crypto: x86/salsa20 - remove x86 salsa20 implementations

The x86 assembly implementations of Salsa20 use the frame base pointer
register (%ebp or %rbp), which breaks frame pointer convention and
breaks stack traces when unwinding from an interrupt in the crypto code.
Recent (v4.10+) kernels will warn about this, e.g.

WARNING: kernel stack regs at 00000000a8291e69 in syzkaller047086:4677 has bad 'bp' value 000000001077994c
[...]

But after looking into it, I believe there's very little reason to still
retain the x86 Salsa20 code.  First, these are *not* vectorized
(SSE2/SSSE3/AVX2) implementations, which would be needed to get anywhere
close to the best Salsa20 performance on any remotely modern x86
processor; they're just regular x86 assembly.  Second, it's still
unclear that anyone is actually using the kernel's Salsa20 at all,
especially given that now ChaCha20 is supported too, and with much more
efficient SSSE3 and AVX2 implementations.  Finally, in benchmarks I did
on both Intel and AMD processors with both gcc 8.1.0 and gcc 4.9.4, the
x86_64 salsa20-asm is actually slightly *slower* than salsa20-generic
(~3% slower on Skylake, ~10% slower on Zen), while the i686 salsa20-asm
is only slightly faster than salsa20-generic (~15% faster on Skylake,
~20% faster on Zen).  The gcc version made little difference.

So, the x86_64 salsa20-asm is pretty clearly useless.  That leaves just
the i686 salsa20-asm, which based on my tests provides a 15-20% speed
boost.  But that's without updating the code to not use %ebp.  And given
the maintenance cost, the small speed difference vs. salsa20-generic,
the fact that few people still use i686 kernels, the doubt that anyone
is even using the kernel's Salsa20 at all, and the fact that a SSE2
implementation would almost certainly be much faster on any remotely
modern x86 processor yet no one has cared enough to add one yet, I don't
think it's worthwhile to keep.

Thus, just remove both the x86_64 and i686 salsa20-asm implementations.

Reported-by: syzbot+ffa3a158337bbc01ff09@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 0 insertions, 805 deletions

diff --git a/arch/x86/crypto/salsa20-x86_64-asm_64.S b/arch/x86/crypto/salsa20-x86_64-asm_64.S
deleted file mode 100644
index 03a4918f41ee..000000000000
--- a/arch/x86/crypto/salsa20-x86_64-asm_64.S
