[Hugs-bugs] internal error

[Ross Paterson]

On Fri, Oct 22, 2004 at 07:45:32AM +0000, fool at sdf-eu.org wrote:
> bla = (if True then (+) else (+)) 0 0

An elegant report.  Here's another version:

	bla = (if True then id else negate) (1::Int)

Unfortunately it seems to point at a whole class of longstanding bugs
in the peephole optimizer: it takes no account of branch targets.
(Here MKAP 1; MKAP 1 => MKAP 2, but the second MKAP was the target of
a TEST branch.)  Another of these optimizations was turned off two
years ago for a similar reason, but they all seem similarly flawed.