This re-commits r375152 which was pulled in r375233 because it broke
the EXPENSIVE_CHECKS bot on Windows.
The reason for the failure was a bug in the pass that the commit turned
on by default. This patch fixes that bug and turns the pass back on.
This patch has been verified on the buildbot that originally failed
thanks to Simon Pilgrim.
Differential revision: https://reviews.llvm.org/D52431
llvm-svn: 375497
Quite a while ago, we implemented a pass that will reduce the number of
CR-logical operations we emit. It does so by converting a CR-logical operation
into a branch. We have kept this off by default because it seemed to cause a
significant regression with one benchmark.
However, that regression turned out to be due to a completely unrelated
reason - AADB introducing a self-copy that is a priority-setting nop and it was
just exacerbated by this pass.
Now that we understand the reason for the only degradation, we can turn this
pass on by default. We have long since fixed the cause for the degradation.
Differential revision: https://reviews.llvm.org/D52431
llvm-svn: 375152
The indirect call sequence on PPC requires that the TOC base register be saved
prior to the indirect call and restored after the call since the indirect call
may branch to a global entry point in another DSO which will update the TOC
base. Over the last couple of years, we have improved this to:
- be able to hoist TOC saves from loops (with changes to MachineLICM)
- avoid multiple saves when one dominates the other[s]
However, it is still possible to have multiple TOC saves dynamically in the
execution path if there is no dominance relationship between them.
This patch moves the TOC save to the prologue when one of the TOC saves is in a
block that post-dominates entry (i.e. it cannot be avoided) or if it is in a
block that is hotter than entry.
Differential revision: https://reviews.llvm.org/D63803
llvm-svn: 365232
For some reason, the update_llc_checks.py script produces checks for
empty lines which cause failures. Corrected that to check for actual
text produced by llc.
llvm-svn: 364377
An upcoming patch will modify the behaviour with respect to saving the TOC
in functions with indirect calls.
Adding a test case so the patch will show the difference in codegen.
llvm-svn: 364375
Nemanja Ivanovic