[gsharp-devel] redraw buglets

[Christophe Rhodes]

Christophe Rhodes <csr21 at cam.ac.uk> writes:

> Can you give me instructions on what you're doing to trigger the
> redraw?  Alternatively, you may wish to try this running under the
> statistical profiler provided by sbcl -- loaded with (require
> :sb-sprof).

I've played around with this idea a little, and have some slightly
surprising results.  Apparently, at least for sbcl, the bottleneck is
bignum gcd.  The top 20 functions (statistically sampled by loading
rapsoden-sjunger.gsh into gsharp and then leaning on C-f) are

   1    231   6.2    231   6.2 SB-BIGNUM:BIGNUM-GCD
   2    177   4.8    408  11.0 "&MORE processing"
   3    164   4.4    572  15.5 SB-BIGNUM::MAKE-GCD-BIGNUM-ODD
   4    140   3.8    712  19.3 "#'(LAMBDA (SB-PCL::.PV-CELL. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0. ...) (DECLARE #) ...)"
   5    129   3.5    841  22.8 SB-BIGNUM::SUBTRACT-BIGNUM-BUFFERS
   6    116   3.1    957  25.9 "#'(SB-KERNEL:INSTANCE-LAMBDA (SB-PCL::.ARG0.) (LET NIL # ...))"
   7    116   3.1   1073  29.0 SB-KERNEL:TWO-ARG-+
   8     99   2.7   1172  31.7 SB-BIGNUM::BIGNUM-BUFFER-ASHIFT-RIGHT
   9     91   2.5   1263  34.2 ASH
  10     83   2.2   1346  36.4 "#'(SB-KERNEL:INSTANCE-LAMBDA (SB-PCL::.ARG0. SB-PCL::.ARG1.) (LET NIL # ...))"
  11     80   2.2   1426  38.6 SB-BIGNUM::BIGNUM-GCD-ORDER-AND-SUBTRACT
  12     77   2.1   1503  40.7 SB-KERNEL:CLASSOID-TYPEP
  13     77   2.1   1580  42.7 SB-KERNEL::%%TYPEP
  14     63   1.7   1643  44.5 SB-VM::GENERIC-+
  15     56   1.5   1699  46.0 SB-BIGNUM::BIGNUM-TRUNCATE-SINGLE-DIGIT
  16     54   1.5   1753  47.4 SB-KERNEL::INTEGER-/-INTEGER
  17     53   1.4   1806  48.9 SB-BIGNUM::%NORMALIZE-BIGNUM-BUFFER
  18     53   1.4   1859  50.3 "hairy arg processor for top level local call SB!BIGNUM::BIGNUM-ASHIFT-LEFT-UNALIGNED"
  19     52   1.4   1911  51.7 GETHASH
  20     51   1.4   1962  53.1 TRUNCATE

Unfortunately, this isn't yielding information about why it's spending
so much time in GCD, though my suspicion would land on integer or
ratio division.

[ No, I don't know what "&MORE processing" is doing quite so high: it
  seems to be connected to certain methods, particuarly
  MAP-OVER-OUTPUT-RECORDS-CONTAINING-POSITION ]

Cheers,

Christophe
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