rs6000.c (init_float128_ieee): Remove IEEE 128-bit comparison functions in cmp_optab and ucmp_optab.

2015-12-29  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/rs6000.c (init_float128_ieee): Remove IEEE 128-bit
	comparison functions in cmp_optab and ucmp_optab.
	(rs6000_generate_compare): Rewrite IEEE 128-bit floating point
	software emulation comparisons to only use __eqkf2, __gekf2,
	__lekf2, and __unordkf2 functions.
	(rs6000_invalid_binary_op): Add support for -mfloat128-convert.

	* config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): Define
	__FLOAT128_HARDWARE__ if hardware IEEE 128-bit support is
	available.

	* config/rs6000/rs6000.opt (-mfloat128-convert): Add debug switch
	to allow IBM extended double and IEEE 128-bit floating point to be
	converted with default conversions.

	* config/rs6000/rs6000.md (extendkftf2): Add converters between
	KFmode and TFmode if -mabi=ieeelongdouble.
	(trunctfkf2): Likewise.
	(ieee128_mfvsrd): Split 64-bit integer conversions into 32-bit and
	64-bit insns.
	(ieee128_mfvsrd_64bit): Likewise.
	(ieee128_mfvsrd_32bit): Likewise.
	(ieee128_mtvsrd): Likewise.
	(ieee128_mtvsrd_64bit): Likewise.
	(ieee128_mtvsrd_32bit): Likewise.

	* doc/extend.texi (Floating Types): Document that complex
	__float128 does not work currently.

	* doc/invoke.texi (RS/6000 and PowerPC Options): Document that
	-mfloat128 is only supported on PowerPC 64-bit Linux systems.

From-SVN: r231996

2 files changed, 11 insertions, 12 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 4578925..65b6a96 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -954,22 +954,20 @@ typedef _Complex float __attribute__((mode(TC))) _Complex128;
 typedef _Complex float __attribute__((mode(XC))) _Complex80;
 @end smallexample
 
-On PowerPC Linux, Freebsd and Darwin systems, the default for
-@code{long double} is to use the IBM extended floating point format
-that uses a pair of @code{double} values to extend the precision.
-This means that the mode @code{TCmode} was already used by the
-traditional IBM long double format, and you would need to use the mode
-@code{KCmode}:
+On PowerPC 64-bit Linux systems there are currently problems in using
+the complex @code{__float128} type.  When these problems are fixed,
+you would use:
 
 @smallexample
 typedef _Complex float __attribute__((mode(KC))) _Complex128;
 @end smallexample
 
-Not all targets support additional floating-point types.  @code{__float80}
-and @code{__float128} types are supported on x86 and IA-64 targets.
-The @code{__float128} type is supported on hppa HP-UX.
-The @code{__float128} type is supported on PowerPC systems by default
-if the vector scalar instruction set (VSX) is enabled.
+Not all targets support additional floating-point types.
+@code{__float80} and @code{__float128} types are supported on x86 and
+IA-64 targets.  The @code{__float128} type is supported on hppa HP-UX.
+The @code{__float128} type is supported on PowerPC 64-bit Linux
+systems by default if the vector scalar instruction set (VSX) is
+enabled.
 
 On the PowerPC, @code{__ibm128} provides access to the IBM extended
 double format, and it is intended to be used by the library functions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 4e2cf8f..b85f9b5 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -19690,7 +19690,8 @@ hardware instructions.
 
 The VSX instruction set (@option{-mvsx}, @option{-mcpu=power7}, or
 @option{-mcpu=power8}) must be enabled to use the @option{-mfloat128}
-option.
+option.  The @code{-mfloat128} option only works on PowerPC 64-bit
+Linux systems.
 
 @item -mfloat128-hardware
 @itemx -mno-float128-hardware