[antlr-interest] ANTLR performance
Kay Röpke
kroepke at classdump.org
Fri Jan 16 09:55:46 PST 2009
Hi!
On Jan 16, 2009, at 3:08 PM, Jan Obdržálek wrote:
>
> The grammar generates a pretty standard AST tree (definitely not a
> flat one). Turning off the tree-building mechanism made all the
> difference - it saved about 80% of the running time. Being on par with
> gcc here (although we still need to remember that gcc does a full
> compilation) is quite a nice result for a generated parser.
may i suggest using -ftime-report for gcc?
it gives you:
Execution times (seconds)
preprocessing : 0.07 (25%) usr 0.04 (26%) sys 0.11
(25%) wall
lexical analysis : 0.08 (28%) usr 0.07 (40%) sys 0.14
(31%) wall
parser : 0.08 (28%) usr 0.04 (23%) sys 0.11
(25%) wall
expand : 0.01 ( 2%) usr 0.00 ( 1%) sys 0.01
( 2%) wall
global alloc : 0.00 ( 2%) usr 0.00 ( 0%) sys 0.01
( 1%) wall
shorten branches : 0.00 ( 0%) usr 0.00 ( 0%) sys 0.02
( 4%) wall
symout : 0.01 ( 4%) usr 0.01 ( 3%) sys 0.02
( 4%) wall
TOTAL : 0.27 0.17 0.45
compilation often isn't as expensive as one might think...it's dealing
with strings that sucks ;)
-fmem-report is also interesting...
cheers,
-k
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