second algorithm, but only loosely. It is more heavily based on the last
discussion I had with Andy. It continues to walk from the inner-most
loop outward, but there is a key difference. With this algorithm we
ensure that as we visit each loop, the entire loop is merged into
a single chain. At the end, the entire function is treated as a "loop",
and merged into a single chain. This chain forms the desired sequence of
blocks within the function. Switching to a single algorithm removes my
biggest problem with the previous approaches -- they had different
behavior depending on which system triggered the layout. Now there is
exactly one algorithm and one basis for the decision making.
The other key difference is how the chain is formed. This is based
heavily on the idea Andy mentioned of keeping a worklist of blocks that
are viable layout successors based on the CFG. Having this set allows us
to consistently select the best layout successor for each block. It is
expensive though.
The code here remains very rough. There is a lot that needs to be done
to clean up the code, and to make the runtime cost of this pass much
lower. Very much WIP, but this was a giant chunk of code and I'd rather
folks see it sooner than later. Everything remains behind a flag of
course.
I've added a couple of tests to exercise the issues that this iteration
was motivated by: loop structure preservation. I've also fixed one test
that was exhibiting the broken behavior of the previous version.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144495 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyAddress to handle either a 12-bit unsigned offset or the ARM +/-imm8
offsets (addressing mode 3). This enables a load followed by an integer
extend to be folded into a single load.
For example:
ldrb r1, [r0] ldrb r1, [r0]
uxtb r2, r1 =>
mov r3, r2 mov r3, r1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144488 91177308-0d34-0410-b5e6-96231b3b80d8
Most of this stuff was supporting the old deferred spill code insertion
mechanism. Modern spillers just edit machine code in place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144484 91177308-0d34-0410-b5e6-96231b3b80d8
It was off by default.
The new register allocators don't have the problems that made it
necessary to reallocate registers during stack slot coloring.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144481 91177308-0d34-0410-b5e6-96231b3b80d8
It is worth noting that the old spiller would split live ranges around
basic blocks. The new spiller doesn't do that.
PBQP should do its own live range splitting with
SplitEditor::splitSingleBlock() if desired. See
RAGreedy::tryBlockSplit().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144476 91177308-0d34-0410-b5e6-96231b3b80d8
RegAllocGreedy has been the default for six months now.
Deleting RegAllocLinearScan makes it possible to also delete
VirtRegRewriter and clean up the spiller code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144475 91177308-0d34-0410-b5e6-96231b3b80d8
This test was committed with a bugfix to RemoveCopyByCommutingDef, but
that optimization is no longer triggered by this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144470 91177308-0d34-0410-b5e6-96231b3b80d8
This test doesn't expose the issue with RAGreedy.
I filed PR11363 to track the missing InlineSpiller feature.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144459 91177308-0d34-0410-b5e6-96231b3b80d8
The test is checking that the output doesn't contains any 'mov '
strings. It does contain movl, though.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144458 91177308-0d34-0410-b5e6-96231b3b80d8
methods but also class methods for Objective-C.
Clang emits Objective-C method names with '\1' at the
beginning, and the JIT has pre-existing logic to try
prepending a '\1' when searching a module for an
instance method (that is, a method whose name begins
with '-'). I simply extended it to do the same thing
when it encountered a class method (a method whose
name begins with '+').
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144451 91177308-0d34-0410-b5e6-96231b3b80d8
instance and a concrete inlined instance are the use of DW_TAG_subprogram
instead of DW_TAG_inlined_subroutine and the who owns the tree.
We were also omitting DW_AT_inline from the abstract roots. To fix this,
make sure we mark abstract instance roots with DW_AT_inline even when
we have only out-of-line instances referring to them with DW_AT_abstract_origin.
FileCheck is not a very good tool for tests like this, maybe we should add
a -verify mode to llvm-dwarfdump.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144441 91177308-0d34-0410-b5e6-96231b3b80d8
These immediate operands all use the same simple logic for rendering to
MCInst, so have them share the method for doing so.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144439 91177308-0d34-0410-b5e6-96231b3b80d8
