February 2009 - Gpc

Inefficiency of `mod'
by Emil Jerabek 26 Oct '10

26 Oct '10

Hi, during some debugging I noticed that GPC generates very hairy code for the `mod' operator with signed arguments. A closer look revealed that the code contains a lot of branching on conditions which can be determined on compile time, and most surprisingly, the value of X mod Y is recomputed _twice_, if X is negative. (I've attached a commented assembler dump.) This may be partially a back-end problem (CSE?), but I feel there's something wrong in the relevant code in gpc-common.c (build_pascal_binary_op) as well. `exp1 mod exp2' gets translated into something like exp2 <= 0 ? error : exp1 >= 0 ? exp1 mod exp2 : ((-exp1) mod exp2) == 0 ? 0 : exp2 - (-exp1) mod exp2 This arranges that both arguments supplied to the "internal mod" are non-negative, but this information is not passed on -- the arguments are still declared as signed types, which apparently makes the back-end to produce the mess it does. I've done a little test: the following replacement for `mod', which differs from the built-in one essentially just by the type-casts to `Cardinal', inline operator xmod (X, Y: Integer) = Z: Integer; begin if Y <= 0 then RuntimeError (714); if X >= 0 then Z := Cardinal (X) mod Y else begin Z := Cardinal (-X) mod Y; if Z <> 0 then Z := Y - Z end end; indeed generates a better code, it measures about 15% faster for positive X and more than twice faster for negative X. YMMV. If this is possible in user code, it should work in the compiler internals as well :) The result type of the whole `mod' expression looks dubious too. IIUIC, `exp1 mod exp2' inherits the type of exp1. Now, the result of `mod' is guaranteed to be nonnegative and to fit in the type of exp2 (or more precisely, it is in 0 .. High (type of (exp2)) - 1), whereas it needn't have anything to do with the type of exp1: consider var X, Z: Integer; Y: LongInt; begin X := -8; Y := High (LongInt); Z := X mod Y { -> overflow } end Or am I missing something? Emil (BTW, where is fjf434c.pas?)

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GPC support for AIX 6?
by Gert Doering 16 Feb '10

16 Feb '10

Hi Gnu Pascal list, we're currently using IBM's xpc pascal compiler on IBM AIX 5.3. New machines are being shipped with AIX 6, and IBM's xpc is no longer supported there - for the time being, it actuall works (the xpc frontend generated intermediate code, and the second stage compiler still groks it). Management is not happy about this, as it might break any day, and I have been asked to "provide GPC" on AIX 6. Googling seems to suggest that the earliest release of GCC to work on AIX 6 is gcc 4.2.4 This mailing list's archive suggests that GPC and GCC 4.2 do not yet work together, due to larger efforts required due to backend changes (Waldek's mail from March 12, 2008). I reported this to management ("there is no GPC on AIX 6"), and they came back with the question "if we pay one of the GPC developers to do a GPC port to a recent GCC, to support AIX 6, how much would that cost?". Here we go - I'm posing this question to you. Is one of you capable and willing to make GPC work on AIX 6? And if yes, what would your conditions be (estimated time to do this, estimated costs)? (I can't promise anything, but will report back to management and they will decide...) thanks, gert -- Gert Doering gd(a)medat.de MEDAT Muenchen Tel: 089/126808-0 Fax: -50

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New (gpc-20060325)
by Waldek Hebisch 08 Dec '09

08 Dec '09

I have put a new gpc snapshot at: http://www.math.uni.wroc.pl/~hebisch/gpc-20060325.tar.bz2 Main change is preliminary gcc-4.0.x support. The other changes are rather small. Note that for "production use" 3.4.x and 3.3.x backend are prefered. Also, using 2.8.1, 2.95.3 and 3.2.3 backend should work, but is depreciated. For more detail see: http://www.math.uni.wroc.pl/~hebisch/gpc/NEWS-20060325 and http://www.math.uni.wroc.pl/~hebisch/gpc/Fixed-20060325 -- Waldek Hebisch hebisch(a)math.uni.wroc.pl

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Re: Linux Binaries and Makefile
by Kevan Hashemi 30 Mar '09

