[turbofan] Change TruncateFloat32ToInt64 to TryTruncateFloat32ToInt64.

src/compiler/mips64/code-generator-mips64.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/ast/scopes.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
@@ skipping 1039 matching lines @@
     }
     case kMips64TruncWD: {
       FPURegister scratch = kScratchDoubleReg;
       // Other arches use round to zero here, so we follow.
       __ trunc_w_d(scratch, i.InputDoubleRegister(0));
       __ mfc1(i.OutputRegister(), scratch);
       break;
     }
     case kMips64TruncLS: {
       FPURegister scratch = kScratchDoubleReg;
+      Register tmp_fcsr = kScratchReg;
+      Register result = kScratchReg2;
+
+      bool load_status = instr->OutputCount() > 1;
+      if (load_status) {
+        // Save FCSR.
+        __ cfc1(tmp_fcsr, FCSR);
+        // Clear FPU flags.
+        __ ctc1(zero_reg, FCSR);
+      }
       // Other arches use round to zero here, so we follow.
       __ trunc_l_s(scratch, i.InputDoubleRegister(0));
       __ dmfc1(i.OutputRegister(), scratch);
+      if (load_status) {
+        __ cfc1(result, FCSR);
+        // Check for overflow and NaNs.
+        __ andi(result, result,
+                (kFCSROverflowFlagMask | kFCSRInvalidOpFlagMask));
+        __ Slt(result, zero_reg, result);
+        __ xori(result, result, 1);
+        __ mov(i.OutputRegister(1), result);
+        // Restore FCSR
+        __ ctc1(tmp_fcsr, FCSR);
+      }
       break;
     }
     case kMips64TruncLD: {
       FPURegister scratch = kScratchDoubleReg;
       Register tmp_fcsr = kScratchReg;
       Register result = kScratchReg2;
 
       bool load_status = instr->OutputCount() > 1;
       if (load_status) {
         // Save FCSR.
@@ skipping 753 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8