Re: delayed branch (in 88k GCC)

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Article #1818

#1818

From: Andrew Klossner
Date: Fri, 11 Aug 1989 19:26

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Dave Lord (lord@se-sd.NCR.COM) writes:

	"I've looked at code generated by three different compilers for
	the 88K (GreenHills, GNU, & LPI) and I don't believe any of
	them EVER put a useful instruction in the delayed branch slot."

The GNU-88k compiler as developed at Data General does a pretty good
job of filling branch delay slots, if you remember to include the -O
(optimize) option.  In a random sample of one big file (malloc.c), I
found that 37 out of 82 branches did useful work in the delay slot
(i.e., the "opcode.n" form of the branch was emitted).

  -=- Andrew Klossner   (uunet!tektronix!frip.WV.TEK!andrew)    [UUCP]
                        (andrew%frip.wv.tek.com@relay.cs.net)   [ARPA]

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From: andrew@frip.WV.TEK.COM (Andrew Klossner)
Newsgroups: comp.arch
Subject: Re: delayed branch (in 88k GCC)
Message-ID: <4203@orca.WV.TEK.COM>
Date: 11 Aug 89 19:26:55 GMT
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