[PATCH 5.4 15/18] crypto: aesni - Use TEST %reg,%reg instead of CMP $0,%reg

From: Greg Kroah-Hartman
Date: Fri Mar 19 2021 - 08:21:04 EST


From: Uros Bizjak <ubizjak@xxxxxxxxx>

commit 032d049ea0f45b45c21f3f02b542aa18bc6b6428 upstream.

CMP $0,%reg can't set overflow flag, so we can use shorter TEST %reg,%reg
instruction when only zero and sign flags are checked (E,L,LE,G,GE conditions).

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/crypto/aesni-intel_asm.S | 20 ++++++++++----------
arch/x86/crypto/aesni-intel_avx-x86_64.S | 20 ++++++++++----------
2 files changed, 20 insertions(+), 20 deletions(-)

--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -319,7 +319,7 @@ _initial_blocks_\@:

# Main loop - Encrypt/Decrypt remaining blocks

- cmp $0, %r13
+ test %r13, %r13
je _zero_cipher_left_\@
sub $64, %r13
je _four_cipher_left_\@
@@ -438,7 +438,7 @@ _multiple_of_16_bytes_\@:

mov PBlockLen(%arg2), %r12

- cmp $0, %r12
+ test %r12, %r12
je _partial_done\@

GHASH_MUL %xmm8, %xmm13, %xmm9, %xmm10, %xmm11, %xmm5, %xmm6
@@ -475,7 +475,7 @@ _T_8_\@:
add $8, %r10
sub $8, %r11
psrldq $8, %xmm0
- cmp $0, %r11
+ test %r11, %r11
je _return_T_done_\@
_T_4_\@:
movd %xmm0, %eax
@@ -483,7 +483,7 @@ _T_4_\@:
add $4, %r10
sub $4, %r11
psrldq $4, %xmm0
- cmp $0, %r11
+ test %r11, %r11
je _return_T_done_\@
_T_123_\@:
movd %xmm0, %eax
@@ -620,7 +620,7 @@ _get_AAD_blocks\@:

/* read the last <16B of AAD */
_get_AAD_rest\@:
- cmp $0, %r11
+ test %r11, %r11
je _get_AAD_done\@

READ_PARTIAL_BLOCK %r10, %r11, \TMP1, \TMP7
@@ -641,7 +641,7 @@ _get_AAD_done\@:
.macro PARTIAL_BLOCK CYPH_PLAIN_OUT PLAIN_CYPH_IN PLAIN_CYPH_LEN DATA_OFFSET \
AAD_HASH operation
mov PBlockLen(%arg2), %r13
- cmp $0, %r13
+ test %r13, %r13
je _partial_block_done_\@ # Leave Macro if no partial blocks
# Read in input data without over reading
cmp $16, \PLAIN_CYPH_LEN
@@ -693,7 +693,7 @@ _no_extra_mask_1_\@:
PSHUFB_XMM %xmm2, %xmm3
pxor %xmm3, \AAD_HASH

- cmp $0, %r10
+ test %r10, %r10
jl _partial_incomplete_1_\@

# GHASH computation for the last <16 Byte block
@@ -728,7 +728,7 @@ _no_extra_mask_2_\@:
PSHUFB_XMM %xmm2, %xmm9
pxor %xmm9, \AAD_HASH

- cmp $0, %r10
+ test %r10, %r10
jl _partial_incomplete_2_\@

# GHASH computation for the last <16 Byte block
@@ -748,7 +748,7 @@ _encode_done_\@:
PSHUFB_XMM %xmm2, %xmm9
.endif
# output encrypted Bytes
- cmp $0, %r10
+ test %r10, %r10
jl _partial_fill_\@
mov %r13, %r12
mov $16, %r13
@@ -2731,7 +2731,7 @@ ENDPROC(aesni_ctr_enc)
*/
ENTRY(aesni_xts_crypt8)
FRAME_BEGIN
- cmpb $0, %cl
+ testb %cl, %cl
movl $0, %ecx
movl $240, %r10d
leaq _aesni_enc4, %r11
--- a/arch/x86/crypto/aesni-intel_avx-x86_64.S
+++ b/arch/x86/crypto/aesni-intel_avx-x86_64.S
@@ -370,7 +370,7 @@ _initial_num_blocks_is_0\@:


_initial_blocks_encrypted\@:
- cmp $0, %r13
+ test %r13, %r13
je _zero_cipher_left\@

sub $128, %r13
@@ -529,7 +529,7 @@ _multiple_of_16_bytes\@:
vmovdqu HashKey(arg2), %xmm13

mov PBlockLen(arg2), %r12
- cmp $0, %r12
+ test %r12, %r12
je _partial_done\@

#GHASH computation for the last <16 Byte block
@@ -574,7 +574,7 @@ _T_8\@:
add $8, %r10
sub $8, %r11
vpsrldq $8, %xmm9, %xmm9
- cmp $0, %r11
+ test %r11, %r11
je _return_T_done\@
_T_4\@:
vmovd %xmm9, %eax
@@ -582,7 +582,7 @@ _T_4\@:
add $4, %r10
sub $4, %r11
vpsrldq $4, %xmm9, %xmm9
- cmp $0, %r11
+ test %r11, %r11
je _return_T_done\@
_T_123\@:
vmovd %xmm9, %eax
@@ -626,7 +626,7 @@ _get_AAD_blocks\@:
cmp $16, %r11
jge _get_AAD_blocks\@
vmovdqu \T8, \T7
- cmp $0, %r11
+ test %r11, %r11
je _get_AAD_done\@

vpxor \T7, \T7, \T7
@@ -645,7 +645,7 @@ _get_AAD_rest8\@:
vpxor \T1, \T7, \T7
jmp _get_AAD_rest8\@
_get_AAD_rest4\@:
- cmp $0, %r11
+ test %r11, %r11
jle _get_AAD_rest0\@
mov (%r10), %eax
movq %rax, \T1
@@ -750,7 +750,7 @@ _done_read_partial_block_\@:
.macro PARTIAL_BLOCK GHASH_MUL CYPH_PLAIN_OUT PLAIN_CYPH_IN PLAIN_CYPH_LEN DATA_OFFSET \
AAD_HASH ENC_DEC
mov PBlockLen(arg2), %r13
- cmp $0, %r13
+ test %r13, %r13
je _partial_block_done_\@ # Leave Macro if no partial blocks
# Read in input data without over reading
cmp $16, \PLAIN_CYPH_LEN
@@ -802,7 +802,7 @@ _no_extra_mask_1_\@:
vpshufb %xmm2, %xmm3, %xmm3
vpxor %xmm3, \AAD_HASH, \AAD_HASH

- cmp $0, %r10
+ test %r10, %r10
jl _partial_incomplete_1_\@

# GHASH computation for the last <16 Byte block
@@ -837,7 +837,7 @@ _no_extra_mask_2_\@:
vpshufb %xmm2, %xmm9, %xmm9
vpxor %xmm9, \AAD_HASH, \AAD_HASH

- cmp $0, %r10
+ test %r10, %r10
jl _partial_incomplete_2_\@

# GHASH computation for the last <16 Byte block
@@ -857,7 +857,7 @@ _encode_done_\@:
vpshufb %xmm2, %xmm9, %xmm9
.endif
# output encrypted Bytes
- cmp $0, %r10
+ test %r10, %r10
jl _partial_fill_\@
mov %r13, %r12
mov $16, %r13