[all-commits] [llvm/llvm-project] 83c26e: [WebAssembly] Remove TEEs when dests are unstackified

[Heejin Ahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 83c26eae234964fd96546265bcb94295f95617f6
      https://github.com/llvm/llvm-project/commit/83c26eae234964fd96546265bcb94295f95617f6
  Author: Heejin Ahn <aheejin at gmail.com>
  Date:   2020-06-19 (Fri, 19 Jun 2020)

  Changed paths:
    M llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
    M llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll

  Log Message:
  -----------
  [WebAssembly] Remove TEEs when dests are unstackified

When created in RegStackify pass, `TEE` has two destinations, where
op0 is stackified and op1 is not. But it is possible that
op0 becomes unstackified in `fixUnwindMismatches` function in
CFGStackify pass when a nested try-catch-end is introduced, violating
the invariant of `TEE`s destinations.

In this case we convert the `TEE` into two `COPY`s, which will
eventually be resolved in ExplicitLocals.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D81851