MIPS: NaNs in the snapshot should be quiet according

src/mips/assembler-mips.cc

Index: src/mips/assembler-mips.cc
===================================================================
--- src/mips/assembler-mips.cc	(revision 11280)
+++ src/mips/assembler-mips.cc	(working copy)
@@ -2137,6 +2137,21 @@
 }
 
 
+#define MIPS_QNAN_HI 0x7ff7ffff
+#define MIPS_QNAN_LO 0xffffffff
+
+
+void Assembler::QuietNaN(HeapObject* object) {
+  // Mips has a different encoding of qNaN than ia32, so any heap NaN built
+  // with simulator must be re-encoded for the snapshot. Performance hit not
+  // critical at mksnapshot/build time.
+  uint64_t mips_qnan_bits =
+      (static_cast<uint64_t>(MIPS_QNAN_HI) << 32) | MIPS_QNAN_LO;
+  Address value_ptr = object->address() + HeapNumber::kValueOffset;

[Vyacheslav Egorov (Chromium), 2012/04/12 09:22:05]

please comment why accessors do not work.

+  memcpy(value_ptr, &mips_qnan_bits, sizeof(mips_qnan_bits));
+}
+
+
 // On Mips, a target address is stored in a lui/ori instruction pair, each
 // of which load 16 bits of the 32-bit address to a register.
 // Patching the address must replace both instr, and flush the i-cache.