* Why does peephole not handle JUMP before barrier?
@ 2001-09-12 9:30 Alan Lehotsky
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From: Alan Lehotsky @ 2001-09-12 9:30 UTC (permalink / raw)
To: gcc
genpeep.c produces a peephole() function that explicitly excludes performing peepholes on
anything that's immediately followed by a barrier instruction.
I've got a machine that has branch delay slots. If the instruction following a branch is another branch,
then the second branch is suppressed. So, if I have something like
jeq $10
nop
jmp $12
....
that can be replaced by
jeq $10
jmp $12
...
avoiding the nop.
But, if I've got
jmp $10
nop
jmp $12
nop
the peephole() NEVER looks at the jmp $10, as it's actually got a barrier after it.
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2001-09-12 9:30 Why does peephole not handle JUMP before barrier? Alan Lehotsky
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