rc4-s390x.pl: allow for older assembler and optimize character loop.

diff --git a/crypto/rc4/asm/rc4-s390x.pl b/crypto/rc4/asm/rc4-s390x.pl
index 4366c4fc1a6c37a5440505c4697ed96b80310f86..96681fa05ec915847036ce1461c8fb0906ad1e59 100644 (file)
--- a/crypto/rc4/asm/rc4-s390x.pl
+++ b/crypto/rc4/asm/rc4-s390x.pl
@@ -9,9 +9,9 @@
 #
 # February 2009
 #
-# Performance is 2x of gcc 3.4.6 on z10. Coding "secret" is to avoid
-# arithmetic instructions, but adhere to load and load address in
-# order to minimize Address Generation Interlock.
+# Performance is 2x of gcc 3.4.6 on z10. Coding "secret" is to
+# "cluster" Address Generation Interlocks, so that one pipeline stall
+# resolves several dependencies.
 
 $rp="%r14";
 $sp="%r15";
@@ -43,10 +43,10 @@ RC4:
        llgc    $XX[0],0($key)
        llgc    $YY,1($key)
        la      $XX[0],1($XX[0])
-       llgcr   $XX[0],$XX[0]
-       llgc    $TX[0],2($XX[0],$key)
+       nill    $XX[0],0xff
        srlg    $cnt,$len,3
        ltgr    $cnt,$cnt
+       llgc    $TX[0],2($XX[0],$key)
        jz      .Lshort
        j       .Loop8
 
@@ -56,17 +56,17 @@ ___
 for ($i=0;$i<8;$i++) {
 $code.=<<___;
        la      $YY,0($YY,$TX[0])       # $i
-       llgcr   $YY,$YY
+       nill    $YY,255
        la      $XX[1],1($XX[0])
-       llgcr   $XX[1],$XX[1]
+       nill    $XX[1],255
+___
+$code.=<<___ if ($i==1);
+       llgc    $acc,2($TY,$key)
 ___
 $code.=<<___ if ($i>1);
        sllg    $acc,$acc,8
        ic      $acc,2($TY,$key)
 ___
-$code.=<<___ if ($i==1);
-       llgc    $acc,2($TY,$key)
-___
 $code.=<<___;
        llgc    $TY,2($YY,$key)
        stc     $TX[0],2($YY,$key)
@@ -77,7 +77,7 @@ $code.=<<___;
        la      $TX[1],0($TX[0])
 .Lcmov$i:
        la      $TY,0($TY,$TX[0])
-       llgcr   $TY,$TY
+       nill    $TY,255
 ___
 push(@TX,shift(@TX)); push(@XX,shift(@XX));     # "rotate" registers
 }
@@ -101,18 +101,18 @@ $code.=<<___;
 .align 16
 .Loop1:
        la      $YY,0($YY,$TX[0])
-       llgcr   $YY,$YY
+       nill    $YY,255
        llgc    $TY,2($YY,$key)
        stc     $TX[0],2($YY,$key)
        stc     $TY,2($XX[0],$key)
-       la      $TY,0($TY,$TX[0])
-       llgcr   $TY,$TY
-       la      $XX[0],1($XX[0])
-       llgcr   $XX[0],$XX[0]
-       llgc    $TY,2($TY,$key)
-       llgc    $TX[0],2($XX[0],$key)
+       ar      $TY,$TX[0]
+       ahi     $XX[0],1
+       nill    $TY,255
+       nill    $XX[0],255
        llgc    $acc,0($inp)
        la      $inp,1($inp)
+       llgc    $TY,2($TY,$key)
+       llgc    $TX[0],2($XX[0],$key)
        xr      $acc,$TY
        stc     $acc,0($out)
        la      $out,1($out)
@@ -168,8 +168,8 @@ RC4_set_key:
        la      $idx,0($idx,$acc)
        la      $ikey,1($ikey)
        la      $idx,0($idx,$dat)
+       nill    $idx,255
        la      $iinp,1($iinp)
-       llgcr   $idx,$idx
        tml     $ikey,255
        llgc    $dat,2($idx,$key)
        stc     $dat,2+256-1($ikey,$key)