s390: preserve src register in MovIntToFloat

src/s390/macro-assembler-s390.cc

 // Copyright 2014 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 <assert.h>  // For assert
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/base/bits.h"
@@ skipping 3813 matching lines @@
 // Subtract Pointer Sized (Register - Memory)
 void MacroAssembler::SubP(Register dst, const MemOperand& opnd) {
 #if V8_TARGET_ARCH_S390X
   sg(dst, opnd);
 #else
   Sub32(dst, opnd);
 #endif
 }
 
 void MacroAssembler::MovIntToFloat(DoubleRegister dst, Register src) {
-  sllg(src, src, Operand(32));
-  ldgr(dst, src);
+  sllg(r0, src, Operand(32));
+  ldgr(dst, r0);
 }
 
 void MacroAssembler::MovFloatToInt(Register dst, DoubleRegister src) {
   lgdr(dst, src);
   srlg(dst, dst, Operand(32));
 }
 
 void MacroAssembler::SubP_ExtendSrc(Register dst, const MemOperand& opnd) {
 #if V8_TARGET_ARCH_S390X
   DCHECK(is_int20(opnd.offset()));
@@ skipping 1337 matching lines @@
   }
   if (mag.shift > 0) ShiftRightArith(result, result, Operand(mag.shift));
   ExtractBit(r0, dividend, 31);
   AddP(result, r0);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390