#!/usr/bin/perl -w
#
# (C) Copyright M. D Mackey 2004. This program may be freely modified and redistributed,
# but I would appreciate feedback to mark\@swallowtail\.org.
#
# A short program to patch an executable compiled with the Intel Fortran Compiler.
# Run with -h for help/
#
# The patch removes the check for the string "GenuineIntel" in the
# CPUID flags of the processor, thus making SSE/SSE2 code work on AMD chips that
# support it.
#
# Tested on executables compiled with compiler versions 7.1.040, 8.1.028 and 9.0.024,
# and should work on other builds.
#
# Creates a backup file before changing anything, so should be easy to undo if
# things go wrong.
#
# If you want to check for a successful patch, do
#
# objdump -d <executable>~ > old
# objdump -d <executable> > new
#
# and examine the differences between 'old' and 'new'. Three lines
# should have changed in __intel_cpu_indicator_init:
#
# 81 fa 47 65 6e 75 cmp $0x756e6547,%edx
# ...
# 81 fa 69 6e 65 49 cmp $0x49656e69,%edx
# ...
# 81 fa 6e 74 65 6c cmp $0x6c65746e,%edx
#
# (these check for "GenuineIntel"). These lines should all be changed to
# f7 c2 00 00 00 00 testl $0x00000000,%edx
#
# (the registers might be %eax, %ebx, %ecx or %edx, depending on compiler version)
use strict;
use Getopt::Std;
# Handle options
my(%opts);
my($ok)=getopts('Hhb:v',\%opts);
usage() if ($opts{h} or $opts{H} or !$ok or !@ARGV);
my($backup)="~";
$backup=$opts{b} if ($opts{b});
my($verbose)=$opts{v};
my($file);
foreach $file (@ARGV) {
print STDERR "Patching file $_...\n" if ($verbose);
# Check backup file
if ($backup and -e "$file$backup") {
warn("Error: backup file '$file$backup' for '$file' already exists, so not patching!");
next;
}
open(FILE,$file) or die("Couldn't open file '$file': $!");
binmode(FILE);
my($contents)=join('',<FILE>); # Shlurp up file into one long binary string
close(FILE);
my($unp)=unpack('H*',$contents); # Unpack into a sequence of hex bytes
my($count);
# Try patching "cmp $0x756e6547,%eax" to "test $0x00000000,%eax" etc
$count+=($unp=~s/3d47656e75/a900000000/g);
$count+=($unp=~s/3d696e6549/a900000000/g);
$count+=($unp=~s/3d6e74656c/a900000000/g);
# Now try patching "cmp $0x756e6547,%ebx" to "testl $0x00000000,%ebx" etc
$count+=($unp=~s/81fb47656e75/f7c300000000/g);
$count+=($unp=~s/81fb696e6549/f7c300000000/g);
$count+=($unp=~s/81fb6e74656c/f7c300000000/g);
# Now try patching "cmp $0x756e6547,%ecx" to "testl $0x00000000,%ecx" etc
$count+=($unp=~s/81f947656e75/f7c100000000/g);
$count+=($unp=~s/81f9696e6549/f7c100000000/g);
$count+=($unp=~s/81f96e74656c/f7c100000000/g);
# Now try patching "cmp $0x756e6547,%edx" to "testl $0x00000000,%edx" etc
$count+=($unp=~s/81fa47656e75/f7c200000000/g);
$count+=($unp=~s/81fa696e6549/f7c200000000/g);
$count+=($unp=~s/81fa6e74656c/f7c200000000/g);
# Now try patching "cmp $0x756e6547,%ebp" to "testl $0x00000000,%ebp" etc
$count+=($unp=~s/81fd47656e75/f7c500000000/g);
$count+=($unp=~s/81fd696e6549/f7c500000000/g);
$count+=($unp=~s/81fd6e74656c/f7c500000000/g);
# Now try patching "cmp $0x756e6547,%esi" to "testl $0x00000000,%esi" etc
$count+=($unp=~s/81fe47656e75/f7c600000000/g);
$count+=($unp=~s/81fe696e6549/f7c600000000/g);
$count+=($unp=~s/81fe6e74656c/f7c600000000/g);
# Now try patching "cmp $0x756e6547,%edi" to "testl $0x00000000,%edi" etc
$count+=($unp=~s/81ff47656e75/f7c700000000/g);
$count+=($unp=~s/81ff696e6549/f7c700000000/g);
$count+=($unp=~s/81ff6e74656c/f7c700000000/g);
#intel ifort 11.1 compiler
# 52cfb8: 81 7d f0 47 65 6e 75 cmpl $0x756e6547,-0x10(%rbp)
# 52cfbf: 75 16 jne 52cfd7 <__intel_cpu_indicator_init+0x97>
# 52cfc1: 81 7d e8 69 6e 65 49 cmpl $0x49656e69,-0x18(%rbp)
# 52cfc8: 75 0d jne 52cfd7 <__intel_cpu_indicator_init+0x97>
# 52cfca: 81 7d e0 6e 74 65 6c cmpl $0x6c65746e,-0x20(%rbp)
# 52cfd1: 75 04 jne 52cfd7 <__intel_cpu_indicator_init+0x97>
$count+=($unp=~s/817df047656e75/f745f000000000/g);
$count+=($unp=~s/817de8696e6549/f745e800000000/g);
$count+=($unp=~s/817de06e74656c/f745e000000000/g);
next if (!$count); # Don't patch if no substitutions made
if ($count % 3) { # Number of substitutions must be a multiple of 3!
