Current tail duplication integrated in bb layout is designed to increase the fallthrough from a BB's predecessor to its successor, but we have observed cases that duplication doesn't increase fallthrough, or it brings too much size overhead.
To overcome these two issues in function canTailDuplicateUnplacedPreds I add two checks:
make sure there is at least one duplication in current work set.
the number of duplication should not exceed the number of successors.
The modification in hasBetterLayoutPredecessor fixes a bug that potential predecessor must be at the bottom of a chain.
Differential Revision: https://reviews.llvm.org/D64376
The pass to expand ISEL instructions into if-then-else sequences in patch D23630
is currently disabled. This patch partially enable it by always removing the
unnecessary ISELs (all registers used by the ISELs are the same one) and folding
the ISELs which have the same input registers into unconditional copies.
Differential Revision: https://reviews.llvm.org/D40497
llvm-svn: 320414
This patch just adds printing of CR bit registers in a more human-readable
form akin to that used by the GNU binutils.
Differential Revision: https://reviews.llvm.org/D31494
llvm-svn: 309001
Generally, the ISEL is expanded into if-then-else sequence, in some
cases (like when the destination register is the same with the true
or false value register), it may just be expanded into just the if
or else sequence.
llvm-svn: 292154
Generally, the ISEL is expanded into if-then-else sequence, in some
cases (like when the destination register is the same with the true
or false value register), it may just be expanded into just the if
or else sequence.
llvm-svn: 292128
Guozhi Wei