From: Mike Frysinger <vapier@gentoo.org>
To: Jiri Gaisler <jiri@gaisler.se>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH 04/23] sim/erc32: Add FPU support on x86_64 hosts.
Date: Sun, 22 Feb 2015 04:40:00 -0000 [thread overview]
Message-ID: <20150222044012.GD25220@vapier> (raw)
In-Reply-To: <54E64B65.4050906@gaisler.se>
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On 19 Feb 2015 21:45, Jiri Gaisler wrote:
> On 02/17/2015 10:05 AM, Mike Frysinger wrote:
> > On 17 Feb 2015 08:44, Jiri Gaisler wrote:
> >> * float.c (get_accex) access FPU control and status words on x64
> >
> > shouldn't you gut this file and use <fenv.h> instead for a portable method ?
> > http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fenv.h.html
> >
> > at the very least, you could cut over to <fpu_control.h> ...
>
> I will switch to fenv.h, but this will produce less accurate results
> on Intel hardware. double on SPARC V8 has 53-bit mantissa while Intel has
> both 53- and 64-bit, and 64-bit is default. To get accurate SPARC V8 FPU
> operations, the Intel FPU should be switched to 53-bit, but the fenv.h
> does not have an API for this. I guess we will have to live with that ...
if you wanted to keep a little inline asm to just that particular bit twiddle,
that should be fine.
normally the sims are functional ... but i guess this part of the simulator is
relying on the inaccuracies of floating point to trade for speed ?
-mike
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next prev parent reply other threads:[~2015-02-22 4:40 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-17 7:45 [PATCH 00/22] Update of the SPARC SIS simulator Jiri Gaisler
2015-02-17 7:45 ` [PATCH 02/23] sim/erc32: corrected wrong CPU implementation and version ID in %psr Jiri Gaisler
2015-02-17 11:03 ` Mike Frysinger
2015-02-17 7:45 ` [PATCH 17/23] sim/erc32: Move local extern declarations into sis.h Jiri Gaisler
2015-02-17 7:45 ` [PATCH 04/23] sim/erc32: Add FPU support on x86_64 hosts Jiri Gaisler
2015-02-17 9:05 ` Mike Frysinger
2015-02-19 20:45 ` Jiri Gaisler
2015-02-22 4:40 ` Mike Frysinger [this message]
2015-02-22 21:43 ` Jiri Gaisler
2015-02-17 7:45 ` [PATCH 16/23] sim/erc32: use readline.h for readline types and functions Jiri Gaisler
2015-02-17 9:21 ` Mike Frysinger
2015-02-17 7:45 ` [PATCH 15/23] sim/erc32: access memory subsystem through struct memsys to allow multiple configurations Jiri Gaisler
2015-02-17 7:45 ` [PATCH 01/23] sim/erc32: Disassembly in stand-alone mode did not work due to API change Jiri Gaisler
2015-02-17 11:03 ` Mike Frysinger
2015-02-17 7:45 ` [PATCH 07/23] sim/erc32: file loading via command line did not work Jiri Gaisler
2015-02-17 9:09 ` Mike Frysinger
2015-02-17 7:45 ` [PATCH 10/23] sim/erc32: Switched emulated memory to host endian order Jiri Gaisler
2015-02-17 7:45 ` [PATCH 05/23] sim/erc32: remove unused defines in Makefile and switch off statistics Jiri Gaisler
2015-02-17 11:04 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 11/23] sim/erc32: use AC_C_BIGENDIAN to probe for host endian Jiri Gaisler
2015-02-17 9:19 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 13/23] sim/erc32: Fix a few compiler warnings Jiri Gaisler
2015-02-17 11:08 ` Mike Frysinger
2015-02-18 16:21 ` Jiri Gaisler
2015-02-18 16:51 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 20/23] sim/erc32: Updated documentation Jiri Gaisler
2015-02-17 11:03 ` Mike Frysinger
2015-02-17 15:52 ` Eli Zaretskii
2015-02-17 7:46 ` [PATCH 03/23] sim/erc32: Perform pseudo-init of system if binary starts from non-zero address Jiri Gaisler
2015-02-17 8:59 ` Mike Frysinger
2015-02-18 14:40 ` Jiri Gaisler
2015-02-18 16:53 ` Mike Frysinger
2015-02-19 16:11 ` Jiri Gaisler
2015-02-19 17:48 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 19/23] sim/erc32: Added support for the Leon2 processor Jiri Gaisler
2015-02-17 7:46 ` [PATCH 21/23] sim/erc32: add data watchpoint support for all cpu targets Jiri Gaisler
2015-02-17 7:46 ` [PATCH 18/23] sim/erc32: Add support for LEON3 processor emulation Jiri Gaisler
2015-02-17 15:58 ` Eli Zaretskii
2015-02-17 7:46 ` [PATCH 06/23] sim/erc32: Fix incorrect simulator performance report Jiri Gaisler
2015-02-17 9:07 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 22/23] Added watchpoint support to gdb simulator interface Jiri Gaisler
2015-02-17 7:46 ` [PATCH 09/23] sim/erc32: removed type mismatch compiler warnings Jiri Gaisler
2015-02-17 9:10 ` Mike Frysinger
2015-02-18 14:41 ` Jiri Gaisler
2015-02-18 16:57 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 12/23] sim/erc32: Use separate memory_iread() function for instruction fetching Jiri Gaisler
2015-02-17 7:46 ` [PATCH 08/23] sim/erc32: added -v and -vv command line switches for verbose output Jiri Gaisler
2015-02-17 9:13 ` Mike Frysinger
2015-02-17 7:46 ` [PATCH 14/23] sim/erc32: Use gdb callback for UART I/O when linked with gdb Jiri Gaisler
2015-02-17 8:54 ` [PATCH 00/22] Update of the SPARC SIS simulator Mike Frysinger
2015-02-17 14:41 ` Jiri Gaisler
2015-02-18 0:16 ` Mike Frysinger
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