[RFA] Altivec ABI patches

Elena Zannoni
2002-04-26T20:45:21Z

As promised, this patch adds the last missing bits of Altivec support.
It handles the new vector types for passing parameters and returning
values.

Elena

2002-04-26 Elena Zannoni <ezannoni@redhat.com>

* rs6000-tdep.c (rs6000_extract_return_value,
rs6000_store_return_value): Handle returning vectors.
(rs6000_gdbarch_init): Use
ppc_sysv_abi_broken_use_struct_convention for native sysv cases.
* ppc-linux-tdep.c (ppc_sysv_abi_broken_use_struct_convention):
New function.
(ppc_sysv_abi_use_struct_convention): Deal with functions returning
vectors.
(ppc_sysv_abi_push_arguments): Handle vector parameters.
* ppc-tdep.h (ppc_sysv_abi_broken_use_struct_convention): Export.

Index: rs6000-tdep.c
===================================================================
RCS file: /cvs/uberbaum/gdb/rs6000-tdep.c,v
retrieving revision 1.60
diff -u -p -r1.60 rs6000-tdep.c
--- rs6000-tdep.c 26 Apr 2002 04:31:47 -0000 1.60
+++ rs6000-tdep.c 26 Apr 2002 20:34:10 -0000
@@ -1144,6 +1144,7 @@ static void
rs6000_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
{
int offset = 0;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
{
@@ -1165,6 +1166,13 @@ rs6000_extract_return_value (struct type
memcpy (valbuf, &ff, sizeof (float));
}
}
+ else if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY
+ && TYPE_LENGTH (valtype) == 16
+ && TYPE_VECTOR (valtype))
+ {
+ memcpy (valbuf, regbuf + REGISTER_BYTE (tdep->ppc_vr0_regnum + 2),
+ TYPE_LENGTH (valtype));
+ }
else
{
/* return value is copied starting from r3. */
@@ -1909,6 +1917,8 @@ rs6000_store_struct_return (CORE_ADDR ad
static void
rs6000_store_return_value (struct type *type, char *valbuf)
{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+
if (TYPE_CODE (type) == TYPE_CODE_FLT)

/* Floating point values are returned starting from FPR1 and up.
@@ -1917,6 +1927,13 @@ rs6000_store_return_value (struct type *

write_register_bytes (REGISTER_BYTE (FP0_REGNUM + 1), valbuf,
TYPE_LENGTH (type));
+ else if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
+ {
+ if (TYPE_LENGTH (type) == 16
+ && TYPE_VECTOR (type))
+ write_register_bytes (REGISTER_BYTE (tdep->ppc_vr0_regnum + 2),
+ valbuf, TYPE_LENGTH (type));
+ }
else
/* Everything else is returned in GPR3 and up. */
write_register_bytes (REGISTER_BYTE (gdbarch_tdep (current_gdbarch)->ppc_gp0_regnum + 3),
@@ -2706,7 +2723,7 @@ rs6000_gdbarch_init (struct gdbarch_info
|| osabi == ELFOSABI_NETBSD
|| osabi == ELFOSABI_FREEBSD)
set_gdbarch_use_struct_convention (gdbarch,
- generic_use_struct_convention);
+ ppc_sysv_abi_broken_use_struct_convention);
else
set_gdbarch_use_struct_convention (gdbarch,
ppc_sysv_abi_use_struct_convention);
Index: ppc-linux-tdep.c
===================================================================
RCS file: /cvs/uberbaum/gdb/ppc-linux-tdep.c,v
retrieving revision 1.16
diff -u -p -r1.16 ppc-linux-tdep.c
--- ppc-linux-tdep.c 24 Apr 2002 16:28:16 -0000 1.16
+++ ppc-linux-tdep.c 26 Apr 2002 20:34:32 -0000
@@ -415,11 +415,29 @@ ppc_linux_frame_chain (struct frame_info
it may be used generically by ports which use either the SysV ABI or
the EABI */

+/* Until November 2001, gcc was not complying to the SYSV ABI for
+ returning structures less than or equal to 8 bytes in size. It was
+ returning everything in memory. When this was corrected, it wasn't
+ fixed for native platforms. */
+int
+ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type)
+{
+ if (TYPE_LENGTH (value_type) == 16
+ && TYPE_VECTOR (value_type))
+ return 0;
+
+ return generic_use_struct_convention (gcc_p, value_type);
+}
+
/* Structures 8 bytes or less long are returned in the r3 & r4
registers, according to the SYSV ABI. */
int
ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type)
{
+ if (TYPE_LENGTH (value_type) == 16
+ && TYPE_VECTOR (value_type))
+ return 0;
+
return (TYPE_LENGTH (value_type) > 8);
}

