During the initial RPO traversal of the basic blocks, remember the ones
that are incomplete because of back-edges from predecessors that haven't
been visited yet.
After the initial RPO, revisit all those loop headers so the incoming
DomainValues on the back-edges can be properly collapsed.
This will properly fix execution domains on software pipelined code,
like the included test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144151 91177308-0d34-0410-b5e6-96231b3b80d8
When merging two uncollapsed DomainValues, place a link to the active
DomainValue from the passive DomainValue. This allows old stale
references to the passive DomainValue to be updated to point to the
active DomainValue.
The new resolve() function finds the active DomainValue and updates the
pointer.
This change makes old live-out lists more useful since they may contain
uncollapsed DomainValues that have since been merged into other
DomainValues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144149 91177308-0d34-0410-b5e6-96231b3b80d8
This new function will decrement the reference count, and collapse a
domain value when the last reference is gone.
This simplifies DomainValue reference counting, and decouples it from
the LiveRegs array.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144131 91177308-0d34-0410-b5e6-96231b3b80d8
The old value may still be referenced by some live-out list, and we
don't wan't to collapse those instructions twice.
This fixes the "Can only swizzle VMOVD" assertion in some armv7 SPEC
builds.
<rdar://problem/10413292>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144117 91177308-0d34-0410-b5e6-96231b3b80d8
DomainValues that are only used by "don't care" instructions are now
collapsed to the first possible execution domain after all basic blocks
have been processed. This typically means the PS domain on x86.
For example, the vsel_i64 and vsel_double functions in sse2-blend.ll are
completely collapsed to the PS domain instead of containing a mix of
execution domains created by isel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144037 91177308-0d34-0410-b5e6-96231b3b80d8
The enterBasicBlock() function is combining live-out values from
predecessor blocks. The RPO traversal means that more predecessors
have been visited when that happens, only back-edges are missing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144025 91177308-0d34-0410-b5e6-96231b3b80d8
