HFA, function descriptor handling for IA-64.

3 files changed, 312 insertions, 84 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 170eebd..64da13b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,18 @@
+2000-03-22  Kevin Buettner  <kevinb@redhat.com>
+
+	* ia64-linux-nat.c: Fix copyright.
+	(fill_gregset): Minor formatting fix.
+	* ia64-tdep.c (template_encoding_table, fetch_instruction,
+	examine_prologue): Clean up some compiler warnings.
+	(is_float_or_hfa_type_recurse, is_float_or_hfa_type, find_func_descr,
+	find_global_pointer, find_extant_func_descr): New functions.
+	(ia64_use_struct_convention, ia64_extract_return_value,
+	ia64_push_arguments): Handle HFAs.
+	(ia64_push_arguments): Find (or build) a function descriptor
+	when given a function address.
+	(ia64_push_return_address): Moved code for finding the
+	global pointer into its own function, find_global_pointer ().
+
 2000-03-22  Elena Zannoni  <ezannoni@kwikemart.cygnus.com>
 
 	* event-loop.c (handle_file_event): Run through indent.
diff --git a/gdb/ia64-linux-nat.c b/gdb/ia64-linux-nat.c
index 2a664d5..9a29c66 100644
--- a/gdb/ia64-linux-nat.c
+++ b/gdb/ia64-linux-nat.c
@@ -1,5 +1,5 @@
-/* Functions specific to running gdb native on IA64 running Linux.
-   Copyright 1999 Free Software Foundation, Inc.
+/* Functions specific to running gdb native on IA-64 running Linux.
+   Copyright 1999, 2000 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -394,6 +394,6 @@ fill_gregset (gregsetp, regno)
      gregset_t *gregsetp;
      int regno;
 {
-  fprintf(stderr, "Warning: fill_gregset not implemented!\n");
+  fprintf (stderr, "Warning: fill_gregset not implemented!\n");
   /* FIXME: Implement later */
 }
diff --git a/gdb/ia64-tdep.c b/gdb/ia64-tdep.c
index be3a900..850b726 100644
--- a/gdb/ia64-tdep.c
+++ b/gdb/ia64-tdep.c
@@ -87,8 +87,8 @@ static gdbarch_push_arguments_ftype ia64_push_arguments;
 static gdbarch_push_return_address_ftype ia64_push_return_address;
 static gdbarch_pop_frame_ftype ia64_pop_frame;
 static gdbarch_saved_pc_after_call_ftype ia64_saved_pc_after_call;
-
 static void ia64_pop_frame_regular (struct frame_info *frame);
+static struct type *is_float_or_hfa_type (struct type *t);
 
 static int ia64_num_regs = 590;
 
@@ -384,7 +384,7 @@ replace_slotN_contents (unsigned char *bundle, long long instr, int slotnum)
   replace_bit_field (bundle, instr, 5+41*slotnum, 41);
 }
 
-static template_encoding_table[32][3] =
+static enum instruction_type template_encoding_table[32][3] =
 {
   { M, I, I },				/* 00 */
   { M, I, I },				/* 01 */
@@ -445,7 +445,7 @@ fetch_instruction (CORE_ADDR addr, instruction_type *it, long long *instr)
   template = extract_bit_field (bundle, 0, 5);
   *it = template_encoding_table[(int)template][slotnum];
 