@@ -445,7 +463,12 @@ ppc_sysv_abi_push_arguments (int nargs,
int struct_return, CORE_ADDR struct_addr)
{
int argno;
- int greg, freg;
+ /* Next available general register for non-float, non-vector arguments. */
+ int greg;
+ /* Next available floating point register for float arguments. */
+ int freg;
+ /* Next available vector register for vector arguments. */
+ int vreg;
int argstkspace;
int structstkspace;
int argoffset;
@@ -458,6 +481,7 @@ ppc_sysv_abi_push_arguments (int nargs,

greg = struct_return ? 4 : 3;
freg = 1;
+ vreg = 2;
argstkspace = 0;
structstkspace = 0;

@@ -500,21 +524,38 @@ ppc_sysv_abi_push_arguments (int nargs,
greg += 2;
}
}
- else
- {
+ else if (!TYPE_VECTOR (type))
+ {
if (len > 4
|| TYPE_CODE (type) == TYPE_CODE_STRUCT
|| TYPE_CODE (type) == TYPE_CODE_UNION)
{
/* Rounding to the nearest multiple of 8 may not be necessary,
- but it is safe. Particularly since we don't know the
- field types of the structure */
+ but it is safe. Particularly since we don't know the
+ field types of the structure */
structstkspace += round2 (len, 8);
}
if (greg <= 10)
greg++;
else
argstkspace += 4;
+ }
+ else
+ {
+ if (len == 16
+ && TYPE_CODE (type) == TYPE_CODE_ARRAY
+ && TYPE_VECTOR (type))
+ {
+ if (vreg <= 13)
+ vreg++;
+ else
+ {
+ /* Vector arguments must be aligned to 16 bytes on
+ the stack. */
+ argstkspace += round2 (argstkspace, 16);
+ argstkspace += 16;
+ }
+ }
}
}

@@ -540,6 +581,7 @@ ppc_sysv_abi_push_arguments (int nargs,
structoffset = argoffset + argstkspace;
freg = 1;
greg = 3;
+ vreg = 2;
/* Fill in r3 with the return structure, if any */
if (struct_return)
{
@@ -599,7 +641,7 @@ ppc_sysv_abi_push_arguments (int nargs,
greg += 2;
}
}
- else
+ else if (!TYPE_VECTOR (type))
{
char val_buf[4];
if (len > 4
@@ -627,6 +669,32 @@ ppc_sysv_abi_push_arguments (int nargs,
argoffset += 4;
}
}
+ else
+ {
+ if (len == 16
+ && TYPE_CODE (type) == TYPE_CODE_ARRAY
+ && TYPE_VECTOR (type))
+ {
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ char *v_val_buf = alloca (16);
+ memset (v_val_buf, 0, 16);
+ memcpy (v_val_buf, VALUE_CONTENTS (arg), len);
+ if (vreg <= 13)
+ {
+ *(int *) &registers[REGISTER_BYTE (tdep->ppc_vr0_regnum
+ + vreg)] = 0;
+ memcpy (&registers[REGISTER_BYTE (tdep->ppc_vr0_regnum
+ + vreg)],
+ v_val_buf, 16);
+ vreg++;
+ }
+ else
+ {
+ write_memory (sp + argoffset, v_val_buf, 16);
+ argoffset += 16;
+ }
+ }
+ }
}

target_store_registers (-1);
Index: ppc-tdep.h
===================================================================
RCS file: /cvs/uberbaum/gdb/ppc-tdep.h,v
retrieving revision 1.9
diff -u -p -r1.9 ppc-tdep.h
--- ppc-tdep.h 12 Apr 2002 19:48:36 -0000 1.9
+++ ppc-tdep.h 26 Apr 2002 20:34:41 -0000
@@ -32,6 +32,7 @@ int ppc_linux_frameless_function_invocat
void ppc_linux_frame_init_saved_regs (struct frame_info *);
CORE_ADDR ppc_linux_frame_chain (struct frame_info *);
int ppc_sysv_abi_use_struct_convention (int, struct type *);
+int ppc_sysv_abi_broken_use_struct_convention (int, struct type *);
CORE_ADDR ppc_sysv_abi_push_arguments (int, struct value **, CORE_ADDR, int,
CORE_ADDR);
int ppc_linux_memory_remove_breakpoint (CORE_ADDR addr, char *contents_cache);