This only adds the interference checks required for correctness.
We still need to take advantage of register masks for the
interference driven live range splitting.

llvm-svn: 150191

Failure to preserve kills was causing LiveIntervals to miss some EFLAGS live
ranges. Unfortunately I've been unable to reduce a good test case yet.

llvm-svn: 150152

llvm-svn: 150150

llvm-svn: 150149

Split CodeGen into stages.
Distinguish between optimization and correctness.

llvm-svn: 150122

llvm-svn: 150121

This does make a difference, at least when using RABasic.

llvm-svn: 150118

I think this was already the intention, but DeadMachineInstructionElim
was accidentally tracking the liveness of reserved registers. Now,
instructions with reserved defs are never deleted.

This prevents the call stack adjustment instructions from getting
deleted when enabling register masks.

llvm-svn: 150116

For simplicity, treat calls with register masks as basic block
boundaries.  This means we can't copy propagate callee-saved registers
across calls, but I don't think that is a big deal.

llvm-svn: 150108

Moving toward a uniform style of pass definition to allow easier target configuration.
Globally declare Pass ID.
Globally declare pass initializer.
Use INITIALIZE_PASS consistently.
Add a call to the initializer from CodeGen.cpp.
Remove redundant "createPass" functions and "getPassName" methods.

While cleaning up declarations, cleaned up comments (sorry for large diff).

llvm-svn: 150100

llvm-svn: 150099

llvm-svn: 150098

llvm-svn: 150097

llvm-svn: 150096

llvm-svn: 150095

llvm-svn: 150094

llvm-svn: 150093

llvm-svn: 150092

llvm-svn: 150091

When a virtual register is live across a call, limit the search space to
call-preserved registers.

llvm-svn: 150081

Build an ordered vector of register mask operands (i.e., calls) when
computing live intervals. Provide a checkRegMaskInterference() function
that computes a bit mask of usable registers for a live range.

This is a quick way of determining of a live range crosses any calls,
and restricting it to the callee saved registers if it does.
Previously, we had to discover call clobbers for each candidate register
independently.

llvm-svn: 150077

llvm-svn: 150044

llvm-svn: 150043

llvm-svn: 150041

llvm-svn: 150012

llvm-svn: 149927

llvm-svn: 149926

We have automatic local renumbering now.

llvm-svn: 149920

llvm-svn: 149910

were no 'unwind' instructions being generated before this, so this is in effect
a no-op.

llvm-svn: 149906

remove the code that handles them.

llvm-svn: 149901

llvm-svn: 149874

Move some llvm_unreachable's from r149849 out of switch statements to satisfy -Wcovered-switch-default

llvm-svn: 149860

llvm-svn: 149834

llvm-svn: 149823

llvm-svn: 149816

but with a critical fix to the SelectionDAG code that optimizes copies
from strings into immediate stores: the previous code was stopping reading
string data at the first nul.  Address this by adding a new argument to
llvm::getConstantStringInfo, preserving the behavior before the patch.

llvm-svn: 149800

A live range that has an early clobber tied redef now looks like a
normal tied redef, except the early clobber def uses the early clobber
slot.

This is enough to handle any strange interference problems.

llvm-svn: 149769

I don't have a test that fails because of this, but a test case like
CodeGen/X86/2009-12-01-EarlyClobberBug.ll exposes the problem.  EAX is
redefined by a tied early clobber operand on inline asm, and the live
range should look like this:

  %EAX,inf = [48r,64e:0)[64e,80r:1)  0@48r 1@64e

Previously, the two values got merged:

  %EAX,inf = [48r,80r:0)  0@48r

With this bug fixed, the REDEF_BY_EC VNInfo flag is no longer needed.

llvm-svn: 149768

Andy, in a previous commit you made this into an ImmutablePass so that you could
add it to the PassManager, then in the next commit you left it a Pass but
removed the code that added it to the PM. If you do add it to the PM then the PM
should take care of deleting it, but it's also true that nothing in codegen
needs this object to exist after it's done its work here. It's not clear to me
which design you want; this should likely either cease to be a Pass or be added
to the PM where other parts of CodeGen will request it.

llvm-svn: 149765