+++ /dev/null
@@ -1,805 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <linux/linkage.h>
-
-# enter salsa20_encrypt_bytes
-ENTRY(salsa20_encrypt_bytes)
-	mov	%rsp,%r11
-	and	$31,%r11
-	add	$256,%r11
-	sub	%r11,%rsp
-	# x = arg1
-	mov	%rdi,%r8
-	# m = arg2
-	mov	%rsi,%rsi
-	# out = arg3
-	mov	%rdx,%rdi
-	# bytes = arg4
-	mov	%rcx,%rdx
-	#               unsigned>? bytes - 0
-	cmp	$0,%rdx
-	# comment:fp stack unchanged by jump
-	# goto done if !unsigned>
-	jbe	._done
-	# comment:fp stack unchanged by fallthrough
-# start:
-._start:
-	# r11_stack = r11
-	movq	%r11,0(%rsp)
-	# r12_stack = r12
-	movq	%r12,8(%rsp)
-	# r13_stack = r13
-	movq	%r13,16(%rsp)
-	# r14_stack = r14
-	movq	%r14,24(%rsp)
-	# r15_stack = r15
-	movq	%r15,32(%rsp)
-	# rbx_stack = rbx
-	movq	%rbx,40(%rsp)
-	# rbp_stack = rbp
-	movq	%rbp,48(%rsp)
-	# in0 = *(uint64 *) (x + 0)
-	movq	0(%r8),%rcx
-	# in2 = *(uint64 *) (x + 8)
-	movq	8(%r8),%r9
-	# in4 = *(uint64 *) (x + 16)
-	movq	16(%r8),%rax
-	# in6 = *(uint64 *) (x + 24)
-	movq	24(%r8),%r10
-	# in8 = *(uint64 *) (x + 32)
-	movq	32(%r8),%r11
-	# in10 = *(uint64 *) (x + 40)
-	movq	40(%r8),%r12
-	# in12 = *(uint64 *) (x + 48)
-	movq	48(%r8),%r13
-	# in14 = *(uint64 *) (x + 56)
-	movq	56(%r8),%r14
-	# j0 = in0
-	movq	%rcx,56(%rsp)
-	# j2 = in2
-	movq	%r9,64(%rsp)
-	# j4 = in4
-	movq	%rax,72(%rsp)
-	# j6 = in6
-	movq	%r10,80(%rsp)
-	# j8 = in8
-	movq	%r11,88(%rsp)
-	# j10 = in10
-	movq	%r12,96(%rsp)
-	# j12 = in12
-	movq	%r13,104(%rsp)
-	# j14 = in14
-	movq	%r14,112(%rsp)
-	# x_backup = x
-	movq	%r8,120(%rsp)
-# bytesatleast1:
-._bytesatleast1:
-	#                   unsigned<? bytes - 64
-	cmp	$64,%rdx
-	# comment:fp stack unchanged by jump
-	#   goto nocopy if !unsigned<
-	jae	._nocopy
-	#     ctarget = out
-	movq	%rdi,128(%rsp)
-	#     out = &tmp
-	leaq	192(%rsp),%rdi
-	#     i = bytes
-	mov	%rdx,%rcx
-	#     while (i) { *out++ = *m++; --i }
-	rep	movsb
-	#     out = &tmp
-	leaq	192(%rsp),%rdi
-	#     m = &tmp
-	leaq	192(%rsp),%rsi
-	# comment:fp stack unchanged by fallthrough
-#   nocopy:
-._nocopy:
-	#   out_backup = out
-	movq	%rdi,136(%rsp)
-	#   m_backup = m
-	movq	%rsi,144(%rsp)
-	#   bytes_backup = bytes
-	movq	%rdx,152(%rsp)
-	#   x1 = j0
-	movq	56(%rsp),%rdi
-	#   x0 = x1
-	mov	%rdi,%rdx
-	#   (uint64) x1 >>= 32
-	shr	$32,%rdi
-	#   		x3 = j2
