path: root/ghc/driver/ghc-asm.lprl

%************************************************************************
%*									*
\section[Driver-asm-fiddling]{Fiddling with assembler files}
%*									*
%************************************************************************

Tasks:
\begin{itemize}
\item
Utterly stomp out C functions' prologues and epilogues; i.e., the
stuff to do with the C stack.
\item
Any other required tidying up.
\end{itemize}

HPPA specific notes:
\begin{itemize}
\item
The HP linker is very picky about symbols being in the appropriate
space (code vs. data).  When we mangle the threaded code to put the
info tables just prior to the code, they wind up in code space
rather than data space.  This means that references to *_info from
un-mangled parts of the RTS (e.g. unthreaded GC code) get
unresolved symbols.  Solution:  mini-mangler for .c files on HP.  I
think this should really be triggered in the driver by a new -rts
option, so that user code doesn't get mangled inappropriately.
\item
With reversed tables, jumps are to the _info label rather than to
the _entry label.  The _info label is just an address in code
space, rather than an entry point with the descriptive blob we
talked about yesterday.  As a result, you can't use the call-style
JMP_ macro.  However, some JMP_ macros take _info labels as targets
and some take code entry points within the RTS.  The latter won't
work with the goto-style JMP_ macro.  Sigh.  Solution: Use the goto
style JMP_ macro, and mangle some more assembly, changing all
"RP'literal" and "LP'literal" references to "R'literal" and
"L'literal," so that you get the real address of the code, rather
than the descriptive blob.  Also change all ".word P%literal"
entries in info tables and vector tables to just ".word literal,"
for the same reason.  Advantage: No more ridiculous call sequences.
\end{itemize}

%************************************************************************
%*									*
\subsection{Constants for various architectures}
%*									*
%************************************************************************

\begin{code}
sub init_TARGET_STUFF {

    #--------------------------------------------------------#
    if ( $TargetPlatform =~ /^alpha-.*-.*/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = ''; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = 'DONT THINK THIS APPLIES'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^\$C(\d+):$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '^(\s*(\.align\s+\d+|\.(globl|ent)\s+\S+|\#.*|\.(file|loc)\s+\S+\s+\S+|\.text|\.r?data)\n)';
    $T_COPY_DIRVS   = '^\s*(\#|\.(file|globl|ent|loc))';

    $T_hsc_cc_PAT   = '\.ascii.*\)(hsc|cc) (.*)\\\\11"\n\t\.ascii\s+"(.*)\\\\0"';
    $T_DOT_WORD	    = '\.quad';
    $T_DOT_GLOBAL   = "\t\.globl";
    $T_HDR_literal  = "\.rdata\n\t\.align 3\n";
    $T_HDR_misc	    = "\.text\n\t\.align 3\n";
    $T_HDR_data	    = "\.data\n\t\.align 3\n";
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 3\n";
    $T_HDR_info	    = "\.text\n\t\.align 3\n";
    $T_HDR_entry    = "\.text\n\t\.align 3\n";
    $T_HDR_fast	    = "\.text\n\t\.align 3\n";
    $T_HDR_vector   = "\.text\n\t\.align 3\n";
    $T_HDR_direct   = "\.text\n\t\.align 3\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^hppa/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = ''; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = 'DONT THINK THIS APPLIES'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^L\$C(\d+)$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = '';

    $T_MOVE_DIRVS   = '^((\s+\.(IMPORT|EXPORT|PARAM).*|\s+\.align\s+\d+|\s+\.(SPACE|SUBSPA)\s+\S+|\s*)\n)';
    $T_COPY_DIRVS   = '^\s+\.(IMPORT|EXPORT)';

    $T_hsc_cc_PAT   = '\.STRING.*\)(hsc|cc) (.*)\\\\x09(.*)\\\\x00';
    $T_DOT_WORD	    = '\.word';
    $T_DOT_GLOBAL   = '\s+\.EXPORT';
    $T_HDR_literal  = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$LIT\$\n";
    $T_HDR_misc	    = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";
    $T_HDR_data	    = "\t.SPACE \$PRIVATE\$\n\t.SUBSPA \$DATA\$\n\t\.align 4\n";
    $T_HDR_consist  = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$LIT\$\n";
    $T_HDR_closure  = "\t.SPACE \$PRIVATE\$\n\t.SUBSPA \$DATA\$\n\t\.align 4\n";
    $T_HDR_info	    = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";
    $T_HDR_entry    = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";
    $T_HDR_fast	    = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";
    $T_HDR_vector   = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";
    $T_HDR_direct   = "\t.SPACE \$TEXT\$\n\t.SUBSPA \$CODE\$\n\t\.align 4\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^i386-.*-(linuxaout|freebsd)/ ) {

    $T_STABBY	    = 1; # 1 iff .stab things (usually if a.out format)
    $T_US	    = '_'; # _ if symbols have an underscore on the front
    $T_DO_GC	    = '_PerformGC_wrapper';
    $T_PRE_APP	    = '^#'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^LC(\d+):$';
    $T_POST_LBL	    = ':';
    $T_X86_PRE_LLBL_PAT = 'L';
    $T_X86_PRE_LLBL	    = 'L';
    $T_X86_BADJMP   = '^\tjmp [^L\*]';

    $T_MOVE_DIRVS   = '^(\s*(\.align\s+\d+(,0x90)?|\.globl\s+\S+|\.text|\.data|\.stab[^n].*|\.type\s+.*|\.size\s+.*)\n)';
    $T_COPY_DIRVS   = '\.(globl|stab)';
    $T_hsc_cc_PAT   = '\.ascii.*\)(hsc|cc) (.*)\\\\11"\n\t\.ascii\s+"(.*)\\\\0"';
    $T_DOT_WORD	    = '\.long';
    $T_DOT_GLOBAL   = '\.globl';
    $T_HDR_literal  = "\.text\n\t\.align 2\n"; # .align 4 is 486-cache friendly
    $T_HDR_misc	    = "\.text\n\t\.align 2,0x90\n";
    $T_HDR_data	    = "\.data\n\t\.align 2\n"; # ToDo: change align??
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 2\n"; # ToDo: change align?
    $T_HDR_info	    = "\.text\n\t\.align 2\n"; # NB: requires padding
    $T_HDR_entry    = "\.text\n"; # no .align so we're right next to _info (arguably wrong...?)
    $T_HDR_fast	    = "\.text\n\t\.align 2,0x90\n";
    $T_HDR_vector   = "\.text\n\t\.align 2\n"; # NB: requires padding
    $T_HDR_direct   = "\.text\n\t\.align 2,0x90\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^i386-.*-(solaris2|linux)$/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = ''; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = '/'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^\.LC(\d+):$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = ':';
    $T_X86_PRE_LLBL_PAT = '\.L';
    $T_X86_PRE_LLBL	    = '.L';
    $T_X86_BADJMP   = '^\tjmp [^\.\*]';

    $T_MOVE_DIRVS   = '^(\s*(\.align\s+\d+(,0x90)?|\.globl\s+\S+|\.text|\.data|\.section\s+.*|\.type\s+.*|\.Lfe.*\n\t\.size\s+.*|\.size\s+.*|\.ident.*)\n)';
    $T_COPY_DIRVS   = '\.(globl)';

    $T_hsc_cc_PAT   = '\.string.*\)(hsc|cc) (.*)\\\\t(.*)"';
    $T_DOT_WORD	    = '\.long';
    $T_DOT_GLOBAL   = '\.globl';
    $T_HDR_literal  = "\.section\t\.rodata\n"; # or just use .text??? (WDP 95/11)
    $T_HDR_misc	    = "\.text\n\t\.align 16\n";
    $T_HDR_data	    = "\.data\n\t\.align 4\n"; # ToDo: change align??
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 4\n"; # ToDo: change align?
    $T_HDR_info	    = "\.text\n\t\.align 16\n"; # NB: requires padding
    $T_HDR_entry    = "\.text\n"; # no .align so we're right next to _info (arguably wrong...?)
    $T_HDR_fast	    = "\.text\n\t\.align 16\n";
    $T_HDR_vector   = "\.text\n\t\.align 16\n"; # NB: requires padding
    $T_HDR_direct   = "\.text\n\t\.align 16\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^m68k-.*-sunos4/ ) {