-  if (slotnum == 2 || slotnum == 1 && *it == L)
+  if (slotnum == 2 || (slotnum == 1 && *it == L))
     addr += 16;
   else
     addr += (slotnum + 1) * SLOT_MULTIPLIER;
@@ -639,7 +639,6 @@ examine_prologue (CORE_ADDR pc, CORE_ADDR lim_pc, struct frame_info *frame)
 {
   CORE_ADDR next_pc;
   CORE_ADDR last_prologue_pc = pc;
-  int done = 0;
   instruction_type it;
   long long instr;
   int do_fsr_stuff = 0;
@@ -1137,20 +1136,45 @@ ia64_get_saved_register (char *raw_buffer,
 int
 ia64_use_struct_convention (int gcc_p, struct type *type)
 {
-  /* FIXME: Need to check for HFAs; structures containing (only) up to 8
-     floating point values of the same size are returned in floating point
-     registers. */
+  struct type *float_elt_type;
+
+  /* HFAs are structures (or arrays) consisting entirely of floating
+     point values of the same length.  Up to 8 of these are returned
+     in registers.  Don't use the struct convention when this is the
+     case. */
+  float_elt_type = is_float_or_hfa_type (type);
+  if (float_elt_type != NULL
+      && TYPE_LENGTH (type) / TYPE_LENGTH (float_elt_type) <= 8)
+    return 0;
+
+  /* Other structs of length 32 or less are returned in r8-r11.
+     Don't use the struct convention for those either. */
   return TYPE_LENGTH (type) > 32;
 }
 
 void
 ia64_extract_return_value (struct type *type, char *regbuf, char *valbuf)
 {
-  if (TYPE_CODE (type) == TYPE_CODE_FLT)
-    ia64_register_convert_to_virtual (IA64_FR8_REGNUM, type,
-      &regbuf[REGISTER_BYTE (IA64_FR8_REGNUM)], valbuf);
+  struct type *float_elt_type;
+
+  float_elt_type = is_float_or_hfa_type (type);
+  if (float_elt_type != NULL)
+    {
+      int offset = 0;
+      int regnum = IA64_FR8_REGNUM;
+      int n = TYPE_LENGTH (type) / TYPE_LENGTH (float_elt_type);
+
+      while (n-- > 0)
+	{
+	  ia64_register_convert_to_virtual (regnum, float_elt_type,
+	    &regbuf[REGISTER_BYTE (regnum)], valbuf + offset);
+	  offset += TYPE_LENGTH (float_elt_type);
+	  regnum++;
+	}
+    }
   else
-    memcpy (valbuf, &regbuf[REGISTER_BYTE (IA64_GR8_REGNUM)], TYPE_LENGTH (type));
+    memcpy (valbuf, &regbuf[REGISTER_BYTE (IA64_GR8_REGNUM)],
+	    TYPE_LENGTH (type));
 }
 
 /* FIXME: Turn this into a stack of some sort.  Unfortunately, something
@@ -1219,7 +1243,6 @@ ia64_init_extra_frame_info (int fromleaf, struct frame_info *frame)
   else
     {
       struct frame_info *frn = frame->next;
-      CORE_ADDR cfm_addr;
 
       FRAME_INIT_SAVED_REGS (frn);
 
@@ -1243,7 +1266,198 @@ ia64_init_extra_frame_info (int fromleaf, struct frame_info *frame)
   frame->extra_info->fp_reg = 0;
 }
 
