bn/asm/armv4-gf2m.pl, modes/asm/ghash-armv4.pl: faster multiplication algorithm suggested in following paper:
Câmara, D.; Gouvêa, C. P. L.; López, J. & Dahab, R.: Fast Software
Polynomial Multiplication on ARM Processors using the NEON Engine.
http://conradoplg.cryptoland.net/files/2010/12/mocrysen13.pdf
(Imported from upstream's 0fb3d5b4fdc76b8d4a4700d03480cda135c6c117)
diff --git a/crypto/modes/asm/ghash-armv4.pl b/crypto/modes/asm/ghash-armv4.pl
index 8e4a52f..cf5fe8d 100644
--- a/crypto/modes/asm/ghash-armv4.pl
+++ b/crypto/modes/asm/ghash-armv4.pl
@@ -35,6 +35,20 @@
# Add NEON implementation featuring polynomial multiplication, i.e. no
# lookup tables involved. On Cortex A8 it was measured to process one
# byte in 15 cycles or 55% faster than integer-only code.
+#
+# April 2014
+#
+# Switch to multiplication algorithm suggested in paper referred
+# below and combine it with reduction algorithm from x86 module.
+# Performance improvement over previous version varies from 65% on
+# Snapdragon S4 to 110% on Cortex A9. In absolute terms Cortex A8
+# processes one byte in 8.45 cycles, A9 - in 10.2, Snapdragon S4 -
+# in 9.33.
+#
+# Câmara, D.; Gouvêa, C. P. L.; López, J. & Dahab, R.: Fast Software
+# Polynomial Multiplication on ARM Processors using the NEON Engine.
+#
+# http://conradoplg.cryptoland.net/files/2010/12/mocrysen13.pdf
# ====================================================================
# Note about "528B" variant. In ARM case it makes lesser sense to
@@ -304,115 +318,158 @@
.size gcm_gmult_4bit,.-gcm_gmult_4bit
___
{
-my $cnt=$Htbl; # $Htbl is used once in the very beginning
+my ($Xl,$Xm,$Xh,$IN)=map("q$_",(0..3));
+my ($t0,$t1,$t2,$t3)=map("q$_",(8..12));
+my ($Hlo,$Hhi,$Hhl,$k48,$k32,$k16)=map("d$_",(26..31));
-my ($Hhi, $Hlo, $Zo, $T, $xi, $mod) = map("d$_",(0..7));
-my ($Qhi, $Qlo, $Z, $R, $zero, $Qpost, $IN) = map("q$_",(8..15));
-
-# Z:Zo keeps 128-bit result shifted by 1 to the right, with bottom bit
-# in Zo. Or should I say "top bit", because GHASH is specified in
-# reverse bit order? Otherwise straightforward 128-bt H by one input
-# byte multiplication and modulo-reduction, times 16.
