-
Sylvain Henry authored
This patch introduces new rules to perform constant folding through case-expressions. E.g., ``` case t -# 10# of _ { ===> case t of _ { 5# -> e1 15# -> e1 8# -> e2 18# -> e2 DEFAULT -> e DEFAULT -> e ``` The initial motivation is that it allows "Merge Nested Cases" optimization to kick in and to further simplify the code (see Trac #12877). Currently we recognize the following operations for Word# and Int#: Add, Sub, Xor, Not and Negate (for Int# only). Test Plan: validate Reviewers: simonpj, austin, bgamari Reviewed By: simonpj, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2762 GHC Trac Issues: #12877
d3b546b1