    $T_STABBY	    = 1; # 1 iff .stab things (usually if a.out format)
    $T_US	    = '_'; # _ if symbols have an underscore on the front
    $T_DO_GC	    = '_PerformGC_wrapper';
    $T_PRE_APP	    = '^# MAY NOT APPLY'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^LC(\d+):$';
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '(\s*(\.align\s+\d+|\.proc\s+\d+|\.const|\.cstring|\.globl\s+\S+|\.text|\.data|\.even|\.stab[^n].*)\n)';
    $T_COPY_DIRVS   = '\.(globl|proc|stab)';
    $T_hsc_cc_PAT   = '\.ascii.*\)(hsc|cc) (.*)\\\\11"\n\t\.ascii\s+"(.*)\\\\0"';

    $T_DOT_WORD	    = '\.long';
    $T_DOT_GLOBAL   = '\.globl';
    $T_HDR_literal  = "\.text\n\t\.even\n";
    $T_HDR_misc	    = "\.text\n\t\.even\n";
    $T_HDR_data	    = "\.data\n\t\.even\n";
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.even\n";
    $T_HDR_info	    = "\.text\n\t\.even\n";
    $T_HDR_entry    = "\.text\n\t\.even\n";
    $T_HDR_fast	    = "\.text\n\t\.even\n";
    $T_HDR_vector   = "\.text\n\t\.even\n";
    $T_HDR_direct   = "\.text\n\t\.even\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^mips-.*/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = ''; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = '^\s*#'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^\$LC(\d+):$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '(\s*(\.align\s+\d+|\.(globl|ent)\s+\S+|\.text|\.r?data)\n)';
    $T_COPY_DIRVS   = '\.(globl|ent)';

    $T_hsc_cc_PAT   = 'I WAS TOO LAZY TO DO THIS BIT (WDP 95/05)';
    $T_DOT_WORD	    = '\.word';
    $T_DOT_GLOBAL   = '\t\.globl';
    $T_HDR_literal  = "\t\.rdata\n\t\.align 2\n";
    $T_HDR_misc	    = "\t\.text\n\t\.align 2\n";
    $T_HDR_data	    = "\t\.data\n\t\.align 2\n";
    $T_HDR_consist  = 'TOO LAZY TO DO THIS TOO';
    $T_HDR_closure  = "\t\.data\n\t\.align 2\n";
    $T_HDR_info	    = "\t\.text\n\t\.align 2\n";
    $T_HDR_entry    = "\t\.text\n\t\.align 2\n";
    $T_HDR_fast	    = "\t\.text\n\t\.align 2\n";
    $T_HDR_vector   = "\t\.text\n\t\.align 2\n";
    $T_HDR_direct   = "\t\.text\n\t\.align 2\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^powerpc-.*/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = '\.'; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = 'NOT APPLICABLE'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^LC\.\.(\d+):$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '^(\s*(\.align\s+\d+(,0x90)?|\.globl\s+\S+|\.text|\.data|\.section\s+.*|\.type\s+.*|\.Lfe.*\n\t\.size\s+.*|\.size\s+.*|\.ident.*)\n)';
    $T_COPY_DIRVS   = '\.(globl)';

    $T_hsc_cc_PAT   = '\.string.*\)(hsc|cc) (.*)\\\\t(.*)"';
    $T_DOT_WORD	    = '\.long';
    $T_DOT_GLOBAL   = '\.globl';
    $T_HDR_literal  = "\.section\t\.rodata\n"; # or just use .text??? (WDP 95/11)
    $T_HDR_misc	    = "\.text\n\t\.align 16\n";
    $T_HDR_data	    = "\.data\n\t\.align 4\n"; # ToDo: change align??
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 4\n"; # ToDo: change align?
    $T_HDR_info	    = "\.text\n\t\.align 16\n"; # NB: requires padding
    $T_HDR_entry    = "\.text\n"; # no .align so we're right next to _info (arguably wrong...?)
    $T_HDR_fast	    = "\.text\n\t\.align 16\n";
    $T_HDR_vector   = "\.text\n\t\.align 16\n"; # NB: requires padding
    $T_HDR_direct   = "\.text\n\t\.align 16\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^sparc-.*-solaris2/ ) {

    $T_STABBY	    = 0; # 1 iff .stab things (usually if a.out format)
    $T_US	    = ''; # _ if symbols have an underscore on the front
    $T_DO_GC	    = 'PerformGC_wrapper';
    $T_PRE_APP	    = 'DOES NOT SEEM TO APPLY'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^\.LLC(\d+):$'; # regexp for what such a lbl looks like
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '^((\s+\.align\s+\d+|\s+\.proc\s+\d+|\s+\.global\s+\S+|\.text|\.data|\.stab.*|\.section.*|\s+\.type.*|\s+\.size.*)\n)';
    $T_COPY_DIRVS   = '\.(global|proc|stab)';

    $T_hsc_cc_PAT   = '\.asciz.*\)(hsc|cc) (.*)\\\\t(.*)"';
    $T_DOT_WORD	    = '\.word';
    $T_DOT_GLOBAL   = '\.global';
    $T_HDR_literal  = "\.text\n\t\.align 8\n";
    $T_HDR_misc	    = "\.text\n\t\.align 4\n";
    $T_HDR_data	    = "\.data\n\t\.align 8\n";
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 4\n";
    $T_HDR_info	    = "\.text\n\t\.align 4\n";
    $T_HDR_entry    = "\.text\n\t\.align 4\n";
    $T_HDR_fast	    = "\.text\n\t\.align 4\n";
    $T_HDR_vector   = "\.text\n\t\.align 4\n";
    $T_HDR_direct   = "\.text\n\t\.align 4\n";

    #--------------------------------------------------------#
    } elsif ( $TargetPlatform =~ /^sparc-.*-sunos4/ ) {

    $T_STABBY	    = 1; # 1 iff .stab things (usually if a.out format)
    $T_US	    = '_'; # _ if symbols have an underscore on the front
    $T_DO_GC	    = '_PerformGC_wrapper';
    $T_PRE_APP	    = '^# DOES NOT SEEM TO APPLY'; # regexp that says what comes before APP/NO_APP
    $T_CONST_LBL    = '^LC(\d+):$';
    $T_POST_LBL	    = ':';

    $T_MOVE_DIRVS   = '^((\s+\.align\s+\d+|\s+\.proc\s+\d+|\s+\.global\s+\S+|\.text|\.data|\.stab.*)\n)';
    $T_COPY_DIRVS   = '\.(global|proc|stab)';
    $T_hsc_cc_PAT   = '\.ascii.*\)(hsc|cc) (.*)\\\\11"\n\t\.ascii\s+"(.*)\\\\0"';

    $T_DOT_WORD	    = '\.word';
    $T_DOT_GLOBAL   = '^\t\.global';
    $T_HDR_literal  = "\.text\n\t\.align 8\n";
    $T_HDR_misc	    = "\.text\n\t\.align 4\n";
    $T_HDR_data	    = "\.data\n\t\.align 8\n";
    $T_HDR_consist  = "\.text\n";
    $T_HDR_closure  = "\.data\n\t\.align 4\n";
    $T_HDR_info	    = "\.text\n\t\.align 4\n";
    $T_HDR_entry    = "\.text\n\t\.align 4\n";
    $T_HDR_fast	    = "\.text\n\t\.align 4\n";
    $T_HDR_vector   = "\.text\n\t\.align 4\n";
    $T_HDR_direct   = "\.text\n\t\.align 4\n";