-	movq	64(%rsp),%rsi
-	#   		x2 = x3
-	mov	%rsi,%rcx
-	#   		(uint64) x3 >>= 32
-	shr	$32,%rsi
-	#   x5 = j4
-	movq	72(%rsp),%r8
-	#   x4 = x5
-	mov	%r8,%r9
-	#   (uint64) x5 >>= 32
-	shr	$32,%r8
-	#   x5_stack = x5
-	movq	%r8,160(%rsp)
-	#   		x7 = j6
-	movq	80(%rsp),%r8
-	#   		x6 = x7
-	mov	%r8,%rax
-	#   		(uint64) x7 >>= 32
-	shr	$32,%r8
-	#   x9 = j8
-	movq	88(%rsp),%r10
-	#   x8 = x9
-	mov	%r10,%r11
-	#   (uint64) x9 >>= 32
-	shr	$32,%r10
-	#   		x11 = j10
-	movq	96(%rsp),%r12
-	#   		x10 = x11
-	mov	%r12,%r13
-	#   		x10_stack = x10
-	movq	%r13,168(%rsp)
-	#   		(uint64) x11 >>= 32
-	shr	$32,%r12
-	#   x13 = j12
-	movq	104(%rsp),%r13
-	#   x12 = x13
-	mov	%r13,%r14
-	#   (uint64) x13 >>= 32
-	shr	$32,%r13
-	#   		x15 = j14
-	movq	112(%rsp),%r15
-	#   		x14 = x15
-	mov	%r15,%rbx
-	#   		(uint64) x15 >>= 32
-	shr	$32,%r15
-	#   		x15_stack = x15
-	movq	%r15,176(%rsp)
-	#   i = 20
-	mov	$20,%r15
-#   mainloop:
-._mainloop:
-	#   i_backup = i
-	movq	%r15,184(%rsp)
-	# 		x5 = x5_stack
-	movq	160(%rsp),%r15
-	# a = x12 + x0
-	lea	(%r14,%rdx),%rbp
-	# (uint32) a <<<= 7
-	rol	$7,%ebp
-	# x4 ^= a
-	xor	%rbp,%r9
-	# 		b = x1 + x5
-	lea	(%rdi,%r15),%rbp
-	# 		(uint32) b <<<= 7
-	rol	$7,%ebp
-	# 		x9 ^= b
-	xor	%rbp,%r10
-	# a = x0 + x4
-	lea	(%rdx,%r9),%rbp
-	# (uint32) a <<<= 9
-	rol	$9,%ebp
-	# x8 ^= a
-	xor	%rbp,%r11
-	# 		b = x5 + x9
-	lea	(%r15,%r10),%rbp
-	# 		(uint32) b <<<= 9
-	rol	$9,%ebp
-	# 		x13 ^= b
-	xor	%rbp,%r13
-	# a = x4 + x8
-	lea	(%r9,%r11),%rbp
-	# (uint32) a <<<= 13
-	rol	$13,%ebp
-	# x12 ^= a
-	xor	%rbp,%r14
-	# 		b = x9 + x13
-	lea	(%r10,%r13),%rbp
-	# 		(uint32) b <<<= 13
-	rol	$13,%ebp
-	# 		x1 ^= b
-	xor	%rbp,%rdi
-	# a = x8 + x12
-	lea	(%r11,%r14),%rbp
-	# (uint32) a <<<= 18
-	rol	$18,%ebp
-	# x0 ^= a
-	xor	%rbp,%rdx
-	# 		b = x13 + x1
-	lea	(%r13,%rdi),%rbp
-	# 		(uint32) b <<<= 18
-	rol	$18,%ebp
-	# 		x5 ^= b
-	xor	%rbp,%r15
-	# 				x10 = x10_stack
-	movq	168(%rsp),%rbp
-	# 		x5_stack = x5
-	movq	%r15,160(%rsp)
-	# 				c = x6 + x10
-	lea	(%rax,%rbp),%r15
-	# 				(uint32) c <<<= 7
-	rol	$7,%r15d
-	# 				x14 ^= c
-	xor	%r15,%rbx
-	# 				c = x10 + x14
-	lea	(%rbp,%rbx),%r15
-	# 				(uint32) c <<<= 9
-	rol	$9,%r15d
-	# 				x2 ^= c
-	xor	%r15,%rcx
-	# 				c = x14 + x2
-	lea	(%rbx,%rcx),%r15
-	# 				(uint32) c <<<= 13
-	rol	$13,%r15d
-	# 				x6 ^= c
