diff -urpN src/gdb/aix-thread.c dev/gdb/aix-thread.c
--- src/gdb/aix-thread.c	2007-06-19 05:22:04.000000000 +0200
+++ dev/gdb/aix-thread.c	2007-08-03 08:23:16.000000000 +0200
@@ -1026,7 +1026,7 @@ aix_thread_wait (ptid_t ptid, struct tar
 static void
 supply_gprs64 (struct regcache *regcache, uint64_t *vals)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
   int regno;
 
   for (regno = 0; regno < ppc_num_gprs; regno++)
@@ -1047,12 +1047,13 @@ supply_reg32 (struct regcache *regcache,
 static void
 supply_fprs (struct regcache *regcache, double *vals)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int regno;
 
   /* This function should never be called on architectures without
      floating-point registers.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
+  gdb_assert (ppc_floating_point_unit_p (gdbarch));
 
   for (regno = 0; regno < ppc_num_fprs; regno++)
     regcache_raw_supply (regcache, regno + tdep->ppc_fp0_regnum,
@@ -1085,9 +1086,10 @@ supply_sprs64 (struct regcache *regcache
 	       uint64_t lr, uint64_t ctr, uint32_t xer,
 	       uint32_t fpscr)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
-  regcache_raw_supply (regcache, gdbarch_pc_regnum (current_gdbarch),
+  regcache_raw_supply (regcache, gdbarch_pc_regnum (gdbarch),
 		       (char *) &iar);
   regcache_raw_supply (regcache, tdep->ppc_ps_regnum, (char *) &msr);
   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, (char *) &cr);
@@ -1108,9 +1110,10 @@ supply_sprs32 (struct regcache *regcache
 	       uint32_t lr, uint32_t ctr, uint32_t xer,
 	       uint32_t fpscr)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
-  regcache_raw_supply (regcache, gdbarch_pc_regnum (current_gdbarch),
+  regcache_raw_supply (regcache, gdbarch_pc_regnum (gdbarch),
 		       (char *) &iar);
   regcache_raw_supply (regcache, tdep->ppc_ps_regnum, (char *) &msr);
   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, (char *) &cr);
@@ -1132,7 +1135,8 @@ supply_sprs32 (struct regcache *regcache
 static void
 fetch_regs_user_thread (struct regcache *regcache, pthdb_pthread_t pdtid)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int status, i;
   pthdb_context_t ctx;
 
@@ -1154,7 +1158,7 @@ fetch_regs_user_thread (struct regcache 
 
   /* Floating-point registers.  */
 
-  if (ppc_floating_point_unit_p (current_gdbarch))
+  if (ppc_floating_point_unit_p (gdbarch))
     supply_fprs (regcache, ctx.fpr);
 
   /* Special registers.  */
@@ -1186,7 +1190,8 @@ static void
 fetch_regs_kernel_thread (struct regcache *regcache, int regno,
 			  pthdb_tid_t tid)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   uint64_t gprs64[ppc_num_gprs];
   uint32_t gprs32[ppc_num_gprs];
   double fprs[ppc_num_fprs];
@@ -1222,7 +1227,7 @@ fetch_regs_kernel_thread (struct regcach
 
   /* Floating-point registers.  */
 
-  if (ppc_floating_point_unit_p (current_gdbarch)
+  if (ppc_floating_point_unit_p (gdbarch)
       && (regno == -1
           || (regno >= tdep->ppc_fp0_regnum
               && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)))
@@ -1247,7 +1252,7 @@ fetch_regs_kernel_thread (struct regcach
 	}
       else
 	{
-	  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+	  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
 	  if (!ptrace32 (PTT_READ_SPRS, tid, (int *) &sprs32, 0, NULL))
 	    memset (&sprs32, 0, sizeof (sprs32));
@@ -1290,7 +1295,7 @@ aix_thread_fetch_registers (struct regca
 static void
 fill_gprs64 (const struct regcache *regcache, uint64_t *vals)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
   int regno;
 
   for (regno = 0; regno < ppc_num_gprs; regno++)
@@ -1302,7 +1307,7 @@ fill_gprs64 (const struct regcache *regc
 static void 
 fill_gprs32 (const struct regcache *regcache, uint32_t *vals)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
   int regno;
 
   for (regno = 0; regno < ppc_num_gprs; regno++)
@@ -1315,12 +1320,13 @@ fill_gprs32 (const struct regcache *regc
 static void
 fill_fprs (const struct regcache *regcache, double *vals)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int regno;
 