    #--------------------------------------------------------#
    } else {
	print STDERR "$Pgm: don't know how to mangle assembly language for: $TargetPlatform\n";
	exit 1;
    }

if ( 0 ) {
print STDERR "T_STABBY: $T_STABBY\n";
print STDERR "T_US: $T_US\n";
print STDERR "T_DO_GC: $T_DO_GC\n";
print STDERR "T_PRE_APP: $T_PRE_APP\n";
print STDERR "T_CONST_LBL: $T_CONST_LBL\n";
print STDERR "T_POST_LBL: $T_POST_LBL\n";
if ( $TargetPlatform =~ /^i386-/ ) {
    print STDERR "T_X86_PRE_LLBL_PAT: $T_X86_PRE_LLBL_PAT\n";
    print STDERR "T_X86_PRE_LLBL: $T_X86_PRE_LLBL\n";
    print STDERR "T_X86_BADJMP: $T_X86_BADJMP\n";
}
print STDERR "T_MOVE_DIRVS: $T_MOVE_DIRVS\n";
print STDERR "T_COPY_DIRVS: $T_COPY_DIRVS\n";
print STDERR "T_hsc_cc_PAT: $T_hsc_cc_PAT\n";
print STDERR "T_DOT_WORD: $T_DOT_WORD\n";
print STDERR "T_HDR_literal: $T_HDR_literal\n";
print STDERR "T_HDR_misc: $T_HDR_misc\n";
print STDERR "T_HDR_data: $T_HDR_data\n";
print STDERR "T_HDR_consist: $T_HDR_consist\n";
print STDERR "T_HDR_closure: $T_HDR_closure\n";
print STDERR "T_HDR_info: $T_HDR_info\n";
print STDERR "T_HDR_entry: $T_HDR_entry\n";
print STDERR "T_HDR_fast: $T_HDR_fast\n";
print STDERR "T_HDR_vector: $T_HDR_vector\n";
print STDERR "T_HDR_direct: $T_HDR_direct\n";
}

}
\end{code}

%************************************************************************
%*									*
\subsection{Mangle away}
%*									*
%************************************************************************

\begin{code}
sub mangle_asm {
    local($in_asmf, $out_asmf) = @_;

    # multi-line regexp matching:
    local($*) = 1;
    local($i, $c);
    &init_TARGET_STUFF();
    &init_FUNNY_THINGS();

    open(INASM, "< $in_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$in_asmf' (to read)\n");
    open(OUTASM,"> $out_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$out_asmf' (to write)\n");

    # read whole file, divide into "chunks":
    #	record some info about what we've found...

    @chk = ();		# contents of the chunk
    $numchks = 0;	# number of them
    @chkcat = ();	# what category of thing in each chunk
    @chksymb = ();	# what symbol(base) is defined in this chunk
    %slowchk = ();	# ditto, its regular "slow" entry code
    %fastchk = ();	# ditto, fast entry code
    %closurechk = ();	# ditto, the (static) closure
    %infochk = (); 	# given a symbol base, say what chunk its info tbl is in
    %vectorchk = ();    # ditto, return vector table
    %directchk = ();    # ditto, direct return code
    $EXTERN_DECLS = '';	# .globl <foo> .text (MIPS only)

    $i = 0; $chkcat[0] = 'misc'; $chk[0] = '';

    while (<INASM>) {
	next if $T_STABBY && /^\.stab.*${T_US}__stg_split_marker/o;
	next if $T_STABBY && /^\.stab.*ghc.*c_ID/;
	next if /${T_PRE_APP}(NO_)?APP/o;

    	next if /^;/ && $TargetPlatform =~ /^hppa/;

	next if /(^$|^\t\.file\t|^ # )/ && $TargetPlatform =~ /^mips-/;

	if ( $TargetPlatform =~ /^mips-/ 
	  && /^\t\.(globl \S+ \.text|comm\t)/ ) {
	    $EXTERN_DECLS .= $_ unless /(__DISCARD__|\b(PK_|ASSIGN_)(FLT|DBL)\b)/;
  
	} elsif ( /^\s+/ ) { # most common case first -- a simple line!
	    # duplicated from the bottom

	    $chk[$i] .= $_;

	} elsif ( /\.\.ng:$/ && $TargetPlatform =~ /^alpha-/ ) {
	    # Alphas: Local labels not to be confused with new chunks
	    $chk[$i] .= $_;
  
	# NB: all the rest start with a non-space

	} elsif ( $TargetPlatform =~ /^mips-/
	       && /^\d+:/ ) { # a funny-looking very-local label
	    $chk[$i] .= $_;

	} elsif ( /$T_CONST_LBL/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'literal';
	    $chksymb[$i] = $1;

	} elsif ( /^${T_US}__stg_split_marker(\d+)${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'splitmarker';
	    $chksymb[$i] = $1;

	} elsif ( /^${T_US}([A-Za-z0-9_]+)_info${T_POST_LBL}$/o ) {
	    $symb = $1;
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'infotbl';
	    $chksymb[$i] = $symb;

	    die "Info table already? $symb; $i\n" if defined($infochk{$symb});

	    $infochk{$symb} = $i;

	} elsif ( /^${T_US}([A-Za-z0-9_]+)_entry${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'slow';
	    $chksymb[$i] = $1;

	    $slowchk{$1} = $i;

	} elsif ( /^${T_US}([A-Za-z0-9_]+)_fast\d+${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'fast';
	    $chksymb[$i] = $1;

	    $fastchk{$1} = $i;

	} elsif ( /^${T_US}([A-Za-z0-9_]+)_closure${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'closure';
	    $chksymb[$i] = $1;

	    $closurechk{$1} = $i;

	} elsif ( /^${T_US}ghc.*c_ID${T_POST_LBL}/o ) {
	    $chk[++$i]  = $_;
	    $chkcat[$i] = 'consist';

	} elsif ( /^(${T_US}__gnu_compiled_c|gcc2_compiled\.)${T_POST_LBL}/o ) {
	    ; # toss it

	} elsif ( /^${T_US}ErrorIO_call_count${T_POST_LBL}$/o	# HACK!!!!
	       || /^${T_US}[A-Za-z0-9_]+\.\d+${T_POST_LBL}$/o
	       || /^${T_US}.*_CAT${T_POST_LBL}$/o 		# PROF: _entryname_CAT
	       || /^${T_US}CC_.*_struct${T_POST_LBL}$/o	  	# PROF: _CC_ccident_struct
	       || /^${T_US}.*_done${T_POST_LBL}$/o		# PROF: _module_done
	       || /^${T_US}_module_registered${T_POST_LBL}$/o	# PROF: _module_registered
	       ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'data';
	    $chksymb[$i] = '';

	} elsif ( /^([A-Za-z0-9_]+)\s+\.comm/ && $TargetPlatform =~ /^hppa/ ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'bss';
  	    $chksymb[$i] = $1;

	} elsif ( /^${T_US}(ret_|djn_)/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'misc';
	    $chksymb[$i] = '';

	} elsif ( /^${T_US}vtbl_([A-Za-z0-9_]+)${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'vector';
	    $chksymb[$i] = $1;

	    $vectorchk{$1} = $i;

	} elsif ( /^${T_US}([A-Za-z0-9_]+)DirectReturn${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'direct';
	    $chksymb[$i] = $1;

	    $directchk{$1} = $i;

	} elsif ( /^${T_US}[A-Za-z0-9_]+_upd${T_POST_LBL}$/o ) {
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'misc';
	    $chksymb[$i] = '';

