computation, the Ancestor field is always set to the Parent, so we can remove
the explicit link entirely and merge the Parent and Ancestor fields. Instead of
checking for whether an ancestor exists for a node or not, we simply check
whether the node has already been processed. This is simpler if Compress is
inlined into Eval, so I did that as well.
This is about a 3% speedup running -domtree on test-suite + SPEC2000 & SPEC2006,
but it also opens up some opportunities for further improvement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124061 91177308-0d34-0410-b5e6-96231b3b80d8
flags. They are still not enable in this revision.
Added TargetInstrInfo::isZeroCost() to fix a fundamental problem with
the scheduler's model of operand latency in the selection DAG.
Generalized unit tests to work with sched-cycles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123969 91177308-0d34-0410-b5e6-96231b3b80d8
TargetInstrInfo:
Change produceSameValue() to take MachineRegisterInfo as an optional argument.
When in SSA form, targets can use it to make more aggressive equality analysis.
Machine LICM:
1. Eliminate isLoadFromConstantMemory, use MI.isInvariantLoad instead.
2. Fix a bug which prevent CSE of instructions which are not re-materializable.
3. Use improved form of produceSameValue.
ARM:
1. Teach ARM produceSameValue to look pass some PIC labels.
2. Look for operands from different loads of different constant pool entries
which have same values.
3. Re-implement PIC GA materialization using movw + movt. Combine the pair with
a "add pc" or "ldr [pc]" to form pseudo instructions. This makes it possible
to re-materialize the instruction, allow machine LICM to hoist the set of
instructions out of the loop and make it possible to CSE them. It's a bit
hacky, but it significantly improve code quality.
4. Some minor bug fixes as well.
With the fixes, using movw + movt to materialize GAs significantly outperform the
load from constantpool method. 186.crafty and 255.vortex improved > 20%, 254.gap
and 176.gcc ~10%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123905 91177308-0d34-0410-b5e6-96231b3b80d8
checks enabled:
1) Use '<' to compare integers in a comparison function rather than '<='.
2) Use the uniqued set DefBlocks rather than Info.DefiningBlocks to initialize
the priority queue.
The speedup of scalarrepl on test-suite + SPEC2000 + SPEC2006 is a bit less, at
just under 16% rather than 17%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123662 91177308-0d34-0410-b5e6-96231b3b80d8
eliminating a potentially quadratic data structure, this also gives a 17%
speedup when running -scalarrepl on test-suite + SPEC2000 + SPEC2006. My initial
experiment gave a greater speedup around 25%, but I moved the dominator tree
level computation from dominator tree construction to PromoteMemToReg.
Since this approach to computing IDFs has a much lower overhead than the old
code using precomputed DFs, it is worth looking at using this new code for the
second scalarrepl pass as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123609 91177308-0d34-0410-b5e6-96231b3b80d8
half a million non-local queries, each of which would otherwise have triggered a
linear scan over a basic block.
Also fix a fixme for memory intrinsics which dereference pointers. With this,
we prove that a pointer is non-null because it was dereferenced by an intrinsic
112 times in llvm-test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123533 91177308-0d34-0410-b5e6-96231b3b80d8
these would try hard to match constants by inverting the bits
and recursively matching. There are two problems with this:
1) some patterns would match when we didn't want them to (theoretical)
2) this is insanely expensive to do, and most often pointless.
This was apparently useful in just 2 instcombine cases, which I
added code to handle explicitly. This change speeds up 'opt'
time on 176.gcc by 1% and produces bitwise identical code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123518 91177308-0d34-0410-b5e6-96231b3b80d8
