tests/JitX64: Add tests for testing data processing instructions with Rd=R15

src/core/arm/dyncom/arm_dyncom_interpreter.cpp

@@ -3888,6 +3888,8 @@ unsigned InterpreterMainLoop(ARMul_State* cpu) {
     LOAD_NZCVT;
     DISPATCH:
     {
+        if (num_instrs >= cpu->NumInstrsToExecute) goto END;
+
         if (!cpu->NirqSig) {
             if (!(cpu->Cpsr & 0x80)) {
                 goto END;

src/core/arm/jit_x64/instructions/data_processing.cpp

@@ -49,10 +49,14 @@ void JitX64::CompileDataProcessingHelper_Reverse(ArmReg Rn_index, ArmReg Rd_inde
 
         body(tmp);
 
+        if (Rd_index != 15) {
             // TODO: Efficiency: Could implement this as a register rebind instead of needing to MOV.
             reg_alloc.LockAndDirtyArm(Rd_index);
             code->MOV(32, reg_alloc.ArmR(Rd_index), R(tmp));
             reg_alloc.UnlockArm(Rd_index);
+        } else {
+            code->MOV(32, MJitStateArmPC(), R(tmp));
+        }
 
         reg_alloc.UnlockTemp(tmp);
     }

src/core/arm/jit_x64/reg_alloc.h

@@ -61,7 +61,7 @@ private:
         ArmReg arm_reg = -1; ///< Only holds a valid value when state == DirtyArmReg / CleanArmReg
     };
 
-    std::array<ArmState, 15> arm_gpr;
+    std::array<ArmState, 16> arm_gpr;
     std::array<X64State, 16> x64_gpr;
 
     Gen::XEmitter* code = nullptr;

src/tests/core/arm/jit_x64/fuzz_arm_data_processing.cpp

@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <cstdio>
+#include <cstring>
 #include <random>
 
 #include <catch.hpp>
@@ -217,6 +218,34 @@ TEST_CASE("Fuzz ARM data processing instructions", "[JitX64]") {
         return instructions[inst_index].first | (assemble_randoms & (~instructions[inst_index].second));
     };
 
-    FuzzJit(5, 10000, instruction_select_without_R15);
+    SECTION("short blocks") {
-    FuzzJit(1024, 500, instruction_select_without_R15);
+        FuzzJit(5, 5000, instruction_select_without_R15);
+    }
+
+    SECTION("long blocks") {
+        FuzzJit(1024, 200, instruction_select_without_R15);
+    }
+
+    auto instruction_select_only_R15 = [&]() -> u32 {
+        size_t inst_index = RandInt(0, instructions.size() - 1);
+
+        u32 cond = 0xE;
+        // Have a one-in-twenty-five chance of actually having a cond.
+        if (RandInt(1, 25) == 1) {
+            cond = RandInt(0x0, 0xD);
+        }
+
+        u32 Rn = RandInt(0, 15);
+        u32 Rd = 15;
+        u32 S = 0;
+        u32 shifter_operand = RandInt(0, 0xFFF);
+
+        u32 assemble_randoms = (shifter_operand << 0) | (Rd << 12) | (Rn << 16) | (S << 20) | (cond << 28);
+
+        return instructions[inst_index].first | (assemble_randoms & (~instructions[inst_index].second));
+    };
+
+    SECTION("R15") {
+        FuzzJit(1, 10000, instruction_select_only_R15);
+    }
 }