C++/C#: Fix missing virtual variables#2629
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rdmarsh2 merged 1 commit intogithub:masterfrom Jan 15, 2020
dbartol:dbartol/missing-vvars
Merged
C++/C#: Fix missing virtual variables#2629rdmarsh2 merged 1 commit intogithub:masterfrom dbartol:dbartol/missing-vvars
rdmarsh2 merged 1 commit intogithub:masterfrom
dbartol:dbartol/missing-vvars
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The aliased SSA code was assuming that, for every automatic variable, there would be at least one memory access that reads or writes the entire variable. We've encountered a couple cases where that isn't true due to extractor issues. As a workaround, we now always create the `VariableMemoryLocation` for every local variable. I've also added a sanity test to detect this condition in the future. Along the way, I had to fix a perf issue in the PrintIR code. When determining the ID of a result based on line number, we were considering all `Instruction`s generated for a particular line, regardless of whether they were all in the same `IRFunction`. In addition, the predicate had what appeared to be a bad join order that made it take forever on large snapshots. I've scoped it down to just consider `Instruction`s in the same function, and outlined that predicate to fix the join order issue. This causes some numbering changes, but they're for the better. I don't think there was actually any nondeterminism there before, but now the numbering won't depend on the number of instantiations of a template, either.
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The aliased SSA code was assuming that, for every automatic variable, there would be at least one memory access that reads or writes the entire variable. We've encountered a couple cases where that isn't true due to extractor issues. As a workaround, we now always create the
VariableMemoryLocationfor every local variable.I've also added a sanity test to detect this condition in the future.
Along the way, I had to fix a perf issue in the PrintIR code. When determining the ID of a result based on line number, we were considering all
Instructions generated for a particular line, regardless of whether they were all in the sameIRFunction. In addition, the predicate had what appeared to be a bad join order that made it take forever on large snapshots. I've scoped it down to just considerInstructions in the same function, and outlined that predicate to fix the join order issue. This causes some numbering changes, but they're for the better. I don't think there was actually any nondeterminism there before, but now the numbering won't depend on the number of instantiations of a template, either.