Commit b58a7f66 authored by Niels Möller's avatar Niels Möller
Browse files

(nettle_arcfour_crypt): Replaced addb ->

addl + andl $0xff, improving speed on PPro by another 15%.

Rev: src/nettle/x86/arcfour-crypt.asm:1.8
parent 1431fcc0
......@@ -33,10 +33,20 @@ nettle_arcfour_crypt:
pushl %esi C 4(%esp)
pushl %edi C 0(%esp)
C Input arguments:
C ctx = 20(%esp)
C length = 24(%esp)
C dst = 28(%esp)
C src = 32(%esp)
C Register usage:
C %ebp = ctx
C %esi = src (updated through out loop)
C %edi = dst (updated through out loop)
C %edx = src + length (end of source area)
C %eax = i
C %ebx = j
C %cl = si
C %ch = sj
movl 24(%esp), %edx C length
testl %edx,%edx
......@@ -50,13 +60,16 @@ nettle_arcfour_crypt:
movzbl 256(%ebp), %eax C i
movzbl 257(%ebp), %ebx C j
C incb %al
incl %eax
andl $0xff, %eax
movzbl (%ebp, %eax), %ecx C si. Clears high bytes
addb %cl, %bl
C addb %cl, %bl
addl %ecx, %ebx
andl $0xff, %ebx
movb (%ebp, %ebx), %ch C sj
movb %ch, (%ebp, %eax) C S[i] = sj
movb %cl, (%ebp, %ebx) C C[j] = si
movb %cl, (%ebp, %ebx) C S[j] = si
addb %ch, %cl
xorb %ch, %ch C Clear, so it can be used
C for indexing.
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