[commit] fix "too much information" bug w/ "info vector" on PowerPC

[Paul Gilliam <pgilliam@us.ibm.com>]

Thank you all for you help and advice.  Here is the patch I just committed:

20050901  Paul Gilliam  <pgilliam@us.ibm.com>

        * ppc-tdep.h (struct gdbarch_tdep): Better explanation of using
        -1 for nonexistant registers.
        * rs6000-tdep.c (rs6000_register_reggroup_p): Don't assume that
        tdep->ppc_vr0_regnum and tdep->ppc_ev0_regnum are not -1.

Index: ppc-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/ppc-tdep.h,v
retrieving revision 1.46
diff -a -u -r1.46 ppc-tdep.h
--- ppc-tdep.h	25 May 2005 03:12:13 -0000	1.46
+++ ppc-tdep.h	1 Sep 2005 17:56:58 -0000
@@ -152,26 +152,33 @@
     int ppc_ctr_regnum;		/* Count register */
     int ppc_xer_regnum;		/* Integer exception register */
 
-    /* On PPC and RS6000 variants that have no floating-point
-       registers, the next two members will be -1.  */
+    /* Not all PPC and RS6000 variants will have the registers
+       represented below.  A -1 is used to indicate that the register
+       is not present in this variant.  */
+
+    /* Floating-point registers.  */
     int ppc_fp0_regnum;         /* floating-point register 0 */
-    int ppc_fpscr_regnum;	/* Floating point status and condition
-    				   register */
+    int ppc_fpscr_regnum;	/* fp status and condition register */
+
+    /* Segment registers.  */
+    int ppc_sr0_regnum;         /* segment register 0 */
 
-    int ppc_sr0_regnum;         /* segment register 0, or -1 on
-                                   variants that have no segment
-                                   registers.  */
+    /* Multiplier-Quotient Register (older POWER architectures only).  */
+    int ppc_mq_regnum;
 
-    int ppc_mq_regnum;		/* Multiply/Divide extension register */
+    /* Altivec registers.  */
     int ppc_vr0_regnum;		/* First AltiVec register */
     int ppc_vrsave_regnum;	/* Last AltiVec register */
+
+    /* SPE registers.  */
     int ppc_ev0_upper_regnum;   /* First GPR upper half register */
     int ppc_ev0_regnum;         /* First ev register */
     int ppc_ev31_regnum;        /* Last ev register */
     int ppc_acc_regnum;         /* SPE 'acc' register */
     int ppc_spefscr_regnum;     /* SPE 'spefscr' register */
-    int lr_frame_offset;	/* Offset to ABI specific location where
-                                   link register is saved.  */
+
+    /* Offset to ABI specific location where link register is saved.  */
+    int lr_frame_offset;	
 
     /* An array of integers, such that sim_regno[I] is the simulator
        register number for GDB register number I, or -1 if the
Index: rs6000-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/rs6000-tdep.c,v
retrieving revision 1.241
diff -a -u -r1.241 rs6000-tdep.c
--- rs6000-tdep.c	25 May 2005 03:12:13 -0000	1.241
+++ rs6000-tdep.c	1 Sep 2005 17:56:58 -0000
@@ -1882,9 +1882,11 @@
   if (group == float_reggroup)
     return float_p;
 
-  vector_p = ((regnum >= tdep->ppc_vr0_regnum
+  vector_p = ((tdep->ppc_vr0_regnum >= 0
+	       && regnum >= tdep->ppc_vr0_regnum
 	       && regnum < tdep->ppc_vr0_regnum + 32)
-	      || (regnum >= tdep->ppc_ev0_regnum
+	      || (tdep->ppc_ev0_regnum >= 0
+		  && regnum >= tdep->ppc_ev0_regnum
 		  && regnum < tdep->ppc_ev0_regnum + 32)
 	      || regnum == tdep->ppc_vrsave_regnum
 	      || regnum == tdep->ppc_acc_regnum