[PATCH] D149563: [TRE] don't escape callsite if its alloca argument is readonly

[Eli Friedman via Phabricator via llvm-commits]

efriedma requested changes to this revision.
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A call cannot be marked `tail` if it may read or write to an alloca in the same function.  There are basically two ways to to "read or write": either the pointer is passed as an argument, or it's captured.

For the function `@test16` in the given testcase, neither call can be marked `tail`.  The call to `@use_readonly` can obviously read the alloca.  The call to `@use_readonly` can also capture the address of the alloca, so the call to `@noarg` can also read the alloca.


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  https://reviews.llvm.org/D149563/new/

https://reviews.llvm.org/D149563