-	xor	%r15,%rax
-	# 				c = x2 + x6
-	lea	(%rcx,%rax),%r15
-	# 				(uint32) c <<<= 18
-	rol	$18,%r15d
-	# 				x10 ^= c
-	xor	%r15,%rbp
-	# 						x15 = x15_stack
-	movq	176(%rsp),%r15
-	# 				x10_stack = x10
-	movq	%rbp,168(%rsp)
-	# 						d = x11 + x15
-	lea	(%r12,%r15),%rbp
-	# 						(uint32) d <<<= 7
-	rol	$7,%ebp
-	# 						x3 ^= d
-	xor	%rbp,%rsi
-	# 						d = x15 + x3
-	lea	(%r15,%rsi),%rbp
-	# 						(uint32) d <<<= 9
-	rol	$9,%ebp
-	# 						x7 ^= d
-	xor	%rbp,%r8
-	# 						d = x3 + x7
-	lea	(%rsi,%r8),%rbp
-	# 						(uint32) d <<<= 13
-	rol	$13,%ebp
-	# 						x11 ^= d
-	xor	%rbp,%r12
-	# 						d = x7 + x11
-	lea	(%r8,%r12),%rbp
-	# 						(uint32) d <<<= 18
-	rol	$18,%ebp
-	# 						x15 ^= d
-	xor	%rbp,%r15
-	# 						x15_stack = x15
-	movq	%r15,176(%rsp)
-	# 		x5 = x5_stack
-	movq	160(%rsp),%r15
-	# a = x3 + x0
-	lea	(%rsi,%rdx),%rbp
-	# (uint32) a <<<= 7
-	rol	$7,%ebp
-	# x1 ^= a
-	xor	%rbp,%rdi
-	# 		b = x4 + x5
-	lea	(%r9,%r15),%rbp
-	# 		(uint32) b <<<= 7
-	rol	$7,%ebp
-	# 		x6 ^= b
-	xor	%rbp,%rax
-	# a = x0 + x1
-	lea	(%rdx,%rdi),%rbp
-	# (uint32) a <<<= 9
-	rol	$9,%ebp
-	# x2 ^= a
-	xor	%rbp,%rcx
-	# 		b = x5 + x6
-	lea	(%r15,%rax),%rbp
-	# 		(uint32) b <<<= 9
-	rol	$9,%ebp
-	# 		x7 ^= b
-	xor	%rbp,%r8
-	# a = x1 + x2
-	lea	(%rdi,%rcx),%rbp
-	# (uint32) a <<<= 13
-	rol	$13,%ebp
-	# x3 ^= a
-	xor	%rbp,%rsi
-	# 		b = x6 + x7
-	lea	(%rax,%r8),%rbp
-	# 		(uint32) b <<<= 13
-	rol	$13,%ebp
-	# 		x4 ^= b
-	xor	%rbp,%r9
-	# a = x2 + x3
-	lea	(%rcx,%rsi),%rbp
-	# (uint32) a <<<= 18
-	rol	$18,%ebp
-	# x0 ^= a
-	xor	%rbp,%rdx
-	# 		b = x7 + x4
-	lea	(%r8,%r9),%rbp
-	# 		(uint32) b <<<= 18
-	rol	$18,%ebp
-	# 		x5 ^= b
-	xor	%rbp,%r15
-	# 				x10 = x10_stack
-	movq	168(%rsp),%rbp
-	# 		x5_stack = x5
-	movq	%r15,160(%rsp)
-	# 				c = x9 + x10
-	lea	(%r10,%rbp),%r15
-	# 				(uint32) c <<<= 7
-	rol	$7,%r15d
-	# 				x11 ^= c
-	xor	%r15,%r12
-	# 				c = x10 + x11
-	lea	(%rbp,%r12),%r15
-	# 				(uint32) c <<<= 9
-	rol	$9,%r15d
-	# 				x8 ^= c
-	xor	%r15,%r11
-	# 				c = x11 + x8
-	lea	(%r12,%r11),%r15
-	# 				(uint32) c <<<= 13
-	rol	$13,%r15d
-	# 				x9 ^= c
-	xor	%r15,%r10
-	# 				c = x8 + x9
-	lea	(%r11,%r10),%r15
-	# 				(uint32) c <<<= 18
-	rol	$18,%r15d
-	# 				x10 ^= c
-	xor	%r15,%rbp
-	# 						x15 = x15_stack
-	movq	176(%rsp),%r15
-	# 				x10_stack = x10
-	movq	%rbp,168(%rsp)
