From: Tom Musta <tommusta@gmail.com>
To: QEMU Developers <qemu-devel@nongnu.org>,
"qemu-ppc@nongnu.org" <qemu-ppc@nongnu.org>
Subject: [Qemu-devel] PowerPC Decimal Floating Point
Date: Tue, 11 Feb 2014 11:14:13 -0600 [thread overview]
Message-ID: <52FA5A65.5080004@gmail.com> (raw)
QEMU is currently lacking support for the Decimal Floating Point category of instructions
(see Power ISA V2.07 Chapter 6). I intend to add this support.
Has this topic been investigated before and if so can anyone point me to that discussion?
A Google search came up empty for me.
My proposal is to incorporate the libdecnumber component of libdfp
(http://www.eglibc.org/cgi-bin/viewvc.cgi/libdfp/trunk/) in a manner analogous to how
softfloat is used for binary floating point. So, for example, the helper for the dadd
instruction would look something like the following:
- map FPSCR state to a decContext.
- convert the contents of the source FPRs to decNumbers (decimal64ToNumber).
- call decNumberAdd
- convert the resultant decNumber to DPD (decimal64FromNumber)
- update FPSCR per the decContext.status and result.
Comments?
next reply other threads:[~2014-02-11 17:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-11 17:14 Tom Musta [this message]
2014-02-12 7:38 ` [Qemu-devel] [Qemu-ppc] PowerPC Decimal Floating Point Alexander Graf
2014-02-14 21:22 ` Richard Henderson
2014-02-14 22:22 ` Tom Musta
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