As the existing comment explains, we should always promote function
arguments and return values. However, notwithstanding its name,
default_promote_function_mode_always_promote does not always promote.
Importantly, it does not for libcalls. This makes ftrapv-[12].c fail
with 64-bit ABIs.
This patch introduces an rs6000_promote_function_mode that _does_
always promote, fixing this.
Tested as usual (c,c++,fortran,ada; -m32,-m32/-mpowerpc64,-m64,-m64/-mlra).
Is this okay for mainline?
Segher
2015-01-08 Segher Boessenkool <seg...@kernel.crashing.org>
gcc/
* config/rs6000/rs6000.c (TARGET_PROMOTE_FUNCTION_MODE): Implement
as rs6000_promote_function_mode. Move comment to there.
(rs6000_promote_function_mode): New function.
---
gcc/config/rs6000/rs6000.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
index e2bfcd6..66a1399 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1498,10 +1498,8 @@ static const struct attribute_spec
rs6000_attribute_table[] =
#undef TARGET_MEMBER_TYPE_FORCES_BLK
#define TARGET_MEMBER_TYPE_FORCES_BLK rs6000_member_type_forces_blk
-/* On rs6000, function arguments are promoted, as are function return
- values. */
#undef TARGET_PROMOTE_FUNCTION_MODE
-#define TARGET_PROMOTE_FUNCTION_MODE
default_promote_function_mode_always_promote
+#define TARGET_PROMOTE_FUNCTION_MODE rs6000_promote_function_mode
#undef TARGET_RETURN_IN_MEMORY
#define TARGET_RETURN_IN_MEMORY rs6000_return_in_memory
@@ -9295,6 +9293,19 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype,
}
}
+/* On rs6000, function arguments are promoted, as are function return
+ values. */
+static machine_mode
+rs6000_promote_function_mode (const_tree, machine_mode mode, int *,
+ const_tree, int)
+{
+ if (GET_MODE_CLASS (mode) == MODE_INT
+ && GET_MODE_SIZE (mode) < GET_MODE_SIZE (Pmode))
+ return Pmode;
+
+ return mode;
+}
+
/* Return true if TYPE must be passed on the stack and not in registers. */
static bool
--
1.8.1.4
