[PATCH] D92744: [WebAssembly] Fix code generated for atomic operations in PIC mode

[Sam Clegg via Phabricator via llvm-commits]

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The main this this test does is to add the IsNotPIC predicate to the all
the atomic instrucitons pattern that directlyr refer to `tglobaladdr`.

This is because in PIC mode we need to generate seperate instruciton
sequence (either a direct global.get, or __memory_base + offset) for
accessing global addreses.

As part of this change I noticed that many of the `Requires` attributes
added to the instruction in `WebAssemblyInstrAtomics.td` were being
honored.  This is because the wrapped in a `let Predicates =
[HasAtomics]` block and it seems that that outer wrapping overrides any
`Requires` on defs within it.   As a workaround I removed the outer
`let` and added `HasAtomics` to all the inner `Requires`.  I believe
that all the instrucitons that don't have `Requires` explcity bottom out
in `ATOMIC_I` and `ATOMIC_NRI` which have `HasAtomics` so this should
not remove this predicate from any patterns (at least that is the idea).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D92744

Files:
  llvm/lib/Target/WebAssembly/WebAssemblyInstrAtomics.td
  llvm/test/CodeGen/WebAssembly/atomic-pic.ll
  llvm/test/CodeGen/WebAssembly/offset-atomics.ll

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