-#define ROUND_UP(n,a) (((n)+(a)-1) & ~((a)-1))
+static int
+is_float_or_hfa_type_recurse (struct type *t, struct type **etp)
+{
+  switch (TYPE_CODE (t))
+    {
+    case TYPE_CODE_FLT:
+      if (*etp)
+	return TYPE_LENGTH (*etp) == TYPE_LENGTH (t);
+      else
+	{
+	  *etp = t;
+	  return 1;
+	}
+      break;
+    case TYPE_CODE_ARRAY:
+      return is_float_or_hfa_type_recurse (TYPE_TARGET_TYPE (t), etp);
+      break;
+    case TYPE_CODE_STRUCT:
+      {
+	int i;
+
+	for (i = 0; i < TYPE_NFIELDS (t); i++)
+	  if (!is_float_or_hfa_type_recurse (TYPE_FIELD_TYPE (t, i), etp))
+	    return 0;
+	return 1;
+      }
+      break;
+    default:
+      return 0;
+      break;
+    }
+}
+
+/* Determine if the given type is one of the floating point types or
+   and HFA (which is a struct, array, or combination thereof whose
+   bottom-most elements are all of the same floating point type.) */
+
+static struct type *
+is_float_or_hfa_type (struct type *t)
+{
+  struct type *et = 0;
+
+  return is_float_or_hfa_type_recurse (t, &et) ? et : 0;
+}
+
+
+/* Attempt to find (and return) the global pointer for the given
+   function.
+
+   This is a rather nasty bit of code searchs for the .dynamic section
+   in the objfile corresponding to the pc of the function we're trying
+   to call.  Once it finds the addresses at which the .dynamic section
+   lives in the child process, it scans the Elf64_Dyn entries for a
+   DT_PLTGOT tag.  If it finds one of these, the corresponding
+   d_un.d_ptr value is the global pointer.  */
+
+static CORE_ADDR
+find_global_pointer (CORE_ADDR faddr)
+{
+  struct partial_symtab *pst;
+     
+  pst = find_pc_psymtab (faddr);
+  if (pst != NULL)
+    {
+      struct obj_section *osect;
+
+      ALL_OBJFILE_OSECTIONS (pst->objfile, osect)
+	{
+	  if (strcmp (osect->the_bfd_section->name, ".dynamic") == 0)
+	    break;
+	}
+
+      if (osect < pst->objfile->sections_end)
+	{
+	  CORE_ADDR addr;
+
+	  addr = osect->addr;
+	  while (addr < osect->endaddr)
+	    {
+	      int status;
+	      LONGEST tag;
+	      char buf[8];
+
+	      status = target_read_memory (addr, buf, sizeof (buf));
+	      if (status != 0)
+		break;
+	      tag = extract_signed_integer (buf, sizeof (buf));
+
+	      if (tag == DT_PLTGOT)
+		{
+		  CORE_ADDR global_pointer;
+
+		  status = target_read_memory (addr + 8, buf, sizeof (buf));
+		  if (status != 0)
+		    break;
+		  global_pointer = extract_address (buf, sizeof (buf));
+
+		  /* The payoff... */
+		  return global_pointer;
+		}
+
+	      if (tag == DT_NULL)
+		break;
+
+	      addr += 16;
+	    }
+	}
+    }
+  return 0;
+}
+
+/* Given a function's address, attempt to find (and return) the
+   corresponding (canonical) function descriptor.  Return 0 if
+   not found. */
+static CORE_ADDR
+find_extant_func_descr (CORE_ADDR faddr)
+{
+  struct partial_symtab *pst;
+  struct obj_section *osect;
+
+  /* Return early if faddr is already a function descriptor */
+  osect = find_pc_section (faddr);
+  if (osect && strcmp (osect->the_bfd_section->name, ".opd") == 0)
+    return faddr;
+
+  pst = find_pc_psymtab (faddr);
+  if (pst != NULL)
+    {
+      ALL_OBJFILE_OSECTIONS (pst->objfile, osect)
+	{
+	  if (strcmp (osect->the_bfd_section->name, ".opd") == 0)
+	    break;
+	}
+
+      if (osect < pst->objfile->sections_end)
+	{
+	  CORE_ADDR addr;
+
+	  addr = osect->addr;
+	  while (addr < osect->endaddr)
+	    {
+	      int status;
+	      LONGEST faddr2;
+	      char buf[8];
+
+	      status = target_read_memory (addr, buf, sizeof (buf));
+	      if (status != 0)
+		break;
+	      faddr2 = extract_signed_integer (buf, sizeof (buf));
+
+	      if (faddr == faddr2)
+		return addr;
+
+	      addr += 16;
+	    }
+	}
+    }
+  return 0;
+}
+
+/* Attempt to find a function descriptor corresponding to the
+   given address.  If none is found, construct one on the
+   stack using the address at fdaptr */
+
+static CORE_ADDR
+find_func_descr (CORE_ADDR faddr, CORE_ADDR *fdaptr)
+{
+  CORE_ADDR fdesc;
+
+  fdesc = find_extant_func_descr (faddr);
+
+  if (fdesc == 0)
+    {
+      CORE_ADDR global_pointer;
+      char buf[16];
+
+      fdesc = *fdaptr;
+      *fdaptr += 16;
+
+      global_pointer = find_global_pointer (faddr);
+
+      if (global_pointer == 0)
+	global_pointer = read_register (IA64_GR1_REGNUM);
+
+      store_address (buf, 8, faddr);
+      store_address (buf + 8, 8, global_pointer);
+
+      write_memory (fdesc, buf, 16);
+    }
+
+  return fdesc; 
+}
 