-	# 						d = x14 + x15
-	lea	(%rbx,%r15),%rbp
-	# 						(uint32) d <<<= 7
-	rol	$7,%ebp
-	# 						x12 ^= d
-	xor	%rbp,%r14
-	# 						d = x15 + x12
-	lea	(%r15,%r14),%rbp
-	# 						(uint32) d <<<= 9
-	rol	$9,%ebp
-	# 						x13 ^= d
-	xor	%rbp,%r13
-	# 						d = x12 + x13
-	lea	(%r14,%r13),%rbp
-	# 						(uint32) d <<<= 13
-	rol	$13,%ebp
-	# 						x14 ^= d
-	xor	%rbp,%rbx
-	# 						d = x13 + x14
-	lea	(%r13,%rbx),%rbp
-	# 						(uint32) d <<<= 18
-	rol	$18,%ebp
-	# 						x15 ^= d
-	xor	%rbp,%r15
-	# 						x15_stack = x15
-	movq	%r15,176(%rsp)
-	# 		x5 = x5_stack
-	movq	160(%rsp),%r15
-	# a = x12 + x0
-	lea	(%r14,%rdx),%rbp
-	# (uint32) a <<<= 7
-	rol	$7,%ebp
-	# x4 ^= a
-	xor	%rbp,%r9
-	# 		b = x1 + x5
-	lea	(%rdi,%r15),%rbp
-	# 		(uint32) b <<<= 7
-	rol	$7,%ebp
-	# 		x9 ^= b
-	xor	%rbp,%r10
-	# a = x0 + x4
-	lea	(%rdx,%r9),%rbp
-	# (uint32) a <<<= 9
-	rol	$9,%ebp
-	# x8 ^= a
-	xor	%rbp,%r11
-	# 		b = x5 + x9
-	lea	(%r15,%r10),%rbp
-	# 		(uint32) b <<<= 9
-	rol	$9,%ebp
-	# 		x13 ^= b
-	xor	%rbp,%r13
-	# a = x4 + x8
-	lea	(%r9,%r11),%rbp
-	# (uint32) a <<<= 13
-	rol	$13,%ebp
-	# x12 ^= a
-	xor	%rbp,%r14
-	# 		b = x9 + x13
-	lea	(%r10,%r13),%rbp
-	# 		(uint32) b <<<= 13
-	rol	$13,%ebp
-	# 		x1 ^= b
-	xor	%rbp,%rdi
-	# a = x8 + x12
-	lea	(%r11,%r14),%rbp
-	# (uint32) a <<<= 18
-	rol	$18,%ebp
-	# x0 ^= a
-	xor	%rbp,%rdx
-	# 		b = x13 + x1
-	lea	(%r13,%rdi),%rbp
-	# 		(uint32) b <<<= 18
-	rol	$18,%ebp
-	# 		x5 ^= b
-	xor	%rbp,%r15
-	# 				x10 = x10_stack
-	movq	168(%rsp),%rbp
-	# 		x5_stack = x5
-	movq	%r15,160(%rsp)
-	# 				c = x6 + x10
-	lea	(%rax,%rbp),%r15
-	# 				(uint32) c <<<= 7
-	rol	$7,%r15d
-	# 				x14 ^= c
-	xor	%r15,%rbx
-	# 				c = x10 + x14
-	lea	(%rbp,%rbx),%r15
-	# 				(uint32) c <<<= 9
-	rol	$9,%r15d
-	# 				x2 ^= c
-	xor	%r15,%rcx
-	# 				c = x14 + x2
-	lea	(%rbx,%rcx),%r15
-	# 				(uint32) c <<<= 13
-	rol	$13,%r15d
-	# 				x6 ^= c
-	xor	%r15,%rax
-	# 				c = x2 + x6
-	lea	(%rcx,%rax),%r15
-	# 				(uint32) c <<<= 18
-	rol	$18,%r15d
-	# 				x10 ^= c
-	xor	%r15,%rbp
-	# 						x15 = x15_stack
-	movq	176(%rsp),%r15
-	# 				x10_stack = x10
-	movq	%rbp,168(%rsp)
-	# 						d = x11 + x15
-	lea	(%r12,%r15),%rbp
-	# 						(uint32) d <<<= 7
-	rol	$7,%ebp
-	# 						x3 ^= d
-	xor	%rbp,%rsi
-	# 						d = x15 + x3
-	lea	(%r15,%rsi),%rbp
-	# 						(uint32) d <<<= 9
-	rol	$9,%ebp
