From f43bedeef3ecdf4d037a2484a0f0a3672ab60299 Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Tue, 24 May 2011 13:18:55 +0100 Subject: [PATCH] make the change to go_pap suggested in #4978. According to nofib, one program is improved quite dramatically (fft2 30% less allocation), and everything else was unchanged. --- compiler/coreSyn/CoreUtils.lhs | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/compiler/coreSyn/CoreUtils.lhs b/compiler/coreSyn/CoreUtils.lhs index a0a229f..4146b62 100644 --- a/compiler/coreSyn/CoreUtils.lhs +++ b/compiler/coreSyn/CoreUtils.lhs @@ -589,12 +589,10 @@ exprIsCheap' good_app other_expr -- Applications and variables go _ _ = False -------------- - go_pap args = all exprIsTrivial args - -- For constructor applications and primops, check that all - -- the args are trivial. We don't want to treat as cheap, say, - -- (1:2:3:4:5:[]) - -- We'll put up with one constructor application, but not dozens - + go_pap args = all (exprIsCheap' good_app) args + -- Used to be "all exprIsTrivial args" due to concerns about + -- duplicating nested constructor applications, but see #4978. + -------------- go_primop op args = primOpIsCheap op && all (exprIsCheap' good_app) args -- In principle we should worry about primops -- 1.7.10.4