warn "WARNING: $count lines were to be patched in '$file': should be a multiple of 3! Skipping this file.\n";
next;
}
print STDERR "Patching $file in $count places...";
die "Error: wanted to create temp file '$file.$$.tmp' but it already exists!" if (-e "$file.$$.tmp");
open(OUTPUT,">$file.$$.tmp") or die("Can't create temporary output file '$file.$$.tmp':$!");
binmode(OUTPUT);
print OUTPUT pack('H*',$unp);
close(OUTPUT) or die "Can't close file '$file.$$.tmp'";
`chmod --reference="$file" "$file.$$.tmp"`; # chmod to original file's mode
# Rename original file to backup
if ($backup) {
rename($file,"$file$backup") or die("Couldn't rename '$file' to '$file$backup': $!\n");
}
rename("$file.$$.tmp",$file) or die("Couldn't rename '$file.$$.tmp' to '$file': $!\n");
if ($backup) {
print STDERR "Patch operation for '$file' successful, original file at '$file$backup'\n" if ($verbose);
} else {
print STDERR "Patch operation for '$file' successful, no backup created\n" if ($verbose);
}
}
exit(0);
sub usage {
print STDERR <<EOUSAGE;
Usage: intel_check_executable_patch.pl [options] <filename> [<filename>...]
Options:
-b <suffix> Use the supplied suffix to name the backup file. The
default is '~', and setting this to '' disables backups.
-v Be more verbose.
Some versions of the Intel Fortran Compiler produce code which checks whether
the CPU is made by Intel or not, and disables MMX/SSE/SSE2 code if it isn't.
This program patches executables produced by the Intel compiler to remove this
check, so that e.g. programs compiled with -axW will use SSE2 code on Athlon
64 chips.
This script was tested against ifc versions 7.1.040, 8.1.028 and 9.0.024 and
should work on other version 7 to 9 releases. The patch process will almost
certainly work with executables compiled with the Intel C compiler as well, and
with Windows executables as well as Linux binaries, but has not been extensively
tested on these, so be careful! If you do test this on icc-compiled
executables, then please let me know how it goes!
Patched files are backed up (by default to 'filename~'), see the -b flag to
change this.
This program is provided with NO WARRANTY: please check that the patched executables
behaves as you would expect! I can't really foresee any problems that could reasonably
be caused by the use of this patch, but you never know  .
# If you want to check for a successful patch, do
#
# objdump -d <executable>~ > old
# objdump -d <executable> > new
#
# and examine the differences between 'old' and 'new'. Three lines
# should have changed in __intel_cpu_indicator_init:
#
# 81 fa 47 65 6e 75 cmp $0x756e6547,%edx
# ...
# 81 fa 69 6e 65 49 cmp $0x49656e69,%edx
# ...
# 81 fa 6e 74 65 6c cmp $0x6c65746e,%edx
#
# (these check for "GenuineIntel"). These lines should all be changed to
# f7 c2 00 00 00 00 testl $0x00000000,%edx
#
# (the registers might be %eax, %ebx, %ecx or %edx, depending on compiler version)
EOUSAGE
exit(1);
}
|
