#!/usr/bin/env perl
# ====================================================================
# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
# project. The module is, however, dual licensed under OpenSSL and
# CRYPTOGAMS licenses depending on where you obtain it. For further
# details see http://www.openssl.org/~appro/cryptogams/.
# ====================================================================
# sha1_block procedure for ARMv4.
#
# January 2007.
# Size/performance trade-off
# ====================================================================
# impl size in bytes comp cycles[*] measured performance
# ====================================================================
# thumb 304 3212 4420
# armv4-small 392/+29% 1958/+64% 2250/+96%
# armv4-compact 740/+89% 1552/+26% 1840/+22%
# armv4-large 1420/+92% 1307/+19% 1370/+34%[***]
# full unroll ~5100/+260% ~1260/+4% ~1300/+5%
# ====================================================================
# thumb = same as 'small' but in Thumb instructions[**] and
# with recurring code in two private functions;
# small = detached Xload/update, loops are folded;
# compact = detached Xload/update, 5x unroll;
# large = interleaved Xload/update, 5x unroll;
# full unroll = interleaved Xload/update, full unroll, estimated[!];
#
# [*] Manually counted instructions in "grand" loop body. Measured
# performance is affected by prologue and epilogue overhead,
# i-cache availability, branch penalties, etc.
# [**] While each Thumb instruction is twice smaller, they are not as
# diverse as ARM ones: e.g., there are only two arithmetic
# instructions with 3 arguments, no [fixed] rotate, addressing
# modes are limited. As result it takes more instructions to do
# the same job in Thumb, therefore the code is never twice as
# small and always slower.
# [***] which is also ~35% better than compiler generated code. Dual-
# issue Cortex A8 core was measured to process input block in
# ~990 cycles.
# August 2010.
#
# Rescheduling for dual-issue pipeline resulted in 13% improvement on
# Cortex A8 core and in absolute terms ~870 cycles per input block
# [or 13.6 cycles per byte].
# February 2011.
#
# Profiler-assisted and platform-specific optimization resulted in 10%
# improvement on Cortex A8 core and 12.2 cycles per byte.
while (($output=shift) && ($output!~/^\w[\w\-]*\.\w+$/)) {}
open STDOUT,">$output";
$ctx="r0";
$inp="r1";
$len="r2";
$a="r3";
$b="r4";
$c="r5";
$d="r6";
$e="r7";
$K="r8";
$t0="r9";
$t1="r10";
$t2="r11";
$t3="r12";
$Xi="r14";
@V=($a,$b,$c,$d,$e);
sub Xupdate {
my ($a,$b,$c,$d,$e,$opt1,$opt2)=@_;
$code.=<<___;
ldr $t0,[$Xi,#15*4]
ldr $t1,[$Xi,#13*4]
ldr $t2,[$Xi,#7*4]
add $e,$K,$e,ror#2 @ E+=K_xx_xx
ldr $t3,[$Xi,#2*4]
eor $t0,$t0,$t1
eor $t2,$t2,$t3 @ 1 cycle stall
eor $t1,$c,$d @ F_xx_xx
mov $t0,$t0,ror#31
add $e,$e,$a,ror#27 @ E+=ROR(A,27)
eor $t0,$t0,$t2,ror#31
str $t0,[$Xi,#-4]!
$opt1 @ F_xx_xx
$opt2 @ F_xx_xx
add $e,$e,$t0 @ E+=X[i]
___
}
sub BODY_00_15 {
my ($a,$b,$c,$d,$e)=@_;
$code.=<<___;
#if __ARM_ARCH__<7
ldrb $t1,[$inp,#2]
ldrb $t0,[$inp,#3]
ldrb $t2,[$inp,#1]
add $e,$K,$e,ror#2 @ E+=K_00_19
ldrb $t3,[$inp],#4
orr $t0,$t0,$t1,lsl#8
eor $t1,$c,$d @ F_xx_xx
orr $t0,$t0,$t2,lsl#16
add $e,$e,$a,ror#27 @ E+=ROR(A,27)
orr $t0,$t0,$t3,lsl#24
#else
ldr $t0,[$inp],#4 @ handles unaligned
add $e,$K,$e,ror#2 @ E+=K_00_19
eor $t1,$c,$d @ F_xx_xx
add $e,$e,$a,ror#27 @ E+=ROR(A,27)
#ifdef __ARMEL__
rev $t0,$t0 @ byte swap
#endif
#endif
and $t1,$b,$t1,ror#2
add $e,$e,$t0 @ E+=X[i]
eor $t1,$t1,$d,ror#2 @ F_00_19(B,C,D)
str $t0,[$Xi,#-4]!