-	# 						x7 ^= d
-	xor	%rbp,%r8
-	# 						d = x3 + x7
-	lea	(%rsi,%r8),%rbp
-	# 						(uint32) d <<<= 13
-	rol	$13,%ebp
-	# 						x11 ^= d
-	xor	%rbp,%r12
-	# 						d = x7 + x11
-	lea	(%r8,%r12),%rbp
-	# 						(uint32) d <<<= 18
-	rol	$18,%ebp
-	# 						x15 ^= d
-	xor	%rbp,%r15
-	# 						x15_stack = x15
-	movq	%r15,176(%rsp)
-	# 		x5 = x5_stack
-	movq	160(%rsp),%r15
-	# a = x3 + x0
-	lea	(%rsi,%rdx),%rbp
-	# (uint32) a <<<= 7
-	rol	$7,%ebp
-	# x1 ^= a
-	xor	%rbp,%rdi
-	# 		b = x4 + x5
-	lea	(%r9,%r15),%rbp
-	# 		(uint32) b <<<= 7
-	rol	$7,%ebp
-	# 		x6 ^= b
-	xor	%rbp,%rax
-	# a = x0 + x1
-	lea	(%rdx,%rdi),%rbp
-	# (uint32) a <<<= 9
-	rol	$9,%ebp
-	# x2 ^= a
-	xor	%rbp,%rcx
-	# 		b = x5 + x6
-	lea	(%r15,%rax),%rbp
-	# 		(uint32) b <<<= 9
-	rol	$9,%ebp
-	# 		x7 ^= b
-	xor	%rbp,%r8
-	# a = x1 + x2
-	lea	(%rdi,%rcx),%rbp
-	# (uint32) a <<<= 13
-	rol	$13,%ebp
-	# x3 ^= a
-	xor	%rbp,%rsi
-	# 		b = x6 + x7
-	lea	(%rax,%r8),%rbp
-	# 		(uint32) b <<<= 13
-	rol	$13,%ebp
-	# 		x4 ^= b
-	xor	%rbp,%r9
-	# a = x2 + x3
-	lea	(%rcx,%rsi),%rbp
-	# (uint32) a <<<= 18
-	rol	$18,%ebp
-	# x0 ^= a
-	xor	%rbp,%rdx
-	# 		b = x7 + x4
-	lea	(%r8,%r9),%rbp
-	# 		(uint32) b <<<= 18
-	rol	$18,%ebp
-	# 		x5 ^= b
-	xor	%rbp,%r15
-	# 				x10 = x10_stack
-	movq	168(%rsp),%rbp
-	# 		x5_stack = x5
-	movq	%r15,160(%rsp)
-	# 				c = x9 + x10
-	lea	(%r10,%rbp),%r15
-	# 				(uint32) c <<<= 7
-	rol	$7,%r15d
-	# 				x11 ^= c
-	xor	%r15,%r12
-	# 				c = x10 + x11
-	lea	(%rbp,%r12),%r15
-	# 				(uint32) c <<<= 9
-	rol	$9,%r15d
-	# 				x8 ^= c
-	xor	%r15,%r11
-	# 				c = x11 + x8
-	lea	(%r12,%r11),%r15
-	# 				(uint32) c <<<= 13
-	rol	$13,%r15d
-	# 				x9 ^= c
-	xor	%r15,%r10
-	# 				c = x8 + x9
-	lea	(%r11,%r10),%r15
-	# 				(uint32) c <<<= 18
-	rol	$18,%r15d
-	# 				x10 ^= c
-	xor	%r15,%rbp
-	# 						x15 = x15_stack
-	movq	176(%rsp),%r15
-	# 				x10_stack = x10
-	movq	%rbp,168(%rsp)
-	# 						d = x14 + x15
-	lea	(%rbx,%r15),%rbp
-	# 						(uint32) d <<<= 7
-	rol	$7,%ebp
-	# 						x12 ^= d
-	xor	%rbp,%r14
-	# 						d = x15 + x12
-	lea	(%r15,%r14),%rbp
-	# 						(uint32) d <<<= 9
-	rol	$9,%ebp
-	# 						x13 ^= d
-	xor	%rbp,%r13
-	# 						d = x12 + x13
-	lea	(%r14,%r13),%rbp
-	# 						(uint32) d <<<= 13
-	rol	$13,%ebp
-	# 						x14 ^= d
-	xor	%rbp,%rbx
-	# 						d = x13 + x14
-	lea	(%r13,%rbx),%rbp
-	# 						(uint32) d <<<= 18
