Date: Thu, 9 Jan 2020 18:14:48 +0000 (UTC) From: Warner Losh <imp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r356560 - head/share/mk Message-ID: <202001091814.009IEmgS073512@repo.freebsd.org>
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Author: imp Date: Thu Jan 9 18:14:48 2020 New Revision: 356560 URL: https://svnweb.freebsd.org/changeset/base/356560 Log: Add note to remind me there are three choices for arm32 floating point. hard use floating point hardware, pass registers to functions in floating point registers. softfp use floating point hardware, but pass registers to functions in integer registers. soft do floating point calcuations without using floating point hardware. Pass arguments in integer registers. FreeBSD 11 and newer assumes hard. 10 and earlier assumed softfp. We have no real support, at the moment, for soft. It's untested, though, if softfp still works. Add a note here since this is a whack-a-doodle combination relative to all other platforms. softfp is likely to go away in the future because it was retained for people using FreeBSD 10 + armv6 needing to transition more slowly from softfp -> hard than the project. It likely is no longer needed, and may be getting in the way of people needing 'soft' support. Modified: head/share/mk/bsd.cpu.mk Modified: head/share/mk/bsd.cpu.mk ============================================================================== --- head/share/mk/bsd.cpu.mk Thu Jan 9 17:21:00 2020 (r356559) +++ head/share/mk/bsd.cpu.mk Thu Jan 9 18:14:48 2020 (r356560) @@ -355,7 +355,11 @@ MACHINE_CPU += softfp # to force that. .if ${MACHINE_ARCH:Marmv[67]*} && defined(CPUTYPE) && ${CPUTYPE:M*soft*} != "" # Needs to be CFLAGS not _CPUCFLAGS because it's needed for the ABI -# not a nice optimization. +# not a nice optimization. Please note: softfp ABI uses hardware floating +# instructions, but passes arguments to function calls in integer regsiters. +# -mfloat-abi=soft is full software floating point, but is not currently +# supported. softfp support in FreeBSD may disappear in FreeBSD 13.0 since +# it was a transition tool from FreeBSD 10 to 11 and is a bit of an odd duck. CFLAGS += -mfloat-abi=softfp .endif .endif
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