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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90951 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89311 91177308-0d34-0410-b5e6-96231b3b80d8
This introduces a new pass, SlotIndexes, which is responsible for numbering
instructions for register allocation (and other clients). SlotIndexes numbering
is designed to match the existing scheme, so this patch should not cause any
changes in the generated code.
For consistency, and to avoid naming confusion, LiveIndex has been renamed
SlotIndex.
The processImplicitDefs method of the LiveIntervals analysis has been moved
into its own pass so that it can be run prior to SlotIndexes. This was
necessary to match the existing numbering scheme.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85979 91177308-0d34-0410-b5e6-96231b3b80d8
a new class, MachineInstrIndex, which hides arithmetic details from
most clients. This is a step towards allowing the register allocator
to update/insert code during allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81040 91177308-0d34-0410-b5e6-96231b3b80d8
as an (index,bool) pair. The bool flag records whether the kill is a
PHI kill or not. This code will be used to enable splitting of live
intervals containing PHI-kills.
A slight change to live interval weights introduced an extra spill
into lsr-code-insertion (outside the critical sections). The test
condition has been updated to reflect this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75097 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69743 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69341 91177308-0d34-0410-b5e6-96231b3b80d8
the subreg field to 0, since the subreg field is only used
for virtual register subregs. This doesn't change
current functionality; it just eliminates bogus noise from
debug output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68955 91177308-0d34-0410-b5e6-96231b3b80d8
register destinations that are tied to source operands. The
TargetInstrDescr::findTiedToSrcOperand method silently fails for inline
assembly. The existing MachineInstr::isRegReDefinedByTwoAddr was very
close to doing what is needed, so this revision makes a few changes to
that method and also renames it to isRegTiedToUseOperand (for consistency
with the very similar isRegTiedToDefOperand and because it handles both
two-address instructions and inline assembly with tied registers).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68714 91177308-0d34-0410-b5e6-96231b3b80d8
