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.
llvm-svn: 144131
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>
llvm-svn: 144117
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.
llvm-svn: 144037
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.
llvm-svn: 144025
Jakob Stoklund Olesen