Use interval sizes instead of spill weights to determine if it is legal to evict
interference. A smaller interval can evict interference if all interfering live
ranges are larger.

Allow multiple interferences to be evicted as along as they are all larger than
the live range being allocated.

Spill weights are still used to select the preferred eviction candidate.

llvm-svn: 126276

This is based on the observation that long live ranges are more difficult to
allocate, so there is a better chance of solving the puzzle by handling the big
pieces first. The allocator will evict and split long alive ranges when they get
in the way.

RABasic is still using spill weights for its priority queue, so the interface to
the queue has been virtualized.

llvm-svn: 126259

llvm-svn: 126258

share entries. Add a DenseSet to MachineConstantPool for the MachineCPVs that
it owns.

This will hopefully fix the MC/ARM/elf-reloc-01.ll failure on the leaks bots.

llvm-svn: 126218

Apparently it's ok for multiple operands to "kill" the same register.
Fixes PR9237.

llvm-svn: 126190

llvm-svn: 126185

at phis. This enables us to eliminate a lot of pointless zexts during the DAGCombine
phase. This fixes <rdar://problem/8760114>.

llvm-svn: 126170

allows for the information propagated across basic blocks to be merged at phis.

llvm-svn: 126169

llvm-svn: 126163

llvm-svn: 126158

In other words, do not keep track of argument's location.  The debugger (gdb) is not prepared to see line table entries for arguments. For the debugger, "second" line table entry marks beginning of function body.
This requires some coordination with debugger to get this working. 
 - The debugger needs to be aware of prolog_end attribute attached with line table entries.
 - The compiler needs to accurately mark prolog_end in line table entries (at -O0 and at -O1+)

llvm-svn: 126155

An original endpoint is an instruction that killed or defined the original live
range before any live ranges were split.

When splitting global live ranges, avoid creating local live ranges without any
original endpoints. We may still create global live ranges without original
endpoints, but such a range won't be split again, and live range splitting still
terminates.

llvm-svn: 126151

Radar 9012638.

llvm-svn: 126127

The DAGCombiner folds the zext into complex load instructions. This patch
prevents this optimization on vectors since none of the supported targets
knows how to perform load+vector_zext in one instruction.

llvm-svn: 126080

Do not emit empty DW_TAG_lexical_block DIEs.  In one test case, size of debug info reduced by almost 7%.

llvm-svn: 126009

llvm-svn: 126005

llvm-svn: 126003

llvm-svn: 126002

llvm-svn: 126001

Do not lose debug info of an inlined function argument even if the argument is only used through GEPs.
This time with a fix that avoids using invalidated DenseMap iterator.

llvm-svn: 125984

All new virtual registers created for spilling or splitting point back to their original.

llvm-svn: 125980

llvm-svn: 125968

The rewriter works almost identically to -rewriter=trivial, except it also
eliminates any identity copies.

This makes the new register allocators independent of VirtRegRewriter.cpp which
will be going away at the same time as RegAllocLinearScan.

llvm-svn: 125967

llvm-svn: 125960

llvm-svn: 125830

llvm-svn: 125802

Do not lose debug info of an inlined function argument even if the argument is only used through GEPs.

llvm-svn: 125794

llvm-svn: 125789

A local live range is live in a single basic block. If such a range fails to
allocate, try to find a sub-range that would get a larger spill weight than its
interference.

llvm-svn: 125764

the time but presumably my email got lost).  Examples where the previous logic
got it wrong: (1) a signed i8 multiply of 64 by 2 overflows, but the high part is
zero; (2) a signed i8 multiple of -128 by 2 overflows, but the high part is all
ones. 

llvm-svn: 125748

llvm-svn: 125728

llvm-svn: 125727

llvm-svn: 125726

other getNode() methods.  Radar 9002173.

llvm-svn: 125665

llvm-svn: 125651

transformation if we can't legally create a build vector of the correct
type. Check that we can make the transformation first, and add a TODO to
refactor this code with similar cases.

Fixes: PR9223 and rdar://9000350
llvm-svn: 125631

llvm-svn: 125625

Ignore DBG_VALUE machine instructions while constructing instruction ranges based on location info. 
Machine instruction range consisting of only DBG_VALUE MIs only contributes consecutive labels in assembly output, which is harmless, and empty scope entry in DebugInfo, which confuses debugger tools.

llvm-svn: 125577

llvm-svn: 125563

llvm-svn: 125552