[PATCH] Support _Complex in hard-VFP abi

Yao Qi
2014-08-11T12:56:34Z

Hi,
When we pass "-mfloat-abi=hard" flag in the GDB testing, we see the
following fails,

FAIL: gdb.base/callfuncs.exp: p t_float_complex_values(fc1, fc2)
FAIL: gdb.base/callfuncs.exp: p t_float_complex_many_args(fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4, fc1, fc2, fc3, fc4)
FAIL: gdb.base/callfuncs.exp: p t_double_complex_values(dc1, dc2)
FAIL: gdb.base/callfuncs.exp: p t_double_complex_many_args(dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_values(ldc1, ldc2)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_many_args(ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4)
FAIL: gdb.base/callfuncs.exp: call inferior func with struct - returns float _Complex
FAIL: gdb.base/callfuncs.exp: call inferior func with struct - returns double _Complex

The hard-VFP ABI was supported by GDB overal, done by this patch
https://sourceware.org/ml/gdb-patches/2009-07/msg00686.html but
"vectors and complex types are not currently supported", mentioned in
the patch. As a result, these tests fail.

This patch is to support _Complex types in hard-VFP abi. As specified
in "7.1.1, Procedure Call Standard for the ARM Arch", the layout of
_Complex types is a struct, which is identical to the layout on amd64,
so I copy Mark's comments to amd64 support.

Regression tested on arm-none-eabi target. OK to apply?

gdb:

2014-08-11 Yao Qi <yao@codesourcery.com>

* arm-tdep.c (arm_vfp_cprc_sub_candidate): Handle _Complex
types.
---
gdb/arm-tdep.c | 34 ++++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index b6ec456..10e74cf 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -3557,8 +3557,8 @@ arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b)
classified from *BASE_TYPE, or two types differently classified
from each other, return -1, otherwise return the total number of
base-type elements found (possibly 0 in an empty structure or
- array). Vectors and complex types are not currently supported,
- matching the generic AAPCS support. */
+ array). Vectors types are not currently supported, matching the
+ generic AAPCS support. */

static int
arm_vfp_cprc_sub_candidate (struct type *t,
@@ -3589,6 +3589,36 @@ arm_vfp_cprc_sub_candidate (struct type *t,
}
break;

+ case TYPE_CODE_COMPLEX:
+ /* Arguments of complex T where T is one of the types float or
+ double get treated as if they are implemented as:
+
+ struct complexT
+ {
+ T real;
+ T imag;
+ };*/
+ switch (TYPE_LENGTH (t))
+ {
+ case 8:
+ if (*base_type == VFP_CPRC_UNKNOWN)
+ *base_type = VFP_CPRC_SINGLE;
+ else if (*base_type != VFP_CPRC_SINGLE)
+ return -1;
+ return 2;
+
+ case 16:
+ if (*base_type == VFP_CPRC_UNKNOWN)
+ *base_type = VFP_CPRC_DOUBLE;
+ else if (*base_type != VFP_CPRC_DOUBLE)
+ return -1;
+ return 2;
+
+ default:
+ return -1;
+ }
+ break;
+
case TYPE_CODE_ARRAY:
{
int count;
--
1.9.0