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Re: Serious performane degradation in bison (1.35 -> 1.75)
From: |
Akim Demaille |
Subject: |
Re: Serious performane degradation in bison (1.35 -> 1.75) |
Date: |
12 Nov 2002 12:19:08 +0100 |
User-agent: |
Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Honest Recruiter) |
| I was looking into updating our build environment to bison 1.75 (and
| possibly trying out the GLR parser). Besides the annoyance that bison
| will not run if not installed (can't find m4sugar otherwise),
Run tests/bison, not src/bison.
| I ran into this:
|
| address@hidden /home/tim/gnu/bison-cvs/src>time ./bison
| ~/xtools/src/coco/cobol.y -o tmp/cobol-grammar.c -d -g
|
| real 0m11.567s
| user 0m10.600s
| sys 0m0.391s
| address@hidden /home/tim/gnu/bison-cvs/src>time bison
| ~/xtools/src/coco/cobol.y -o tmp/cobol-grammar.c -d -g
|
| real 0m0.627s
| user 0m0.381s
| sys 0m0.064s
|
|
| I fear this is to blame on the m4 integration; given that this is a
| HUGE performance loss (2000% slower!!!), this should probably be
| addressed somehow. Just try to avoid bison4te.cache directories :-)
Yes, we are aware of this :( There are means to fix this issue: back
onto M4 again. The cycle is not completed yet, but M4 is scheduled.