SIL: Fix memory behavior of mark_dependence #79110
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… values. We want to keep the original lifetime of the base. If we would eliminate the base alloc_stack, we risk to insert a destroy_addr too early.
If the base value of a mark_dependence is an address, that memory location must be initialized at the mark_dependence. This requires that the mark_dependence is considered to read from the base address.
The check is not perfect, because it only checks that the base operand is alive _at_ the mark_dependence. Ideally it should check that the base operand is alive during the whole lifetime of the value operand.
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If the base value of a
mark_dependenceis an address, that memory location must be initialized at themark_dependence.This requires that the
mark_dependenceis considered to read from the base address.Also, verify that the base value is initialized in the MemoryLifetimeVerifier.
The check is not perfect, because it only checks that the base operand is alive at the mark_dependence. Ideally it should check that the base operand is alive during the whole lifetime of the value operand.
The verification uncovered a problem in TempRValueOptimization which is fixed by not optimizing copies to
mark_dependencebase values.