[all-commits] [llvm/llvm-project] b13f6b: BypassSlowDivision: Fix dropping debug info

[Matt Arsenault via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b13f6b0fe0263ea53f628652d31ec0983ca6b751
      https://github.com/llvm/llvm-project/commit/b13f6b0fe0263ea53f628652d31ec0983ca6b751
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2020-06-18 (Thu, 18 Jun 2020)

  Changed paths:
    M llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
    A llvm/test/Transforms/CodeGenPrepare/AMDGPU/bypass-slow-div-debug-info.ll

  Log Message:
  -----------
  BypassSlowDivision: Fix dropping debug info

I don't know anything about debug info, but this seems like more work
should be necessary. This constructs a new IRBuilder and reconstructs
the original divides rather than moving the original.

One problem this has is if a div/rem pair are handled, both end up
with the same debugloc. I'm not sure how to fix this, since this uses
a cache when it sees the same input operands again, which will have
the first instance's location attached.


  Commit: ae5adb8da561fa4dd59915e4c97358278fb610a9
      https://github.com/llvm/llvm-project/commit/ae5adb8da561fa4dd59915e4c97358278fb610a9
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2020-06-18 (Thu, 18 Jun 2020)

  Changed paths:
    M llvm/docs/AMDGPUUsage.rst

  Log Message:
  -----------
  AMDGPU: Update private null pointer value in documentation

Private pointers used to workaround IR semantics by artifically
reserving an object at offset 0 so no user object would be allocated
there. Since alloca now uses a non-0 address space, that workaround is
unnecssary and 0 can be treated as a valid pointer.


Compare: https://github.com/llvm/llvm-project/compare/27505565515e...ae5adb8da561