-
Simon Peyton Jones authored
It turned out that the terrible compiler performance in Trac #10527 arose because we were simplifying a function argument that subseuqently was discarded, so the work was wasted. Moreover, the work turned out to be substantial; indeed it made an asymptotic difference to compile time. Ths solution in this 7.10 branch is a bit brutal; just duplicate CoreSubst.substExpr to be SimplEnv.substExprS. It works fine I'm working on a better solution for HEAD.
07a1f32e