30 Mar '09

Dear Prof O, > On your "desktop" in Linux? That sounds odd to me. Everything I do is a bit odd. > If you don't know what you're doing, yes. That's precisely my point: I don't know what I'm doing. > An exaggeration. As I said, on a modern PC (e.g., an Athlon XP 3800), it > only takes a few minutes I was not refering to "compile time". I was referring to "Where on earth do I get a non-broken version of sed? What is sed anyway? Why won't patch work on this machine with these diff files? Is it patch that's not working or is it just that I'm a retard? What does it mean that the .tar.bz.tar archive is in an unrecognizable format?" Compiling GPC will be four hours work for me, minimum. > If you find one, it may not work. So far, that 20041218 distribution of binaries has worked on every single one of the two dozen machines we have loaded it onto. Why would the 20070904 distribution fail to work? Yours, Kevan -- Kevan Hashemi, Electrical Engineer Physics Department, Brandeis University http://alignment.hep.brandeis.edu/

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Re: instal gnu pascal
by samiam＠moorecad.com 24 Feb '09

24 Feb '09

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Re: instal gnu pascal
by samiam＠moorecad.com 23 Feb '09

23 Feb '09

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instal gnu pascal
by Palmerim Soares 23 Feb '09

23 Feb '09

Help! I use Windows XP. I just want to instal and use GNU pascal but it seens to be very very very difficult!!!!!! What i have to do to simply instal and use GNU Pascal without guesses and a lot of complications????????????? Thanks for your help Palmerim

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With statement behaviour for objects
by Adriaan van Os 21 Feb '09

21 Feb '09

Any comments on <http://bugs.freepascal.org/view.php?id=13210> ? Regards, Adriaan van Os

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GNU Pascal and warnings.
by Lennart Thelander 19 Feb '09

19 Feb '09

Hello. For quite many functions/Procedures, I get two warnings: warning: frame size too large for reliable stack checking warning: try reducing the number of local variables Say what? Reducing the number of local variables? Here's an example: PROCEDURE TTextEditItem.HandleKey(VAR theEvent:EventRecord); VAR i : SInt16; pt : Point; theChr : Char; theKey : SInt16; shift : BOOLEAN; option : BOOLEAN; control : BOOLEAN; command : BOOLEAN; lineHeight, ascent : SInt16; theStyle : TextStyle; I say that's a small amount of (small) local variables, so how can there be too many? And what is a "frame" and how can I reduce its size? Or better: How do I allow for a larger frame size? This is GNU Pascal 3.4.6u2 on Mac OS X and Xcode 2.5. Regards Lennart Thelander System Developer Lennart.Thelander(a)atex.com Phone +46 (0) 42 25 39 05 Fax +46 (0) 42 25 39 29 Atex Media AB Garnisonsgatan 10C S-254 66 Helsingborg SWEDEN Bringing new life to your media business www.atex.com THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers.

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[Commit] gdb/pascal language 2 or 4 byte char support in strings
by Pierre Muller 10 Feb '09

10 Feb '09

I committed the patch below to add support for fixed width chars greater than 1 for pascal language. This works nicely for Free Pascal, I couldn't test it for GPC because I didn't find out if those kind of char are supported... Pierre Muller Pascal language support maintainer for GDB ChangeLog entry: 2009-02-08 Pierre Muller <muller(a)ics.u-strasbg.fr> * p-lang.c (is_pascal_string_type): Fix comment. Determine exact size of char elements for GPC strings. (pascal_printstr): Handle char width of 2 or 4. * p-valprint.c (pascal_val_print): Handle char of width 2 or 4. Index: gdb/p-lang.c =================================================================== RCS file: /cvs/src/src/gdb/p-lang.c,v retrieving revision 1.45 diff -u -p -r1.45 p-lang.c --- gdb/p-lang.c 5 Feb 2009 12:16:25 -0000 1.45 +++ gdb/p-lang.c 9 Feb 2009 23:54:58 -0000 @@ -86,7 +86,7 @@ pascal_main_name (void) } /* Determines if type TYPE is a pascal string type. - Returns 1 if the type is a known pascal type + Returns a positive value if the type is a known pascal string type. This function is used by p-valprint.c code to allow better string display. If it is a pascal string type, then it also sets info needed to get the length and the data of the string @@ -126,14 +126,20 @@ is_pascal_string_type (struct type *type && strcmp (TYPE_FIELDS (type)[0].name, "Capacity") == 0 && strcmp (TYPE_FIELDS (type)[1].name, "length") == 0) { - if (length_pos) + struct type *char_type; + if (length_pos) *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT; - if (length_size) + if (length_size) *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1)); - if (string_pos) + if (string_pos) *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT; /* FIXME: how can I detect wide chars in GPC ?? */ - if (char_size) + char_type = TYPE_FIELD_TYPE (type,2); + if (char_size && TYPE_CODE (char_type) == TYPE_CODE_ARRAY) + { + *char_size = TYPE_LENGTH (TYPE_TARGET_TYPE (char_type)); + } + else if (char_size) *char_size = 1; if (arrayname) *arrayname = TYPE_FIELDS (type)[2].name; @@ -218,7 +224,8 @@ pascal_printstr (struct ui_file *stream, /* If the string was not truncated due to `set print elements', and the last byte of it is a null, we don't print that, in traditional C style. */ - if ((!force_ellipses) && length > 0 && string[length - 1] == '\0') + if ((!force_ellipses) && length > 0 + && extract_unsigned_integer (string + (length - 1) * width, width) == 0) length--; if (length == 0) @@ -234,6 +241,7 @@ pascal_printstr (struct ui_file *stream, unsigned int rep1; /* Number of repetitions we have detected so far. */ unsigned int reps; + unsigned long int current_char; QUIT; @@ -243,9 +251,13 @@ pascal_printstr (struct ui_file *stream, need_comma = 0; } + current_char = extract_unsigned_integer (string + i * width, width); + rep1 = i + 1; reps = 1; - while (rep1 < length && string[rep1] == string[i]) + while (rep1 < length + && extract_unsigned_integer (string + rep1 * width, width) + == current_char) { ++rep1; ++reps; @@ -261,7 +273,7 @@ pascal_printstr (struct ui_file *stream, fputs_filtered ("', ", stream); in_quotes = 0; } - pascal_printchar (string[i], stream); + pascal_printchar (current_char, stream); fprintf_filtered (stream, " <repeats %u times>", reps); i = rep1 - 1; things_printed += options->repeat_count_threshold; @@ -269,8 +281,7 @@ pascal_printstr (struct ui_file *stream, } else { - int c = string[i]; - if ((!in_quotes) && (PRINT_LITERAL_FORM (c))) + if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char))) { if (options->inspect_it) fputs_filtered ("\\'", stream); @@ -278,7 +289,7 @@ pascal_printstr (struct ui_file *stream, fputs_filtered ("'", stream); in_quotes = 1; } - pascal_one_char (c, stream, &in_quotes); + pascal_one_char (current_char, stream, &in_quotes); ++things_printed; } } Index: gdb/p-valprint.c =================================================================== RCS file: /cvs/src/src/gdb/p-valprint.c,v retrieving revision 1.59 diff -u -p -r1.59 p-valprint.c --- gdb/p-valprint.c 3 Jan 2009 05:57:52 -0000 1.59 +++ gdb/p-valprint.c 9 Feb 2009 23:54:58 -0000 @@ -79,7 +79,7 @@ pascal_val_print (struct type *type, con print_spaces_filtered (2 + 2 * recurse, stream); } /* For an array of chars, print with string syntax. */ - if (eltlen == 1 + if ((eltlen == 1 || eltlen == 2 || eltlen == 4) && ((TYPE_CODE (elttype) == TYPE_CODE_INT) || ((current_language->la_language == language_pascal) && (TYPE_CODE (elttype) == TYPE_CODE_CHAR))) @@ -93,14 +93,15 @@ pascal_val_print (struct type *type, con /* Look for a NULL char. */ for (temp_len = 0; - (valaddr + embedded_offset)[temp_len] + extract_unsigned_integer (valaddr + embedded_offset + + temp_len * eltlen, eltlen) && temp_len < len && temp_len < options->print_max; temp_len++); len = temp_len; } - LA_PRINT_STRING (stream, valaddr + embedded_offset, len, 1, 0, - options); + LA_PRINT_STRING (stream, valaddr + embedded_offset, len, + eltlen, 0, options); i = len; } else @@ -165,14 +166,17 @@ pascal_val_print (struct type *type, con /* For a pointer to char or unsigned char, also print the string pointed to, unless pointer is null. */ - if (TYPE_LENGTH (elttype) == 1 - && (TYPE_CODE (elttype) == TYPE_CODE_INT - || TYPE_CODE(elttype) == TYPE_CODE_CHAR) + if (((TYPE_LENGTH (elttype) == 1 + && (TYPE_CODE (elttype) == TYPE_CODE_INT + || TYPE_CODE (elttype) == TYPE_CODE_CHAR)) + || ((TYPE_LENGTH (elttype) == 2 || TYPE_LENGTH (elttype) == 4) + && TYPE_CODE (elttype) == TYPE_CODE_CHAR)) && (options->format == 0 || options->format == 's') && addr != 0) { /* no wide string yet */ - i = val_print_string (addr, -1, 1, stream, options); + i = val_print_string (addr, -1, TYPE_LENGTH (elttype), stream, + options); } /* also for pointers to pascal strings */ /* Note: this is Free Pascal specific:

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