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[wasm] Reorder WasmInstanceObject fields for alignment

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While pointer-compression still doesn't guarantee 8-byte alignment
for objects, the WasmInstanceObject definition should be prepared
for a future where that changes.
No behavioral differences are expected from this, and likely no
performance differences for now either.

Change-Id: Iedd85f4361d45e1e3cf5d645496b9ad34acf533b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3038527
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75855}
This commit is contained in:
Jakob Kummerow 2021-07-21 16:01:48 +02:00 committed by V8 LUCI CQ
parent 9a12f2736b
commit da63900c50
1 changed files with 14 additions and 11 deletions
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25
src/wasm/wasm-objects.h
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@ -389,27 +389,36 @@ class V8_EXPORT_PRIVATE WasmInstanceObject : public JSObject {
// Layout description.
#define WASM_INSTANCE_OBJECT_FIELDS(V) \
/* Often-accessed fields go first to minimize generated code size. */ \
/* Less than system pointer sized fields come first. */ \
V(kImportedFunctionRefsOffset, kTaggedSize) \
V(kIndirectFunctionTableRefsOffset, kTaggedSize) \
V(kIndirectFunctionTableSizeOffset, kUInt32Size) \
/* Optional padding to align system pointer size fields */ \
V(kOptionalPaddingOffset, POINTER_SIZE_PADDING(kOptionalPaddingOffset)) \
V(kMemoryStartOffset, kSystemPointerSize) \
V(kMemorySizeOffset, kSizetSize) \
V(kMemoryMaskOffset, kSizetSize) \
V(kStackLimitAddressOffset, kSystemPointerSize) \
V(kImportedFunctionRefsOffset, kTaggedSize) \
V(kImportedFunctionTargetsOffset, kSystemPointerSize) \
V(kIndirectFunctionTableRefsOffset, kTaggedSize) \
V(kIndirectFunctionTableTargetsOffset, kSystemPointerSize) \
V(kIndirectFunctionTableSigIdsOffset, kSystemPointerSize) \
V(kIndirectFunctionTableSizeOffset, kUInt32Size) \
/* Optional padding to align system pointer size fields */ \
V(kOptionalPaddingOffset, POINTER_SIZE_PADDING(kOptionalPaddingOffset)) \
V(kGlobalsStartOffset, kSystemPointerSize) \
V(kImportedMutableGlobalsOffset, kSystemPointerSize) \
V(kIsolateRootOffset, kSystemPointerSize) \
V(kJumpTableStartOffset, kSystemPointerSize) \
/* End of often-accessed fields. */ \
/* Continue with system pointer size fields to maintain alignment. */ \
V(kNewAllocationLimitAddressOffset, kSystemPointerSize) \
V(kNewAllocationTopAddressOffset, kSystemPointerSize) \
V(kOldAllocationLimitAddressOffset, kSystemPointerSize) \
V(kOldAllocationTopAddressOffset, kSystemPointerSize) \
V(kRealStackLimitAddressOffset, kSystemPointerSize) \
V(kDataSegmentStartsOffset, kSystemPointerSize) \
V(kDataSegmentSizesOffset, kSystemPointerSize) \
V(kDroppedElemSegmentsOffset, kSystemPointerSize) \
V(kHookOnFunctionCallAddressOffset, kSystemPointerSize) \
V(kNumLiftoffFunctionCallsArrayOffset, kSystemPointerSize) \
/* Less than system pointer size aligned fields are below. */ \
V(kModuleObjectOffset, kTaggedSize) \
V(kExportsObjectOffset, kTaggedSize) \
V(kNativeContextOffset, kTaggedSize) \
@ -423,12 +432,6 @@ class V8_EXPORT_PRIVATE WasmInstanceObject : public JSObject {
V(kExceptionsTableOffset, kTaggedSize) \
V(kWasmExternalFunctionsOffset, kTaggedSize) \
V(kManagedObjectMapsOffset, kTaggedSize) \
V(kRealStackLimitAddressOffset, kSystemPointerSize) \
V(kDataSegmentStartsOffset, kSystemPointerSize) \
V(kDataSegmentSizesOffset, kSystemPointerSize) \
V(kDroppedElemSegmentsOffset, kSystemPointerSize) \
V(kHookOnFunctionCallAddressOffset, kSystemPointerSize) \
V(kNumLiftoffFunctionCallsArrayOffset, kSystemPointerSize) \
V(kBreakOnEntryOffset, kUInt8Size) \
/* More padding to make the header pointer-size aligned */ \
V(kHeaderPaddingOffset, POINTER_SIZE_PADDING(kHeaderPaddingOffset)) \