For B's GP accessors, encode the type and offset in the XS alias integer.

This allows most of the code for simple structure lookups in the GP of a GV to
be merged into one XS routine. This saves over 5.5K of object code on this
platform.

diff --git a/ext/B/B.xs b/ext/B/B.xs
index e70ea54..dc63ece 100644 (file)
--- a/ext/B/B.xs
+++ b/ext/B/B.xs
@@ -831,12 +831,12 @@ threadsv_names()
 # endif
 #endif
 
-#define OPp            0x00000
-#define PADOFFSETp     0x10000
-#define U8p            0x20000
-#define U32p           0x30000
-#define SVp            0x40000
-#define line_tp                0x50000
+#define SVp            0x00000
+#define U32p           0x10000
+#define line_tp                0x20000
+#define OPp            0x30000
+#define PADOFFSETp     0x40000
+#define U8p            0x50000
 #define IVp            0x60000
 #define char_pp                0x70000
 
@@ -1689,45 +1689,55 @@ B::HV
 GvSTASH(gv)
        B::GV   gv
 
-B::SV
-GvSV(gv)
-       B::GV   gv
-
-B::IO
-GvIO(gv)
-       B::GV   gv
-
-B::FM
-GvFORM(gv)
-       B::GV   gv
-    CODE:
-       RETVAL = (SV*)GvFORM(gv);
-    OUTPUT:
-       RETVAL
-
-B::AV
-GvAV(gv)
-       B::GV   gv
-
-B::HV
-GvHV(gv)
-       B::GV   gv
-
-B::GV
-GvEGV(gv)
-       B::GV   gv
-
-B::CV
-GvCV(gv)
-       B::GV   gv
-
-U32
-GvCVGEN(gv)
-       B::GV   gv
+#define GP_sv_ix       SVp | offsetof(struct gp, gp_sv)
+#define GP_io_ix       SVp | offsetof(struct gp, gp_io)
+#define GP_cv_ix       SVp | offsetof(struct gp, gp_cv)
+#define GP_cvgen_ix    U32p | offsetof(struct gp, gp_cvgen)
+#define GP_refcnt_ix   U32p | offsetof(struct gp, gp_refcnt)
+#define GP_hv_ix       SVp | offsetof(struct gp, gp_hv)
+#define GP_av_ix       SVp | offsetof(struct gp, gp_av)
+#define GP_form_ix     SVp | offsetof(struct gp, gp_form)
+#define GP_egv_ix      SVp | offsetof(struct gp, gp_egv)
+#define GP_line_ix     line_tp | offsetof(struct gp, gp_line)
 
-U32
-GvLINE(gv)
+void
+SV(gv)
        B::GV   gv
+    ALIAS:
+       SV = GP_sv_ix
+       IO = GP_io_ix
+       CV = GP_cv_ix
+       CVGEN = GP_cvgen_ix
+       GvREFCNT = GP_refcnt_ix
+       HV = GP_hv_ix
+       AV = GP_av_ix
+       FORM = GP_form_ix
+       EGV = GP_egv_ix
+       LINE = GP_line_ix
+    PREINIT:
+       GP *gp;
+       char *ptr;
+       SV *ret;
+    PPCODE:
+       gp = GvGP(gv);
+       if (!gp) {
+           const GV *const gv = CvGV(cv);
+           croak(aTHX_ "NULL gp in B::GV::%s", gv ? GvNAME(gv) : "???");
+       }
+       ptr = (ix & 0xFFFF) + (char *)gp;
+       switch ((U8)(ix >> 16)) {
+       case (U8)(SVp >> 16):
+           ret = make_sv_object(aTHX_ NULL, *((SV **)ptr));
+           break;
+       case (U8)(U32p >> 16):
+           ret = sv_2mortal(newSVuv(*((U32*)ptr)));
+           break;
+       case (U8)(line_tp >> 16):
+           ret = sv_2mortal(newSVuv(*((line_t *)ptr)));
+           break;
+       }
+       ST(0) = ret;
+       XSRETURN(1);
 
 char *
 GvFILE(gv)
@@ -1739,10 +1749,6 @@ GvFILEGV(gv)
 
 MODULE = B     PACKAGE = B::GV
 
-U32
-GvREFCNT(gv)
-       B::GV   gv
-
 U8
 GvFLAGS(gv)
        B::GV   gv