	} elsif ( $TargetPlatform =~ /^i386-.*-solaris2/
	     &&   /^(_uname|uname|stat|fstat):/ ) {
	    # for some utterly bizarre reason, this platform
	    # likes to drop little local C routines with these names
	    # into each and every .o file that #includes the
	    # relevant system .h file.  Yuck.  We just don't
	    # tolerate them in .hc files (which we are processing
	    # here).  If you need to call one of these things from
	    # Haskell, make a call to your own C wrapper, then
	    # put that C wrapper (which calls one of these) in a
	    # plain .c file.  WDP 95/12
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'toss';
	    $chksymb[$i] = $1;

	} elsif ( /^${T_US}[A-Za-z0-9_]/o
		&& ( $TargetPlatform !~ /^hppa/ # need to avoid local labels in this case
		   || /^L\$\d+$/ ) ) {
	    local($thing);
	    chop($thing = $_);
	    print STDERR "Funny global thing?: $_"
		unless $KNOWN_FUNNY_THING{$thing}
		    || /^${T_US}_(PRIn|PRStart).*${T_POST_LBL}$/o # pointer reversal GC routines
		    || /^${T_US}CC_.*${T_POST_LBL}$/o		# PROF: _CC_ccident
		    || /^${T_US}_reg.*${T_POST_LBL}$/o;		# PROF: __reg<module>
	    $chk[++$i]   = $_;
	    $chkcat[$i]  = 'misc';
	    $chksymb[$i] = '';

	} else { # simple line (duplicated at the top)

	    $chk[$i] .= $_;
	}
    }
    $numchks = $#chk + 1;

    # the division into chunks is imperfect;
    # we throw some things over the fence into the next
    # chunk.
    #
    # also, there are things we would like to know
    # about the whole module before we start spitting
    # output.

    local($FIRST_MANGLABLE) = ($TargetPlatform =~ /^(alpha-|hppa|mips-)/) ? 1 : 0;

#   print STDERR "first chunk to mangle: $FIRST_MANGLABLE\n";

    # Alphas: NB: we start meddling at chunk 1, not chunk 0
    # The first ".rdata" is quite magical; as of GCC 2.7.x, it
    # spits a ".quad 0" in after the v first ".rdata"; we
    # detect this special case (tossing the ".quad 0")!
    local($magic_rdata_seen) = 0;
  
    # HPPAs, MIPSen: also start medding at chunk 1

    for ($i = $FIRST_MANGLABLE; $i < $numchks; $i++) {
	$c = $chk[$i]; # convenience copy

#	print STDERR "\nCHK $i (BEFORE) (",$chkcat[$i],"):\n", $c;

	# toss all prologue stuff; HPPA is pretty weird
	# (see elsewhere)
	$c = &mash_hppa_prologue($c) if $TargetPlatform =~ /^hppa/;

	# be slightly paranoid to make sure there's
	# nothing surprising in there
	if ( $c =~ /--- BEGIN ---/ ) {
	    if (($p, $r) = split(/--- BEGIN ---/, $c)) {

		if ($TargetPlatform =~ /^i386-/) {
		    $p =~ s/^\tpushl \%edi\n//;
		    $p =~ s/^\tpushl \%esi\n//;
		    $p =~ s/^\tsubl \$\d+,\%esp\n//;
		} elsif ($TargetPlatform =~ /^m68k-/) {
		    $p =~ s/^\tlink a6,#-?\d.*\n//;
		    $p =~ s/^\tmovel d2,sp\@-\n//;
		    $p =~ s/^\tmovel d5,sp\@-\n//; # SMmark.* only?
		    $p =~ s/^\tmoveml \#0x[0-9a-f]+,sp\@-\n//; # SMmark.* only?
		} elsif ($TargetPlatform =~ /^mips-/) {
		    # the .frame/.mask/.fmask that we use is the same
		    # as that produced by GCC for miniInterpret; this
		    # gives GDB some chance of figuring out what happened
		    $FRAME = "\t.frame\t\$sp,2168,\$31\n\t.mask\t0x90000000,-4\n\t.fmask\t0x00000000,0\n";
		    $p =~ s/^\t\.(frame).*\n/__FRAME__/g;
		    $p =~ s/^\t\.(mask|fmask).*\n//g;
		    $p =~ s/^\t\.cprestore.*\n/\t\.cprestore 416\n/; # 16 + 100 4-byte args
		    $p =~ s/^\tsubu\t\$sp,\$sp,\d+\n//;
		    $p =~ s/^\tsw\t\$31,\d+\(\$sp\)\n//;
		    $p =~ s/^\tsw\t\$fp,\d+\(\$sp\)\n//;
		    $p =~ s/^\tsw\t\$28,\d+\(\$sp\)\n//;
		    $p =~ s/__FRAME__/$FRAME/;
		} else {
		    print STDERR "$Pgm: unknown prologue mangling? $TargetPlatform\n";
		}

		die "Prologue junk?: $p\n" if $p =~ /^\t[^\.]/;

		# glue together what's left
		$c = $p . $r;
	    }
	}

	# toss all epilogue stuff; again, paranoidly
	if ( $c =~ /--- END ---/ ) {
	    if (($r, $e) = split(/--- END ---/, $c)) {
		if ($TargetPlatform =~ /^i386-/) {
		    $e =~ s/^\tret\n//;
		    $e =~ s/^\tpopl \%edi\n//;
		    $e =~ s/^\tpopl \%esi\n//;
		    $e =~ s/^\taddl \$\d+,\%esp\n//;
		} elsif ($TargetPlatform =~ /^m68k-/) {
		    $e =~ s/^\tunlk a6\n//;
		    $e =~ s/^\trts\n//;
		} elsif ($TargetPlatform =~ /^mips-/) {
		    $e =~ s/^\tlw\t\$31,\d+\(\$sp\)\n//;
		    $e =~ s/^\tlw\t\$fp,\d+\(\$sp\)\n//;
		    $e =~ s/^\taddu\t\$sp,\$sp,\d+\n//;
		    $e =~ s/^\tj\t\$31\n//;
		} else {
		    print STDERR "$Pgm: unknown epilogue mangling? $TargetPlatform\n";
		}
		die "Epilogue junk?: $e\n" if $e =~ /^\t[^\.]/;

		# glue together what's left
		$c = $r . $e;
		$c =~ s/\n\t\n/\n/; # junk blank line
	    }
	}

	# On SPARCs, we don't do --- BEGIN/END ---, we just
	# toss the register-windowing save/restore/ret* instructions
	# directly:
	if ( $TargetPlatform =~ /^sparc-/ ) {
	    $c =~ s/^\t(save .*|restore|ret|retl)\n//g;
	    # throw away PROLOGUE comments
	    $c =~ s/^\t!#PROLOGUE# 0\n\t!#PROLOGUE# 1\n//;
	}

	# On Alphas, the prologue mangling is done a little later (below)

    	# toss all calls to __DISCARD__
	$c =~ s/^\t(call|jbsr|jal) ${T_US}__DISCARD__\n//go;

	# MIPS: that may leave some gratuitous asm macros around
	# (no harm done; but we get rid of them to be tidier)
	$c =~ s/^\t\.set\tnoreorder\n\t\.set\tnomacro\n\taddu\t(\S+)\n\t\.set\tmacro\n\t\.set\treorder\n/\taddu\t$1\n/
	    if $TargetPlatform =~ /^mips-/;

    	# toss stack adjustment after DoSparks
    	$c =~ s/^(\tjbsr _DoSparks\n)\taddqw #8,sp/$1/g
		if $TargetPlatform =~ /^m68k-/; # this looks old...

	if ( $TargetPlatform =~ /^alpha-/ &&
	   ! $magic_rdata_seen &&
	   $c =~ /^\s*\.rdata\n\t\.quad 0\n\t\.align \d\n/ ) {
	    $c =~ s/^\s*\.rdata\n\t\.quad 0\n\t\.align (\d)\n/\.rdata\n\t\.align $1\n/;
	    $magic_rdata_seen = 1;
	}