   /* This function should never be called on architectures without
      floating-point registers.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
+  gdb_assert (ppc_floating_point_unit_p (gdbarch));
 
   for (regno = tdep->ppc_fp0_regnum;
        regno < tdep->ppc_fp0_regnum + ppc_num_fprs;
@@ -1338,7 +1344,8 @@ fill_sprs64 (const struct regcache *regc
 	     uint64_t *lr, uint64_t *ctr, uint32_t *xer,
 	     uint32_t *fpscr)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
   /* Verify that the size of the size of the IAR buffer is the
      same as the raw size of the PC (in the register cache).  If
@@ -1346,11 +1353,10 @@ fill_sprs64 (const struct regcache *regc
      there's some other kind of internal error.  To be really safe,
      we should check all of the sizes.   */
   gdb_assert (sizeof (*iar) == register_size
-				 (current_gdbarch,
-				  gdbarch_pc_regnum (current_gdbarch)));
+				 (gdbarch, gdbarch_pc_regnum (gdbarch)));
 
-  if (regcache_valid_p (regcache, gdbarch_pc_regnum (current_gdbarch)))
-    regcache_raw_collect (regcache, gdbarch_pc_regnum (current_gdbarch), iar);
+  if (regcache_valid_p (regcache, gdbarch_pc_regnum (gdbarch)))
+    regcache_raw_collect (regcache, gdbarch_pc_regnum (gdbarch), iar);
   if (regcache_valid_p (regcache, tdep->ppc_ps_regnum))
     regcache_raw_collect (regcache, tdep->ppc_ps_regnum, msr);
   if (regcache_valid_p (regcache, tdep->ppc_cr_regnum))
@@ -1372,19 +1378,19 @@ fill_sprs32 (const struct regcache *regc
 	     uint32_t *lr, uint32_t *ctr, uint32_t *xer,
 	     uint32_t *fpscr)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
   /* Verify that the size of the size of the IAR buffer is the
      same as the raw size of the PC (in the register cache).  If
      they're not, then either GDB has been built incorrectly, or
      there's some other kind of internal error.  To be really safe,
      we should check all of the sizes.  */
-  gdb_assert (sizeof (*iar) == register_size (current_gdbarch,
-					      gdbarch_pc_regnum
-					      (current_gdbarch)));
+  gdb_assert (sizeof (*iar) == register_size (gdbarch,
+					      gdbarch_pc_regnum (gdbarch)));
 
-  if (regcache_valid_p (regcache, gdbarch_pc_regnum (current_gdbarch)))
-    regcache_raw_collect (regcache, gdbarch_pc_regnum (current_gdbarch), iar);
+  if (regcache_valid_p (regcache, gdbarch_pc_regnum (gdbarch)))
+    regcache_raw_collect (regcache, gdbarch_pc_regnum (gdbarch), iar);
   if (regcache_valid_p (regcache, tdep->ppc_ps_regnum))
     regcache_raw_collect (regcache, tdep->ppc_ps_regnum, msr);
   if (regcache_valid_p (regcache, tdep->ppc_cr_regnum))
@@ -1409,7 +1415,8 @@ fill_sprs32 (const struct regcache *regc
 static void
 store_regs_user_thread (const struct regcache *regcache, pthdb_pthread_t pdtid)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int status, i;
   pthdb_context_t ctx;
   uint32_t int32;
@@ -1447,7 +1454,7 @@ store_regs_user_thread (const struct reg
       }
 
   /* Collect floating-point register values from the regcache.  */
-  if (ppc_floating_point_unit_p (current_gdbarch))
+  if (ppc_floating_point_unit_p (gdbarch))
     fill_fprs (regcache, ctx.fpr);
 
   /* Special registers (always kept in ctx as 64 bits).  */
@@ -1465,7 +1472,7 @@ store_regs_user_thread (const struct reg
 
       fill_sprs32 (regcache, &tmp_iar, &tmp_msr, &tmp_cr, &tmp_lr, &tmp_ctr,
 			     &tmp_xer, &tmp_fpscr);
-      if (regcache_valid_p (regcache, gdbarch_pc_regnum (current_gdbarch)))
+      if (regcache_valid_p (regcache, gdbarch_pc_regnum (gdbarch)))
 	ctx.iar = tmp_iar;
       if (regcache_valid_p (regcache, tdep->ppc_ps_regnum))
 	ctx.msr = tmp_msr;
@@ -1499,7 +1506,8 @@ static void
 store_regs_kernel_thread (const struct regcache *regcache, int regno,
 			  pthdb_tid_t tid)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   uint64_t gprs64[ppc_num_gprs];
   uint32_t gprs32[ppc_num_gprs];
   double fprs[ppc_num_fprs];
@@ -1535,7 +1543,7 @@ store_regs_kernel_thread (const struct r
 
   /* Floating-point registers.  */
 
-  if (ppc_floating_point_unit_p (current_gdbarch)
+  if (ppc_floating_point_unit_p (gdbarch)
       && (regno == -1
           || (regno >= tdep->ppc_fp0_regnum
               && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)))