[PATCH 2/4] Aarch64: Float register detection for _push_dummy_call
Alan Hayward
alan.hayward@arm.com
Mon Aug 20 09:30:00 GMT 2018
Use aapcs_is_vfp_call_or_return_candidate to detect float register
args, then pass in registers if there is room.
pass_in_v_or_stack is no longer used. Remove it.
2018-08-20 Alan Hayward <alan.hayward@arm.com>
* aarch64-tdep.c
(aapcs_is_vfp_call_or_return_candidate): Make static
(pass_in_v_or_stack): Remove function.
(pass_in_v_vfp_candidate): New function.
(aarch64_push_dummy_call): Check for float register candidates.
---
gdb/aarch64-tdep.c | 149 +++++++++++++++++++++++++++--------------------------
1 file changed, 75 insertions(+), 74 deletions(-)
diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index d3ea13f6f6..45dde8a37e 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -1329,7 +1329,7 @@ aapcs_is_vfp_call_or_return_candidate_1 (struct type *type,
Note that HFAs and HVAs can include nested structures and arrays. */
-bool
+static bool
aapcs_is_vfp_call_or_return_candidate (struct type *type, int *count,
struct type **fundamental_type)
{
@@ -1522,19 +1522,57 @@ pass_in_x_or_stack (struct gdbarch *gdbarch, struct regcache *regcache,
}
}
-/* Pass a value in a V register, or on the stack if insufficient are
- available. */
-
-static void
-pass_in_v_or_stack (struct gdbarch *gdbarch,
- struct regcache *regcache,
- struct aarch64_call_info *info,
- struct type *type,
- struct value *arg)
+/* Pass a value, which is of type arg_type, in a V register. Assumes value is a
+ aapcs_is_vfp_call_or_return_candidate and there are enough spare V
+ registers. A return value of false is an error state as the value will have
+ been partially passed to the stack. */
+static bool
+pass_in_v_vfp_candidate (struct gdbarch *gdbarch, struct regcache *regcache,
+ struct aarch64_call_info *info, struct type *arg_type,
+ struct value *arg)
{
- if (!pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (type),
- value_contents (arg)))
- pass_on_stack (info, type, arg);
+ switch (TYPE_CODE (arg_type))
+ {
+ case TYPE_CODE_FLT:
+ return pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (arg_type),
+ value_contents (arg));
+ break;
+
+ case TYPE_CODE_COMPLEX:
+ {
+ const bfd_byte *buf = value_contents (arg);
+ struct type *target_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
+
+ if (!pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (target_type),
+ buf))
+ return false;
+
+ return pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (target_type),
+ buf + TYPE_LENGTH (target_type));
+ }
+
+ case TYPE_CODE_ARRAY:
+ if (TYPE_VECTOR (arg_type))
+ return pass_in_v (gdbarch, regcache, info, TYPE_LENGTH (arg_type),
+ value_contents (arg));
+ /* fall through. */
+
+ case TYPE_CODE_STRUCT:
+ case TYPE_CODE_UNION:
+ for (int i = 0; i < TYPE_NFIELDS (arg_type); i++)
+ {
+ struct value *field = value_primitive_field (arg, 0, i, arg_type);
+ struct type *field_type = check_typedef (value_type (field));
+
+ if (!pass_in_v_vfp_candidate (gdbarch, regcache, info, field_type,
+ field))
+ return false;
+ }
+ return true;
+
+ default:
+ return false;
+ }
}
/* Implement the "push_dummy_call" gdbarch method. */
@@ -1623,12 +1661,33 @@ aarch64_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
for (argnum = 0; argnum < nargs; argnum++)
{
struct value *arg = args[argnum];
- struct type *arg_type;
- int len;
+ struct type *arg_type, *fundamental_type;
+ int len, elements;
arg_type = check_typedef (value_type (arg));
len = TYPE_LENGTH (arg_type);
+ /* If arg can be passed in v registers as per the AAPCS64, then do so if
+ if there are enough spare registers. */
+ if (aapcs_is_vfp_call_or_return_candidate (arg_type, &elements,
+ &fundamental_type))
+ {
+ if (info.nsrn + elements <= 8)
+ {
+ /* We know that we have sufficient registers available therefore
+ this will never need to fallback to the stack. */
+ if (!pass_in_v_vfp_candidate (gdbarch, regcache, &info, arg_type,
+ arg))
+ error (_("Failed to push args"));
+ }
+ else
+ {
+ info.nsrn = 8;
+ pass_on_stack (&info, arg_type, arg);
+ }
+ continue;
+ }
+
switch (TYPE_CODE (arg_type))
{
case TYPE_CODE_INT:
@@ -1648,68 +1707,10 @@ aarch64_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
pass_in_x_or_stack (gdbarch, regcache, &info, arg_type, arg);
break;
- case TYPE_CODE_COMPLEX:
- if (info.nsrn <= 6)
- {
- const bfd_byte *buf = value_contents (arg);
- struct type *target_type =
- check_typedef (TYPE_TARGET_TYPE (arg_type));
-
- pass_in_v (gdbarch, regcache, &info,
- TYPE_LENGTH (target_type), buf);
- pass_in_v (gdbarch, regcache, &info,
- TYPE_LENGTH (target_type),
- buf + TYPE_LENGTH (target_type));
- }
- else
- {
- info.nsrn = 8;
- pass_on_stack (&info, arg_type, arg);
- }
- break;
- case TYPE_CODE_FLT:
- pass_in_v_or_stack (gdbarch, regcache, &info, arg_type, arg);
- break;
-
case TYPE_CODE_STRUCT:
case TYPE_CODE_ARRAY:
case TYPE_CODE_UNION:
- if (is_hfa_or_hva (arg_type))
- {
- int elements = TYPE_NFIELDS (arg_type);
-
- /* Homogeneous Aggregates */
- if (info.nsrn + elements < 8)
- {
- int i;
-
- for (i = 0; i < elements; i++)
- {
- /* We know that we have sufficient registers
- available therefore this will never fallback
- to the stack. */
- struct value *field =
- value_primitive_field (arg, 0, i, arg_type);
- struct type *field_type =
- check_typedef (value_type (field));
-
- pass_in_v_or_stack (gdbarch, regcache, &info,
- field_type, field);
- }
- }
- else
- {
- info.nsrn = 8;
- pass_on_stack (&info, arg_type, arg);
- }
- }
- else if (TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
- && TYPE_VECTOR (arg_type) && (len == 16 || len == 8))
- {
- /* Short vector types are passed in V registers. */
- pass_in_v_or_stack (gdbarch, regcache, &info, arg_type, arg);
- }
- else if (len > 16)
+ if (len > 16)
{
/* PCS B.7 Aggregates larger than 16 bytes are passed by
invisible reference. */
--
2.15.2 (Apple Git-101.1)
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