 CORE_ADDR
 ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
@@ -1253,11 +1467,12 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
   value_ptr arg;
   struct type *type;
   int len, argoffset;
-  int nslots, rseslots, memslots, slotnum;
+  int nslots, rseslots, memslots, slotnum, nfuncargs;
   int floatreg;
-  CORE_ADDR bsp, cfm, pfs, new_bsp;
+  CORE_ADDR bsp, cfm, pfs, new_bsp, funcdescaddr;
 
   nslots = 0;
+  nfuncargs = 0;
   /* Count the number of slots needed for the arguments */
   for (argno = 0; argno < nargs; argno++)
     {
@@ -1270,12 +1485,17 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
       if (len > 8 && (nslots & 1))
 	nslots++;
 
+      if (TYPE_CODE (type) == TYPE_CODE_FUNC)
+	nfuncargs++;
+
       nslots += (len + 7) / 8;
     }
 
+  /* Divvy up the slots between the RSE and the memory stack */
   rseslots = (nslots > 8) ? 8 : nslots;
   memslots = nslots - rseslots;
 
+  /* Allocate a new RSE frame */
   cfm = read_register (IA64_CFM_REGNUM);
 
   bsp = read_register (IA64_BSP_REGNUM);
@@ -1292,18 +1512,51 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
   cfm |= rseslots;
   write_register (IA64_CFM_REGNUM, cfm);
   
-
-  
-  sp = sp - 16 - memslots * 8;
+  /* We will attempt to find function descriptors in the .opd segment,
+     but if we can't we'll construct them ourselves.  That being the
+     case, we'll need to reserve space on the stack for them. */
+  funcdescaddr = sp - nfuncargs * 16;
+  funcdescaddr &= ~0xfLL;
+
+  /* Adjust the stack pointer to it's new value.  The calling conventions
+     require us to have 16 bytes of scratch, plus whatever space is
+     necessary for the memory slots and our function descriptors */
+  sp = sp - 16 - (memslots + nfuncargs) * 8;
   sp &= ~0xfLL;				/* Maintain 16 byte alignment */
 
