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