QIR Runner disagrees with Simulator #3781

Activity

1. Andrew Casey (amcasey)

   added

   bugSomething isn't workingSomething isn't working

   needs triage

   on Oct 2, 2026
2. Andrew Casey (amcasey)

   added sub-issues on Oct 2, 2026

   • [Miscompile] Callable chosen by a condition: changing the condition in a later loop changes which callable runs #3791
   • [Miscompile] Callable chosen by a condition: writing the condition inside the same branch changes which callable runs #3792
   • [Miscompile] Callable read from an array by a mutable index: the index is read again at the call #3793
   • [Miscompile] let f = if Op() {X} else {I}: the condition's side effects run at every call of f #3794
   • [Miscompile] Partial application: the fixed arguments are evaluated when the callable is called, not when it's created #3795
   • [Miscompile] Closure returned from a function reads the caller's argument variable at call time #3796
   • [Miscompile] Tuple == / != repeats, skips and reorders side effects in its operands #3797
   • [Miscompile] set s = new P { A = s.B, B = s.A } assigns the fields one after another #3798
   • [Miscompile] set (a, b) = (b, a) of runtime values gives (b, b) #3799
   • [Miscompile] An array literal holds a reference to a mutable, not its value #3800
   • [Miscompile] An assignment inside a compile-time if/for/while is lost when a later branch isn't taken #3801
   • [Miscompile] An assignment in the skipped right operand of and/or still takes effect #3802
   • [Miscompile] Doubles that differ by less than 2.2e-16 are treated as equal when merging branches #3803
3. 4 remaining items

   Load more
4. Andrew Casey (amcasey)

   added sub-issues on Oct 2, 2026

   • [Miscompile] Adaptive: let h = n aliases n after store pruning, so set n = 7 changes h #3808
   • [Miscompile] Adaptive: let h = n inside a runtime branch aliases n when n has a known value #3809
   • [Miscompile] Adaptive: a value assigned inside a loop leaks out even when the loop body never runs #3810
   • [Miscompile] Adaptive: let t = a inside a loop aliases a #3811
   • [Miscompile] Adaptive: every level of a recursive operation reads the innermost level's measurement #3812
   • [Miscompile] Adaptive: Double array literals that differ by less than 2.2e-16 are merged #3813
   • [Miscompile] Adaptive: a Qubit-typed mutable produces invalid QIR #3814
   • [Miscompile] Adaptive: a user function named like a math intrinsic produces invalid QIR #3815
   • [Miscompile] Adaptive: a runtime-indexed read used in a later block is the element's address, not its value #3816
   • [Miscompile] Incorrect SSA aliasing #3769
   • [Miscompile] Incorrect defunctionalization #3768
5. Stefan J. Wernli (swernli)

   added a commit that references this issue on Oct 7, 2026

   More comprehensive update for variable updates in static exprs

   ...

   This issue will close once commit 1cb7c86 is merged into the 'main' branch.

   1cb7c86
6. Andrew Casey (amcasey)

   added sub-issues on Oct 9, 2026

   • Adaptive_RI/RIF: a copy of a mutable, read inside a later runtime branch, loses its value #3908
   • [Miscompile] A global phase controlled by two or more qubits is dropped in QIR (Controlled R1, R(PauliI, …), all-identity Exp) #3927
   • [Type check] An and/or whose right operand returns counts as divergent, so a non-Unit function can end without a value #3929