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bug#11935: XINT etc. should be functions
From: |
Paul Eggert |
Subject: |
bug#11935: XINT etc. should be functions |
Date: |
Sat, 08 Jun 2013 17:52:05 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 |
On 06/06/13 09:42, Stefan Monnier wrote:
> Having XCONS and friends duplicated into a macro version and a function
> version is a non-starter for me.
Yes, I didn't like those macros either. I'll remove them; they're no
longer needed now that GCC has the -Og option. In case you haven't
run into it yet, -Og means "optimize for debugging", and causes GCC to
generate code that's easy to debug, without having the big runtime
performance penalty of -O0.
Like -O2 but unlike -O0, with -Og the CPU time for my little Lisp
nthcdr benchmark is unaffected by the proposed patch (assuming those
macros are removed). C compilation time is considerably faster for
-Og than for -O2; it's not as fast as -O0, but for the common case of
changing one C source file and then typing "make emacs", -Og is faster
than -O0 (because bootstrap-emacs runs faster) and is a tad faster
than -O2 (because the C compiler runs faster).
Here are the detailed times, if you're curious. I got these on a
Fedora 17 x86-64 (AMD Phenom II X4 910e) that was otherwise unloaded.
I used plain 'make' without parallelism. Everything was built with
GCC 4.8.1 and with Texinfo 5.1. All times are user+system CPU times;
the low-order digits of the times aren't that reliable.
(benchmark make \ rm fns.o; rm *.o; make \
100000) xdisp.o make emacs make emacs bootstrap
-O0 unpatched 2.89 3.1 12.4 57 1099
-O0 patched 21.66 3.0 20.0 63 2442
-Og unpatched 1.15 5.9 9.2 80 860
-Og patched 1.15 6.4 9.5 87 879
-O2 unpatched 1.57 11.3 9.6 110 843
-O2 patched 1.57 11.1 9.9 119 847
In (benchmark 100000) the -Og code runs faster than -O2, which is
surprising, but I think it's an anomaly; I may find the time to fire
off a performance bug-report to the GCC developers.
- bug#11935: XINT etc. should be functions, Paul Eggert, 2013/06/06
- bug#11935: XINT etc. should be functions, Andreas Schwab, 2013/06/06
- bug#11935: XINT etc. should be functions, Stefan Monnier, 2013/06/06
- bug#11935: XINT etc. should be functions,
Paul Eggert <=
- bug#11935: XINT etc. should be functions, Paul Eggert, 2013/06/09
- bug#11935: XINT etc. should be functions, Stefan Monnier, 2013/06/09
- bug#11935: XINT etc. should be functions, Paul Eggert, 2013/06/13
- bug#11935: XINT etc. should be functions, Stefan Monnier, 2013/06/13
- bug#11935: XINT etc. should be functions, Paul Eggert, 2013/06/15
- bug#11935: XINT etc. should be functions, Stefan Monnier, 2013/06/15
- bug#11935: XINT etc. should be functions, Paul Eggert, 2013/06/17