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| author | klebinger.andreas@gmx.at <klebinger.andreas@gmx.at> | 2018-06-03 00:37:59 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-06-03 00:38:07 -0400 |
| commit | f68c2cb60f881a0a41ae2e8cafc5de193ef9c3fb (patch) | |
| tree | 43c63e49469e8e04f0f67338b9b7830298fca2b8 /docs/users_guide/debugging.rst | |
| parent | 9b7eec8614f531e20a34e8dd2f62293ab0fedf8c (diff) | |
| download | haskell-f68c2cb60f881a0a41ae2e8cafc5de193ef9c3fb.tar.gz | |
Allow aligning of cmm procs at specific boundry
Allows to align CmmProcs at the given boundries.
It makes performance usually worse but can be helpful
to limit the effect of a unrelated function B becoming
faster/slower after changing function A.
Test Plan: ci, using it.
Reviewers: bgamari
Reviewed By: bgamari
Subscribers: rwbarton, thomie, carter
GHC Trac Issues: #15148
Differential Revision: https://phabricator.haskell.org/D4706
Diffstat (limited to 'docs/users_guide/debugging.rst')
| -rw-r--r-- | docs/users_guide/debugging.rst | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/docs/users_guide/debugging.rst b/docs/users_guide/debugging.rst index 4e0be937f4..7adcc84f13 100644 --- a/docs/users_guide/debugging.rst +++ b/docs/users_guide/debugging.rst @@ -758,6 +758,17 @@ Checking for consistency Compile with alignment checks for all info table dereferences. This can be useful when finding pointer tagging issues. +.. ghc-flag:: -fproc-alignment + :shortdesc: Align functions at given boundry. + :type: dynamic + + Align functions to multiples of the given value. Only valid values are powers + of two. + + ``-fproc-alignment=64`` can be used to limit alignment impact on performance + as each function will start at a cache line. + However forcing larger alignments in general reduces performance. + .. ghc-flag:: -fcatch-bottoms :shortdesc: Insert ``error`` expressions after bottoming expressions; useful when debugging the compiler. |