Commit 68e95f5c authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: x86/aes-xts - more code size optimizations 



Prefer immediates of -128 to 128, since the former fits in a signed
byte, saving 3 bytes per instruction.  Also prefer VEX-coded
instructions to EVEX where this is easy to do.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 77a4b567

arch/x86/crypto/aes-xts-avx-x86_64.S

+13 −11
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ 
.endm



// Move a vector between memory and a register.

// The register operand must be in the first 16 vector registers.

.macro	_vmovdqu	src, dst

.if VL < 64

	vmovdqu		\src, \dst
@@ -208,11 +209,12 @@ 
.endm



// XOR two vectors together.

// Any register operands must be in the first 16 vector registers.

.macro	_vpxor	src1, src2, dst

.if USE_AVX10

	vpxord		\src1, \src2, \dst

.else

.if VL < 64

	vpxor		\src1, \src2, \dst

.else

	vpxord		\src1, \src2, \dst

.endif

.endm
@@ -555,7 +557,7 @@ 
	// Compute the first set of tweaks TWEAK[0-3].

	_compute_first_set_of_tweaks



	sub		$4*VL, LEN

	add		$-4*VL, LEN  // shorter than 'sub 4*VL' when VL=32

	jl		.Lhandle_remainder\@



.Lmain_loop\@:
@@ -563,10 +565,10 @@ 


	// XOR each source block with its tweak and the zero-th round key.

.if USE_AVX10

	vmovdqu8	0*VL(SRC), V0

	vmovdqu8	1*VL(SRC), V1

	vmovdqu8	2*VL(SRC), V2

	vmovdqu8	3*VL(SRC), V3

	_vmovdqu	0*VL(SRC), V0

	_vmovdqu	1*VL(SRC), V1

	_vmovdqu	2*VL(SRC), V2

	_vmovdqu	3*VL(SRC), V3

	vpternlogd	$0x96, TWEAK0, KEY0, V0

	vpternlogd	$0x96, TWEAK1, KEY0, V1

	vpternlogd	$0x96, TWEAK2, KEY0, V2
@@ -612,9 +614,9 @@ 
	// Finish computing the next set of tweaks.

	_tweak_step	1000



	add		$4*VL, SRC

	add		$4*VL, DST

	sub		$4*VL, LEN

	sub		$-4*VL, SRC  // shorter than 'add 4*VL' when VL=32

	sub		$-4*VL, DST

	add		$-4*VL, LEN

	jge		.Lmain_loop\@



	// Check for the uncommon case where the data length isn't a multiple of