[PATCH] gdb/riscv: Handle passing variadic floating point arguments

[Andrew Burgess]

This commit fixes some test failures in gdb.base/varargs.exp when
running on targets with floating point hardware. Floating point
unnamed (variadic) arguments should be passed in integer registers
according to the abi.

After this commit I see no failures in gdb.base/varargs.exp on 32 or
64 bit targets with floating point hardware.

gdb/ChangeLog:

* riscv-tdep.c (riscv_call_arg_scalar_float): Unnamed (variadic)
arguments are passed in integer registers.
(riscv_call_arg_complex_float): Likewise.
---
gdb/ChangeLog | 6 ++++++
gdb/riscv-tdep.c | 5 +++--
2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index da4d61dc856..127cef66d36 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
[phone] Andrew Burgess <***@embecosm.com>
+
+ * riscv-tdep.c (riscv_call_arg_scalar_float): Unnamed (variadic)
+ arguments are passed in integer registers.
+ (riscv_call_arg_complex_float): Likewise.
+
2018-12-05 Andrew Burgess <***@embecosm.com>

* riscv-tdep.c (riscv_features_from_gdbarch_info): New function.
diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index d812b7c8693..fafb0d15d8a 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -1935,7 +1935,7 @@ static void
riscv_call_arg_scalar_float (struct riscv_arg_info *ainfo,
struct riscv_call_info *cinfo)
{
- if (ainfo->length > cinfo->flen)
+ if (ainfo->length > cinfo->flen || ainfo->is_unnamed)
return riscv_call_arg_scalar_int (ainfo, cinfo);
else
{
@@ -1955,7 +1955,8 @@ riscv_call_arg_complex_float (struct riscv_arg_info *ainfo,
struct riscv_call_info *cinfo)
{
if (ainfo->length <= (2 * cinfo->flen)
- && riscv_arg_regs_available (&cinfo->float_regs) >= 2)
+ && riscv_arg_regs_available (&cinfo->float_regs) >= 2
+ && !ainfo->is_unnamed)
{
bool result;
int len = ainfo->length / 2;