add $e,$e,$t1 @ E+=F_00_19(B,C,D)
___
}
sub BODY_16_19 {
my ($a,$b,$c,$d,$e)=@_;
&Xupdate(@_,"and $t1,$b,$t1,ror#2");
$code.=<<___;
eor $t1,$t1,$d,ror#2 @ F_00_19(B,C,D)
add $e,$e,$t1 @ E+=F_00_19(B,C,D)
___
}
sub BODY_20_39 {
my ($a,$b,$c,$d,$e)=@_;
&Xupdate(@_,"eor $t1,$b,$t1,ror#2");
$code.=<<___;
add $e,$e,$t1 @ E+=F_20_39(B,C,D)
___
}
sub BODY_40_59 {
my ($a,$b,$c,$d,$e)=@_;
&Xupdate(@_,"and $t1,$b,$t1,ror#2","and $t2,$c,$d");
$code.=<<___;
add $e,$e,$t1 @ E+=F_40_59(B,C,D)
add $e,$e,$t2,ror#2
___
}
$code=<<___;
#include "arm_arch.h"
.text
.global sha1_block_data_order
.type sha1_block_data_order,%function
.align 2
sha1_block_data_order:
stmdb sp!,{r4-r12,lr}
add $len,$inp,$len,lsl#6 @ $len to point at the end of $inp
ldmia $ctx,{$a,$b,$c,$d,$e}
.Lloop:
ldr $K,.LK_00_19
mov $Xi,sp
sub sp,sp,#15*4
mov $c,$c,ror#30
mov $d,$d,ror#30
mov $e,$e,ror#30 @ [6]
.L_00_15:
___
for($i=0;$i<5;$i++) {
&BODY_00_15(@V); unshift(@V,pop(@V));
}
$code.=<<___;
teq $Xi,sp
bne .L_00_15 @ [((11+4)*5+2)*3]
sub sp,sp,#25*4
___
&BODY_00_15(@V); unshift(@V,pop(@V));
&BODY_16_19(@V); unshift(@V,pop(@V));
&BODY_16_19(@V); unshift(@V,pop(@V));
&BODY_16_19(@V); unshift(@V,pop(@V));
&BODY_16_19(@V); unshift(@V,pop(@V));
$code.=<<___;
ldr $K,.LK_20_39 @ [+15+16*4]
cmn sp,#0 @ [+3], clear carry to denote 20_39
.L_20_39_or_60_79:
___
for($i=0;$i<5;$i++) {
&BODY_20_39(@V); unshift(@V,pop(@V));
}
$code.=<<___;
teq $Xi,sp @ preserve carry
bne .L_20_39_or_60_79 @ [+((12+3)*5+2)*4]
bcs .L_done @ [+((12+3)*5+2)*4], spare 300 bytes
ldr $K,.LK_40_59
sub sp,sp,#20*4 @ [+2]
.L_40_59:
___
for($i=0;$i<5;$i++) {
&BODY_40_59(@V); unshift(@V,pop(@V));
}
$code.=<<___;
teq $Xi,sp
bne .L_40_59 @ [+((12+5)*5+2)*4]
ldr $K,.LK_60_79
sub sp,sp,#20*4
cmp sp,#0 @ set carry to denote 60_79
b .L_20_39_or_60_79 @ [+4], spare 300 bytes
.L_done:
add sp,sp,#80*4 @ "deallocate" stack frame
ldmia $ctx,{$K,$t0,$t1,$t2,$t3}
add $a,$K,$a
add $b,$t0,$b
add $c,$t1,$c,ror#2
add $d,$t2,$d,ror#2
add $e,$t3,$e,ror#2
stmia $ctx,{$a,$b,$c,$d,$e}
teq $inp,$len
bne .Lloop @ [+18], total 1307
#if __ARM_ARCH__>=5
ldmia sp!,{r4-r12,pc}
#else
ldmia sp!,{r4-r12,lr}
tst lr,#1
moveq pc,lr @ be binary compatible with V4, yet
bx lr @ interoperable with Thumb ISA:-)
#endif
.align 2
.LK_00_19: .word 0x5a827999
.LK_20_39: .word 0x6ed9eba1
.LK_40_59: .word 0x8f1bbcdc
.LK_60_79: .word 0xca62c1d6
.size sha1_block_data_order,.-sha1_block_data_order
.asciz "SHA1 block transform for ARMv4, CRYPTOGAMS by <appro\@openssl.org>"
.align 2
___
$code =~ s/\bbx\s+lr\b/.word\t0xe12fff1e/gm; # make it possible to compile with -march=armv4
print $code;
close STDOUT; # enforce flush