den@hpfinote.HP.COM (Don Novy) (06/06/90)
I have read some articles about the 68040 and am confused about one point. Why have the fcmp and fbcc instructions been eliminated from the floating point unit? I have found these instructions to be VERY helpful in speeding up some double precision floating point intensive software. One program was sped up by 23% by using fcmp and fbcc instead of 68020 instructions (cmp.l). Any ideas? Don Novy Hewlett-Packard den@hpfitst2.hp.com
eric@oakhill.UUCP (Eric Quintana) (06/09/90)
In article <16340002@hpfinote.HP.COM> den@hpfinote.HP.COM (Don Novy) writes: > > I have read some articles about the 68040 and am confused about one point. >Why have the fcmp and fbcc instructions been eliminated from the floating point >unit? > > Don Novy FCMP and FBcc have not been eliminated. They are fully implemented. Eric Quintana ...!cs.utexas.edu!oakhill!eric
dfields@neutrino.urbana.mcd.mot.com (David Fields) (06/14/90)
In article <16340002@hpfinote.HP.COM>, den@hpfinote.HP.COM (Don Novy) writes: |> |> I have read some articles about the 68040 and am confused about one point. |>Why have the fcmp and fbcc instructions been eliminated from the floating point |>unit? I have found these instructions to be VERY helpful in speeding up some |>double precision floating point intensive software. One program was sped up by |>23% by using fcmp and fbcc instead of 68020 instructions (cmp.l). I'm not sure which execution unit the fcmp and fbcc instructions are in but according to the '040 manual I've got on my desk, the instructions are still implemented in hardware. Dave Fields // Motorola MCD // uiucuxc!udc!dfields // dfields@urbana.mcd.mot.com