Use system default for long double if not specified on PowerPC.
If the user did not specify a default long double format, use the long double
default for the build compiler for the long double default. This patch will
allow compilers built on a distribution that has changed the 128-bit floating
point format to use the default used on the system.
I did a normal normal bootstrap and make check regression on a little
endian power9 system and there were no regressions.
In addition, I built a compiler where I configured the default to use IEEE
128-bit floating point for long double. I then used that compiler to
build a bootstrap with this patch applied and I did not set the floating
point format. I verified that the compiler built with this patch defaults
long double to be IEEE 128-bit.
Can I apply this patch to the trunk for GCC 12?
gcc/
2022-01-12 Michael Meissner <meiss...@the-meissners.org>
* config/rs6000/rs6000.c (TARGET_IEEEQUAD_DEFAULT): If the
compiler used to build this compiler defaults long double to IEEE
128-bit, then make it the default for the target.
---
gcc/config/rs6000/rs6000.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 0e3481c8327..e59f7aa49c8 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -91,14 +91,22 @@
explicitly redefine TARGET_IEEEQUAD and TARGET_IEEEQUAD_DEFAULT to 0, so
those systems will not pick up this default. This needs to be after all
of the include files, so that POWERPC_LINUX and POWERPC_FREEBSD are
- properly defined. */
+ properly defined.
+
+ If we are being built by a compiler that uses IEEE 128-bit as the default
+ long double and no explicit long double format was selected, then also
+ default long double to IEEE 128-bit. */
#ifndef TARGET_IEEEQUAD_DEFAULT
#if !defined (POWERPC_LINUX) && !defined (POWERPC_FREEBSD)
#define TARGET_IEEEQUAD_DEFAULT 1
#else
+#ifdef __LONG_DOUBLE_IEEE128__
+#define TARGET_IEEEQUAD_DEFAULT 1
+#else
#define TARGET_IEEEQUAD_DEFAULT 0
#endif
#endif
+#endif
/* Don't enable PC-relative addressing if the target does not support it. */
#ifndef PCREL_SUPPORTED_BY_OS
--
2.34.1
--
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meiss...@linux.ibm.com