-	rol	$18,%ebp
-	# 						x15 ^= d
-	xor	%rbp,%r15
-	# 						x15_stack = x15
-	movq	%r15,176(%rsp)
-	#   i = i_backup
-	movq	184(%rsp),%r15
-	#                  unsigned>? i -= 4
-	sub	$4,%r15
-	# comment:fp stack unchanged by jump
-	# goto mainloop if unsigned>
-	ja	._mainloop
-	#   (uint32) x2 += j2
-	addl	64(%rsp),%ecx
-	#   x3 <<= 32
-	shl	$32,%rsi
-	#   x3 += j2
-	addq	64(%rsp),%rsi
-	#   (uint64) x3 >>= 32
-	shr	$32,%rsi
-	#   x3 <<= 32
-	shl	$32,%rsi
-	#   x2 += x3
-	add	%rsi,%rcx
-	#   (uint32) x6 += j6
-	addl	80(%rsp),%eax
-	#   x7 <<= 32
-	shl	$32,%r8
-	#   x7 += j6
-	addq	80(%rsp),%r8
-	#   (uint64) x7 >>= 32
-	shr	$32,%r8
-	#   x7 <<= 32
-	shl	$32,%r8
-	#   x6 += x7
-	add	%r8,%rax
-	#   (uint32) x8 += j8
-	addl	88(%rsp),%r11d
-	#   x9 <<= 32
-	shl	$32,%r10
-	#   x9 += j8
-	addq	88(%rsp),%r10
-	#   (uint64) x9 >>= 32
-	shr	$32,%r10
-	#   x9 <<= 32
-	shl	$32,%r10
-	#   x8 += x9
-	add	%r10,%r11
-	#   (uint32) x12 += j12
-	addl	104(%rsp),%r14d
-	#   x13 <<= 32
-	shl	$32,%r13
-	#   x13 += j12
-	addq	104(%rsp),%r13
-	#   (uint64) x13 >>= 32
-	shr	$32,%r13
-	#   x13 <<= 32
-	shl	$32,%r13
-	#   x12 += x13
-	add	%r13,%r14
-	#   (uint32) x0 += j0
-	addl	56(%rsp),%edx
-	#   x1 <<= 32
-	shl	$32,%rdi
-	#   x1 += j0
-	addq	56(%rsp),%rdi
-	#   (uint64) x1 >>= 32
-	shr	$32,%rdi
-	#   x1 <<= 32
-	shl	$32,%rdi
-	#   x0 += x1
-	add	%rdi,%rdx
-	#   x5 = x5_stack
-	movq	160(%rsp),%rdi
-	#   (uint32) x4 += j4
-	addl	72(%rsp),%r9d
-	#   x5 <<= 32
-	shl	$32,%rdi
-	#   x5 += j4
-	addq	72(%rsp),%rdi
-	#   (uint64) x5 >>= 32
-	shr	$32,%rdi
-	#   x5 <<= 32
-	shl	$32,%rdi
-	#   x4 += x5
-	add	%rdi,%r9
-	#   x10 = x10_stack
-	movq	168(%rsp),%r8
-	#   (uint32) x10 += j10
-	addl	96(%rsp),%r8d
-	#   x11 <<= 32
-	shl	$32,%r12
-	#   x11 += j10
-	addq	96(%rsp),%r12
-	#   (uint64) x11 >>= 32
-	shr	$32,%r12
-	#   x11 <<= 32
-	shl	$32,%r12
-	#   x10 += x11
-	add	%r12,%r8
-	#   x15 = x15_stack
-	movq	176(%rsp),%rdi
-	#   (uint32) x14 += j14
-	addl	112(%rsp),%ebx
-	#   x15 <<= 32
-	shl	$32,%rdi
-	#   x15 += j14
-	addq	112(%rsp),%rdi
-	#   (uint64) x15 >>= 32
-	shr	$32,%rdi
-	#   x15 <<= 32
-	shl	$32,%rdi
-	#   x14 += x15
-	add	%rdi,%rbx
-	#   out = out_backup
-	movq	136(%rsp),%rdi
-	#   m = m_backup
-	movq	144(%rsp),%rsi
-	#   x0 ^= *(uint64 *) (m + 0)
-	xorq	0(%rsi),%rdx
-	#   *(uint64 *) (out + 0) = x0
