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From: Tejas Joshi <tejasjoshi9673@gmail.com>
To: gcc@gcc.gnu.org
Cc: Martin Jambor <mjambor@suse.cz>, hubicka@ucw.cz, joseph@codesourcery.com
Subject: [GSoC-19] Expanding fromfp variants on AArch64
Date: Mon, 19 Aug 2019 11:01:00 -0000	[thread overview]
Message-ID: <CACMrGjBWoU3Ao8sTCiBpNQqGNSO5c6Ezq7goqsGXu-EXiySZzw@mail.gmail.com> (raw)

Hello.
The fromfp/fromfpx variants round to integers with a specified number
of bits, to a specified rounding mode. They come with their own
complications as Joseph had stated in an initial mail and expected to
expand them in AArch64 :

> The fromfp / fromfpx / ufromfp / ufromfpx functions (round to integers
> of a specified number of bits, in a specified rounding mode, with
> specified handling of inexact results) are a case with some other
> complications.  Typically I'd expect them to be expanded inline only (for
> constant arguments or) for constant values of the number of bits and
> rounding mode, if the target machine has an appropriate instruction.  A
> target hook would need adding for a target to specify the FP_INT_* values
> used in libm, since that's an ABI that's defined by libm, not by GCC.
> Then you'd need instruction patterns that might only be supported in
> certain cases.

How can I add a target hook to specify the FP_INT_* values from libm ?
Also as this includes rounding to integers, does it involve any RTL
related complications that we have encountered in FADD ?

Thanks,
Tejas

             reply	other threads:[~2019-08-19 11:01 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-19 11:01 Tejas Joshi [this message]
2019-08-19 14:43 ` Joseph Myers

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