-
-sub Dlo() { shift=~m|q([1]?[0-9])|?"d".($1*2):""; }
-sub Dhi() { shift=~m|q([1]?[0-9])|?"d".($1*2+1):""; }
-sub Q() { shift=~m|d([1-3]?[02468])|?"q".($1/2):""; }
+sub clmul64x64 {
+my ($r,$a,$b)=@_;
+$code.=<<___;
+ vext.8 $t0#lo, $a, $a, #1 @ A1
+ vmull.p8 $t0, $t0#lo, $b @ F = A1*B
+ vext.8 $r#lo, $b, $b, #1 @ B1
+ vmull.p8 $r, $a, $r#lo @ E = A*B1
+ vext.8 $t1#lo, $a, $a, #2 @ A2
+ vmull.p8 $t1, $t1#lo, $b @ H = A2*B
+ vext.8 $t3#lo, $b, $b, #2 @ B2
+ vmull.p8 $t3, $a, $t3#lo @ G = A*B2
+ vext.8 $t2#lo, $a, $a, #3 @ A3
+ veor $t0, $t0, $r @ L = E + F
+ vmull.p8 $t2, $t2#lo, $b @ J = A3*B
+ vext.8 $r#lo, $b, $b, #3 @ B3
+ veor $t1, $t1, $t3 @ M = G + H
+ vmull.p8 $r, $a, $r#lo @ I = A*B3
+ veor $t0#lo, $t0#lo, $t0#hi @ t0 = (L) (P0 + P1) << 8
+ vand $t0#hi, $t0#hi, $k48
+ vext.8 $t3#lo, $b, $b, #4 @ B4
+ veor $t1#lo, $t1#lo, $t1#hi @ t1 = (M) (P2 + P3) << 16
+ vand $t1#hi, $t1#hi, $k32
+ vmull.p8 $t3, $a, $t3#lo @ K = A*B4
+ veor $t2, $t2, $r @ N = I + J
+ veor $t0#lo, $t0#lo, $t0#hi
+ veor $t1#lo, $t1#lo, $t1#hi
+ veor $t2#lo, $t2#lo, $t2#hi @ t2 = (N) (P4 + P5) << 24
+ vand $t2#hi, $t2#hi, $k16
+ vext.8 $t0, $t0, $t0, #15
+ veor $t3#lo, $t3#lo, $t3#hi @ t3 = (K) (P6 + P7) << 32
+ vmov.i64 $t3#hi, #0
+ vext.8 $t1, $t1, $t1, #14
+ veor $t2#lo, $t2#lo, $t2#hi
+ vmull.p8 $r, $a, $b @ D = A*B
+ vext.8 $t3, $t3, $t3, #12
+ vext.8 $t2, $t2, $t2, #13
+ veor $t0, $t0, $t1
+ veor $t2, $t2, $t3
+ veor $r, $r, $t0
+ veor $r, $r, $t2
+___
+}
$code.=<<___;
#if __ARM_ARCH__>=7
.fpu neon
+.global gcm_init_neon
+.type gcm_init_neon,%function
+.align 4
+gcm_init_neon:
+ vld1.64 $IN#hi,[r1,:64]! @ load H
+ vmov.i8 $t0,#0xe1
+ vld1.64 $IN#lo,[r1,:64]
+ vshl.i64 $t0#hi,#57
+ vshr.u64 $t0#lo,#63 @ t0=0xc2....01
+ vdup.8 $t1,$IN#hi[7]
+ vshr.u64 $Hlo,$IN#lo,#63
+ vshr.s8 $t1,#7 @ broadcast carry bit
+ vshl.i64 $IN,$IN,#1
+ vand $t0,$t0,$t1
+ vorr $IN#hi,$Hlo @ H<<<=1
+ veor $IN,$IN,$t0 @ twisted H
+ vstmia r0,{$IN}
+
+ bx lr
+.size gcm_init_neon,.-gcm_init_neon
+
.global gcm_gmult_neon
.type gcm_gmult_neon,%function
.align 4
gcm_gmult_neon:
- sub $Htbl,#16 @ point at H in GCM128_CTX
- vld1.64 `&Dhi("$IN")`,[$Xi,:64]!@ load Xi
- vmov.i32 $mod,#0xe1 @ our irreducible polynomial
- vld1.64 `&Dlo("$IN")`,[$Xi,:64]!
- vshr.u64 $mod,#32
- vldmia $Htbl,{$Hhi-$Hlo} @ load H
- veor $zero,$zero
+ vld1.64 $IN#hi,[$Xi,:64]! @ load Xi
+ vld1.64 $IN#lo,[$Xi,:64]!
