Patch by Johnny Chen.

llvm-svn: 83983

llvm-svn: 83982

llvm-svn: 83973

llvm-svn: 83917

before its reference is only supported on ARM has not been true for a while.
In fact, until recently, that was only supported for Thumb.  Besides that,
CPEs are always a multiple of 4 bytes in size, so inserting a CPE should have
no effect on Thumb alignment.

llvm-svn: 83916

should have been a pointer to a reference.

llvm-svn: 83915

llvm-svn: 83905

MultiSource/Benchmarks/MiBench/automotive-susan test.  The failure has
since been masked by an unrelated change (just randomly), so I don't have
a testcase for this now.  Radar 7291928.

The situation where this happened is that a constant pool entry (CPE) was
placed at a lower address than the load that referenced it.  There were in
fact 2 CPEs placed at adjacent addresses and referenced by 2 loads that were
close together in the code.  The distance from the loads to the CPEs was
right at the limit of what they could handle, so that only one of the CPEs
could be placed within range.  On every iteration, the first CPE was found
to be out of range, causing a new CPE to be inserted.  The second CPE had
been in range but the newly inserted entry pushed it too far away.  Thus the
second CPE was also replaced by a new entry, which in turn pushed the first
CPE out of range.  Etc.

Judging from some comments in the code, the initial implementation of this
pass did not support CPEs placed _before_ their references.  In the case
where the CPE is placed at a higher address, the key to making the algorithm
terminate is that new CPEs are only inserted at the end of a group of adjacent
CPEs.  This is implemented by removing a basic block from the "WaterList"
once it has been used, and then adding the newly inserted CPE block to the
list so that the next insertion will come after it.  This avoids the ping-pong
effect where CPEs are repeatedly moved to the beginning of a group of
adjacent CPEs.  This does not work when going backwards, however, because the
entries at the end of an adjacent group of CPEs are closer than the CPEs
earlier in the group.

To make this pass terminate, we need to maintain a property that changes can
only happen in some sort of monotonic fashion.  The fix used here is to require
that the CPE for a particular constant pool load can only move to lower
addresses.  This is a very simple change to the code and should not cause
any significant degradation in the results.

llvm-svn: 83902

llvm-svn: 83897

llvm-svn: 83894

llvm-svn: 83874

llvm-svn: 83873

llvm-svn: 83872

when loading from an invariant memory location.

llvm-svn: 83688

lists.  Changed ARMAsmParser::MatchRegisterName to return -1 instead of 0 on
errors so 0-15 values could be returned as register numbers.  Also added the
rest of the arm register names to the currently hacked up version to allow more
testing.  Some changes to ARMAsmParser::ParseOperand to give different errors
for things not yet supported and some additions to the hacked
ARMAsmParser::MatchInstruction to allow more testing for now.

llvm-svn: 83673

llvm-svn: 83600

llvm-svn: 83598

llvm-svn: 83596

Also fix some copy-and-paste errors in previous changes.

llvm-svn: 83590

llvm-svn: 83585

llvm-svn: 83572

llvm-svn: 83568

llvm-svn: 83566

llvm-svn: 83565

llvm-svn: 83526

llvm-svn: 83522

llvm-svn: 83521

llvm-svn: 83518

llvm-svn: 83513

llvm-svn: 83508

llvm-svn: 83506

llvm-svn: 83502

llvm-svn: 83501

llvm-svn: 83494

llvm-svn: 83490

llvm-svn: 83486

llvm-svn: 83484

llvm-svn: 83482

llvm-svn: 83479

with writeback, things like "sp!", etc.  Also added some more stuff to the
temporarily hacked methods ARMAsmParser::MatchRegisterName and
ARMAsmParser::MatchInstruction to allow more parser testing.

llvm-svn: 83477