[all-commits] [llvm/llvm-project] a1f6bb: [AArch64][GlobalISel] Emit G_ASSERT_ZEXT in assign...

[Jessica Paquette via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a1f6bb20db14ec72e2a01731dff222565eedb2ff
      https://github.com/llvm/llvm-project/commit/a1f6bb20db14ec72e2a01731dff222565eedb2ff
  Author: Jessica Paquette <jpaquette at apple.com>
  Date:   2021-02-03 (Wed, 03 Feb 2021)

  Changed paths:
    M llvm/lib/Target/AArch64/GISel/AArch64CallLowering.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/call-lowering-zeroext.ll

  Log Message:
  -----------
  [AArch64][GlobalISel] Emit G_ASSERT_ZEXT in assignValueToAddress for ZExt params

When we have a zeroext parameter coming in on the stack, build

```
%x = G_LOAD ...
%x_assert_zext = G_ASSERT_ZEXT %x, narrow_size
%trunc = G_TRUNC %x_assert_zext
```

Rather than just loading into the truncated type.

This allows us to optimize cases like this: https://godbolt.org/z/vfjhW8

Differential Revision: https://reviews.llvm.org/D95805