X87: [turbofan] Prevent storing signalling NaNs into holey double arrays.

src/compiler/x87/code-generator-x87.cc

 // Copyright 2013 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 1569 matching lines @@
       __ X87SetRC(0x0000);
       break;
     }
     case kX87Float64Cmp: {
       __ fld_d(MemOperand(esp, kDoubleSize));
       __ fld_d(MemOperand(esp, 0));
       __ FCmp();
       __ lea(esp, Operand(esp, 2 * kDoubleSize));
       break;
     }
+    case kX87Float64SilenceNaN: {
+      Label end, return_qnan;
+      __ fstp(0);
+      __ push(ebx);
+      // Load Half word of HoleNan(SNaN) into ebx
+      __ mov(ebx, MemOperand(esp, 2 * kInt32Size));
+      __ cmp(ebx, Immediate(kHoleNanUpper32));
+      // Check input is HoleNaN(SNaN)?
+      __ j(equal, &return_qnan, Label::kNear);
+      // If input isn't HoleNaN(SNaN), just load it and return
+      __ fld_d(MemOperand(esp, 1 * kInt32Size));
+      __ jmp(&end);
+      __ bind(&return_qnan);
+      // If input is HoleNaN(SNaN), Return QNaN
+      __ push(Immediate(0xffffffff));
+      __ push(Immediate(0xfff7ffff));
+      __ fld_d(MemOperand(esp, 0));
+      __ lea(esp, Operand(esp, kDoubleSize));
+      __ bind(&end);
+      __ pop(ebx);
+      // Clear stack.
+      __ lea(esp, Operand(esp, 1 * kDoubleSize));
+      break;
+    }
     case kX87Movsxbl:
       __ movsx_b(i.OutputRegister(), i.MemoryOperand());
       break;
     case kX87Movzxbl:
       __ movzx_b(i.OutputRegister(), i.MemoryOperand());
       break;
     case kX87Movb: {
       size_t index = 0;
       Operand operand = i.MemoryOperand(&index);
       if (HasImmediateInput(instr, index)) {
@@ skipping 956 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8