+  /* Place the arguments where they belong.  The arguments will be
+     either placed in the RSE backing store or on the memory stack.
+     In addition, floating point arguments or HFAs are placed in
+     floating point registers. */
   slotnum = 0;
   floatreg = IA64_FR8_REGNUM;
   for (argno = 0; argno < nargs; argno++)
     {
+      struct type *float_elt_type;
+
       arg = args[argno];
       type = check_typedef (VALUE_TYPE (arg));
       len = TYPE_LENGTH (type);
+
+      /* Special handling for function parameters */
+      if (len == 8 
+          && TYPE_CODE (type) == TYPE_CODE_PTR 
+	  && TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC)
+	{
+	  char val_buf[8];
+
+	  store_address (val_buf, 8,
+	    find_func_descr (extract_address (VALUE_CONTENTS (arg), 8),
+	                     &funcdescaddr));
+	  if (slotnum < rseslots)
+	    write_memory (rse_address_add (bsp, slotnum), val_buf, 8);
+	  else
+	    write_memory (sp + 16 + 8 * (slotnum - rseslots), val_buf, 8);
+	  slotnum++;
+	  continue;
+	}
+
+      /* Normal slots */
       if (len > 8 && (slotnum & 1))
 	slotnum++;
       argoffset = 0;
@@ -1323,14 +1576,28 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
 	  len -= 8;
 	  slotnum++;
 	}
-      if (TYPE_CODE (type) == TYPE_CODE_FLT && floatreg < IA64_FR16_REGNUM)
-        {
-	  ia64_register_convert_to_raw (type, floatreg, VALUE_CONTENTS (arg),
-	    &registers[REGISTER_BYTE (floatreg)]);
-	  floatreg++;
+
+      /* Handle floating point types (including HFAs) */
+      float_elt_type = is_float_or_hfa_type (type);
+      if (float_elt_type != NULL)
+	{
+	  argoffset = 0;
+	  len = TYPE_LENGTH (type);
+	  while (len > 0 && floatreg < IA64_FR16_REGNUM)
+	    {
+	      ia64_register_convert_to_raw (
+		float_elt_type,
+		floatreg,
+	        VALUE_CONTENTS (arg) + argoffset,
+		&registers[REGISTER_BYTE (floatreg)]);
+	      floatreg++;
+	      argoffset += TYPE_LENGTH (float_elt_type);
+	      len -= TYPE_LENGTH (float_elt_type);
+	    }
 	}
     }
 
+  /* Store the struct return value in r8 if necessary. */
   if (struct_return)
     {
       store_address (&registers[REGISTER_BYTE (IA64_GR8_REGNUM)],
@@ -1338,7 +1605,7 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
 		     struct_addr);
     }
 
-
+  /* Sync gdb's idea of what the registers are with the target. */
   target_store_registers (-1);
 
   /* FIXME: This doesn't belong here!  Instead, SAVE_DUMMY_FRAME_TOS needs
@@ -1359,64 +1626,10 @@ ia64_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
 CORE_ADDR
 ia64_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
 {
-  struct partial_symtab *pst;
-
-  /* Attempt to determine and set global pointer (r1) for this pc.
-     
-     This rather nasty bit of code searchs for the .dynamic section
-     in the objfile corresponding to the pc of the function we're
-     trying to call.  Once it finds the addresses at which the .dynamic
-     section lives in the child process, it scans the Elf64_Dyn entries
-     for a DT_PLTGOT tag.  If it finds one of these, the corresponding
-     d_un.d_ptr value is the global pointer. */
-  pst = find_pc_psymtab (pc);
-  if (pst != NULL)
-    {
-      struct obj_section *osect;
-
-      ALL_OBJFILE_OSECTIONS (pst->objfile, osect)
-	{
-	  if (strcmp (osect->the_bfd_section->name, ".dynamic") == 0)
-	    break;
-	}
-
-      if (osect < pst->objfile->sections_end)
-	{
-	  CORE_ADDR addr;
-
-	  addr = osect->addr;
-	  while (addr < osect->endaddr)
-	    {
-	      int status;
-	      LONGEST tag;
-	      char buf[8];
+  CORE_ADDR global_pointer = find_global_pointer (pc);
 
-	      status = target_read_memory (addr, buf, sizeof (buf));
-	      if (status != 0)
-		break;
-	      tag = extract_signed_integer (buf, sizeof (buf));
-
-	      if (tag == DT_PLTGOT)
-		{
-		  CORE_ADDR global_pointer;
-
-		  status = target_read_memory (addr + 8, buf, sizeof (buf));
-		  if (status != 0)
-		    break;
-		  global_pointer = extract_address (buf, sizeof (buf));
-
-		  /* The payoff... */
-		  write_register (IA64_GR1_REGNUM, global_pointer);
-		  break;
-		}
-
-	      if (tag == DT_NULL)
-		break;
-
-	      addr += 16;
-	    }
-	}
-    }
+  if (global_pointer != 0)
+    write_register (IA64_GR1_REGNUM, global_pointer);
 
   write_register (IA64_BR0_REGNUM, CALL_DUMMY_ADDRESS ());
   return sp;