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| author | Andreas Klebinger <klebinger.andreas@gmx.at> | 2021-11-13 15:18:27 +0100 |
|---|---|---|
| committer | Andreas Klebinger <klebinger.andreas@gmx.at> | 2022-05-12 21:57:03 +0200 |
| commit | d99152db02424b50854ab5d379d6e84d3f4260af (patch) | |
| tree | b01f922780ac867b03df8365837b9ce1426b2671 /docs/users_guide/using-optimisation.rst | |
| parent | a4fbb589fd176e6c2f6648dea6c93e25668f1db8 (diff) | |
| download | haskell-wip/andreask/cmm_aliasing.tar.gz | |
Cmm: Sink - Track hp aliasing.wip/andreask/cmm_aliasing
See Note [Heap Kinds]. We now split heap into "new" and "old" heap
for the purpose of determining memory conflicts during CmmSink.
With an assumption that writes to memory via [Hp] don't conflict
with reads from regular heap memory.
We can turn this on/off with the new flag -fcmm-sink-alias which is now
enabled at -O2 by default.
This fixes the issues laid out in #20679.
-------------------------
Metric Increase:
T9233
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Diffstat (limited to 'docs/users_guide/using-optimisation.rst')
| -rw-r--r-- | docs/users_guide/using-optimisation.rst | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/docs/users_guide/using-optimisation.rst b/docs/users_guide/using-optimisation.rst index ab49f08ade..2db1455186 100644 --- a/docs/users_guide/using-optimisation.rst +++ b/docs/users_guide/using-optimisation.rst @@ -225,6 +225,17 @@ by saying ``-fno-wombat``. to their usage sites. It also inlines simple expressions like literals or registers. +.. ghc-flag:: -fcmm-sink-alias + :shortdesc: Enable more complex aliasing analysis to improve the sinking pass. Implied by :ghc-flag:`-O2`. + :type: dynamic + :reverse: -fno-cmm-sink + :category: + + :default: off but enabled with :ghc-flag:`-O2`. + + This allows us to remove more intermediate variables in the Cmm pass. + For some programs this can avoid excessive spilling. + .. ghc-flag:: -fcmm-static-pred :shortdesc: Enable static control flow prediction. Implied by :ghc-flag:`-O`. :type: dynamic |