Matthew Pickering authored 2 years ago and Marge Bot committed 2 years ago

LLVM 15 turns on the new pass manager by default, which we have yet to
migrate to so for new we pass the `-enable-new-pm-0` flag in our
llvm-passes flag.

LLVM 11 was the first version to support the `-enable-new-pm` flag so we
bump the lowest supported version to 11.

Our CI jobs are using LLVM 12 so they should continue to work despite
this bump to the lower bound.

Fixes #21936

Ben Gamari authored 5 years ago and Marge Bot committed 5 years ago

@kavon says that this will improve block layout for stack checks.

This reverts commit adcb5fb4.

Kavon Farvardin authored 6 years ago and Ben Gamari committed 6 years ago

- Fix for #13904 -- stop "trashing" callee-saved registers, since it is
  not actually doing anything useful.

- Fix for #14251 -- fixes the calling convention for functions passing
  raw SSE-register values by adding padding as needed to get the values
  in the right registers. This problem cropped up when some args were
  unused an dropped from the live list.

- Fixed a typo in 'readnone' attribute

- Added 'lower-expect' pass to level 0 LLVM optimization passes to
  improve block layout in LLVM for stack checks, etc.

Test Plan: `make test WAYS=optllvm` and `make test WAYS=llvm`

Reviewers: bgamari, simonmar, angerman

Reviewed By: angerman

Subscribers: rwbarton, carter

GHC Trac Issues: #13904, #14251

Differential Revision: https://phabricator.haskell.org/D5190

Kavon Farvardin authored 6 years ago and Ben Gamari committed 6 years ago

To resolve ticket #11295, I think it makes sense to stop hard-coding
the pass sequences used by GHC when compiling with LLVM into the
compiler
itself.

This patchset introduces a companion to the existing `llvm-targets` file
called `llvm-passes`. The passes file is a simple association list that
holds the default LLVM `opt` pass sequence used by GHC. This allows end
users to easily save their favorite optimization flags when compiling
with LLVM.

The main benefit for ticket #11295 is that when adding a custom pass
sequence, it tends to be an extremely long string that would be
unsightly in the code.

This is essentially part 1 of 2 for ticket #11295.

Test Plan: ./validate

Reviewers: bgamari, angerman

Reviewed By: angerman

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4695