Re: [PATCH 1/3] [AArch64] Support gnu vector in inferior call

Yao Qi
2015-11-20T16:35:31Z

Pedro Alves <palves@redhat.com> writes:

>> + 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);
>
> Indentation looks odd here.

Ur, sorry. Patch is updated.

--
Yao (齐尧)

From: Yao Qi <yao.qi@linaro.org>
Subject: [PATCH] [AArch64] Support gnu vector in inferior call

As defined in AArch64 AAPCS, short vectors are passed through V
registers, and its maximum alignment is 16-byte. This patch is
to reflect these rules in GDB. This patch fixes some fails in
gdb.base/gnu_vector.exp.

gdb:

2015-11-20 Yao Qi <yao.qi@linaro.org>

* aarch64-tdep.c (aarch64_type_align): For vector type, return
its length, but with the maximum of 16 bytes.
(is_hfa): Return zero for vector type.
(aarch64_push_dummy_call): Handle short vectors.
(aarch64_extract_return_value): Likewise.
(aarch64_store_return_value): Likewise.

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index de85cb0..8ce0eaa 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -894,6 +894,17 @@ aarch64_type_align (struct type *t)
return TYPE_LENGTH (t);

case TYPE_CODE_ARRAY:
+ if (TYPE_VECTOR (t))
+ {
+ /* Use the natural alignment for vector types (the same for
+ scalar type), but the maximum alignment is 128-bit. */
+ if (TYPE_LENGTH (t) > 16)
+ return 16;
+ else
+ return TYPE_LENGTH (t);
+ }
+ else
+ return aarch64_type_align (TYPE_TARGET_TYPE (t));
case TYPE_CODE_COMPLEX:
return aarch64_type_align (TYPE_TARGET_TYPE (t));

@@ -921,6 +932,10 @@ is_hfa (struct type *ty)
case TYPE_CODE_ARRAY:
{
struct type *target_ty = TYPE_TARGET_TYPE (ty);
+
+ if (TYPE_VECTOR (ty))
+ return 0;
+
if (TYPE_CODE (target_ty) == TYPE_CODE_FLT && TYPE_LENGTH (ty) <= 4)
return 1;
break;
@@ -1318,6 +1333,12 @@ aarch64_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
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)
{
/* PCS B.7 Aggregates larger than 16 bytes are passed by
@@ -1643,6 +1664,15 @@ aarch64_extract_return_value (struct type *type, struct regcache *regs,
valbuf += len;
}
}
+ else if (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
+ && (TYPE_LENGTH (type) == 16 || TYPE_LENGTH (type) == 8))
+ {
+ /* Short vector is returned in V register. */
+ gdb_byte buf[V_REGISTER_SIZE];
+
+ regcache_cooked_read (regs, AARCH64_V0_REGNUM, buf);
+ memcpy (valbuf, buf, TYPE_LENGTH (type));
+ }
else
{
/* For a structure or union the behaviour is as if the value had
@@ -1772,6 +1802,15 @@ aarch64_store_return_value (struct type *type, struct regcache *regs,
valbuf += len;
}
}
+ else if (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
+ && (TYPE_LENGTH (type) == 8 || TYPE_LENGTH (type) == 16))
+ {
+ /* Short vector. */
+ gdb_byte buf[V_REGISTER_SIZE];
+
+ memcpy (buf, valbuf, TYPE_LENGTH (type));
+ regcache_cooked_write (regs, AARCH64_V0_REGNUM, buf);
+ }
else
{
/* For a structure or union the behaviour is as if the value had