--- /dev/null
+#! /usr/bin/perl
+
+# Copyright 2000, 2001 Free Software Foundation, Inc.
+#
+# This file is part of the GNU MP Library.
+#
+# The GNU MP Library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation; either version 3 of the License, or (at
+# your option) any later version.
+#
+# The GNU MP Library is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+# License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
+
+
+# Usage: cross.pl [filename.o]...
+#
+# Produce an annotated disassembly of the given object files, indicating
+# certain code alignment and addressing mode problems afflicting K6 chips.
+# "ZZ" is used on all annotations, so this can be searched for.
+#
+# With no arguments, all .o files corresponding to .asm files are processed.
+# This is good in the mpn object directory of a k6*-*-* build.
+#
+# Code alignments of 8 bytes or more are handled. When 32 is used, cache
+# line boundaries will fall in at offsets 0x20,0x40,etc and problems are
+# flagged at those locations. When 16 is used, the line boundaries can also
+# fall at offsets 0x10,0x30,0x50,etc, depending where the file is loaded, so
+# problems are identified there too. Likewise when 8 byte alignment is used
+# problems are flagged additionally at 0x08,0x18,0x28,etc.
+#
+# Usually 32 byte alignment is used for k6 routines, but less is certainly
+# possible if through good luck, or a little tweaking, cache line crossing
+# problems can be avoided at the extra locations.
+#
+# Bugs:
+#
+# Instructions without mod/rm bytes or which are already vector decoded are
+# unaffected by cache line boundary crossing, but not all of these have yet
+# been put in as exceptions. All that occur in practice in GMP are present
+# though.
+#
+# There's no messages for using the vector decoded addressing mode (%esi),
+# but that's easy to avoid when coding.
+#
+# Future:
+#
+# Warn about jump targets that are poorly aligned (less than 2 instructions
+# before a cache line boundary).
+
+use strict;
+
+sub disassemble {
+ my ($file) = @_;
+ my ($addr,$b1,$b2,$b3, $prefix,$opcode,$modrm);
+ my $align;
+
+ open (IN, "objdump -Srfh $file |")
+ || die "Cannot open pipe from objdump\n";
+ while (<IN>) {
+ print;
+
+ if (/^[ \t]*[0-9]+[ \t]+\.text[ \t]/ && /2\*\*([0-9]+)$/) {
+ $align = 1 << $1;
+ if ($align < 8) {
+ print "ZZ cross.pl cannot handle alignment < 2**3\n";
+ $align = 8
+ }
+ }
+
+ if (/^[ \t]*([0-9a-f]*):[ \t]*([0-9a-f]+)[ \t]+([0-9a-f]+)[ \t]+([0-9a-f]+)/) {
+ ($addr,$b1,$b2,$b3) = ($1,$2,$3,$4);
+
+ } elsif (/^[ \t]*([0-9a-f]*):[ \t]*([0-9a-f]+)[ \t]+([0-9a-f]+)/) {
+ ($addr,$b1,$b2,$b3) = ($1,$2,$3,'');
+
+ } elsif (/^[ \t]*([0-9a-f]*):[ \t]*([0-9a-f]+)/) {
+ ($addr,$b1,$b2,$b3) = ($1,$2,'','');
+
+ } else {
+ next;
+ }
+
+ if ($b1 =~ /0f/) {
+ $prefix = $b1;
+ $opcode = $b2;
+ $modrm = $b3;
+ } else {
+ $prefix = '';
+ $opcode = $b1;
+ $modrm = $b2;
+ }
+
+ # modrm of the form 00-xxx-100 with an 0F prefix is the problem case
+ # for K6 and pre-CXT K6-2
+ if ($prefix =~ /0f/
+ && $opcode !~ /^8/ # jcond disp32
+ && $modrm =~ /^[0-3][4c]/) {
+ print "ZZ ($file) >3 bytes to determine instruction length [K6]\n";
+ }
+
+ # with just an opcode, starting 1f mod 20h
+ if (($align==32 && $addr =~ /[13579bdf]f$/
+ || $align==16 && $addr =~ /f$/
+ || $align==8 && $addr =~ /[7f]$/)
+ && $prefix !~ /0f/
+ && $opcode !~ /1[012345]/ # adc
+ && $opcode !~ /1[89abcd]/ # sbb
+ && $opcode !~ /^4/ # inc/dec reg
+ && $opcode !~ /^5/ # push/pop reg
+ && $opcode !~ /68/ # push $imm32
+ && $opcode !~ /^7/ # jcond disp8
+ && $opcode !~ /a[89]/ # test+imm
+ && $opcode !~ /a[a-f]/ # stos/lods/scas
+ && $opcode !~ /b8/ # movl $imm32,%eax
+ && $opcode !~ /d[0123]/ # rcl
+ && $opcode !~ /e[0123]/ # loop/loopz/loopnz/jcxz
+ && $opcode !~ /e8/ # call disp32
+ && $opcode !~ /e[9b]/ # jmp disp32/disp8
+ && $opcode !~ /f[89abcd]/ # clc,stc,cli,sti,cld,std
+ && !($opcode =~ /f[67]/ # grp 1
+ && $modrm =~ /^[2367abef]/) # mul, imul, div, idiv
+ && $modrm !~ /^$/) {
+ print "ZZ ($file) opcode/modrm cross 32-byte boundary\n";
+ }
+
+ # with an 0F prefix, anything starting at 1f mod 20h
+ if (($align==32 && $addr =~ /[13579bdf][f]$/
+ || $align==16 && $addr =~ /f$/
+ || $align==8 && $addr =~ /[7f]$/)
+ && $prefix =~ /0f/
+ && $opcode !~ /af/ # imul
+ && $opcode !~ /a[45]/ # shldl
+ && $opcode !~ /a[cd]/ # shrdl
+ ) {
+ print "ZZ ($file) prefix/opcode cross 32-byte boundary\n";
+ }
+
+ # with an 0F prefix, anything with mod/rm starting at 1e mod 20h
+ if (($align==32 && $addr =~ /[13579bdf][e]$/
+ || $align==16 && $addr =~ /[e]$/
+ || $align==8 && $addr =~ /[6e]$/)
+ && $prefix =~ /0f/
+ && $opcode !~ /^8/ # jcond disp32
+ && $opcode !~ /af/ # imull reg,reg
+ && $opcode !~ /a[45]/ # shldl
+ && $opcode !~ /a[cd]/ # shrdl
+ && $modrm !~ /^$/) {
+ print "ZZ ($file) prefix/opcode/modrm cross 32-byte boundary\n";
+ }
+ }
+ close IN || die "Error from objdump (or objdump not available)\n";
+}
+
+
+my @files;
+if ($#ARGV >= 0) {
+ @files = @ARGV;
+} else {
+ @files = glob "*.asm";
+ map {s/.asm/.o/} @files;
+}
+
+foreach (@files) {
+ disassemble($_);
+}
projects / msp430-gcc.git / blobdiff