#7258: Compiling DynFlags is jolly slow
-------------------------------------+-------------------------------------
Reporter: simonpj | Owner: simonpj
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.6.1
Resolution: | Keywords: deriving-perf
Operating System: Unknown/Multiple | Architecture:
Type of failure: Compile-time | Unknown/Multiple
performance bug | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ben Gamari ):
In [changeset:"43537568579a63cb6b8d70b4815d76c46bb9a692/ghc" 4353756/ghc]:
{{{
#!CommitTicketReference repository="ghc"
revision="43537568579a63cb6b8d70b4815d76c46bb9a692"
CmmSink: Use a IntSet instead of a list
CmmProcs which have *lots* of local variables take a considerable
amount of time in CmmSink. This was noticed by @tdammers in #7258
while compiling files with large records (~200-400 fields).
Before:
```
Sun Oct 29 19:58 2017 Time and Allocation Profiling Report (Final)
ghc-stage2 +RTS -p -RTS
-B/Users/alexbiehl/git/ghc/inplace/lib /Users/alexbiehl/Downloads/W2.hs
-fforce-recomp -O2
total time = 26.00 secs (25996 ticks @ 1000 us, 1
processor)
total alloc = 14,921,627,912 bytes (excludes profiling overheads)
COST CENTRE MODULE SRC %time %alloc
sink CmmPipeline
compiler/cmm/CmmPipeline.hs:(104,13)-(105,59) 55.7 15.9
SimplTopBinds SimplCore compiler/simplCore/SimplCore.hs:761:39-74 19.5
30.6
FloatOutwards SimplCore compiler/simplCore/SimplCore.hs:471:40-66 4.2
9.0
RegAlloc-linear AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(658,27)-(660,55) 4.0 11.1
pprNativeCode AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(529,37)-(530,65) 2.8 6.3
NewStranal SimplCore compiler/simplCore/SimplCore.hs:480:40-63 1.6
3.7
OccAnal SimplCore
compiler/simplCore/SimplCore.hs:(739,22)-(740,67) 1.5 3.5
StgCmm HscMain compiler/main/HscMain.hs:(1426,13)-(1427,62)
1.2 2.4
regLiveness AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(591,17)-(593,52) 1.2 1.9
genMachCode AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(580,17)-(582,62) 0.9 1.8
NativeCodeGen CodeOutput compiler/main/CodeOutput.hs:171:18-78 0.9
2.1
CoreTidy HscMain compiler/main/HscMain.hs:1253:27-67 0.8 1.9
```
After:
```
Sun Oct 29 19:18 2017 Time and Allocation Profiling Report (Final)
ghc-stage2 +RTS -p -RTS
-B/Users/alexbiehl/git/ghc/inplace/lib /Users/alexbiehl/Downloads/W2.hs
-fforce-recomp -O2
total time = 13.31 secs (13307 ticks @ 1000 us, 1
processor)
total alloc = 15,772,184,488 bytes (excludes profiling overheads)
COST CENTRE MODULE SRC %time %alloc
SimplTopBinds SimplCore
compiler/simplCore/SimplCore.hs:761:39-74 38.3 29.0
sink CmmPipeline compiler/cmm/CmmPipeline.hs:(104,13)-(105,59)
13.2 20.3
RegAlloc-linear AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(658,27)-(660,55) 8.3 10.5
FloatOutwards SimplCore compiler/simplCore/SimplCore.hs:471:40-66
8.1 8.5
pprNativeCode AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(529,37)-(530,65) 5.4 5.9
NewStranal SimplCore compiler/simplCore/SimplCore.hs:480:40-63
3.1 3.5
OccAnal SimplCore
compiler/simplCore/SimplCore.hs:(739,22)-(740,67) 2.9 3.3
StgCmm HscMain compiler/main/HscMain.hs:(1426,13)-(1427,62)
2.3 2.3
regLiveness AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(591,17)-(593,52) 2.1 1.8
NativeCodeGen CodeOutput compiler/main/CodeOutput.hs:171:18-78 1.7
2.0
genMachCode AsmCodeGen
compiler/nativeGen/AsmCodeGen.hs:(580,17)-(582,62) 1.6 1.7
CoreTidy HscMain compiler/main/HscMain.hs:1253:27-67 1.4
1.8
foldNodesBwdOO Hoopl.Dataflow
compiler/cmm/Hoopl/Dataflow.hs:(397,1)-(403,17) 1.1 0.8
```
Reviewers: austin, bgamari, simonmar
Reviewed By: bgamari
Subscribers: duog, rwbarton, thomie, tdammers
GHC Trac Issues: #7258
Differential Revision: https://phabricator.haskell.org/D4145
}}}
--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7258#comment:79
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler
