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Fix fuzzer nondeterminism #8886

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Merged
stevenfontanella merged 1 commit into from
Jul 7, 2026
+90 −59
Merged

Fix fuzzer nondeterminism #8886

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11 changes: 3 additions & 8 deletions src/tools/fuzzing/fuzzing.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5265,15 +5265,10 @@ Expression* TranslateToFuzzReader::makeAtomic(Type type) {
auto* ptr = makePointer();
if (oneIn(2)) {
auto* value = make(type);
auto op = pick(RMWAdd, RMWSub, RMWAnd, RMWOr, RMWXor, RMWXchg);
auto order = pick(atomicMemoryOrders);
return builder.makeAtomicRMW(
pick(RMWAdd, RMWSub, RMWAnd, RMWOr, RMWXor, RMWXchg),
bytes,
offset,
ptr,
value,
type,
wasm.memories[0]->name,
pick(atomicMemoryOrders));
op, bytes, offset, ptr, value, type, wasm.memories[0]->name, order);
} else {
auto* expected = make(type);
auto* replacement = make(type);
Expand Down
138 changes: 87 additions & 51 deletions test/passes/translate-to-fuzz_all-features_metrics_noprint.txt
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Original file line number Diff line number Diff line change
@@ -1,56 +1,92 @@
Metrics
total
[exports] : 9
[funcs] : 5
[globals] : 2
[imports] : 12
[exports] : 124
[funcs] : 223
[globals] : 13
[imports] : 13
[memories] : 1
[memory-data] : 16
[table-data] : 3
[memory-data] : 31
[table-data] : 40
[tables] : 2
[tags] : 2
[total] : 717
[vars] : 24
ArrayNew : 4
ArrayNewFixed : 9
AtomicFence : 2
AtomicNotify : 2
Binary : 40
Block : 114
BrOn : 3
Break : 24
Call : 15
CallRef : 3
Const : 122
Drop : 8
GlobalGet : 40
GlobalSet : 36
I31Get : 1
If : 34
Load : 7
LocalGet : 27
LocalSet : 36
Loop : 13
Nop : 19
Pop : 6
RefAs : 3
RefEq : 3
RefFunc : 10
RefI31 : 5
RefIsNull : 1
RefNull : 3
Return : 2
SIMDExtract : 5
Select : 3
Store : 4
StringConst : 15
StringEncode : 5
StringEq : 2
StringMeasure : 1
StructNew : 8
Try : 7
TryTable : 6
TupleExtract : 3
TupleMake : 7
Unary : 40
Unreachable : 19
[total] : 78541
[vars] : 4770
ArrayCmpxchg : 45
ArrayCopy : 41
ArrayFill : 38
ArrayGet : 391
ArrayLen : 602
ArrayNew : 1109
ArrayNewFixed : 415
ArrayRMW : 55
ArraySet : 82
AtomicCmpxchg : 37
AtomicFence : 74
AtomicNotify : 45
AtomicRMW : 63
Binary : 3946
Block : 7421
BrOn : 319
Break : 1166
Call : 1109
CallIndirect : 187
CallRef : 274
Const : 11911
ContBind : 1
ContNew : 29
DataDrop : 15
Drop : 598
GlobalGet : 4167
GlobalSet : 2340
I31Get : 67
If : 2686
Load : 364
LocalGet : 6969
LocalSet : 4277
Loop : 942
MemoryCopy : 16
MemoryFill : 9
MemoryInit : 14
Nop : 805
Pop : 323
RefAs : 4383
RefCast : 197
RefEq : 358
RefFunc : 1205
RefGetDesc : 59
RefI31 : 667
RefIsNull : 78
RefNull : 5442
RefTest : 78
Return : 363
SIMDExtract : 159
SIMDLoad : 2
SIMDReplace : 1
SIMDShift : 2
SIMDShuffle : 1
SIMDTernary : 1
Select : 348
Store : 185
StringConcat : 1
StringConst : 432
StringEncode : 59
StringEq : 60
StringMeasure : 77
StringNew : 8
StringWTF16Get : 98
StructCmpxchg : 50
StructGet : 560
StructNew : 5387
StructRMW : 55
StructSet : 79
Switch : 6
TableGet : 1
TableSet : 79
Throw : 114
ThrowRef : 8
Try : 426
TryTable : 532
TupleExtract : 253
TupleMake : 294
Unary : 2283
Unreachable : 1198
Binary file modified test/passes/translate-to-fuzz_all-features_metrics_noprint.wast
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