Add Montgomery multiplication module for IA-64.

[openssl.git] / crypto / bn / asm / x86-mont.pl

diff --git a/crypto/bn/asm/x86-mont.pl b/crypto/bn/asm/x86-mont.pl
index 319c17de65237f538a4f1c0ecd4102c8f3a4ac85..5cd3cd2ed50a968fa2ab60bcd361b185dce923ac 100755 (executable)
--- a/crypto/bn/asm/x86-mont.pl
+++ b/crypto/bn/asm/x86-mont.pl
@@ -41,7 +41,7 @@ for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
 
 $i="edx";
 $j="ecx";
-$ap="esi";
+$ap="esi";     $tp="esi";              # overlapping variables!!!
 $rp="edi";     $bp="edi";              # overlapping variables!!!
 $np="ebp";
 $num="ebx";
@@ -551,41 +551,36 @@ $sbit=$num;
 }
 \f
 &set_label("common_tail",16);
-       &mov    ($np,$_np);
-       &mov    ("esi",&DWP($frame+4,"esp",$num,4));# load upmost overflow bit
+       &mov    ($np,$_np);                     # load modulus pointer
        &mov    ($rp,$_rp);                     # load result pointer
-                                               # [$ap and $bp are zapped]
-       &xor    ($i,$i);                        # i=0
+       &lea    ($tp,&DWP($frame,"esp"));       # [$ap and $bp are zapped]
+
+       &mov    ("eax",&DWP(0,$tp));            # tp[0]
        &mov    ($j,$num);                      # j=num-1
-       &cmp    ("esi",0);                      # clears CF unconditionally
-       &jnz    (&label("sub"));
-       &mov    ("eax",&DWP($frame,"esp",$j,4));
-       &cmp    ("eax",&DWP(0,$np,$j,4));       # tp[num-1]-np[num-1]?
-       &jae    (&label("sub"));                # if taken CF is cleared
-&set_label("copy",16);
-       &mov    ("eax",&DWP($frame,"esp",$j,4));
-       &mov    (&DWP(0,$rp,$j,4),"eax");       # rp[i]=tp[i]
-       &mov    (&DWP($frame,"esp",$j,4),$j);   # zap temporary vector
-       &dec    ($j);
-       &jge    (&label("copy"));
-       &jmp    (&label("exit"));
+       &xor    ($i,$i);                        # i=0 and clear CF!
 
 &set_label("sub",16);
-       &mov    ("eax",&DWP($frame,"esp",$i,4));
        &sbb    ("eax",&DWP(0,$np,$i,4));
        &mov    (&DWP(0,$rp,$i,4),"eax");       # rp[i]=tp[i]-np[i]
-       &lea    ($i,&DWP(1,$i));                # i++
        &dec    ($j);                           # doesn't affect CF!
+       &mov    ("eax",&DWP(4,$tp,$i,4));       # tp[i+1]
+       &lea    ($i,&DWP(1,$i));                # i++
        &jge    (&label("sub"));
-       &mov    ($j,$num);                      # j=num-1
-       &sbb    ("esi",0);                      # esi holds upmost overflow bit
-       &jc     (&label("copy"));
-&set_label("zap",8);
-       &mov    (&DWP($frame,"esp",$j,4),$i);   # zap temporary vector
-       &dec    ($j);
-       &jge    (&label("zap"));
-
-&set_label("exit",8);
+
+       &sbb    ("eax",0);                      # handle upmost overflow bit
+       &and    ($tp,"eax");
+       &not    ("eax");
+       &mov    ($np,$rp);
+       &and    ($np,"eax");
+       &or     ($tp,$np);                      # tp=carry?tp:rp
+
+&set_label("copy",16);                         # copy or in-place refresh
+       &mov    ("eax",&DWP(0,$tp,$num,4));
+       &mov    (&DWP(0,$rp,$num,4),"eax");     # rp[i]=tp[i]
+       &mov    (&DWP($frame,"esp",$num,4),$j); # zap temporary vector
+       &dec    ($num);
+       &jge    (&label("copy"));
+
        &mov    ("esp",$_sp);           # pull saved stack pointer
        &mov    ("eax",1);
 &set_label("just_leave");