	# pick some end-things and move them to the next chunk

	# pin a funny end-thing on (for easier matching):
	$c .= 'FUNNY#END#THING';

	while ( $c =~ /${T_MOVE_DIRVS}FUNNY#END#THING/o ) {
	    $to_move = $1;

	    if ( $i < ($numchks - 1)
	      && ( $to_move =~ /${T_COPY_DIRVS}/
	        || ($TargetPlatform =~ /^hppa/ && $to_move =~ /align/ && $chkcat[$i+1] eq 'literal') )) {
		$chk[$i + 1] = $to_move . $chk[$i + 1];
		# otherwise they're tossed
	    }

	    $c =~ s/${T_MOVE_DIRVS}FUNNY#END#THING/FUNNY#END#THING/o;
	}

    	if ( $TargetPlatform =~ /^alpha-/ && $c =~ /^\t\.ent\s+(\S+)/ ) {
    	    $ent = $1;
	    # toss all prologue stuff, except for loading gp, and the ..ng address
	    if (($p, $r) = split(/^\t\.prologue/, $c)) {
    	        if (($keep, $junk) = split(/\.\.ng:/, $p)) {
    	    	    $c = $keep . "..ng:\n";
    	        } else {
    	    	    print STDERR "malformed code block ($ent)?\n"
    	    	}
    	    }
    	    $c .= "\t.frame \$30,0,\$26,0\n\t.prologue" . $r;
    	}
  
	$c =~ s/FUNNY#END#THING//;

#	print STDERR "\nCHK $i (AFTER) (",$chkcat[$i],"):\n", $c;

	$chk[$i] = $c; # update w/ convenience copy
    }

    if ( $TargetPlatform =~ /^alpha-/ ) {
	# print out the header stuff first
	$chk[0] =~ s/^(\t\.file.*)"(ghc\d+\.c)"/$1"$ifile_root.hc"/;
	print OUTASM $chk[0];

    } elsif ( $TargetPlatform =~ /^hppa/ ) {
	print OUTASM $chk[0];

    } elsif ( $TargetPlatform =~ /^mips-/ ) {
	$chk[0] = "\t\.file\t1 \"$ifile_root.hc\"\n" . $chk[0];

	# get rid of horrible "<dollar>Revision: .*$" strings
	local(@lines0) = split(/\n/, $chk[0]);
	local($z) = 0;
	while ( $z <= $#lines0 ) {
	    if ( $lines0[$z] =~ /^\t\.byte\t0x24,0x52,0x65,0x76,0x69,0x73,0x69,0x6f$/ ) {
		undef($lines0[$z]);
		$z++;
		while ( $z <= $#lines0 ) {
		    undef($lines0[$z]);
		    last if $lines0[$z] =~ /[,\t]0x0$/;
		    $z++;
		}
	    }
	    $z++;
	}
	$chk[0] = join("\n", @lines0);
	$chk[0] =~ s/\n\n+/\n/;
	print OUTASM $chk[0];
    }

    # print out all the literal strings next
    for ($i = 0; $i < $numchks; $i++) {
	if ( $chkcat[$i] eq 'literal' ) {
	    print OUTASM $T_HDR_literal, $chk[$i];
	    print OUTASM "; end literal\n" if $TargetPlatform =~ /^hppa/; # for the splitter

	    $chkcat[$i] = 'DONE ALREADY';
	}
    }

    # on the HPPA, print out all the bss next
    if ( $TargetPlatform =~ /^hppa/ ) {
	for ($i = 1; $i < $numchks; $i++) {
	    if ( $chkcat[$i] eq 'bss' ) {
		print OUTASM "\t.SPACE \$PRIVATE\$\n\t.SUBSPA \$BSS\$\n\t.align 4\n";
		print OUTASM $chk[$i];

		$chkcat[$i] = 'DONE ALREADY';
	    }
	}
    }

    for ($i = $FIRST_MANGLABLE; $i < $numchks; $i++) {
#	print STDERR "$i: cat $chkcat[$i], symb $chksymb[$i]\n";

	next if $chkcat[$i] eq 'DONE ALREADY';

	if ( $chkcat[$i] eq 'misc' ) {
	    if ($chk[$i] ne '') {
		print OUTASM $T_HDR_misc;
		&print_doctored($chk[$i], 0);
	    }

	} elsif ( $chkcat[$i] eq 'toss' ) {
	    print STDERR "*** NB: TOSSING code for $chksymb[$i] !!! ***\n";

	} elsif ( $chkcat[$i] eq 'data' ) {
	    if ($chk[$i] ne '') {
		print OUTASM $T_HDR_data;
		print OUTASM $chk[$i];
	    }

	} elsif ( $chkcat[$i] eq 'consist' ) {
	    if ( $chk[$i] =~ /$T_hsc_cc_PAT/o ) {
		local($consist) = "$1.$2.$3";
		$consist =~ s/,/./g;
		$consist =~ s/\//./g;
		$consist =~ s/-/_/g;
		$consist =~ s/[^A-Za-z0-9_.]/ZZ/g; # ToDo: properly?
		print OUTASM $T_HDR_consist, "${consist}${T_POST_LBL}\n"
		    if $TargetPlatform !~ /^mips-/; # we just don't try in that case
	    } else {
		print STDERR "Couldn't grok consistency: ", $chk[$i];
	    }

	} elsif ( $chkcat[$i] eq 'splitmarker' ) {
	    # we can just re-constitute this one...
	    # NB: we emit _three_ underscores no matter what,
	    # so ghc-split doesn't have to care.
	    print OUTASM "___stg_split_marker",$chksymb[$i],"${T_POST_LBL}\n";

	} elsif ( $chkcat[$i] eq 'closure'
	       || $chkcat[$i] eq 'infotbl'
	       || $chkcat[$i] eq 'slow'
	       || $chkcat[$i] eq 'fast' ) { # do them in that order
	    $symb = $chksymb[$i];

	    # CLOSURE
	    if ( defined($closurechk{$symb}) ) {
		print OUTASM $T_HDR_closure;
		print OUTASM $chk[$closurechk{$symb}];
		$chkcat[$closurechk{$symb}] = 'DONE ALREADY';
	    }

	    # INFO TABLE
	    if ( defined($infochk{$symb}) ) {

		print OUTASM $T_HDR_info;
		print OUTASM &rev_tbl($symb, $chk[$infochk{$symb}], 1);
		# entry code will be put here!

		# paranoia
		if ( $chk[$infochk{$symb}] =~ /${T_DOT_WORD}\s+([A-Za-z0-9_]+_entry)$/o
		  && $1 ne "${T_US}${symb}_entry" ) {
		    print STDERR "!!! entry point???\n",$chk[$infochk{$symb}];
		}

