diff options
Diffstat (limited to 'compilerplugins')
| -rwxr-xr-x | compilerplugins/clang/pahole-all-classes.py | 66 | ||||
| -rw-r--r-- | compilerplugins/clang/pahole.results | 66 |
2 files changed, 38 insertions, 94 deletions
diff --git a/compilerplugins/clang/pahole-all-classes.py b/compilerplugins/clang/pahole-all-classes.py index 9fda73c8789f..088e9cad2949 100755 --- a/compilerplugins/clang/pahole-all-classes.py +++ b/compilerplugins/clang/pahole-all-classes.py @@ -3,11 +3,15 @@ # Find holes in structures, so that we can pack them and improve our memory density. # # In order to make this work, you need to -# (1) be operating in a workspace where you have a debug build of LibreOffice -# (2) first run the unusedfields loplugin to generate a log file -# (3) install the pahole stuff into your gdb, I used this one: https://github.com/PhilArmstrong/pahole-gdb -# (4) ./compilerplugins/clang/pahole-all-classes.py > ./compilerplugins/clang/pahole.results -# Warning: running this script will make GDB soak up about 8G of RAM +# (1) Be operating in a workspace where you have a __NON-DEBUG__ build of LibreOffice, but __WITH SYMBOLS__. +# (A debug build has different sizes for some things in the standard library.) +# (2) First run the unusedfields loplugin to generate a log file +# (3) Install the pahole stuff into your gdb, I used this one: +# https://github.com/PhilArmstrong/pahole-gdb +# (4) Edit the loop near the top of the script to only produce results for one of our modules. +# Note that this will make GDB soak up about 8G of RAM, which is why I don't do more than one module at a time +# (5) Run the script +# ./compilerplugins/clang/pahole-all-classes.py > ./compilerplugins/clang/pahole.results # import _thread @@ -19,7 +23,7 @@ import re # search for all the class names in the file produced by the unusedfields loplugin #a = subprocess.Popen("grep 'definition:' workdir/loplugin.unusedfields.log | sort -u", stdout=subprocess.PIPE, shell=True) -a = subprocess.Popen("cat n1", stdout=subprocess.PIPE, shell=True) +a = subprocess.Popen("cat ../libo/n1", stdout=subprocess.PIPE, shell=True) classSourceLocDict = dict() classSet = set() @@ -28,13 +32,14 @@ with a.stdout as txt: tokens = line.decode('utf8').strip().split("\t") className = tokens[2].strip() srcLoc = tokens[5].strip() + # ignore things like unions if "anonymous" in className: continue - # for now, just check the stuff in /sc/inc - if not srcLoc.startswith("sc/inc/"): - continue + # ignore duplicates if className in classSet: continue - classSourceLocDict[srcLoc] = className - classSet.add(className) + # for now, just check the stuff in /sc/inc + if srcLoc.startswith("a"): + classSourceLocDict[srcLoc] = className + classSet.add(className) a.terminate() gdbProc = subprocess.Popen("gdb", stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=True) @@ -65,8 +70,6 @@ def write_pahole_commands(): _thread.start_new_thread( write_pahole_commands, () ) -time.sleep(2) - # Use generator because lines often end up merged together in gdb's output, and we need # to split them up, and that creates a mess in the parsing logic. def read_generator(): @@ -79,13 +82,17 @@ def read_generator(): yield split firstLineRegex = re.compile("/\*\s+(\d+)\s+\*/ struct") -fieldLineRegex = re.compile("/\*\s+\d+\s+(\d+)\s+\*/ ") +fieldLineRegex = re.compile("/\*\s+(\d+)\s+(\d+)\s+\*/ ") holeLineRegex = re.compile("/\* XXX (\d+) bit hole, try to pack \*/") +# sometimes pahole can't determine the size of a sub-struct, and then it returns bad data +bogusLineRegex = re.compile("/\*\s+\d+\s+0\s+\*/") structLines = list() foundHole = False cumulativeHoleBits = 0 structSize = 0 -found8ByteField = False +foundBogusLine = False +# pahole doesn't report space at the end of the structure, so work it out myself +sizeOfFields = 0 for line in read_generator(): structLines.append(line) firstLineMatch = firstLineRegex.match(line) @@ -97,27 +104,30 @@ for line in read_generator(): cumulativeHoleBits += int(holeLineMatch.group(1)) fieldLineMatch = fieldLineRegex.match(line) if fieldLineMatch: - fieldSize = int(fieldLineMatch.group(1)) - if fieldSize == 8: - found8ByteField = True + fieldSize = int(fieldLineMatch.group(2)) + sizeOfFields = int(fieldLineMatch.group(1)) + fieldSize + if bogusLineRegex.match(line): + foundBogusLine = True if line == "}": # Ignore very large structs, packing those is not going to help much, and # re-organising them can make them much less readable. - if foundHole and len(structLines) < 12 and structSize < 100: - # If we have an 8-byte field, then the whole structure must be 8-byte aligned, otherwise - # it must be 4-byte aligned. (that's my approximation of the rules, the real ones are probably - # more complicated). So check if removing the holes will remove enough space to actually shrink - # this structure. - alignBytes = 4 - if found8ByteField: alignBytes = 8 - if (cumulativeHoleBits / 8) >= alignBytes: - # print("Found one " + str(structSize) + " " + str(cumulativeHoleBits/8) + " " + str(newStructSize%4)) + if foundHole and len(structLines) < 12 and structSize < 100 and not foundBogusLine: + # Verify that we have enough hole-space that removing it will result in a structure + # that still satifies alignment requirements, otherwise the compiler will just put empty + # space at the end of the struct. + # TODO improve detection of the required alignment for a structure + potentialSpace = (cumulativeHoleBits / 8) + (sizeOfFields - structSize) + if potentialSpace >= 8: for line in structLines: print(line) + if (sizeOfFields - structSize) > 0: + print("hole at end of struct: " + str(sizeOfFields - structSize)) + # reset state structLines.clear() foundHole = False cumulativeHoleBits = 0 structSize = 0 - found8ByteField = False + foundBogusLine = False + actualStructSize = 0 gdbProc.terminate()
\ No newline at end of file diff --git a/compilerplugins/clang/pahole.results b/compilerplugins/clang/pahole.results deleted file mode 100644 index 5d7129eb31a5..000000000000 --- a/compilerplugins/clang/pahole.results +++ /dev/null @@ -1,66 +0,0 @@ -ScColorScaleEntry sc/inc/colorscale.hxx:46 -/* 48 */ struct ScColorScaleEntry { -/* 0 8 */ double mnVal -/* 8 4 */ class Color maColor -/* XXX 32 bit hole, try to pack */ -/* 16 8 */ class std::unique_ptr<ScFormulaCell, std::default_delete<ScFormulaCell> > mpCell -/* 24 8 */ class std::unique_ptr<ScFormulaListener, std::default_delete<ScFormulaListener> > mpListener -/* 32 4 */ enum ScColorScaleEntryType meType -/* XXX 32 bit hole, try to pack */ -/* 40 8 */ class ScConditionalFormat * mpFormat -} -ScDetOpList sc/inc/detdata.hxx:66 -/* 64 */ struct ScDetOpList { -/* 0 1 */ bool bHasAddError -/* XXX 56 bit hole, try to pack */ -/* 8 56 */ class std::__debug::vector<std::unique_ptr<ScDetOpData, std::default_delete<ScDetOpData> >, std::allocator<std::unique_ptr<ScDetOpData, std::default_delete<ScDetOpData> > > > aDetOpDataVector -} -ScDocRowHeightUpdater::TabRanges sc/inc/dociter.hxx:569 -/* 24 */ struct ScDocRowHeightUpdater::TabRanges { -/* 0 2 */ short mnTab -/* XXX 48 bit hole, try to pack */ -/* 8 16 */ class std::shared_ptr<ScFlatBoolRowSegments> mpRanges -} -ScPivotField sc/inc/pivot.hxx:122 -/* 56 */ struct ScPivotField { -/* 0 2 */ short nCol -/* XXX 48 bit hole, try to pack */ -/* 8 8 */ long mnOriginalDim -/* 16 4 */ enum PivotFunc nFuncMask -/* 20 1 */ unsigned char mnDupCount -/* XXX 24 bit hole, try to pack */ -/* 24 32 */ struct com::sun::star::sheet::DataPilotFieldReference maFieldRef -} -ScPivotFuncData sc/inc/pivot.hxx:164 -/* 56 */ struct ScPivotFuncData { -/* 0 2 */ short mnCol -/* XXX 48 bit hole, try to pack */ -/* 8 8 */ long mnOriginalDim -/* 16 4 */ enum PivotFunc mnFuncMask -/* 20 1 */ unsigned char mnDupCount -/* XXX 24 bit hole, try to pack */ -/* 24 32 */ struct com::sun::star::sheet::DataPilotFieldReference maFieldRef -} -ScExternalSingleRefToken sc/inc/token.hxx:131 -/* 56 */ struct ScExternalSingleRefToken { -/* 0 16 */ class formula::FormulaToken formula::FormulaToken -/* 16 2 */ const unsigned short mnFileId -/* XXX 48 bit hole, try to pack */ -/* 24 16 */ const class svl::SharedString maTabName -/* 40 12 */ struct ScSingleRefData maSingleRef -} -ScExternalDoubleRefToken sc/inc/token.hxx:155 -/* 64 */ struct ScExternalDoubleRefToken { -/* 0 16 */ class formula::FormulaToken formula::FormulaToken -/* 16 2 */ const unsigned short mnFileId -/* XXX 48 bit hole, try to pack */ -/* 24 16 */ const class svl::SharedString maTabName -/* 40 24 */ struct ScComplexRefData maDoubleRef -} -ScExternalNameToken sc/inc/token.hxx:182 -/* 40 */ struct ScExternalNameToken { -/* 0 16 */ class formula::FormulaToken formula::FormulaToken -/* 16 2 */ const unsigned short mnFileId -/* XXX 48 bit hole, try to pack */ -/* 24 16 */ const class svl::SharedString maName -} |