update llir/llvm to support 12.0

[dannypsnl]

• 2021/03/11 https://www.phoronix.com/scan.php?page=news_item&px=LLVM-12.0-RC3-Released
• 2021/04/01 https://www.phoronix.com/scan.php?page=news_item&px=LLVM-12.0-rc4-Released

NOTE: send pull requests to branch llvm12.

Changes to LLVM IR

• Added the byref attribute to better represent argument passing for the amdgpu_kernel calling convention.
• Added type parameter to the sret attribute to continue work on removing pointer element types.
• The llvm.experimental.vector.reduce family of intrinsics has been renamed to drop the “experimental” from the name, reflecting their now fully supported status in the IR.

[mewmew]

LLVM 12.0 has now been released https://github.com/llvm/llvm-project/releases/tag/llvmorg-12.0.0

Release announcement: https://releases.llvm.org/12.0.0/docs/ReleaseNotes.html

[mewmew]

The work updating llir/llvm to support LLVM 12.0 is similar to that done for supporting LLVM 11.0. See #147 and #158 for reference.

[dannypsnl]

Compare ASM parser changes:

$ wget https://github.com/llvm/llvm-project/archive/llvmorg-11.0.0.tar.gz
$ wget https://github.com/llvm/llvm-project/archive/llvmorg-12.0.0.tar.gz
$ tar zxf llvmorg-11.0.0.tar.gz
$ tar zxf llvmorg-12.0.0.tar.gz
$ git diff llvm-project-llvmorg-11.0.0/llvm/lib/AsmParser llvm-project-llvmorg-12.0.0/llvm/lib/AsmParser

I cannot paste the result this time since

[dannypsnl]

Instead of pasting the result, I would create a diff file, delete the updated part from it in PR.

[mewmew]

I cannot paste the result this time since

Post as a GitHub gist file? https://gist.github.com/

[dannypsnl]

I cannot paste the result this time since

Post as a GitHub gist file? https://gist.github.com/

I want to track with PR, using diff file can see changes, maybe put it at llir/grammar?

update

and gist is personal I remember? Then we cannot track changes.

[mewmew]

I want to track with PR, using diff file can see changes, maybe put it at llir/grammar?

You can keep it in llir/llvm (or llir/grammar if you prefer), as both repos have to be updated in either case. So long as we keep the diff in a branch, and then remove the diff before merging it should be possible to keep repository size down.

and gist is personal I remember? Then we cannot track changes.

Fair point. Keep the diff in the llvm-12 branch is a good idea then.

[mewmew]

Added type parameter to the sret attribute to continue work on removing pointer element types.

ref: llir/ll#7 and llir/ll#8.

[dannypsnl]

@mewmew would you like to start working on test cases updating?

[mewmew]

@mewmew would you like to start working on test cases updating?

If you would like to try updating the test cases this time, then feel free. Otherwise, I can update them later on. I'll be heading out on vacation soon; will be tenting this weekend and then going for a longer trek in the south of Sweden starting next week.

[mewmew]

@mewmew would you like to start working on test cases updating?

I had some time left over :) So sent a PR for updating the test cases: llir/testdata#9

There are currently 1 known parse error (see #195 (comment))

• Test cases failing with syntax error:
  • testdata/llvm/test/Bitcode/compatibility.ll (line 46)

[mewmew]

Translating AST to IR

• support for *ast.StructRetAttr not yet implemented

l-tm testdata/llvm/test/DebugInfo/ARM/selectiondag-deadcode.ll
# Output:
# === [ testdata/llvm/test/DebugInfo/ARM/selectiondag-deadcode.ll ] =======================
# 
# panic: support for parameter attribute *ast.StructRetAttr not yet implemented
#
# goroutine 1 [running]:
# github.com/llir/llvm/asm.(*generator).irParamAttribute(0x686bd8, {0x7f0ffd834390, 0xc00000e1a0})
#	/home/u/life/projects/github.com/llir/llvm/asm/helper.go:630 +0x693

Edit: fixed in commit a84775f.

• dso_local_equivalent
  • fixed in commit 78aeedd
• poison
  • fixed in commit 29ebd5a