Fix issue 18461 - Do not remove assignments to ambiguous symbols #8015
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src/dmd/backend/gother.c
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| continue; | ||
| /* Do not remove assignments to ambiguous values as | ||
| * they might be reached trough a pointer */ | ||
| if (!(v->Sflags & SFLunambig)) |
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I suspect the bug is elsewhere, as the testbit on b->Boutlv should take into account ambiguous values
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The variable doesn't escape the BB, that's why it's missing from there.
I've pushed another fix that's simpler and hopefully more correct.
Variables may be referenced via OPrelconst beside OPvar, take that into account.
| @@ -1488,6 +1488,7 @@ STATIC void accumda(elem *n,vec_t DEAD, vec_t POSS) | |||
| vec_free(Pr); vec_free(Dr); | |||
| break; | |||
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| case OPrelconst: | |||
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This is close, but not quite right. The fix is to add a case for OPbt. I'll work on that tomorrow.
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Turns out there was a bit more to fixing it. I rebooted it as #8065 Thank you for identifying where things were going wrong in the optimizer. That's 90% of the work in fixing this problem. This made it easy for me. |
If a value is reached through a pointer don't consider it as definitely
dead.
cc @WalterBright