SUN-4 FPU
Marcel Bernards
mcvax!ecn!marcel at uunet.uu.net
Sun Feb 19 12:27:52 AEST 1989
In article <MONTNARO.89Feb1125820 at sprite.steinmetz.ge.com> montanaro at sprite.steinmetz.ge.com writes:
>The Sun-4 compilers always assume that an FPU is installed. Without an FPU
>(as on Bruce Barnett's Sun-4/110) attempts to execute FP instructions
>cause a trap to the kernel, where they are then executed in software...
This is not quite true.
I tried some testprograms on our 4/110 and our 4/280S SUN. The 4/110 is
delivered without FPU yes -> ;-(
The test program (from barnett at steinmetz.ge.com (Bruce Barnett)) I tested
results in the following data
SUN 4/280-S Weitec Co's
f=100000
0.2u 0.2s 0:00 68% 0+248k 9+0io 5pf+0w
SUN 4/110 NOCO
f=100000
1.2u 31.1s 0:32 99% 0+136k 2+9io 2pf+0w
SUN 3/50 68881 Diskless
f=100000
7.5u 2.2s 0:18 53% 0+96k 5+0io 7pf+0w
SUN 3/60 COLOR W SCSI + 68881
f=100000
4.4u 1.1s 0:06 84% 0+96k 2+1io 2pf+0w
I used the following program with csh time command
main() {
int i = 100000;
double f = 0.0;
while (i--) f += 1.0;
printf("f=%g\n",f);
}
So SUN 4/110 _does_ emulate FP .
But VERY VERY SLOOOOOOOOW !!!!!!!!!!!
I think i'm gonna screw some budgets there ordering FPU for a 4/110 :-)
Marcel Bernards, UNIX & Net sysadm Netherlands Energy Research Foundation ECN
P.O. Box 1, 1755 ZG Petten, UUCP: marcel at ecn.UUCP, marcel%ecn.uucp at uunet.uu.net
PHONE: -31 2246 4342 ,EARN: ESU0130 at HPEENR51L
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