(nettle_arcfour_crypt): Replaced addb ->

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

Rev: src/nettle/x86/arcfour-crypt.asm:1.8

diff --git a/x86/arcfour-crypt.asm b/x86/arcfour-crypt.asm
index 6b99cc579560b946ccf1b9aac899979490164cf1..7056c50b588c5aa1c669e668e349dc24c18e3617 100644 (file)
--- a/x86/arcfour-crypt.asm
+++ b/x86/arcfour-crypt.asm
@@ -33,11 +33,21 @@ 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
        jz      .Lend
@@ -50,13 +60,16 @@ nettle_arcfour_crypt:
        movzbl  256(%ebp), %eax         C  i
        movzbl  257(%ebp), %ebx         C  j
 .Lloop:
+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.