Date: Wed, 17 Dec 1997 14:28:37 -0600 (CST) From: Dave Bodenstab <imdave@mcs.net> To: questions@FreeBSD.org Subject: Cyrex floating point problem? Message-ID: <199712172028.OAA18268@base486.home.org>
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I've got a new pc (built from used parts) and it has a Cyrix cpu. Everything is working (dos/windows/fbsd 2.2.5) with one glaring problem. When I run a floating point intensive program such as povray, I get intermittent SIGFPE core dumps. The same input, the same program, etc. sometimes works, and other times core dumps. If I just run pov and don't touch the machine until it finishes, my success rate increases. My guess is that there's some problem with context switching and saving/restoring the FP state. Or else there's some problem handling masked FP exceptions... Any ideas? Here are snippets from the boot probes and kernel config: /var/log/messages: Dec 17 02:09:20 base586 /kernel.new: Copyright (c) 1992-1997 FreeBSD Inc. Dec 17 02:09:20 base586 /kernel.new: Copyright (c) 1982, 1986, 1989, 1991, 1993 Dec 17 02:09:20 base586 /kernel.new: The Regents of the University of California. All rights reserved. Dec 17 02:09:20 base586 /kernel.new: Dec 17 02:09:20 base586 /kernel.new: FreeBSD 2.2.5-RELEASE #4: Wed Dec 17 01:44:04 CST 1997 Dec 17 02:09:20 base586 /kernel.new: bin@base586.home.org:/usr/src/sys/compile/base586 Dec 17 02:09:20 base586 /kernel.new: CPU: Cyrix 6x86 (486-class CPU) Dec 17 02:09:20 base586 /kernel.new: Origin = "CyrixInstead" DIR=0x1631 Stepping=1 Revision=6 Dec 17 02:09:21 base586 /kernel.new: CPU cache: write-through mode Dec 17 02:09:21 base586 /kernel.new: real memory = 33554432 (32768K bytes) Dec 17 02:09:21 base586 /kernel.new: avail memory = 30474240 (29760K bytes) Dec 17 02:09:21 base586 /kernel.new: Probing for devices on PCI bus 0: Dec 17 02:09:21 base586 /kernel.new: chip0 <Intel 82437VX PCI cache memory controller> rev 2 on pci0:0 Dec 17 02:09:21 base586 /kernel.new: chip1 <Intel 82371SB PCI-ISA bridge> rev 1 on pci0:7:0 Dec 17 02:09:21 base586 /kernel.new: chip2 <Intel 82371SB IDE interface> rev 0 on pci0:7:1 Dec 17 02:09:21 base586 /kernel.new: vga0 <VGA-compatible display device> rev 1 int a irq ?? on pci0:10 Dec 17 02:09:21 base586 /kernel.new: Probing for devices on the ISA bus: Dec 17 02:09:22 base586 /kernel.new: npx0 on motherboard Dec 17 02:09:22 base586 /kernel.new: npx0: INT 16 interface kernel config: machine "i386" cpu "I486_CPU" options "AUTO_EOI_1" options BOUNCE_BUFFERS device npx0 at isa? port "IO_NPX" iosiz 0x0 flags 0x0 irq 13 vector npxintr The comments in LINT about the npx flags imply that they do not apply to me since I do not have "I586_CPU" as an option. Dave Bodenstab imdave@mcs.net
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