update all code that this affects.

llvm-svn: 79830

MachineInstr and MachineOperand.  This required eliminating a
bunch of stuff that was using DOUT, I hope that bill doesn't
mind me stealing his fun. ;-)

llvm-svn: 79813

llvm-svn: 79795

llvm-svn: 79752

Modified VNInfo. The "copy" member is now a union which holds the copy for a register interval, or the defining register for a stack interval. Access is via getCopy/setCopy and getReg/setReg.

llvm-svn: 78620

llvm-svn: 78151

Re-apply LiveInterval index dumping patch, with fixes suggested by Bill
and others.

llvm-svn: 78003

llvm-svn: 77754

 - Some clients which used DOUT have moved to DEBUG. We are deprecating the
   "magic" DOUT behavior which avoided calling printing functions when the
   statement was disabled. In addition to being unnecessary magic, it had the
   downside of leaving code in -Asserts builds, and of hiding potentially
   unnecessary computations.

llvm-svn: 77019

llvm-svn: 76963

Constify the key in Mi2IndexMap.

llvm-svn: 76801

llvm-svn: 76646

Prefix IR dumps with LiveInterval indices when possible.  This turns
this:

	%ESI<def> = MOV32rr %EDI<kill>
	ADJCALLSTACKDOWN64 0, %RSP<imp-def>, %EFLAGS<imp-def,dead>, %RSP<imp-use>
	%reg1027<def> = MOVZX64rr32 %ESI
	%reg1027<def> = ADD64ri8 %reg1027, 15, %EFLAGS<imp-def,dead>
	%reg1027<def> = AND64ri8 %reg1027, -16, %EFLAGS<imp-def,dead>
	%RDI<def> = MOV64rr %RSP
	%RDI<def> = SUB64rr %RDI, %reg1027<kill>, %EFLAGS<imp-def,dead>
	%RSP<def> = MOV64rr %RDI

into this:

4	%reg1024<def> = MOV32rr %EDI<kill>
12	ADJCALLSTACKDOWN64 0, %RSP<imp-def>, %EFLAGS<imp-def,dead>, %RSP<imp-use>
20	%reg1025<def> = MOVZX64rr32 %reg1024
28	%reg1026<def> = MOV64rr %reg1025<kill>
36	%reg1026<def> = ADD64ri8 %reg1026, 15, %EFLAGS<imp-def,dead>
44	%reg1027<def> = MOV64rr %reg1026<kill>
52	%reg1027<def> = AND64ri8 %reg1027, -16, %EFLAGS<imp-def,dead>
60	%reg1028<def> = MOV64rr %RSP
68	%reg1029<def> = MOV64rr %reg1028<kill>
76	%reg1029<def> = SUB64rr %reg1029, %reg1027<kill>, %EFLAGS<imp-def,dead>
84	%RSP<def> = MOV64rr %reg1029

This helps greatly when debugging register allocation and coalescing
problems.

llvm-svn: 76615

Simplify the coalescer (finally!) by making LiveIntervals::processImplicitDefs a little more aggressive and teaching liveintervals to make use of isUndef marker on MachineOperands.

llvm-svn: 76223

llvm-svn: 76100

Avoid remat'ing instructions whose def have sub-register indices for now. It's just really really hard to get all the cases right.

llvm-svn: 75900

This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").

llvm-svn: 75640

Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.

llvm-svn: 75379

and abort()/exit() -> llvm_report_error().

llvm-svn: 75363

llvm-svn: 75267

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.

llvm-svn: 75097

Remove special handling of implicit_def. Fix a couple more bugs in liveintervalanalysis and coalescer handling of implicit_def.

Note, isUndef marker must be placed even on implicit_def def operand or else the scavenger will not ignore it. This is necessary because -O0 path does not use liveintervalanalysis, it treats implicit_def just like any other def.

llvm-svn: 74601

Handle IMPLICIT_DEF with isUndef operand marker, part 2. This patch moves the code to annotate machineoperands to LiveIntervalAnalysis. It also add markers for implicit_def that define physical registers. The rest, is just a lot of details.

llvm-svn: 74580

Add a bit IsUndef to MachineOperand. This indicates the def / use register operand is defined by an implicit_def. That means it can def / use any register and passes (e.g. register scavenger) can feel free to ignore them.

The register allocator, when it allocates a register to a virtual register defined by an implicit_def, can allocate any physical register without worrying about overlapping live ranges. It should mark all of operands of the said virtual register so later passes will do the right thing.

