Summary:
This is brought up in
https://reviews.llvm.org/D64662?id=209923#inline-599490
CFI information are non-relevant to quite some testcases,
we should get rid of checking them when its unecessary.
This patch avoid generating cfi info in testcases that are not
testing prolog/epilog or exception handling.
Reviewers: kbarton, hfinkel, nemanjai, #powerpc
Reviewed By: hfinkel
Subscribers: MaskRay, shchenz, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67016
llvm-svn: 370505
Generally speaking, we lower to an optimal rotate sequence for nodes visible in
the SDAG. However, there are instances where the two rotates are not visible at
ISEL time - most notably those in a very common sequence when lowering switch
statements to jump tables.
A common situation is a switch on a 32-bit integer. This value has to have the
upper 32 bits cleared and because jump table offsets are word offsets, the value
needs to be shifted left by 2 bits. We currently emit the clear and the left
shift as two separate instructions, but this is not needed as we can lower it to
a single RLDIC.
This patch just cleans that up.
Differential revision: https://reviews.llvm.org/D60402
llvm-svn: 362576
Jinsong Ji