opportunities that only present themselves after late optimizations
such as tail duplication .e.g.
## BB#1:
movl %eax, %ecx
movl %ecx, %eax
ret
The register allocator also leaves some of them around (due to false
dep between copies from phi-elimination, etc.)
This required some changes in codegen passes. Post-ra scheduler and the
pseudo-instruction expansion passes have been moved after branch folding
and tail merging. They were before branch folding before because it did
not always update block livein's. That's fixed now. The pass change makes
independently since we want to properly schedule instructions after
branch folding / tail duplication.
rdar://10428165
rdar://10640363
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147716 91177308-0d34-0410-b5e6-96231b3b80d8
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.
For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146026 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid using the same register for two def operands or and earlyclobber
def and use operand. This fixes PR8986 and improves on the prior fix
for rdar://problem/8959122.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125089 91177308-0d34-0410-b5e6-96231b3b80d8
<rdar://problem/8959122> illegal register operands for UMULL instruction in cfrac nightly test
I'm stil working on a unit test, but the case is:
rx = movcc rx, r3
r2 = ldr
r2, r3 = umull r2, r2
The anti-dep breaker should not convert this into an illegal instruction:
r2, r2 = umull
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124932 91177308-0d34-0410-b5e6-96231b3b80d8
breaker needs to check all definitions of the antidepenent register to
avoid multiple defs of the same new register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118032 91177308-0d34-0410-b5e6-96231b3b80d8
scheduling change in svn 115121. The CriticalAntiDepBreaker had bad
liveness information. It was calculating the KillIndices for one scheduling
region in a basic block, rescheduling that region so the KillIndices were
no longer valid, and then using those wrong KillIndices to make decisions
for the next scheduling region. I've not been able to reduce a small
testcase for this. Radar 8502534.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115400 91177308-0d34-0410-b5e6-96231b3b80d8
