                UNREACHABLE();
+            }
+            }
 
-            regs.SetRegisterToInteger(instr.gpr0, true, 0,
-                                      "((" + op_a + " << " + shift + ") + " + op_b + ')', 1, 1);
             break;
         }
         case OpCode::Type::Ffma: {