		$chkcat[$infochk{$symb}] = 'DONE ALREADY';
	    }

	    # STD ENTRY POINT
	    if ( defined($slowchk{$symb}) ) {

		# teach it to drop through to the fast entry point:
		$c = $chk[$slowchk{$symb}];

		if ( defined($fastchk{$symb}) ) {
		    if ( $TargetPlatform =~ /^alpha-/ ) {
			$c =~ s/^\tjmp \$31,\(\$27\),0\n\t\.align 4\n\t\.end/\t.align 4\n\t.end/;
		    } elsif ( $TargetPlatform =~ /^hppa/ ) {
			$c =~ s/^\s+ldil.*\n\s+ldo.*\n\s+bv.*\n(.*\n)?\s+\.EXIT/$1\t.EXIT/;
		    } elsif ( $TargetPlatform =~ /^i386-/ ) {
			$c =~ s/^\tmovl \$${T_US}${symb}_fast\d+,\%edx\n\tjmp \*\%edx\n//;
			$c =~ s/^\tmovl \$${T_US}${symb}_fast\d+,\%eax\n\tjmp \*\%eax\n//;
		    } elsif ( $TargetPlatform =~ /^mips-/ ) {
			$c =~ s/^\tjmp \$31,\(\$27\),0\n\t\.align 4\n\t\.end/\t.align 4\n\t.end/;
		    } elsif ( $TargetPlatform =~ /^m68k-/ ) {
			$c =~ s/^\tjmp ${T_US}${symb}_fast\d+.*\n\tnop\n//;
			$c =~ s/^\tjmp ${T_US}${symb}_fast\d+.*\n//;
		    } elsif ( $TargetPlatform =~ /^sparc-/ ) {
			$c =~ s/^\tcall ${T_US}${symb}_fast\d+,.*\n\tnop\n//;
			$c =~ s/^\tcall ${T_US}${symb}_fast\d+,.*\n(\t[a-z].*\n)/$1/;
		    } else {
			print STDERR "$Pgm: mystery slow-fast dropthrough: $TargetPlatform\n";
		    }
		}

		if ( $TargetPlatform !~ /^(alpha-|hppa|mips-)/ ) {
		    # On alphas, hppa: no very good way to look for "dangling"
		    # references to fast-entry point.
		    # (questionable re hppa and mips...)
		    print STDERR "still has jump to fast entry point:\n$c"
			if $c =~ /${T_US}${symb}_fast/; # NB: paranoia
		}

		print OUTASM $T_HDR_entry;

		&print_doctored($c, 1); # NB: the 1!!!

		$chkcat[$slowchk{$symb}] = 'DONE ALREADY';
	    }
	    
	    # FAST ENTRY POINT
	    if ( defined($fastchk{$symb}) ) {
    	    	if ( ! defined($slowchk{$symb})
		   # ToDo: the || clause can go once we're no longer
		   # concerned about producing exactly the same output as before
		   || $TargetPlatform =~ /^(m68k|sparc|i386)-/
		   ) {
		    print OUTASM $T_HDR_fast;
		}
		&print_doctored($chk[$fastchk{$symb}], 0);
		$chkcat[$fastchk{$symb}] = 'DONE ALREADY';
	    }

	} elsif ( $chkcat[$i] eq 'vector'
	       || $chkcat[$i] eq 'direct' ) { # do them in that order
	    $symb = $chksymb[$i];

	    # VECTOR TABLE
	    if ( defined($vectorchk{$symb}) ) {
		print OUTASM $T_HDR_vector;
		print OUTASM &rev_tbl($symb, $chk[$vectorchk{$symb}], 0);
		# direct return code will be put here!
		$chkcat[$vectorchk{$symb}] = 'DONE ALREADY';
	    }

	    # DIRECT RETURN
	    if ( defined($directchk{$symb}) ) {
		print OUTASM $T_HDR_direct;
		&print_doctored($chk[$directchk{$symb}], 0);
		$chkcat[$directchk{$symb}] = 'DONE ALREADY';

	    } elsif ( $TargetPlatform =~ /^alpha-/ ) {
		# Alphas: the commented nop is for the splitter, to ensure
		# that no module ends with a label as the very last
		# thing.  (The linker will adjust the label to point
		# to the first code word of the next module linked in,
		# even if alignment constraints cause the label to move!)

		print OUTASM "\t# nop\n";
	    }
	    
	} else {
	    &tidy_up_and_die(1,"$Pgm: unknown chkcat (ghc-asm: $TargetPlatform)\n$chkcat[$i]\n$chk[$i]\n");
	}
    }
    # finished
    close(OUTASM) || &tidy_up_and_die(1,"Failed writing to $out_asmf\n");
    close(INASM)  || &tidy_up_and_die(1,"Failed reading from $in_asmf\n");
}
\end{code}

\begin{code}
sub mash_hppa_prologue { # OK, epilogue, too
    local($_) = @_;

    # toss all prologue stuff
    s/^\s+\.ENTRY[^\0]*--- BEGIN ---/\t.ENTRY/;

    # Lie about our .CALLINFO
    s/^\s+\.CALLINFO.*$/\t.CALLINFO NO_CALLS,NO_UNWIND/;

    # Get rid of P'

    s/LP'/L'/g;
    s/RP'/R'/g;

    # toss all epilogue stuff
    s/^\s+--- END ---[^\0]*\.EXIT/\t.EXIT/;

    # Sorry; we moved the _info stuff to the code segment.
    s/_info,DATA/_info,CODE/g;

    return($_);
}
\end{code}

\begin{code}
sub print_doctored {
    local($_, $need_fallthru_patch) = @_;

    if ( $TargetPlatform !~ /^i386-/ 
      || ! /^\t[a-z]/ ) { # no instructions in here, apparently
	print OUTASM $_;
	return;
    }
    # OK, must do some x86 **HACKING**

    local($entry_patch)	= '';
    local($exit_patch)	= '';
    local($call_entry_patch)= '';
    local($call_exit_patch)	= '';

#OLD:	# first, convert calls to *very magic form*: (ToDo: document
    # for real!)  from
    #
    #	pushl $768
    #	call _?PerformGC_wrapper
    #	addl $4,%esp
    # to
    #	movl $768, %eax
    #	call _?PerformGC_wrapper
    #
    # The reason we do this now is to remove the apparent use of
    # %esp, which would throw off the "what patch code do we need"
    # decision.
    #
    # Special macros in ghc/includes/COptWraps.lh, used in
    # ghc/runtime/CallWrap_C.lc, are required for this to work!
    #

    s/^\tpushl \$(\d+)\n\tcall ${T_DO_GC}\n\taddl \$4,\%esp\n/\tmovl \$$1,\%eax\n\tcall ${T_DO_GC}\n/go;
    s/^\tpushl \%eax\n\tcall ${T_DO_GC}\n\taddl \$4,\%esp\n/\tcall ${T_DO_GC}\n/go;
    s/^\tpushl \%edx\n\tcall ${T_DO_GC}\n\taddl \$4,\%esp\n/\tmovl \%edx,\%eax\n\tcall ${T_DO_GC}\n/go;

#=  if ( $StolenX86Regs <= 4 ) { # %ecx is ordinary reg
#=	s/^\tpushl \%ecx\n\tcall ${T_DO_GC}\n\taddl \$4,\%esp\n/\tmovl \%ecx,\%eax\n\tcall ${T_DO_GC}\n/go;
#=  }

    # gotta watch out for weird instructions that
    # invisibly smash various regs:
    #   rep*	%ecx used for counting
    #   scas*	%edi used for destination index
    #   cmps*	%e[sd]i used for indices
    #   loop*	%ecx used for counting
    #
    # SIGH.

    # We cater for:
    #  * use of STG reg [ nn(%ebx) ] where no machine reg avail
    #
    #  * GCC used an "STG reg" for its own purposes
    #
    #  * some secret uses of machine reg, requiring STG reg
    #    to be saved/restored

    # The most dangerous "GCC uses" of an "STG reg" are when
    # the reg holds the target of a jmp -- it's tricky to
    # insert the patch-up code before we get to the target!
    # So here we change the jmps:

