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.
llvm-svn: 144149
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
basic blocks containing calls. This works around a problem in which
these artificial dependencies can get tied up in calling seqeunce
scheduling in a way that makes the graph unschedulable with the current
approach of using artificial physical register dependencies for calling
sequences. This fixes PR11314.
llvm-svn: 144124
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
Add support for trimming constants to GetDemandedBits. This fixes some funky
constant generation that occurs when stores are expanded for targets that don't
support unaligned stores natively.
llvm-svn: 144102
When this field is true it means that the load is from constant (runt-time or compile-time) and so can be hoisted from loops or moved around other memory accesses
llvm-svn: 144100
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
the pubnames and pubtypes tables. LLDB can currently use this format
and a full spec is forthcoming and submission for standardization is planned.
A basic summary:
The dwarf accelerator tables are an indirect hash table optimized
for null lookup rather than access to known data. They are output into
an on-disk format that looks like this:
.-------------.
| HEADER |
|-------------|
| BUCKETS |
|-------------|
| HASHES |
|-------------|
| OFFSETS |
|-------------|
| DATA |
`-------------'
where the header contains a magic number, version, type of hash function,
the number of buckets, total number of hashes, and room for a special
struct of data and the length of that struct.
The buckets contain an index (e.g. 6) into the hashes array. The hashes
section contains all of the 32-bit hash values in contiguous memory, and
the offsets contain the offset into the data area for the particular
hash.
For a lookup example, we could hash a function name and take it modulo the
number of buckets giving us our bucket. From there we take the bucket value
as an index into the hashes table and look at each successive hash as long
as the hash value is still the same modulo result (bucket value) as earlier.
If we have a match we look at that same entry in the offsets table and
grab the offset in the data for our final match.
llvm-svn: 143921
the mailing list. Suggestions for other statistics to collect would be
awesome. =]
Currently these are implemented as a separate pass guarded by a separate
flag. I'm not thrilled by that, but I wanted to be able to collect the
statistics for the old code placement as well as the new in order to
have a point of comparison. I'm planning on folding them into the single
pass if / when there is only one pass of interest.
llvm-svn: 143537