+ vmov.i64 $k48,#0x0000ffffffffffff
+ vldmia $Htbl,{$Hlo-$Hhi} @ load twisted H
+ vmov.i64 $k32,#0x00000000ffffffff
#ifdef __ARMEL__
vrev64.8 $IN,$IN
#endif
- veor $Qpost,$Qpost
- veor $R,$R
- mov $cnt,#16
- veor $Z,$Z
+ vmov.i64 $k16,#0x000000000000ffff
+ veor $Hhl,$Hlo,$Hhi @ Karatsuba pre-processing
mov $len,#16
- veor $Zo,$Zo
- vdup.8 $xi,`&Dlo("$IN")`[0] @ broadcast lowest byte
- b .Linner_neon
+ b .Lgmult_neon
.size gcm_gmult_neon,.-gcm_gmult_neon
.global gcm_ghash_neon
.type gcm_ghash_neon,%function
.align 4
gcm_ghash_neon:
- vld1.64 `&Dhi("$Z")`,[$Xi,:64]! @ load Xi
- vmov.i32 $mod,#0xe1 @ our irreducible polynomial
- vld1.64 `&Dlo("$Z")`,[$Xi,:64]!
- vshr.u64 $mod,#32
- vldmia $Xi,{$Hhi-$Hlo} @ load H
- veor $zero,$zero
- nop
+ vld1.64 $Xl#hi,[$Xi,:64]! @ load Xi
+ vld1.64 $Xl#lo,[$Xi,:64]!
+ vmov.i64 $k48,#0x0000ffffffffffff
+ vldmia $Htbl,{$Hlo-$Hhi} @ load twisted H
+ vmov.i64 $k32,#0x00000000ffffffff
#ifdef __ARMEL__
- vrev64.8 $Z,$Z
+ vrev64.8 $Xl,$Xl
#endif
-.Louter_neon:
- vld1.64 `&Dhi($IN)`,[$inp]! @ load inp
- veor $Qpost,$Qpost
- vld1.64 `&Dlo($IN)`,[$inp]!
- veor $R,$R
- mov $cnt,#16
+ vmov.i64 $k16,#0x000000000000ffff
+ veor $Hhl,$Hlo,$Hhi @ Karatsuba pre-processing
+
+.Loop_neon:
+ vld1.64 $IN#hi,[$inp]! @ load inp
+ vld1.64 $IN#lo,[$inp]!
#ifdef __ARMEL__
vrev64.8 $IN,$IN
#endif
- veor $Zo,$Zo
- veor $IN,$Z @ inp^=Xi
- veor $Z,$Z
- vdup.8 $xi,`&Dlo("$IN")`[0] @ broadcast lowest byte
-.Linner_neon:
- subs $cnt,$cnt,#1
- vmull.p8 $Qlo,$Hlo,$xi @ H.lo·Xi[i]
- vmull.p8 $Qhi,$Hhi,$xi @ H.hi·Xi[i]
- vext.8 $IN,$zero,#1 @ IN>>=8
+ veor $IN,$Xl @ inp^=Xi
+.Lgmult_neon:
+___
+ &clmul64x64 ($Xl,$Hlo,"$IN#lo"); # H.lo·Xi.lo
+$code.=<<___;
+ veor $IN#lo,$IN#lo,$IN#hi @ Karatsuba pre-processing
+___
+ &clmul64x64 ($Xm,$Hhl,"$IN#lo"); # (H.lo+H.hi)·(Xi.lo+Xi.hi)
+ &clmul64x64 ($Xh,$Hhi,"$IN#hi"); # H.hi·Xi.hi
+$code.=<<___;
+ veor $Xm,$Xm,$Xl @ Karatsuba post-processing
+ veor $Xm,$Xm,$Xh
+ veor $Xl#hi,$Xl#hi,$Xm#lo
+ veor $Xh#lo,$Xh#lo,$Xm#hi @ Xh|Xl - 256-bit result
- veor $Z,$Qpost @ modulo-scheduled part
- vshl.i64 `&Dlo("$R")`,#48
- vdup.8 $xi,`&Dlo("$IN")`[0] @ broadcast lowest byte
- veor $T,`&Dlo("$Qlo")`,`&Dlo("$Z")`
+ @ equivalent of reduction_avx from ghash-x86_64.pl
+ vshl.i64 $t1,$Xl,#57 @ 1st phase
+ vshl.i64 $t2,$Xl,#62
+ veor $t2,$t2,$t1 @
+ vshl.i64 $t1,$Xl,#63
+ veor $t2, $t2, $t1 @
+ veor $Xl#hi,$Xl#hi,$t2#lo @
+ veor $Xh#lo,$Xh#lo,$t2#hi
- veor `&Dhi("$Z")`,`&Dlo("$R")`
- vuzp.8 $Qlo,$Qhi
- vsli.8 $Zo,$T,#1 @ compose the "carry" byte
- vext.8 $Z,$zero,#1 @ Z>>=8
+ vshr.u64 $t2,$Xl,#1 @ 2nd phase
+ veor $Xh,$Xh,$Xl
+ veor $Xl,$Xl,$t2 @
+ vshr.u64 $t2,$t2,#6
+ vshr.u64 $Xl,$Xl,#1 @
+ veor $Xl,$Xl,$Xh @
+ veor $Xl,$Xl,$t2 @
- vmull.p8 $R,$Zo,$mod @ "carry"·0xe1
- vshr.u8 $Zo,$T,#7 @ save Z's bottom bit
- vext.8 $Qpost,$Qlo,$zero,#1 @ Qlo>>=8
- veor $Z,$Qhi
- bne .Linner_neon
-
- veor $Z,$Qpost @ modulo-scheduled artefact
- vshl.i64 `&Dlo("$R")`,#48
- veor `&Dhi("$Z")`,`&Dlo("$R")`
-
- @ finalization, normalize Z:Zo
- vand $Zo,$mod @ suffices to mask the bit
- vshr.u64 `&Dhi(&Q("$Zo"))`,`&Dlo("$Z")`,#63
- vshl.i64 $Z,#1
subs $len,#16
- vorr $Z,`&Q("$Zo")` @ Z=Z:Zo<<1
- bne .Louter_neon
+ bne .Loop_neon
#ifdef __ARMEL__
- vrev64.8 $Z,$Z
+ vrev64.8 $Xl,$Xl
#endif
sub $Xi,#16
- vst1.64 `&Dhi("$Z")`,[$Xi,:64]! @ write out Xi
- vst1.64 `&Dlo("$Z")`,[$Xi,:64]
+ vst1.64 $Xl#hi,[$Xi,:64]! @ write out Xi
+ vst1.64 $Xl#lo,[$Xi,:64]
bx lr
.size gcm_ghash_neon,.-gcm_ghash_neon
@@ -426,7 +483,12 @@
#endif
___
-$code =~ s/\`([^\`]*)\`/eval $1/gem;
-$code =~ s/\bbx\s+lr\b/.word\t0xe12fff1e/gm; # make it possible to compile with -march=armv4
-print $code;
+foreach (split("\n",$code)) {
+ s/\`([^\`]*)\`/eval $1/geo;
+
+ s/\bq([0-9]+)#(lo|hi)/sprintf "d%d",2*$1+($2 eq "hi")/geo or
+ s/\bbx\s+lr\b/.word\t0xe12fff1e/go; # make it possible to compile with -march=armv4
+
+ print $_,"\n";
+}
close STDOUT; # enforce flush
diff --git a/crypto/modes/gcm.c b/crypto/modes/gcm.c
index b950d9f..116eab8 100644
--- a/crypto/modes/gcm.c
+++ b/crypto/modes/gcm.c
@@ -350,6 +350,7 @@
#if __ARM_ARCH__ >= 7
#define GHASH_ASM_ARM
#define GCM_FUNCREF_4BIT
+void gcm_init_neon(u128 Htable[16],const uint64_t Xi[2]);
void gcm_gmult_neon(uint64_t Xi[2], const u128 Htable[16]);
void gcm_ghash_neon(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
size_t len);
@@ -433,6 +434,7 @@
#endif
#elif defined(GHASH_ASM_ARM)
if (CRYPTO_is_NEON_capable()) {
+ gcm_init_neon(ctx->Htable,ctx->H.u);
ctx->gmult = gcm_gmult_neon;
ctx->ghash = gcm_ghash_neon;
} else {
