PATCH 21.5 This change improves performance for VM with large folder a little, though it’s not a complete solution. In particular, when hitting q in a modified folder with index files turned on and non-ASCII bytes in the buffer, #'vm-sort-compare-physical-order is called about 5 N times for N messages, giving 10 N calls to marker-position, which is expensive. This shows up as char-byte conversion in XEmacs profiling, and my below change improves this, such that the majority of the time in the described context is now in #'write-file-internal, not char-byte conversion. diff -r 4e69b24a2301 src/bytecode.c --- a/src/bytecode.c Mon Oct 28 16:03:53 2013 +0100 +++ b/src/bytecode.c Sun Dec 01 11:16:59 2013 +0000 ＠＠ -287,7 +287,7 ＠＠ bytecode_arithcompare (Lisp_Object obj1, Lisp_Object obj2) { #ifdef WITH_NUMBER_TYPES - switch (promote_args (&obj1, &obj2)) + switch (promote_args_lazy (&obj1, &obj2)) { case FIXNUM_T: { ＠＠ -306,6 +306,13 ＠＠ case BIGFLOAT_T: return bigfloat_cmp (XBIGFLOAT_DATA (obj1), XBIGFLOAT_DATA (obj2)); #endif + case MARKER_T: + { + Bytebpos ival1 = byte_marker_position (obj1); + Bytebpos ival2 = byte_marker_position (obj2); + return ival1 < ival2 ? -1 : ival1 > ival2 ? 1 : 0; + } + default: /* FLOAT_T */ { double dval1 = XFLOAT_DATA (obj1), dval2 = XFLOAT_DATA (obj2); ＠＠ -320,7 +327,19 ＠＠ if (FIXNUMP (obj1)) ival1 = XFIXNUM (obj1); else if (CHARP (obj1)) ival1 = XCHAR (obj1); - else if (MARKERP (obj1)) ival1 = marker_position (obj1); + else if (MARKERP (obj1)) + { + /* Handle markers specially, since #'marker-position can be O(N): */ + if (MARKERP (obj2) + && (XMARKER (obj1)->buffer == XMARKER (obj2)->buffer)) + { + Bytebpos ival1 = byte_marker_position (obj1); + Bytebpos ival2 = byte_marker_position (obj2); + return ival1 < ival2 ? -1 : ival1 > ival2 ? 1 : 0; + } + + ival1 = marker_position (obj1); + } else goto arithcompare_float; if (FIXNUMP (obj2)) ival2 = XFIXNUM (obj2); diff -r 4e69b24a2301 src/data.c --- a/src/data.c Mon Oct 28 16:03:53 2013 +0100 +++ b/src/data.c Sun Dec 01 11:16:59 2013 +0000 ＠＠ -936,10 +936,10 ＠＠ { \ obj1 = args[i - 1]; \ obj2 = args[i]; \ - switch (promote_args (&obj1, &obj2)) \ + switch (promote_args_lazy (&obj1, &obj2)) \ { \ case FIXNUM_T: \ - if (!(XREALFIXNUM (obj1) c_op XREALFIXNUM (obj2))) \ + if (!(XREALFIXNUM (obj1) c_op XREALFIXNUM (obj2))) \ return Qnil; \ break; \ BIGNUM_CASE (op) \ ＠＠ -949,11 +949,20 ＠＠ return Qnil; \ break; \ BIGFLOAT_CASE (op) \ + case MARKER_T: \ + if (!(byte_marker_position (obj1) c_op \ + byte_marker_position (obj2))) \ + return Qnil; \ + break; \ } \ } \ return Qt; \ } #else /* !WITH_NUMBER_TYPES */ +/* We don't convert markers lazily here, although we could. It's more + important that we do this lazily in bytecode, which is the case; see + bytecode_arithcompare(). + */ #define ARITHCOMPARE_MANY(c_op,op) \ { \ int_or_double iod1, iod2, *p = &iod1, *q = &iod2; \ diff -r 4e69b24a2301 src/number.h --- a/src/number.h Mon Oct 28 16:03:53 2013 +0100 +++ b/src/number.h Sun Dec 01 11:16:59 2013 +0000 ＠＠ -373,11 +373,40 ＠＠ EXFUN (Fcanonicalize_number, 1); -enum number_type {FIXNUM_T, BIGNUM_T, RATIO_T, FLOAT_T, BIGFLOAT_T}; +#define NUMBER_TYPES(prefix) prefix##FIXNUM_T, prefix##BIGNUM_T, \ + prefix##RATIO_T, prefix##FLOAT_T, prefix##BIGFLOAT_T + +enum number_type { NUMBER_TYPES() }; +enum lazy_number_type { NUMBER_TYPES(LAZY_), MARKER_T }; extern enum number_type get_number_type (Lisp_Object); extern enum number_type promote_args (Lisp_Object *, Lisp_Object *); +/* promote_args() *always* converts a marker argument to an integer. + + Unfortunately, for a marker with byte position N, getting the (character) + marker position is O(N). Getting the character position isn't necessary + for bytecode_arithcompare() if two markers being compared are in the same + buffer, comparing the byte position is enough. + + It is necessary for those operations implemented by bytecode_arithop(), + though, with the exception that Bmax and Bmin could be changed to call + marker-position once rather than twice. */ +DECLARE_INLINE_HEADER ( +enum lazy_number_type +promote_args_lazy (Lisp_Object *obj1, Lisp_Object *obj2)) +{ + if (MARKERP (*obj1) && MARKERP (*obj2) && + XMARKER (*obj1)->buffer == XMARKER (*obj2)->buffer) + { + return MARKER_T; + } + + return (enum lazy_number_type) promote_args (obj1, obj2); +} + +#undef NUMBER_TYPES + #ifdef WITH_NUMBER_TYPES DECLARE_INLINE_HEADER ( int -- ‘Liston operated so fast that he once accidentally amputated an assistant’s fingers along with a patient’s leg, […] The patient and the assistant both died of sepsis, and a spectator reportedly died of shock, resulting in the only known procedure with a 300% mortality.’ (Atul Gawande, NEJM, 2012) _______________________________________________ XEmacs-Patches mailing list XEmacs-Patches(a)xemacs.org http://lists.xemacs.org/mailman/listinfo/xemacs-patches