[Libreoffice-commits] core.git: Branch 'libreoffice-4-3' - i18npool/source

[Michael Stahl]

 i18npool/source/transliteration/transliterationImpl.cxx |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

New commits:
commit 5e28588770fa27eb210d004aec2f56e28fe01252
Author: Michael Stahl <mstahl at redhat.com>
Date:   Fri Feb 20 20:57:59 2015 +0100

    tdf#89665: i18npool: fix pathological transliterate slow-path
    
    TransliterationImpl::transliterate() has a slow-path for the case when
    more than one trasliteration module is cascaded which swaps 2
    uno::Sequence.  This is unbelievably slow because non-const
    Sequence::operator[] does a function call into cppu to check whether COW
    has to be done.
    
    This speeds up transliterate() from 344 billion to 101 billion callgrind
    cycles when built with GCC 4.9.2 -m32 -Os.
    
    Commit d2771b63b94a8aae3c25c83e9dae9f83242f46c1 added a second
    transliteration module that is enabled by default, making the problem
    visible, especially with long paragraphs in Writer.
    
    Change-Id: I2799df9173ac73aab8c4eb4cc6f592976b06c8da
    (cherry picked from commit 88d4b2fb08b983531b1e0abc71b07f4bdecdc925)
    Reviewed-on: https://gerrit.libreoffice.org/14644
    Reviewed-by: Eike Rathke <erack at redhat.com>
    Tested-by: Eike Rathke <erack at redhat.com>

diff --git a/i18npool/source/transliteration/transliterationImpl.cxx b/i18npool/source/transliteration/transliterationImpl.cxx
index b9e4445..20d22f0 100644
--- a/i18npool/source/transliteration/transliterationImpl.cxx
+++ b/i18npool/source/transliteration/transliterationImpl.cxx
@@ -326,9 +326,17 @@ TransliterationImpl::transliterate( const OUString& inStr, sal_Int32 startPos, s
 
             nCount = tmpStr.getLength();
 
+            assert(off[from].getLength() == nCount);
             tmp = from; from = to; to = tmp;
+            // tdf#89665: don't use operator[] to write - too slow!
+            // interestingly gcc 4.9 -Os won't even inline the const operator[]
+            sal_Int32 const*const pFrom(off[from].getConstArray());
+            sal_Int32 *const pTo(off[to].getArray());
             for (sal_Int32 j = 0; j < nCount; j++)
-                off[to][j] = off[from][off[to][j]];
+            {
+                assert(pTo[j] < off[from].getLength());
+                pTo[j] = pFrom[pTo[j]];
+            }
         }
         offset = off[to];
         return tmpStr;