A32: Implement ARM-mode MLS

src/frontend/A32/decoder/arm.inc

@@ -199,6 +199,7 @@ INST(arm_UDIV,          "UDIV",                "cccc01110011dddd1111mmmm0001nnnn
 
 // Multiply (Normal) instructions
 INST(arm_MLA,           "MLA",                 "cccc0000001Sddddaaaammmm1001nnnn") // v2
+INST(arm_MLS,           "MLS",                 "cccc00000110ddddaaaammmm1001nnnn") // v6T2
 INST(arm_MUL,           "MUL",                 "cccc0000000Sdddd0000mmmm1001nnnn") // v2
 
 // Multiply (Long) instructions

src/frontend/A32/disassembler/disassembler_arm.cpp

@@ -664,6 +664,9 @@ public:
     std::string arm_MLA(Cond cond, bool S, Reg d, Reg a, Reg m, Reg n) {
         return fmt::format("mla{}{} {}, {}, {}, {}", S ? "s" : "", CondToString(cond), d, n, m, a);
     }
+    std::string arm_MLS(Cond cond, Reg d, Reg a, Reg m, Reg n) {
+        return fmt::format("mls{} {}, {}, {}, {}", CondToString(cond), d, n, m, a);
+    }
     std::string arm_MUL(Cond cond, bool S, Reg d, Reg m, Reg n) {
         return fmt::format("mul{}{} {}, {}, {}", S ? "s" : "", CondToString(cond), d, n, m);
     }

src/frontend/A32/translate/translate_arm/multiply.cpp

@@ -28,6 +28,25 @@ bool ArmTranslatorVisitor::arm_MLA(Cond cond, bool S, Reg d, Reg a, Reg m, Reg n
     return true;
 }
 
+// MLS<c> <Rd>, <Rn>, <Rm>, <Ra>
+bool ArmTranslatorVisitor::arm_MLS(Cond cond, Reg d, Reg a, Reg m, Reg n) {
+    if (d == Reg::PC || a == Reg::PC || m == Reg::PC || n == Reg::PC) {
+        return UnpredictableInstruction();
+    }
+
+    if (!ConditionPassed(cond)) {
+        return true;
+    }
+
+    const IR::U32 operand1 = ir.GetRegister(n);
+    const IR::U32 operand2 = ir.GetRegister(m);
+    const IR::U32 operand3 = ir.GetRegister(a);
+    const IR::U32 result = ir.Sub(operand3, ir.Mul(operand1, operand2));
+
+    ir.SetRegister(d, result);
+    return true;
+}
+
 // MUL{S}<c> <Rd>, <Rn>, <Rm>
 bool ArmTranslatorVisitor::arm_MUL(Cond cond, bool S, Reg d, Reg m, Reg n) {
     if (d == Reg::PC || n == Reg::PC || m == Reg::PC) {

src/frontend/A32/translate/translate_arm/translate_arm.h

@@ -242,6 +242,7 @@ struct ArmTranslatorVisitor final {
 
     // Multiply (Normal) instructions
     bool arm_MLA(Cond cond, bool S, Reg d, Reg a, Reg m, Reg n);
+    bool arm_MLS(Cond cond, Reg d, Reg a, Reg m, Reg n);
     bool arm_MUL(Cond cond, bool S, Reg d, Reg m, Reg n);
 
     // Multiply (Long) instructions

tests/A32/fuzz_arm.cpp

@@ -848,6 +848,7 @@ TEST_CASE("Fuzz ARM multiply instructions", "[JitX64][A32]") {
 
     const std::array instructions = {
         InstructionGenerator("cccc0000001Sddddaaaammmm1001nnnn", validate_d_a_m_n), // MLA
+        InstructionGenerator("cccc00000110ddddaaaammmm1001nnnn", validate_d_a_m_n), // MLS
         InstructionGenerator("cccc0000000Sdddd0000mmmm1001nnnn", validate_d_m_n),   // MUL
 
         InstructionGenerator("cccc0000111Sddddaaaammmm1001nnnn", validate_h_l_m_n), // SMLAL