    # --------------------------------------------------------
    # it can happen that we have jumps of the form...
    #   jmp *<something involving %esp>
    # or
    #   jmp <something involving another naughty register...>
    #
    # a reasonably-common case is:
    #
    #   movl $_blah,<bad-reg>
    #   jmp  *<bad-reg>
    #
    # which is easily fixed as:
    #
    # sigh! try to hack around it...
    #

    if ($StolenX86Regs <= 2 ) { # YURGH! spurious uses of esi?
	s/^\tmovl (.*),\%esi\n\tjmp \*%esi\n/\tmovl $1,\%eax\n\tjmp \*\%eax\n/g;
	s/^\tjmp \*(-?\d*)\((.*\%esi.*)\)\n/\tmovl $2,\%eax\n\tjmp \*$1\(\%eax\)\n/g;
	s/^\tjmp \*\%esi\n/\tmovl \%esi,\%eax\n\tjmp \*\%eax\n/g;
	die "$Pgm: (mangler) still have jump involving \%esi!\n$_"
	    if /(jmp|call) .*\%esi/;
    }
    if ($StolenX86Regs <= 3 ) { # spurious uses of edi?
	s/^\tmovl (.*),\%edi\n\tjmp \*%edi\n/\tmovl $1,\%eax\n\tjmp \*\%eax\n/g;
	s/^\tjmp \*(-?\d*)\((.*\%edi.*)\)\n/\tmovl $2,\%eax\n\tjmp \*$1\(\%eax\)\n/g;
	s/^\tjmp \*\%edi\n/\tmovl \%edi,\%eax\n\tjmp \*\%eax\n/g;
	die "$Pgm: (mangler) still have jump involving \%edi!\n$_"
	    if /(jmp|call) .*\%edi/;
    }
#=  if ($StolenX86Regs <= 4 ) { # spurious uses of ecx?
#=	s/^\tmovl (.*),\%ecx\n\tjmp \*%ecx\n/\tmovl $1,\%eax\n\tjmp \*\%eax\n/g;
#=	s/^\tjmp \*(-?\d*)\((.*\%ecx.*)\)\n/\tmovl $2,\%eax\n\tjmp \*$1\(\%eax\)\n/g;
#=	s/^\tjmp \*\%ecx\n/\tmovl \%ecx,\%eax\n\tjmp \*\%eax\n/g;
#=	die "$Pgm: (mangler) still have jump involving \%ecx!\n$_"
#=	    if /(jmp|call) .*\%ecx/;
#=  }

    # OK, now we can decide what our patch-up code is going to
    # be:
    if ( $StolenX86Regs <= 2
	 && ( /32\(\%ebx\)/ || /\%esi/ || /^\tcmps/ ) ) { # R1 (esi)
	$entry_patch .= "\tmovl \%esi,32(\%ebx)\n";
	$exit_patch  .= "\tmovl 32(\%ebx),\%esi\n";
	# nothing for call_{entry,exit} because %esi is callee-save
    }
    if ( $StolenX86Regs <= 3
	 && ( /64\(\%ebx\)/ || /\%edi/ || /^\t(scas|cmps)/ ) ) { # SpA (edi)
	$entry_patch .= "\tmovl \%edi,64(\%ebx)\n";
	$exit_patch  .= "\tmovl 64(\%ebx),\%edi\n";
	# nothing for call_{entry,exit} because %edi is callee-save
    }
#=  if ( $StolenX86Regs <= 4
#=	 && ( /80\(\%ebx\)/ || /\%ecx/ || /^\t(rep|loop)/ ) ) { # Hp (ecx)
#=	$entry_patch .= "\tmovl \%ecx,80(\%ebx)\n";
#=	$exit_patch  .= "\tmovl 80(\%ebx),\%ecx\n";
#=
#=	$call_exit_patch  .= "\tmovl \%ecx,108(\%ebx)\n";
#=	$call_entry_patch .= "\tmovl 108(\%ebx),\%ecx\n";
#=	# I have a really bad feeling about this if we ever
#=	# have a nested call...
#=	# NB: should just hide it somewhere in the C stack.
#=  }
    # --------------------------------------------------------
    # next, here we go with non-%esp patching!
    #
    s/^(\t[a-z])/$entry_patch$1/; # before first instruction
    s/^(\tcall .*\n(\taddl \$\d+,\%esp\n)?)/$call_exit_patch$1$call_entry_patch/g; # _all_ calls

    # fix _all_ non-local jumps:

    s/^\tjmp \*${T_X86_PRE_LLBL_PAT}/\tJMP___SL/go;
    s/^\tjmp ${T_X86_PRE_LLBL_PAT}/\tJMP___L/go;

    s/^(\tjmp .*\n)/$exit_patch$1/g; # here's the fix...

    s/^\tJMP___SL/\tjmp \*${T_X86_PRE_LLBL}/go;
    s/^\tJMP___L/\tjmp ${T_X86_PRE_LLBL}/go;

    # fix post-PerformGC wrapper (re-)entries ???

    if ($StolenX86Regs == 2 ) {
	die "ARGH! Jump uses \%esi or \%edi with -monly-2-regs:\n$_" 
	    if /^\t(jmp|call) .*\%e(si|di)/;
#=	die "ARGH! Jump uses \%esi, \%edi, or \%ecx with -monly-2-regs:\n$_" 
#=	    if /^\t(jmp|call) .*\%e(si|di|cx)/;
    } elsif ($StolenX86Regs == 3 ) {
	die "ARGH! Jump uses \%edi with -monly-3-regs:\n$_" 
	    if /^\t(jmp|call) .*\%edi/;
#=	die "ARGH! Jump uses \%edi or \%ecx with -monly-3-regs:\n$_" 
#=	    if /^\t(jmp|call) .*\%e(di|cx)/;
#=  } elsif ($StolenX86Regs == 4 ) {
#=	die "ARGH! Jump uses \%ecx with -monly-4-regs:\n$_" 
#=	    if /^\t(jmp|call) .*\%ecx/;
    }

    # final peephole fixes

    s/^\tmovl \%eax,36\(\%ebx\)\n\tjmp \*36\(\%ebx\)\n/\tmovl \%eax,36\(\%ebx\)\n\tjmp \*\%eax\n/;
    s/^\tmovl \$_(.*),(\%e[abcd]x)\n\tjmp \*$2/\tjmp _$1/g;

    # Hacks to eliminate some reloads of Hp.  Worth about 5% code size.
    # We could do much better than this, but at least it catches about
    # half of the unnecessary reloads.
    # Note that these will stop working if either:
    #  (i) the offset of Hp from BaseReg changes from 80, or
    #  (ii) the register assignment of BaseReg changes from %ebx

    s/^\tmovl 80\(\%ebx\),\%e.x\n\tmovl \$(.*),(-?[0-9]*)\(\%e.x\)\n\tmovl 80\(\%ebx\),\%e(.)x/\tmovl 80\(\%ebx\),\%e$3x\n\tmovl \$$1,$2\(\%e$3x\)/g;

    s/^\tmovl 80\(\%ebx\),\%e(.)x\n\tmovl (.*),\%e(.)x\n\tmovl \%e$3x,(-?[0-9]*\(\%e$1x\))\n\tmovl 80\(\%ebx\),\%e$1x/\tmovl 80\(\%ebx\),\%e$1x\n\tmovl $2,\%e$3x\n\tmovl \%e$3x,$4/g;

    s/^\tmovl 80\(\%ebx\),\%edx((\n\t(movl|addl) .*,((-?[0-9]*\(.*)|(\%e[abc]x)))+)\n\tmovl 80\(\%ebx\),\%edx/\tmovl 80\(\%ebx\),\%edx$1/g;
    s/^\tmovl 80\(\%ebx\),\%eax((\n\t(movl|addl) .*,((-?[0-9]*\(.*)|(\%e[bcd]x)))+)\n\tmovl 80\(\%ebx\),\%eax/\tmovl 80\(\%ebx\),\%eax$1/g;

