Date: Mon, 19 Jun 2023 10:21:56 -0600 From: Warner Losh <imp@bsdimp.com> To: Thomas David Rivers <rivers@dignus.com> Cc: freebsd-arm@freebsd.org Subject: Re: -mfloat-abi=soft no longer viable? Message-ID: <CANCZdfrsizJtBpPptqx47%2Bko2=7N1UhUDqx7D8WT5b0pjm10yA@mail.gmail.com> In-Reply-To: <202306191455.35JEtuV0085343@office.dignus.com> References: <202306191455.35JEtuV0085343@office.dignus.com>
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--0000000000009b81b105fe7def47 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Jun 19, 2023 at 8:56=E2=80=AFAM Thomas David Rivers <rivers@dignus.= com> wrote: > > Just curious - I can't seem to find an answer to this question > on-line. > > Seems in 2019 ARM (32-bit) support moved to -mfloat-abi=3Dhard > armv6 and armv7, yes. The legacy armv[45] didn't move, but they've been removed from the tree. > (unless you built your own system?) But, in the postings > I've stumbled over there was mention of /libsoft and /usr/libsoft. > > But - in my recent FreeBSD-13.2 install I don't see those. > > Has this gone away? Is there no way to build a program > with -mfloat-abi=3Dsoft and link with the math library (-lm)? > We switch the default then. For a while we had a soft compat directory as a transition, but have stopped doing that. make buildworld TARGET_ARCH=3Darmv7 CPUTYPE=3Dsoft will give you the old -mfloat=3Dsoft. However, be advised that the -mfloat=3Dsoft means 'use hard floating point code, but pass argument args in integer registers rather than floating point ones'. This is different than what most people think when they think of what -mfloat=3Dsof= t might mean w/o reading the manual. The libsoft stuff you've stumbled upon was the compat libraries that we used to transition from mfloat=3Dsoft to mfloat=3Dhard. Hope that helps. Warner --0000000000009b81b105fe7def47 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">= <div dir=3D"ltr" class=3D"gmail_attr">On Mon, Jun 19, 2023 at 8:56=E2=80=AF= AM Thomas David Rivers <<a href=3D"mailto:rivers@dignus.com">rivers@dign= us.com</a>> wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"m= argin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left= :1ex"><br> Just curious - I can't seem to find an answer to this question<br> on-line.<br> <br> Seems in 2019 ARM (32-bit) support moved to -mfloat-abi=3Dhard<br></blockqu= ote><div><br></div><div>armv6 and armv7, yes. The legacy armv[45] didn'= t move, but they've been</div><div>removed from the tree.</div><div>=C2= =A0=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0p= x 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> (unless you built your own system?)=C2=A0 =C2=A0But, in the postings <br> I've stumbled over there was mention of /libsoft and /usr/libsoft.<br> <br> But - in my recent FreeBSD-13.2 install I don't see those.<br> <br> Has this gone away?=C2=A0 Is there no way to build a program<br> with -mfloat-abi=3Dsoft and link with the math library (-lm)?<br></blockquo= te><div><br></div><div>We switch the default then. For a while we had a sof= t compat directory as</div><div>a transition, but have stopped doing that.<= /div><div><br></div><div>make buildworld TARGET_ARCH=3Darmv7 CPUTYPE=3Dsoft= </div><div><br></div><div>will give you the old -mfloat=3Dsoft. However, be= advised that the</div><div>-mfloat=3Dsoft means 'use hard floating poi= nt code, but pass argument</div><div>args in integer registers rather than = floating point ones'. This is</div><div>different than what most people= think when they think of what -mfloat=3Dsoft</div><div>might mean w/o read= ing the manual.=C2=A0</div><div><br></div><div>The libsoft stuff you've= stumbled upon was the compat libraries</div><div>that we used to transitio= n from mfloat=3Dsoft to mfloat=3Dhard.</div><div><br></div><div>Hope that h= elps.</div><div><br></div><div>Warner</div></div></div> --0000000000009b81b105fe7def47--
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