s390: Optimize LoadDoubleLiteral

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 4316 matching lines @@
   llilf(dst, Operand(value));
 #endif
 }
 
 void MacroAssembler::LoadDoubleLiteral(DoubleRegister result, uint64_t value,
                                        Register scratch) {
   uint32_t hi_32 = value >> 32;
   uint32_t lo_32 = static_cast<uint32_t>(value);
 
   // Load the 64-bit value into a GPR, then transfer it to FPR via LDGR
-  iihf(scratch, Operand(hi_32));
-  iilf(scratch, Operand(lo_32));
-  ldgr(result, scratch);
+  if (value == 0) {
+    lzdr(result);
+  } else if (lo_32 == 0) {
+    llihf(scratch, Operand(hi_32));
+    ldgr(result, scratch);
+  } else {
+    iihf(scratch, Operand(hi_32));
+    iilf(scratch, Operand(lo_32));
+    ldgr(result, scratch);
+  }
 }
 
 void MacroAssembler::LoadDoubleLiteral(DoubleRegister result, double value,
                                        Register scratch) {
   uint64_t int_val = bit_cast<uint64_t, double>(value);
   LoadDoubleLiteral(result, int_val, scratch);
 }
 
 void MacroAssembler::LoadFloat32Literal(DoubleRegister result, float value,
                                         Register scratch) {
-  uint32_t hi_32 = bit_cast<uint32_t>(value);
-  uint32_t lo_32 = 0;
-
-  // Load the 64-bit value into a GPR, then transfer it to FPR via LDGR
-  iihf(scratch, Operand(hi_32));
-  iilf(scratch, Operand(lo_32));
-  ldgr(result, scratch);
+  uint64_t int_val = static_cast<uint64_t>(bit_cast<uint32_t, float>(value))
+                     << 32;
+  LoadDoubleLiteral(result, int_val, scratch);
 }
 
 void MacroAssembler::CmpSmiLiteral(Register src1, Smi* smi, Register scratch) {
 #if V8_TARGET_ARCH_S390X
   if (CpuFeatures::IsSupported(DISTINCT_OPS)) {
     cih(src1, Operand(reinterpret_cast<intptr_t>(smi) >> 32));
   } else {
     LoadSmiLiteral(scratch, smi);
     cgr(src1, scratch);
   }
@@ skipping 760 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