    # --------------------------------------------------------
    # that's it -- print it
    #
    #die "Funny jumps?\n$_" if /${T_X86_BADJMP}/o; # paranoia

    print OUTASM $_;

    if ( $need_fallthru_patch ) { # exit patch for end of slow entry code
	print OUTASM $exit_patch;
	# ToDo: make it not print if there is a "jmp" at the end
    }
}
\end{code}

\begin{code}
sub init_FUNNY_THINGS {
    %KNOWN_FUNNY_THING = (
	"${T_US}CheckHeapCode${T_POST_LBL}", 1,
	"${T_US}CommonUnderflow${T_POST_LBL}", 1,
	"${T_US}Continue${T_POST_LBL}", 1,
	"${T_US}EnterNodeCode${T_POST_LBL}", 1,
	"${T_US}ErrorIO_call_count${T_POST_LBL}", 1,
	"${T_US}ErrorIO_innards${T_POST_LBL}", 1,
	"${T_US}IndUpdRetDir${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV0${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV1${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV2${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV3${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV4${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV5${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV6${T_POST_LBL}", 1,
	"${T_US}IndUpdRetV7${T_POST_LBL}", 1,
	"${T_US}PrimUnderflow${T_POST_LBL}", 1,
	"${T_US}StackUnderflowEnterNode${T_POST_LBL}", 1,
	"${T_US}StdErrorCode${T_POST_LBL}", 1,
	"${T_US}UnderflowVect0${T_POST_LBL}", 1,
	"${T_US}UnderflowVect1${T_POST_LBL}", 1,
	"${T_US}UnderflowVect2${T_POST_LBL}", 1,
	"${T_US}UnderflowVect3${T_POST_LBL}", 1,
	"${T_US}UnderflowVect4${T_POST_LBL}", 1,
	"${T_US}UnderflowVect5${T_POST_LBL}", 1,
	"${T_US}UnderflowVect6${T_POST_LBL}", 1,
	"${T_US}UnderflowVect7${T_POST_LBL}", 1,
	"${T_US}UpdErr${T_POST_LBL}", 1,
	"${T_US}UpdatePAP${T_POST_LBL}", 1,
	"${T_US}WorldStateToken${T_POST_LBL}", 1,
	"${T_US}_Enter_Internal${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextAStack${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextBStack${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextCAF${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextGA${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextRoot${T_POST_LBL}", 1,
	"${T_US}_PRMarking_MarkNextSpark${T_POST_LBL}", 1,
	"${T_US}_Scavenge_Forward_Ref${T_POST_LBL}", 1,
	"${T_US}__std_entry_error__${T_POST_LBL}", 1,
	"${T_US}_startMarkWorld${T_POST_LBL}", 1,
	"${T_US}resumeThread${T_POST_LBL}", 1,
	"${T_US}startCcRegisteringWorld${T_POST_LBL}", 1,
	"${T_US}startEnterFloat${T_POST_LBL}", 1,
	"${T_US}startEnterInt${T_POST_LBL}", 1,
	"${T_US}startPerformIO${T_POST_LBL}", 1,
	"${T_US}startStgWorld${T_POST_LBL}", 1,
	"${T_US}stopPerformIO${T_POST_LBL}", 1
    );
}
\end{code}

The following table reversal is used for both info tables and return
vectors.  In both cases, we remove the first entry from the table,
reverse the table, put the label at the end, and paste some code
(that which is normally referred to by the first entry in the table)
right after the table itself.  (The code pasting is done elsewhere.)

\begin{code}
sub rev_tbl {
    local($symb, $tbl, $discard1) = @_;

    local($before) = '';
    local($label) = '';
    local(@imports) = (); # hppa only
    local(@words) = ();
    local($after) = '';
    local(@lines) = split(/\n/, $tbl);
    local($i, $extra, $words_to_pad, $j);

    for ($i = 0; $i <= $#lines && $lines[$i] !~ /^\t${T_DOT_WORD}\s+/o; $i++) {
	$label .= $lines[$i] . "\n",
	    next if $lines[$i] =~ /^[A-Za-z0-9_]+_info${T_POST_LBL}$/o
		 || $lines[$i] =~ /^${T_DOT_GLOBAL}/o
		 || $lines[$i] =~ /^${T_US}vtbl_\S+${T_POST_LBL}$/o;

	$before .= $lines[$i] . "\n"; # otherwise...
    }

    if ( $TargetPlatform !~ /^hppa/ ) {
	for ( ; $i <= $#lines && $lines[$i] =~ /^\t${T_DOT_WORD}\s+/o; $i++) {
	    push(@words, $lines[$i]);
	}
    } else { # hppa weirdness
	for ( ; $i <= $#lines && $lines[$i] =~ /^\s+\.(word|IMPORT)/; $i++) {
	    if ($lines[$i] =~ /^\s+\.IMPORT/) {
		push(@imports, $lines[$i]);
	    } else {
		# We don't use HP's ``function pointers''
		# We just use labels in code space, like normal people
		$lines[$i] =~ s/P%//;
		push(@words, $lines[$i]);
	    }
	}
    }

    # now throw away the first word (entry code):
    shift(@words) if $discard1;

# Padding removed to reduce code size and improve performance on Pentiums.
# Simon M. 13/4/96
    # for 486-cache-friendliness, we want our tables aligned
    # on 16-byte boundaries (.align 4).  Let's pad:
#    $extra = ($#words + 1) % 4;
#    $words_to_pad = ($extra == 0) ? 0 : 4 - $extra;
#    for ($j = 0; $j < $words_to_pad; $j++) { push(@words, "\t${T_DOT_WORD} 0"); }

    for (; $i <= $#lines; $i++) {
	$after .= $lines[$i] . "\n";
    }

    # Alphas:If we have anonymous text (not part of a procedure), the
    # linker may complain about missing exception information.  Bleh.
    if ( $TargetPlatform =~ /^alpha-/ && $label =~ /^([A-Za-z0-9_]+):$/) {
    	$before = "\t.ent $1\n" . $before;
    	$after .= "\t.end $1\n";
    }

    $tbl = $before
	 . (($TargetPlatform !~ /^hppa/) ? '' : join("\n", @imports) . "\n")
	 . join("\n", (reverse @words)) . "\n"
	 . $label . $after;

#   print STDERR "before=$before\n";
#   print STDERR "label=$label\n";
#   print STDERR "words=",(reverse @words),"\n";
#   print STDERR "after=$after\n";

    $tbl;
}
\end{code}

\begin{code}
sub mini_mangle_asm_i386 {
    local($in_asmf, $out_asmf) = @_;

    &init_TARGET_STUFF();

    open(INASM, "< $in_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$in_asmf' (to read)\n");
    open(OUTASM,"> $out_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$out_asmf' (to write)\n");

    while (<INASM>) {
	print OUTASM;

        next unless
	    /^${T_US}(PerformGC|StackOverflow|Yield|PerformReschedule)_wrapper${T_POST_LBL}\n/o;
	print OUTASM "\tmovl \%esp, ${T_US}__temp_esp\n";
	print OUTASM "\tmovl \%eax, ${T_US}__temp_eax\n";
    }

    # finished:
    close(OUTASM) || &tidy_up_and_die(1,"Failed writing to $out_asmf\n");
    close(INASM)  || &tidy_up_and_die(1,"Failed reading from $in_asmf\n");
}
\end{code}

The HP is a major nuisance.  The threaded code mangler moved info
tables from data space to code space, but unthreaded code in the RTS
still has references to info tables in data space.  Since the HP
linker is very precise about where symbols live, we need to patch the
references in the unthreaded RTS as well.

\begin{code}
sub mini_mangle_asm_hppa {
    local($in_asmf, $out_asmf) = @_;

    open(INASM, "< $in_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$in_asmf' (to read)\n");
    open(OUTASM,"> $out_asmf")
	|| &tidy_up_and_die(1,"$Pgm: failed to open `$out_asmf' (to write)\n");

    while (<INASM>) {
	s/_info,DATA/_info,CODE/;   # Move _info references to code space
	s/P%_PR/_PR/;
	print OUTASM;
    }

    # finished:
    close(OUTASM) || &tidy_up_and_die(1,"Failed writing to $out_asmf\n");
    close(INASM)  || &tidy_up_and_die(1,"Failed reading from $in_asmf\n");
}

# make "require"r happy...
1;
\end{code}