[SystemZ] Optimize fcmp X, 0 in cases where X is also negated
authorRichard Sandiford <rsandifo@linux.vnet.ibm.com>
Wed, 11 Dec 2013 11:45:08 +0000 (11:45 +0000)
committerRichard Sandiford <rsandifo@linux.vnet.ibm.com>
Wed, 11 Dec 2013 11:45:08 +0000 (11:45 +0000)
commite54c1060a6a3f2a30b26c3289c08ae1bc8a845b9
tree9cdb87baabfdf2ab0619894ffef44de7212952dd
parent3c14ba596248d64cc3f464e244d23abf934cde3e
[SystemZ] Optimize fcmp X, 0 in cases where X is also negated

In such cases it's often better to test the result of the negation instead,
since the negation also sets CC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197032 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Target/SystemZ/SystemZISelLowering.cpp
test/CodeGen/SystemZ/fp-cmp-04.ll