Revision: 11283
Author: [email protected]
Date: Thu Apr 12 02:23:26 2012
Log: MIPS: NaNs in the snapshot should be quiet according
to the MIPS FPU even when cross-building the snapshot.
This is based on code from Daniel Kalmar from
http://codereview.chromium.org/9910029/
Review URL: https://chromiumcodereview.appspot.com/10068006
http://code.google.com/p/v8/source/detail?r=11283
Modified:
/branches/bleeding_edge/src/assembler.h
/branches/bleeding_edge/src/mips/assembler-mips.cc
/branches/bleeding_edge/src/mips/assembler-mips.h
/branches/bleeding_edge/src/serialize.cc
=======================================
--- /branches/bleeding_edge/src/assembler.h Thu Apr 5 07:10:39 2012
+++ /branches/bleeding_edge/src/assembler.h Thu Apr 12 02:23:26 2012
@@ -61,6 +61,10 @@
Isolate* isolate() const { return isolate_; }
int jit_cookie() { return jit_cookie_; }
+
+ // Overwrite a host NaN with a quiet target NaN. Used by mksnapshot for
+ // cross-snapshotting.
+ static void QuietNaN(HeapObject* nan) { }
private:
Isolate* isolate_;
=======================================
--- /branches/bleeding_edge/src/mips/assembler-mips.cc Thu Apr 5 08:18:22
2012
+++ /branches/bleeding_edge/src/mips/assembler-mips.cc Thu Apr 12 02:23:26
2012
@@ -2135,6 +2135,22 @@
UNREACHABLE();
return (Address)0x0;
}
+
+
+#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. We can't use set_value because
that
+ // will put the NaN in an fp register, which changes the bits.
+ uint64_t mips_qnan_bits =
+ (static_cast<uint64_t>(MIPS_QNAN_HI) << 32) | MIPS_QNAN_LO;
+ Address value_ptr = object->address() + HeapNumber::kValueOffset;
+ memcpy(value_ptr, &mips_qnan_bits, sizeof(mips_qnan_bits));
+}
// On Mips, a target address is stored in a lui/ori instruction pair, each
=======================================
--- /branches/bleeding_edge/src/mips/assembler-mips.h Thu Apr 5 08:18:22
2012
+++ /branches/bleeding_edge/src/mips/assembler-mips.h Thu Apr 12 02:23:26
2012
@@ -570,6 +570,8 @@
static void JumpLabelToJumpRegister(Address pc);
+ static void QuietNaN(HeapObject* nan);
+
// This sets the branch destination (which gets loaded at the call
address).
// This is for calls and branches within generated code. The serializer
// has already deserialized the lui/ori instructions etc.
=======================================
--- /branches/bleeding_edge/src/serialize.cc Wed Mar 21 07:29:14 2012
+++ /branches/bleeding_edge/src/serialize.cc Thu Apr 12 02:23:26 2012
@@ -1443,6 +1443,8 @@
sink_->Put(kNewPage, "NewPage");
sink_->PutSection(space, "NewPageSpace");
}
+
+ if (object_->IsNaN()) Assembler::QuietNaN(object_);
// Serialize the map (first word of the object).
serializer_->SerializeObject(object_->map(), kPlain, kStartOfObject);
--
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