[Gcl-devel] Re: gcl bad code generation for setf fill-pointer for fixnum value

[Tim Josling]

You can generate this problem more easily from the REPL as sollows

(disassemble '(lambda () (setf (fill-pointer xxx) 0))

However this is OK

(disassemble '(lambda (n) (setf (fill-pointer xxx) n)))

But this is not... it looks like an optimization that happens when it
knows the parameter is a fixnum.

(disassemble '(lambda (n) (declare (fixnum n)) (setf (fill-pointer xxx)
n)))

Regards,
Tim Josling

On Sun, 2007-12-16 at 06:54 +1100, Tim Josling wrote:
> System:
> uname -a
> Linux tim-gcc 2.6.20-15-generic #2 SMP Sun Apr 15 06:17:24 UTC 2007
> x86_64 GNU/Linux
> 
> GCL:
> GCL (GNU Common Lisp)  2.6.7 CLtL1    Nov 10 2006 14:25:02
> 
> Run log of error:
> 
> make cobol-tests
> gcl  \
>        -eval  "(compile-file
> \"/home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.lisp\")"
> GCL (GNU Common Lisp)  2.6.7 CLtL1    Nov 10 2006 14:25:02
> Source License: LGPL(gcl,gmp), GPL(unexec,bfd,xgcl)
> Binary License:  GPL due to GPL'ed components: (XGCL READLINE BFD
> UNEXEC)
> Modifications of this banner must retain notice of a compatible license
> Dedicated to the memory of W. Schelter
> 
> Use (help) to get some basic information on how to use GCL.
> Temporary directory for compiler files set to /tmp/
> Compiling /home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.lisp.
> End of Pass 1.  
> End of Pass 2.  
> /home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.c: In function 'L1':
> /home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.c:5158: error: invalid
> lvalue in assignment
> 
> Error: (SYSTEM "gcc -c -Wall -DVOL=volatile -fsigned-char -pipe
> -I/usr/lib/gcl-2.6.7/unixport/../h  -O3 -fomit-frame-pointer -c
> \"/home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.c\" -o
> \"/home2/gcb/gcb/gcc/gcc/gcb/gcbc-compiler-lexer.o\" -w") returned a
> non-zero value 0.
> Fast links are on: do (si::use-fast-links nil) for debugging
> Error signalled by UNLESS.
> Broken at CERROR.  Type :H for Help.
> >>
> 
> Input program:
> ;;; -*- lisp -*-
> 
> (defvar *current-token-chars* nil)
> 
> (defun init-token-chars () 
>   (setf (fill-pointer *current-token-chars*) 0))
> 
> Output C code (excerpt):
> 
> #include "gcbc-compiler-lexer.h"
> void init_code(){do_init((void *)VV);}
> /*    function definition for INIT-TOKEN-CHARS        */
> 
> static void L1()
> {register object *base=vs_base;
>       register object *sup=base+VM1; VC1
>       vs_check;
>       vs_top=sup;
>       goto TTL;
> TTL:;
>       base[0]=
> CMPmake_fixnum((long)(((((object)VV[0])->s.s_dbind))->st.st_fillp)=((long)0));
>  
>       vs_top=(vs_base=base+0)+1;
>       return;
> }
> 
> This is the bad line:
> CMPmake_fixnum((long)(((((object)VV[0])->s.s_dbind))->st.st_fillp)=((long)0));
>  
> 
> Regards,
> Tim Josling