[?PATCH] terser pp_eq

Message-ID: <20011119230901.O62891@plum.flirble.org>

p4raw-id: //depot/perl@13136

diff --git a/pp_hot.c b/pp_hot.c
index f1274a6..be94e10 100644 (file)
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -252,49 +252,40 @@ PP(pp_eq)
            bool auvok = SvUOK(TOPm1s);
            bool buvok = SvUOK(TOPs);
        
-           if (!auvok && !buvok) { /* ## IV == IV ## */
-               IV aiv = SvIVX(TOPm1s);
-               IV biv = SvIVX(TOPs);
+           if (auvok == buvok) { /* ## IV == IV or UV == UV ## */
+                /* Casting IV to UV before comparison isn't going to matter
+                   on 2s complement. On 1s complement or sign&magnitude
+                   (if we have any of them) it could to make negative zero
+                   differ from normal zero. As I understand it. (Need to
+                   check - is negative zero implementation defined behaviour
+                   anyway?). NWC  */
+               UV buv = SvUVX(POPs);
+               UV auv = SvUVX(TOPs);
                
-               SP--;
-               SETs(boolSV(aiv == biv));
-               RETURN;
-           }
-           if (auvok && buvok) { /* ## UV == UV ## */
-               UV auv = SvUVX(TOPm1s);
-               UV buv = SvUVX(TOPs);
-               
-               SP--;
                SETs(boolSV(auv == buv));
                RETURN;
            }
            {                   /* ## Mixed IV,UV ## */
+                SV *ivp, *uvp;
                IV iv;
-               UV uv;
                
-               /* == is commutative so swap if needed (save code) */
+               /* == is commutative so doesn't matter which is left or right */
                if (auvok) {
-                   /* swap. top of stack (b) is the iv */
-                   iv = SvIVX(TOPs);
-                   SP--;
-                   if (iv < 0) {
-                       /* As (a) is a UV, it's >0, so it cannot be == */
-                       SETs(&PL_sv_no);
-                       RETURN;
-                   }
-                   uv = SvUVX(TOPs);
-               } else {
-                   iv = SvIVX(TOPm1s);
-                   SP--;
-                   if (iv < 0) {
-                       /* As (b) is a UV, it's >0, so it cannot be == */
-                       SETs(&PL_sv_no);
-                       RETURN;
-                   }
-                   uv = SvUVX(*(SP+1)); /* Do I want TOPp1s() ? */
-               }
+                   /* top of stack (b) is the iv */
+                    ivp = *SP;
+                    uvp = *--SP;
+                } else {
+                    uvp = *SP;
+                    ivp = *--SP;
+                }
+                iv = SvIVX(ivp);
+                if (iv < 0) {
+                    /* As uv is a UV, it's >0, so it cannot be == */
+                    SETs(&PL_sv_no);
+                    RETURN;
+                }
                /* we know iv is >= 0 */
-               SETs(boolSV((UV)iv == uv));
+               SETs(boolSV((UV)iv == SvUVX(uvp)));
                RETURN;
            }
        }