problem w/ igen, multiple -M models, and -G gen-multi-sim.

[cgd at broadcom dot com]

So, doing some MIPS sim hacking last week I noticed an interesting
problem, and wanted to investigate it and post about it before
forgetting it entirely.  (It seems to predate my intrusions into the
MIPS code. 8-)


Anyway, using the example files in the shar file below (specifically,
run_igen.sh, foo.igen and foo.dc), a problem results.  (These were all
derived from the mips sim, but there were too many instructions there
to allow sane debugging.  8-)

two instructions in the igen file.  same bit encoding for each, but
different model lists (and different semantics to go with those
different models 8-).

run igen w/ -M flag that specifies both models, and -G
gen-multi-sim=<either of them>.

the engine which is built calls both functions:

	semantic_DMxC1_COP1Sa
	semantic_DMxC1_COP1Sb

however, only semantic_DMxC1_COP1Sa is output into the semantics.c
file.

what's happening is that make_gen_semantics_list() is calling
insn_list_insert() to insert the DMxC1_COP1Sb on to the semantics list
(OK), but insn_list_insert finds that all of the keys it cares about
are the same, thinks it's a duplicate of DMxC1_COP1Sa, and merges it
into DMxC1_COP1Sa (not so OK), and as a result no semantic function is
generated for DMxC1_COP1Sb.


I don't know what the right solution here is, but I figured others
might want to be aware of the problem and might have comments.

Having talked w/ Andrew a bit about the future of the MIPS sim, it's
going to move away from using -M like this, and instead use multiple
igen runs to generate simulators for different machines.  So, this
isn't something that I need a solution to.

I just wanted people who might care in the future to have a reference
in the list archives.  If a solution comes out of this, well, that'd
be fine by me, too.  8-)