This is not the best solution. But it should be a lot less fragile to having the scavenger try to track what is defined by implicit_def.

llvm-svn: 74518

by Evan.

llvm-svn: 74370

llvm-svn: 73750

llvm-svn: 73727

llvm-svn: 73634

Move register allocation preference (or hint) from LiveInterval to MachineRegisterInfo. This allows more passes to set them.

llvm-svn: 73346

llvm-svn: 72729

entries as there are basic blocks in the function.  LiveVariables::getVarInfo
creates a VarInfo struct for every register in the function, leading to
quadratic space use.  This patch changes the BitVector to a SparseBitVector,
which doesn't help the worst-case memory use but does reduce the actual use in
very long functions with short-lived variables.

llvm-svn: 72426

In some rare cases, the register allocator can spill registers but end up not utilizing registers at all. The fundamental problem is linearscan's backtracking can end up freeing more than one allocated registers. However,  reloads and restores might be folded into uses / defs and freed registers might not be used at all.

VirtRegMap keeps track of allocations so it knows what's not used. As a horrible hack, the stack coloring can color spill slots with *free* registers. That is, it replace reload and spills with copies from and to the free register. It unfold instructions that load and store the spill slot and replace them with register using variants.

Not yet enabled. This is part 1. More coming.

llvm-svn: 70787

llvm-svn: 70245

Fix PR4056. It's possible a physical register def is dead if its implicit use is deleted by two-address pass.

llvm-svn: 70213

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

Added a linearscan register allocation optimization. When the register allocator spill an interval with multiple uses in the same basic block, it creates a different virtual register for each of the reloads. e.g.

	%reg1498<def> = MOV32rm %reg1024, 1, %reg0, 12, %reg0, Mem:LD(4,4) [sunkaddr39 + 0]
        %reg1506<def> = MOV32rm %reg1024, 1, %reg0, 8, %reg0, Mem:LD(4,4) [sunkaddr42 + 0]
        %reg1486<def> = MOV32rr %reg1506
        %reg1486<def> = XOR32rr %reg1486, %reg1498, %EFLAGS<imp-def,dead>
        %reg1510<def> = MOV32rm %reg1024, 1, %reg0, 4, %reg0, Mem:LD(4,4) [sunkaddr45 + 0]

=>

        %reg1498<def> = MOV32rm %reg2036, 1, %reg0, 12, %reg0, Mem:LD(4,4) [sunkaddr39 + 0]
        %reg1506<def> = MOV32rm %reg2037, 1, %reg0, 8, %reg0, Mem:LD(4,4) [sunkaddr42 + 0]
        %reg1486<def> = MOV32rr %reg1506
        %reg1486<def> = XOR32rr %reg1486, %reg1498, %EFLAGS<imp-def,dead>
        %reg1510<def> = MOV32rm %reg2038, 1, %reg0, 4, %reg0, Mem:LD(4,4) [sunkaddr45 + 0]

From linearscan's point of view, each of reg2036, 2037, and 2038 are separate registers, each is "killed" after a single use. The reloaded register is available and it's often clobbered right away. e.g. In thise case reg1498 is allocated EAX while reg2036 is allocated RAX. This means we end up with multiple reloads from the same stack slot in the same basic block.

Now linearscan recognize there are other reloads from same SS in the same BB. So it'll "downgrade" RAX (and its aliases) after reg2036 is allocated until the next reload (reg2037) is done. This greatly increase the likihood reloads from SS are reused.

This speeds up sha1 from OpenSSL by 5.8%. It is also an across the board win for SPEC2000 and 2006.

llvm-svn: 69585

a live interval. This is needed for some upcoming subreg changes.

llvm-svn: 68956

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).

llvm-svn: 68714

with SUBREG_TO_REG, teach SimpleRegisterCoalescing to coalesce
SUBREG_TO_REG instructions (which are similar to INSERT_SUBREG
instructions), and teach the DAGCombiner to take advantage of this on
targets which support it. This eliminates many redundant
zero-extension operations on x86-64.

This adds a new TargetLowering hook, isZExtFree. It's similar to
isTruncateFree, except it only applies to actual definitions, and not
no-op truncates which may not zero the high bits.

Also, this adds a new optimization to SimplifyDemandedBits: transform
operations like x+y into (zext (add (trunc x), (trunc y))) on targets
where all the casts are no-ops. In contexts where the high part of the
add is explicitly masked off, this allows the mask operation to be
eliminated. Fix the DAGCombiner to avoid undoing these transformations
to eliminate casts on targets where the casts are no-ops.

Also, this adds a new two-address lowering heuristic. Since
two-address lowering runs before coalescing, it helps to be able to
look through copies when deciding whether commuting and/or
three-address conversion are profitable.

Also, fix a bug in LiveInterval::MergeInClobberRanges. It didn't handle
the case that a clobber range extended both before and beyond an
existing live range. In that case, multiple live ranges need to be
added. This was exposed by the new subreg coalescing code.

Remove 2008-05-06-SpillerBug.ll. It was bugpoint-reduced, and the
spiller behavior it was looking for no longer occurrs with the new
instruction selection.

llvm-svn: 68576

llvm-svn: 67764