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From: Roland M. <rol...@nr...> - 2014-02-24 14:26:19
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On Mon, Feb 24, 2014 at 11:02 AM, Julian Seward <js...@ac...> wrote: > >>>> But of course, we all agree it would be nice to have 80 bits floats >>>> properly supported by Valgrind. > > To support this for 64-bit processes would require, roughly: > > * add an F80 (80-bit floating point) type to IR > * add relevant 80-bit equivalents of the relevant IROps > (AddF80, SubF80, SinF80, etc) > * change the front end (guest_amd64_toIR.c) to generate > IR that uses those new IROps > * change the back end (host_amd64_isel.c) to generate 80 > bit FP instructions from that IR. > > Much of the back end stuff could be imported from the x86 (32-bit) > compilation pipeline. That already has machinery to generate > x87 code and in particular to deal with the x87 register-stack > wierdness. > > That would get a baseline simulator (--tool=none) that works OK, > Getting Memcheck to work requires extra steps: [snip] Just curious: Does valgrind have 128bit floating-point support somewhere? If "yes" ... could core parts of it be adopted/"dumbed down" to do some of the 80bit parts ? ---- Bye, Roland -- __ . . __ (o.\ \/ /.o) rol...@nr... \__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer /O /==\ O\ TEL +49 641 3992797 (;O/ \/ \O;) |
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From: Florian K. <fl...@ei...> - 2014-02-24 15:14:04
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On 02/24/2014 03:26 PM, Roland Mainz wrote: > On Mon, Feb 24, 2014 at 11:02 AM, Julian Seward <js...@ac...> wrote: > > Just curious: > Does valgrind have 128bit floating-point support somewhere? If "yes" > ... could core parts of it be adopted/"dumbed down" to do some of the > 80bit parts ? The s390 port supports 128-bit floating point. You could look at that for how it is integrated. But it won't buy you much otherwise. The problem with this task is not that it is difficult. The issue is that it is mostly busy work and the testing part is as unsexy as it is important. Maybe somebody with ties into Intel or AMD can convince them to sponsor a person to do the work.... Florian |