[turbofan] Fixed a bug in TryTruncateFloatXXToInt64 with INT64_MIN.

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index e22c3441f38f5048a74b7b212ce666cc997b1bfe..b4b8a2945f06304aa757688eb1cc8970d438cab8 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -1046,6 +1046,11 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
         __ Fccmp(i.InputFloat32Register(0), i.InputFloat32Register(0), VFlag,
                  vc);
         __ Cset(i.OutputRegister(1), vc);

[jbramley, 2015/12/16 12:47:01]

This can now be a simple "__ Mov(i.OutputRegister(1), 1)". In the !vc case, it
gets overwritten anyway.

The same applies for Float64ToInt64.

[ahaas, 2015/12/16 14:35:23]

Done.

+        Label done;
+        __ B(vc, &done);
+        __ Fcmp(i.InputFloat32Register(0), -9223372036854775808.0f);

[jbramley, 2015/12/16 12:47:01]

Consider using "static_cast<float>(-INT64_MIN)" here to make the intention
clear.

[Michael Starzinger, 2015/12/16 13:01:29]

+1, magic number is being magic, please use a named value.

[ahaas, 2015/12/16 14:35:23]

Done.

+        __ Cset(i.OutputRegister(1), eq);
+        __ Bind(&done);
       }
       break;
     case kArm64Float64ToInt64:
@@ -1055,6 +1060,11 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
         __ Ccmp(i.OutputRegister(0), -1, VFlag, vc);
         __ Fccmp(i.InputDoubleRegister(0), i.InputDoubleRegister(0), VFlag, vc);
         __ Cset(i.OutputRegister(1), vc);
+        Label done;
+        __ B(vc, &done);
+        __ Fcmp(i.InputDoubleRegister(0), -9223372036854775808.0f);

[jbramley, 2015/12/16 12:47:01]

Ditto. (Otherwise, remove the "f" since this is a double.)

[Michael Starzinger, 2015/12/16 13:01:29]

+1

[ahaas, 2015/12/16 14:35:23]

Done.

+        __ Cset(i.OutputRegister(1), eq);
+        __ Bind(&done);
       }
       break;
     case kArm64Float32ToUint64: