llvm-svn: 127388

Soon, RegAllocGreedy will start splitting live ranges, and then deferred
spilling won't work anyway.

llvm-svn: 121591

benchmarks hitting an assertion.
Adds LiveIntervalUnion::collectInterferingVRegs.
Fixes "late spilling" by checking for any unspillable live vregs among
all physReg aliases.

llvm-svn: 118701

llvm-svn: 117272

The earliestStart argument is entirely specific to linear scan allocation, and
can be easily calculated by RegAllocLinearScan.

Replace std::vector with SmallVector.

llvm-svn: 111055

The spillers can pluck the analyses they need from the pass reference.

Switch some never-null pointers to references.

llvm-svn: 108969

non-const.

llvm-svn: 108734

llvm-svn: 107351

vector instead. This avoids needless copying and allocation.

Add documentation.

llvm-svn: 106788

When a call is placed to spill an interval this spiller will first try to
break the interval up into its component values. Single value intervals and
intervals which have already been split (or are the result of previous splits)
are spilled by the default spiller.

Splitting intervals as described above may improve the performance of generated
code in some circumstances. This work is experimental however, and it still
miscompiles many benchmarks. It's not recommended for general use yet.

llvm-svn: 90951

llvm-svn: 89422

All spiller calls in RegAllocLinearScan now go through the new Spiller interface.
The "-new-spill-framework" command line option has been removed. To use the trivial in-place spiller you should now pass "-spiller=trivial -rewriter=trivial".
(Note the trivial spiller/rewriter are only meant to serve as examples of the new in-place modification work. Enabling them will yield terrible, though hopefully functional, code).

llvm-svn: 89311

Fixed the in-place spiller and trivial rewriter, which had been broken by the recent SlotIndexes work.

llvm-svn: 89238

llvm-svn: 76356

llvm-svn: 75440

llvm-svn: 73750

llvm-svn: 73634

llvm-svn: 72729

llvm-svn: 72114

llvm-svn: 72113

llvm-svn: 72112

llvm-svn: 72030

llvm-svn: 71057

This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue.

llvm-svn: 69743

register is available and when it's profitable.

e.g.
     xorq  %r12<kill>, %r13
     addq  %rax, -184(%rbp)
     addq  %r13, -184(%rbp)
==>
     xorq  %r12<kill>, %r13
     movq  -184(%rbp), %r12
     addq  %rax, %r12
     addq  %r13, %r12
     movq  %r12, -184(%rbp)

Two more instructions, but fewer memory accesses. It can also open up
opportunities for more optimizations.

llvm-svn: 69341

llvm-svn: 68099

llvm-svn: 68092

Spiller may unfold load / mod / store instructions as an optimization when the would be loaded value is available in a register. It needs to check if it's legal to clobber the register. Also, the register can contain values of multiple spill slots, make sure to check all instead of just the one being unfolded.

llvm-svn: 67068

llvm-svn: 66780

Reorganization: Move the Spiller out of VirtRegMap.cpp into its own files.  No (intended) functionality change.

llvm-svn: 66720