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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Uros Bizjak <ubizjak@gmail.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, Ard Biesheuvel <ardb@google.com>
Subject: [PATCH 5.4 15/18] crypto: aesni - Use TEST %reg,%reg instead of CMP $0,%reg
Date:   Fri, 19 Mar 2021 13:18:53 +0100
Message-Id: <20210319121745.975439460@linuxfoundation.org>
In-Reply-To: <20210319121745.449875976@linuxfoundation.org>
References: <20210319121745.449875976@linuxfoundation.org>
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From: Uros Bizjak <ubizjak@gmail.com>

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@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ard Biesheuvel <ardb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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