crypto: arm/chacha20 - always use vrev for 16-bit rotates
Subsystems (2)
PATCH 1/1 crypto: arm/chacha20 - always use vrev for 16-bit rotates
From: Eric Biggers <[email protected]>
The 4-way ChaCha20 NEON code implements 16-bit rotates with vrev32.16, but the one-way code (used on remainder blocks) implements it with vshl + vsri, which is slower. Switch the one-way code to vrev32.16 too.
--- arch/arm/crypto/chacha20-neon-core.S | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
arch/arm/crypto/chacha20-neon-core.S +4 -6
@@ -51,9 +51,8 @@ ENTRY(chacha20_block_xor_neon) .Ldoubleround: // x0 += x1, x3 = rotl32(x3 ^ x0, 16) vadd.i32 q0, q0, q1 - veor q4, q3, q0 - vshl.u32 q3, q4, #16 - vsri.u32 q3, q4, #16 + veor q3, q3, q0 + vrev32.16 q3, q3 // x2 += x3, x1 = rotl32(x1 ^ x2, 12) vadd.i32 q2, q2, q3
@@ -82,9 +81,8 @@ ENTRY(chacha20_block_xor_neon) // x0 += x1, x3 = rotl32(x3 ^ x0, 16) vadd.i32 q0, q0, q1 - veor q4, q3, q0 - vshl.u32 q3, q4, #16 - vsri.u32 q3, q4, #16 + veor q3, q3, q0 + vrev32.16 q3, q3 // x2 += x3, x1 = rotl32(x1 ^ x2, 12) vadd.i32 q2, q2, q3
Signature · 1 line
2.18.0
PATCH 1/1 crypto: arm/chacha20 - always use vrev for 16-bit rotates
Quoted 7 lines · Eric Biggers
From: Eric Biggers <[email protected]>
The 4-way ChaCha20 NEON code implements 16-bit rotates with vrev32.16, but the one-way code (used on remainder blocks) implements it with vshl + vsri, which is slower. Switch the one-way code to vrev32.16 too.
Signed-off-by Eric Biggers <[email protected]>
Quoted 35 lines
--- arch/arm/crypto/chacha20-neon-core.S | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)arch/arm/crypto/chacha20-neon-core.S +4
-7@@ -51,9 +51,8 @@ ENTRY(chacha20_block_xor_neon) .Ldoubleround: // x0 += x1, x3 = rotl32(x3 ^ x0, 16) vadd.i32 q0, q0, q1 - veor q4, q3, q0 - vshl.u32 q3, q4, #16 - vsri.u32 q3, q4, #16 + veor q3, q3, q0 + vrev32.16 q3, q3 // x2 += x3, x1 = rotl32(x1 ^ x2, 12) vadd.i32 q2, q2, q3@@ -82,9 +81,8 @@ ENTRY(chacha20_block_xor_neon) // x0 += x1, x3 = rotl32(x3 ^ x0, 16) vadd.i32 q0, q0, q1 - veor q4, q3, q0 - vshl.u32 q3, q4, #16 - vsri.u32 q3, q4, #16 + veor q3, q3, q0 + vrev32.16 q3, q3 // x2 += x3, x1 = rotl32(x1 ^ x2, 12) vadd.i32 q2, q2, q3 --2.18.0
Herbert Xu
maintainerPATCH 1/1 crypto: arm/chacha20 - always use vrev for 16-bit rotates
In reply to Eric BiggersQuoted 7 lines · Eric Biggers
From: Eric Biggers <[email protected]>
The 4-way ChaCha20 NEON code implements 16-bit rotates with vrev32.16, but the one-way code (used on remainder blocks) implements it with vshl + vsri, which is slower. Switch the one-way code to vrev32.16 too.
Signed-off-by Eric Biggers <[email protected]>
Patch applied. Thanks.
Signature · 3 lines
Email: Herbert Xu <[email protected]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt