S390: [wasm] Int64Lowering of Int64Mul on ia32 and arm.

src/compiler/s390/code-generator-s390.cc

Index: src/compiler/s390/code-generator-s390.cc
diff --git a/src/compiler/s390/code-generator-s390.cc b/src/compiler/s390/code-generator-s390.cc
index 2759c50dbdd649e2a85b132a4796385c9569a03a..b6b8c2e328610f22b340350861f457d4956474ff 100644
--- a/src/compiler/s390/code-generator-s390.cc
+++ b/src/compiler/s390/code-generator-s390.cc
@@ -882,6 +882,19 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ SubLogicalWithBorrow32(i.OutputRegister(1), i.InputRegister(1),
                                 i.InputRegister(3));
       break;
+    case kS390_MulPair:
+      // i.InputRegister(0) ... left low word.
+      // i.InputRegister(1) ... left high word.
+      // i.InputRegister(2) ... right low word.
+      // i.InputRegister(3) ... right high word.
+      __ sllg(r0, i.InputRegister(1), Operand(32));
+      __ sllg(r1, i.InputRegister(3), Operand(32));
+      __ lr(r0, i.InputRegister(0));
+      __ lr(r1, i.InputRegister(2));
+      __ msgr(r1, r0);
+      __ lr(i.OutputRegister(0), r1);
+      __ srag(i.OutputRegister(1), r1, Operand(32));
+      break;
     case kS390_ShiftLeftPair:
       if (instr->InputAt(2)->IsImmediate()) {
         __ ShiftLeftPair(i.OutputRegister(0), i.OutputRegister(1),