Fix swapped mergeIf arguments in no-else case in Dataflow IR #8282
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…mbly#8273) In doVisitIf, when an if has no else branch, the two state arguments passed to mergeIf were in the wrong order. This caused the phi node to pair the "condition true" value with the initial state and the "condition false" value with the after-if-true state.
tlively
reviewed
Feb 10, 2026
| disjoint_sets.cpp | ||
| glbs.cpp | ||
| interpreter.cpp | ||
| ir-bug-verification.cpp |
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Summary
mergeIfarguments indoVisitIfwhen anifhas noelsebranchFixes #8273.
In the no-else case,
mergeIf(initialState, afterIfTrueState, ...)incorrectly paired the initial state (before the if body ran) with theifTruecondition and the after-if-true state with theifFalsecondition. The fix swaps the arguments tomergeIf(afterIfTrueState, initialState, ...), matching the convention used in the if-with-else case.Test plan
DataflowTest.IfNoElseMergeOrderGTest that builds a dataflow graph for an if-no-else function and verifies the phi node selects the correct values for each branch