PPC64: [turbofan] Change TruncateFloat64ToUint64 to TryTruncateFloatToUint64.

src/compiler/ppc/code-generator-ppc.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 "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 1148 matching lines @@
     case kPPC_DoubleToUint32:
     case kPPC_DoubleToInt64:
       __ ConvertDoubleToInt64(i.InputDoubleRegister(0),
 #if !V8_TARGET_ARCH_PPC64
                               kScratchReg,
 #endif
                               i.OutputRegister(), kScratchDoubleReg);
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
 #if V8_TARGET_ARCH_PPC64
-    case kPPC_DoubleToUint64:
+    case kPPC_DoubleToUint64: {
+      bool check_conversion = (i.OutputCount() > 1);
+      if (check_conversion) {
+        __ mtfsb0(VXCVI);  // clear FPSCR:VXCVI bit
+      }
       __ ConvertDoubleToUnsignedInt64(i.InputDoubleRegister(0),
-                                      i.OutputRegister(), kScratchDoubleReg);
+                                      i.OutputRegister(0), kScratchDoubleReg);
+      if (check_conversion) {
+        // Set 2nd output to zero if conversion fails.
+        CRBit crbit = static_cast<CRBit>(VXCVI % CRWIDTH);
+        __ mcrfs(cr7, VXCVI);  // extract FPSCR field containing VXCVI into cr7
+        __ li(i.OutputRegister(1), Operand(1));
+        __ isel(i.OutputRegister(1), r0, i.OutputRegister(1),
+                v8::internal::Assembler::encode_crbit(cr7, crbit));
+      }
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
+    }
 #endif
     case kPPC_DoubleToFloat32:
       ASSEMBLE_FLOAT_UNOP_RC(frsp);
       break;
     case kPPC_Float32ToDouble:
       // Nothing to do.
       __ Move(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
     case kPPC_DoubleExtractLowWord32:
@@ skipping 586 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8