[PATCH, V2] Define KFmode constants for libgcc.
This patch defines the constants needed for libgcc for the PowerPC
specific IEEE 128-bit floating point types (KFmode). The 4/28 changes to
libgcc need these constants defined.
We only define the KFmode constants if IEEE 128-bit floating point is
supported, but long double does not use the IEEE 128-bit format. If long
double uses the IEEE 128-bit format, it will use TFmode and not KFmode.
With this patch, we don't have to modify _divkc3.c to use the FLT128
constants. Instead, the -fbuilting-libgcc option will build the appropriate
__LIBGCC_KF_* macros.
I have built a bootstrap compiler on a little endian power9 system and it
finished. Previously it had crashed in building libgcc. I also build a
non-bootstrap compiler where the default long double format is IEEE 128-bit and
it built ok
Can I check this into the trunk for GCC 12?
gcc/
2021-04-29 Michael Meissner <meiss...@linux.ibm.com>
PR bootstrap/100327
* config/rs6000/rs6000.c
(TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): Define.
(rs6000_iibgcc_floating_mode_supported_p): New target hook.
---
gcc/config/rs6000/rs6000.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index cdeb049986f..23485027d85 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1569,6 +1569,10 @@ static const struct attribute_spec
rs6000_attribute_table[] =
#undef TARGET_SCALAR_MODE_SUPPORTED_P
#define TARGET_SCALAR_MODE_SUPPORTED_P rs6000_scalar_mode_supported_p
+#undef TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P
+#define TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P \
+ rs6000_libgccc_floating_mode_supported_p
+
#undef TARGET_VECTOR_MODE_SUPPORTED_P
#define TARGET_VECTOR_MODE_SUPPORTED_P rs6000_vector_mode_supported_p
@@ -24089,6 +24093,31 @@ rs6000_scalar_mode_supported_p (scalar_mode mode)
return default_scalar_mode_supported_p (mode);
}
+/* Target hook for libgcc_floating_mode_supported_p. */
+
+static bool
+rs6000_libgccc_floating_mode_supported_p (scalar_float_mode mode)
+{
+ switch (mode)
+ {
+ case E_SFmode:
+ case E_DFmode:
+ case E_TFmode:
+ return true;
+
+ /* We only return true for KFmode if IEEE 128-bit types are supported,
and
+ if long double does not use the IEEE 128-bit format. If long double
+ uses the IEEE 128-bit format, it will use TFmode and not KFmode.
+ Because the code will not use KFmode in that case, there will be aborts
+ because it can't find KFmode in the Floatn types. */
+ case E_KFmode:
+ return TARGET_FLOAT128_TYPE && !TARGET_IEEEQUAD;
+
+ default:
+ return false;
+ }
+}
+
/* Target hook for vector_mode_supported_p. */
static bool
rs6000_vector_mode_supported_p (machine_mode mode)
--
2.22.0
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
