Revision: 21906
Author: [email protected]
Date: Fri Jun 20 23:02:36 2014 UTC
Log: MIPS: Fix big-endian after r21774/r21803.
Fix big-endian ordering of InstanceType and BitField by always loading
the pair as a 16-bit value, even in the API accessor. Clean up some
assertions.
[email protected], [email protected]
Review URL: https://codereview.chromium.org/334403003
http://code.google.com/p/v8/source/detail?r=21906
Modified:
/branches/bleeding_edge/include/v8.h
/branches/bleeding_edge/src/hydrogen-instructions.h
/branches/bleeding_edge/src/objects.h
=======================================
--- /branches/bleeding_edge/include/v8.h Fri Jun 20 07:44:05 2014 UTC
+++ /branches/bleeding_edge/include/v8.h Fri Jun 20 23:02:36 2014 UTC
@@ -5523,7 +5523,8 @@
// These values match non-compiler-dependent values defined within
// the implementation of v8.
static const int kHeapObjectMapOffset = 0;
- static const int kMapInstanceTypeOffset = 1 * kApiPointerSize +
kApiIntSize;
+ static const int kMapInstanceTypeAndBitFieldOffset =
+ 1 * kApiPointerSize + kApiIntSize;
static const int kStringResourceOffset = 3 * kApiPointerSize;
static const int kOddballKindOffset = 3 * kApiPointerSize;
@@ -5601,7 +5602,9 @@
V8_INLINE static int GetInstanceType(const internal::Object* obj) {
typedef internal::Object O;
O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
- return ReadField<uint8_t>(map, kMapInstanceTypeOffset);
+ // Map::InstanceType is defined so that it will always be loaded into
+ // the LS 8 bits of one 16-bit word, regardless of endianess.
+ return ReadField<uint16_t>(map, kMapInstanceTypeAndBitFieldOffset) &
0xff;
}
V8_INLINE static int GetOddballKind(const internal::Object* obj) {
=======================================
--- /branches/bleeding_edge/src/hydrogen-instructions.h Fri Jun 20 11:26:17
2014 UTC
+++ /branches/bleeding_edge/src/hydrogen-instructions.h Fri Jun 20 23:02:36
2014 UTC
@@ -6094,10 +6094,12 @@
}
static HObjectAccess ForMapInstanceTypeAndBitField() {
- STATIC_ASSERT((Map::kInstanceTypeOffset & 1) == 0);
- STATIC_ASSERT(Map::kBitFieldOffset == Map::kInstanceTypeOffset + 1);
+ STATIC_ASSERT((Map::kInstanceTypeAndBitFieldOffset & 1) == 0);
+ // Ensure the two fields share one 16-bit word, endian-independent.
+ STATIC_ASSERT((Map::kBitFieldOffset & ~1) ==
+ (Map::kInstanceTypeOffset & ~1));
return HObjectAccess(kInobject,
- Map::kInstanceTypeOffset,
+ Map::kInstanceTypeAndBitFieldOffset,
Representation::UInteger16());
}
=======================================
--- /branches/bleeding_edge/src/objects.h Fri Jun 20 20:52:57 2014 UTC
+++ /branches/bleeding_edge/src/objects.h Fri Jun 20 23:02:36 2014 UTC
@@ -6704,17 +6704,20 @@
#if V8_TARGET_LITTLE_ENDIAN
// Order instance type and bit field together such that they can be
loaded
// together as a 16-bit word with instance type in the lower 8 bits
regardless
- // of endianess.
+ // of endianess. Also provide endian-independent offset to that 16-bit
word.
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
#else
static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
#endif
+ static const int kInstanceTypeAndBitFieldOffset =
+ kInstanceAttributesOffset + 0;
static const int kBitField2Offset = kInstanceAttributesOffset + 2;
static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset
+ 3;
- STATIC_ASSERT(kInstanceTypeOffset == Internals::kMapInstanceTypeOffset);
+ STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
+ Internals::kMapInstanceTypeAndBitFieldOffset);
// Bit positions for bit field.
static const int kHasNonInstancePrototype = 0;
--
--
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