chris
=======================================================================
#!/bin/sh
# This is a shell archive (produced by GNU sharutils 4.2.1).
# To extract the files from this archive, save it to some FILE, remove
# everything before the `!/bin/sh' line above, then type `sh FILE'.
#
# Made on 2002-03-12 12:46 PST by <cgd@hardy.sj.broadcom.com>.
# Source directory was `/projects/bbp_ext7/systems/cgd/proj/gnu/write/gdb/src.igen-bug/mips64-elf/sim/mips'.
#
# Existing files will *not* be overwritten unless `-c' is specified.
#
# This shar contains:
# length mode       name
# ------ ---------- ------------------------------------------
#    774 -rw-rw-r-- run_igen.sh
#    559 -rw-rw-r-- foo.dc
#    527 -rw-rw-r-- foo.igen
#
save_IFS="${IFS}"
IFS="${IFS}:"
gettext_dir=FAILED
locale_dir=FAILED
first_param="$1"
for dir in $PATH
do
  if test "$gettext_dir" = FAILED && test -f $dir/gettext \
     && ($dir/gettext --version >/dev/null 2>&1)
  then
    set `$dir/gettext --version 2>&1`
    if test "$3" = GNU
    then
      gettext_dir=$dir
    fi
  fi
  if test "$locale_dir" = FAILED && test -f $dir/shar \
     && ($dir/shar --print-text-domain-dir >/dev/null 2>&1)
  then
    locale_dir=`$dir/shar --print-text-domain-dir`
  fi
done
IFS="$save_IFS"
if test "$locale_dir" = FAILED || test "$gettext_dir" = FAILED
then
  echo=echo
else
  TEXTDOMAINDIR=$locale_dir
  export TEXTDOMAINDIR
  TEXTDOMAIN=sharutils
  export TEXTDOMAIN
  echo="$gettext_dir/gettext -s"
fi
if touch -am -t 200112312359.59 $$.touch >/dev/null 2>&1 && test ! -f 200112312359.59 -a -f $$.touch; then
  shar_touch='touch -am -t $1$2$3$4$5$6.$7 "$8"'
elif touch -am 123123592001.59 $$.touch >/dev/null 2>&1 && test ! -f 123123592001.59 -a ! -f 123123592001.5 -a -f $$.touch; then
  shar_touch='touch -am $3$4$5$6$1$2.$7 "$8"'
elif touch -am 1231235901 $$.touch >/dev/null 2>&1 && test ! -f 1231235901 -a -f $$.touch; then
  shar_touch='touch -am $3$4$5$6$2 "$8"'
else
  shar_touch=:
  echo
  $echo 'WARNING: not restoring timestamps.  Consider getting and'
  $echo "installing GNU \`touch', distributed in GNU File Utilities..."
  echo
fi
rm -f 200112312359.59 123123592001.59 123123592001.5 1231235901 $$.touch
#
if mkdir _sh06977; then
  $echo 'x -' 'creating lock directory'
else
  $echo 'failed to create lock directory'
  exit 1
fi
# ============= run_igen.sh ==============
if test -f 'run_igen.sh' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'run_igen.sh' '(file already exists)'
else
  $echo 'x -' extracting 'run_igen.sh' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'run_igen.sh' &&
set -e
X
(cd ../igen && gmake )
X
X../igen/igen \
X	 \
X	-Werror \
X	-Wnodiscard \
X	-F 32,64,f -M mipsIV,mipsIII -G gen-multi-sim=mipsIV -G trace-all -N 0 \
X	-G gen-direct-access \
X	-G gen-zero-r0 \
X	-B 32 \
X	-H 31 \
X	-i foo.igen \
X	-o foo.dc \
X	-x \
X	-n icache.h    -hc tmp-icache.h \
X	-n icache.c    -c  tmp-icache.c \
X	-n semantics.h -hs tmp-semantics.h \
X	-n semantics.c -s  tmp-semantics.c \
X	-n idecode.h   -hd tmp-idecode.h \
X	-n idecode.c   -d  tmp-idecode.c \
X	-n model.h     -hm tmp-model.h \
X	-n model.c     -m  tmp-model.c \
X	-n support.h   -hf tmp-support.h \
X	-n support.c   -f  tmp-support.c \
X	-n itable.h    -ht tmp-itable.h \
X	-n itable.c    -t  tmp-itable.c \
X	-n engine.h    -he tmp-engine.h \
X	-n engine.c    -e  tmp-engine.c \
X	-n irun.c      -r  tmp-irun.c
SHAR_EOF
  (set 20 02 03 12 12 45 54 'run_igen.sh'; eval "$shar_touch") &&
  chmod 0664 'run_igen.sh' ||
  $echo 'restore of' 'run_igen.sh' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'run_igen.sh:' 'MD5 check failed'
c1cde0b4f6dc81769aa9e46ac1840200  run_igen.sh
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'run_igen.sh'`"
    test 774 -eq "$shar_count" ||
    $echo 'run_igen.sh:' 'original size' '774,' 'current size' "$shar_count!"
  fi
fi
# ============= foo.dc ==============
if test -f 'foo.dc' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'foo.dc' '(file already exists)'
else
  $echo 'x -' extracting 'foo.dc' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'foo.dc' &&
# most instructions
# ------ options ------ : Fst : Lst : ff : fl : fe : word : --- fmt --- : model ...
# { : mask : value : word }
X
# Top level - create a very big switch statement.
X
X  padded-switch,combine :  31 :  26 :    :    :    :      :             :
X
X  switch,combine        :   5 :   0 :    :    :    :      :             :
X
X  switch,combine        :  20 :  16 :    :    :    :      :             :
X
X  switch,combine        :  25 :  21 :    :    :    :      :             :
X
X  switch,combine        :  10 :   6 :    :    :    :      :             :
X
SHAR_EOF
  (set 20 02 03 12 10 57 43 'foo.dc'; eval "$shar_touch") &&
  chmod 0664 'foo.dc' ||
  $echo 'restore of' 'foo.dc' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'foo.dc:' 'MD5 check failed'
0cc85f54d1aaffc21fa0a619b2e23020  foo.dc
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'foo.dc'`"
    test 559 -eq "$shar_count" ||
    $echo 'foo.dc:' 'original size' '559,' 'current size' "$shar_count!"
  fi
fi
# ============= foo.igen ==============
if test -f 'foo.igen' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'foo.igen' '(file already exists)'
else
  $echo 'x -' extracting 'foo.igen' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'foo.igen' &&
X
X
:option:32::insn-specifying-widths:true
:option:32::gen-delayed-branch:false
X
X
:model:::mipsIII:mips4000:
:model:::mipsIV:mips8000:
X
X
:internal::::illegal:
{
X  SignalException (ReservedInstruction, 0);
}
X
X
000000,5.RS,5.RT,5.RD,00000,100000:SPECIAL:32::ADD
"add r<RD>, r<RS>, r<RT>"
*mipsIII:
*mipsIV:
{
X  foo();
}
X
X
010001,00,X,01,5.RT,5.FS,00000000000:COP1Sa:64,f::DMxC1
"dm%s<X>c1 r<RT>, f<FS>"
*mipsIII:
{
X  bar();
}
X
010001,00,X,01,5.RT,5.FS,00000000000:COP1Sb:64,f::DMxC1
"dm%s<X>c1 r<RT>, f<FS>"
*mipsIV:
{
X  baz();
}
SHAR_EOF
  (set 20 02 03 12 12 34 38 'foo.igen'; eval "$shar_touch") &&
  chmod 0664 'foo.igen' ||
  $echo 'restore of' 'foo.igen' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'foo.igen:' 'MD5 check failed'
86fe1ccfd33f1dd1c746b9b0746cbe2b  foo.igen
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'foo.igen'`"
    test 527 -eq "$shar_count" ||
    $echo 'foo.igen:' 'original size' '527,' 'current size' "$shar_count!"
  fi
fi
rm -fr _sh06977
exit 0