[PATCH] PowerPC: Set long double size for IBM/IEEE.
I originally posted this patch to an internal IBM mailing list instead of
gcc-patches.
As I was working with compilers where the long double default was 64-bit, it
became annoying to have to use two options to switch to one of the 128-bit long
double types (i.e. you need both -mlong-double-128 and the
-mabi={ieee,ibm}longdouble to switch the long double type).
I did this patch so that if you explicitly set the long double ABI via the
-mabi= option, it would automatically set the long double size if that was not
set explicitly.
gcc/
2020-11-17 Michael Meissner <meiss...@linux.ibm.com>
* config/rs6000/rs6000.c (rs6000_option_override_internal): If the
user explicitly used -mabi=ieeelongdouble or -mabi=ibmlongdouble,
set the long double size to 128.
* doc/invoke.texi (PowerPC options): Document that an explicit
-mabi=ieeelongdouble or -mabi=ibmlongdouble implicitly sets
-mlong-double-128.
---
gcc/config/rs6000/rs6000.c | 9 +++++++--
gcc/doc/invoke.texi | 7 ++++---
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 35e9c844e17..6edd17a0b69 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -4131,8 +4131,13 @@ rs6000_option_override_internal (bool global_init_p)
/* Use long double size to select the appropriate long double. We use
TYPE_PRECISION to differentiate the 3 different long double types. We map
- 128 into the precision used for TFmode. */
- int default_long_double_size = (RS6000_DEFAULT_LONG_DOUBLE_SIZE == 64
+ 128 into the precision used for TFmode.
+
+ If the user explicitly used -mabi=ieeelongdouble or -mabi=ibmlongdouble,
+ but the compiler was configured for default 64-bit long doubles, set the
+ long double to be 128. */
+ int default_long_double_size = ((RS6000_DEFAULT_LONG_DOUBLE_SIZE == 64
+ && !global_options_set.x_rs6000_ieeequad)
? 64
: FLOAT_PRECISION_TFmode);
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 3510a54c6c4..89d530f1d1e 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -27113,7 +27113,8 @@ Change the current ABI to use IBM extended-precision
long double.
This is not likely to work if your system defaults to using IEEE
extended-precision long double. If you change the long double type
from IEEE extended-precision, the compiler will issue a warning unless
-you use the @option{-Wno-psabi} option. Requires @option{-mlong-double-128}
+you use the @option{-Wno-psabi} option. If this option is used, it
+will implicitly enable @option{-mlong-double-128}.
to be enabled.
@item -mabi=ieeelongdouble
@@ -27122,8 +27123,8 @@ Change the current ABI to use IEEE extended-precision
long double.
This is not likely to work if your system defaults to using IBM
extended-precision long double. If you change the long double type
from IBM extended-precision, the compiler will issue a warning unless
-you use the @option{-Wno-psabi} option. Requires @option{-mlong-double-128}
-to be enabled.
+you use the @option{-Wno-psabi} option. If this option is used, it
+will implicitly enable @option{-mlong-double-128}.
@item -mabi=elfv1
@opindex mabi=elfv1
--
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
