S390: Fix Mod64/ModU64 sequence

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

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 1147 matching lines @@
       }
       break;
     case kS390_Mod32:
       ASSEMBLE_MODULO(dr, srda);
       break;
     case kS390_ModU32:
       ASSEMBLE_MODULO(dlr, srdl);
       break;
 #if V8_TARGET_ARCH_S390X
     case kS390_Mod64:
-      ASSEMBLE_MODULO(dr, srda);
+      __ LoadRR(r1, i.InputRegister(0));
+      __ dsgr(r0, i.InputRegister(1));  // R1: Dividend
+      __ ltgr(i.OutputRegister(), r0);  // Copy R0: Remainder to output
       break;
     case kS390_ModU64:
-      ASSEMBLE_MODULO(dlr, srdl);
+      __ LoadRR(r1, i.InputRegister(0));
+      __ LoadImmP(r0, Operand::Zero());
+      __ dlgr(r0, i.InputRegister(1));  // R0:R1: Dividend
+      __ ltgr(i.OutputRegister(), r0);  // Copy R0: Remainder to output
       break;
 #endif
     case kS390_AbsFloat:
       __ lpebr(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_SqrtFloat:
       ASSEMBLE_FLOAT_UNOP(sqebr);
       break;
     case kS390_FloorFloat:
       //      ASSEMBLE_FLOAT_UNOP_RC(frim);
@@ skipping 880 matching lines @@
       padding_size -= 2;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8