-	movq	%rdx,0(%rdi)
-	#   x2 ^= *(uint64 *) (m + 8)
-	xorq	8(%rsi),%rcx
-	#   *(uint64 *) (out + 8) = x2
-	movq	%rcx,8(%rdi)
-	#   x4 ^= *(uint64 *) (m + 16)
-	xorq	16(%rsi),%r9
-	#   *(uint64 *) (out + 16) = x4
-	movq	%r9,16(%rdi)
-	#   x6 ^= *(uint64 *) (m + 24)
-	xorq	24(%rsi),%rax
-	#   *(uint64 *) (out + 24) = x6
-	movq	%rax,24(%rdi)
-	#   x8 ^= *(uint64 *) (m + 32)
-	xorq	32(%rsi),%r11
-	#   *(uint64 *) (out + 32) = x8
-	movq	%r11,32(%rdi)
-	#   x10 ^= *(uint64 *) (m + 40)
-	xorq	40(%rsi),%r8
-	#   *(uint64 *) (out + 40) = x10
-	movq	%r8,40(%rdi)
-	#   x12 ^= *(uint64 *) (m + 48)
-	xorq	48(%rsi),%r14
-	#   *(uint64 *) (out + 48) = x12
-	movq	%r14,48(%rdi)
-	#   x14 ^= *(uint64 *) (m + 56)
-	xorq	56(%rsi),%rbx
-	#   *(uint64 *) (out + 56) = x14
-	movq	%rbx,56(%rdi)
-	#   bytes = bytes_backup
-	movq	152(%rsp),%rdx
-	#   in8 = j8
-	movq	88(%rsp),%rcx
-	#   in8 += 1
-	add	$1,%rcx
-	#   j8 = in8
-	movq	%rcx,88(%rsp)
-	#                          unsigned>? unsigned<? bytes - 64
-	cmp	$64,%rdx
-	# comment:fp stack unchanged by jump
-	#   goto bytesatleast65 if unsigned>
-	ja	._bytesatleast65
-	# comment:fp stack unchanged by jump
-	#     goto bytesatleast64 if !unsigned<
-	jae	._bytesatleast64
-	#       m = out
-	mov	%rdi,%rsi
-	#       out = ctarget
-	movq	128(%rsp),%rdi
-	#       i = bytes
-	mov	%rdx,%rcx
-	#       while (i) { *out++ = *m++; --i }
-	rep	movsb
-	# comment:fp stack unchanged by fallthrough
-#     bytesatleast64:
-._bytesatleast64:
-	#     x = x_backup
-	movq	120(%rsp),%rdi
-	#     in8 = j8
-	movq	88(%rsp),%rsi
-	#     *(uint64 *) (x + 32) = in8
-	movq	%rsi,32(%rdi)
-	#     r11 = r11_stack
-	movq	0(%rsp),%r11
-	#     r12 = r12_stack
-	movq	8(%rsp),%r12
-	#     r13 = r13_stack
-	movq	16(%rsp),%r13
-	#     r14 = r14_stack
-	movq	24(%rsp),%r14
-	#     r15 = r15_stack
-	movq	32(%rsp),%r15
-	#     rbx = rbx_stack
-	movq	40(%rsp),%rbx
-	#     rbp = rbp_stack
-	movq	48(%rsp),%rbp
-	# comment:fp stack unchanged by fallthrough
-#     done:
-._done:
-	#     leave
-	add	%r11,%rsp
-	mov	%rdi,%rax
-	mov	%rsi,%rdx
-	ret
-#   bytesatleast65:
-._bytesatleast65:
-	#   bytes -= 64
-	sub	$64,%rdx
-	#   out += 64
-	add	$64,%rdi
-	#   m += 64
-	add	$64,%rsi
-	# comment:fp stack unchanged by jump
-	# goto bytesatleast1
-	jmp	._bytesatleast1
-ENDPROC(salsa20_encrypt_bytes)