s390: use new mul instruction

src/s390/macro-assembler-s390.cc

Index: src/s390/macro-assembler-s390.cc
diff --git a/src/s390/macro-assembler-s390.cc b/src/s390/macro-assembler-s390.cc
index ef82606012a04b5f5d841034509738d10d2375e0..744fc475fadde833c8a6bb1d77fdb175cdef65eb 100644
--- a/src/s390/macro-assembler-s390.cc
+++ b/src/s390/macro-assembler-s390.cc
@@ -3364,13 +3364,17 @@ void MacroAssembler::Mul64(Register dst, const Operand& src1) {
 }
 
 void MacroAssembler::Mul(Register dst, Register src1, Register src2) {
-  if (dst.is(src2)) {
-    MulP(dst, src1);
-  } else if (dst.is(src1)) {
-    MulP(dst, src2);
+  if (CpuFeatures::IsSupported(MISC_INSTR_EXT2)) {
+    MulPWithCondition(dst, src1, src2);
   } else {
-    Move(dst, src1);
-    MulP(dst, src2);
+    if (dst.is(src2)) {
+      MulP(dst, src1);
+    } else if (dst.is(src1)) {
+      MulP(dst, src2);
+    } else {
+      Move(dst, src1);
+      MulP(dst, src2);
+    }
   }
 }
 
@@ -3502,6 +3506,16 @@ void MacroAssembler::MulP(Register dst, Register src) {
 #endif
 }
 
+void MacroAssembler::MulPWithCondition(Register dst, Register src1,
+                                       Register src2) {
+  CHECK(CpuFeatures::IsSupported(MISC_INSTR_EXT2));
+#if V8_TARGET_ARCH_S390X
+  msgrkc(dst, src1, src2);
+#else
+  msrkc(dst, src1, src2);
+#endif
+}
+
 void MacroAssembler::MulP(Register dst, const MemOperand& opnd) {
 #if V8_TARGET_ARCH_S390X
   if (is_uint16(opnd.offset())) {