From cef4b65070a67ba1afa3359f21c48e4529ac154b Mon Sep 17 00:00:00 2001 From: Michael Meissner Date: Fri, 8 Jul 2016 14:49:37 +0000 Subject: re PR target/71806 (PowerPC -mcpu=power9 enables __float128 without an explicit -mfloat128) [gcc] 2016-07-08 Michael Meissner PR target/71806 * config/rs6000/rs6000-cpus.def (ISA_3_0_MASKS_SERVER): Do not enable -mfloat128-hardware by default. (ISA_3_0_MASKS_IEEE): New macro to give all of the VSX options that IEEE 128-bit hardware support needs. * config/rs6000/rs6000.c (rs6000_option_override_internal): If -mcpu=power9 -mfloat128, enable -mfloat128-hardware by default. Use ISA_3_0_MASKS_IEEE as the set of options that IEEE 128-bit floating point requires. * doc/invoke.texi (RS/6000 and PowerPC Options): Document -mfloat128 and -mfloat128-hardware changes. [gcc/testsuite] 2016-07-08 Michael Meissner PR target/71806 * gcc.target/powerpc/p9-lxvx-stxvx-3.c: Add -mfloat128 option. From-SVN: r238164 --- gcc/doc/invoke.texi | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'gcc/doc') diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index b6398ff..e185178 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -20355,9 +20355,14 @@ hardware instructions. The VSX instruction set (@option{-mvsx}, @option{-mcpu=power7}, or @option{-mcpu=power8}) must be enabled to use the @option{-mfloat128} -option. The @code{-mfloat128} option only works on PowerPC 64-bit +option. The @option{-mfloat128} option only works on PowerPC 64-bit Linux systems. +If you use the ISA 3.0 instruction set (@option{-mcpu=power9}), the +@option{-mfloat128} option will also enable the generation of ISA 3.0 +IEEE 128-bit floating point instructions. Otherwise, IEEE 128-bit +floating point will be done with software emulation. + @item -mfloat128-hardware @itemx -mno-float128-hardware @opindex mfloat128-hardware @@ -20365,6 +20370,13 @@ Linux systems. Enable/disable using ISA 3.0 hardware instructions to support the @var{__float128} data type. +If you use @option{-mfloat128-hardware}, it will enable the option +@option{-mfloat128} as well. + +If you select ISA 3.0 instructions with @option{-mcpu=power9}, but do +not use either @option{-mfloat128} or @option{-mfloat128-hardware}, +the IEEE 128-bit floating point support will not be enabled. + @item -mmodulo @itemx -mno-modulo @opindex mmodulo -- cgit v1.1