Commit Graph

76 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
0cb80d9f0f More dead code elimination in VirtRegMap.
This thing is looking a lot like a virtual register map now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144486 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13 01:23:34 +00:00
Jakob Stoklund Olesen
cb39064e7a Stop tracking spill slot uses in VirtRegMap.
Nobody cared, StackSlotColoring scans the instructions to find used stack
slots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144485 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13 01:23:30 +00:00
Jakob Stoklund Olesen
3cb0b0edd9 Remove dead code and data from VirtRegMap.
Most of this stuff was supporting the old deferred spill code insertion
mechanism.  Modern spillers just edit machine code in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144484 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13 01:02:04 +00:00
Jakob Stoklund Olesen
929e4da68b Stop tracking unused registers in VirtRegMap.
The information was only used by the register allocator in
StackSlotColoring.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144482 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13 00:39:45 +00:00
Jakob Stoklund Olesen
51458ed09e Be more aggressive about following hints.
RAGreedy::tryAssign will now evict interference from the preferred
register even when another register is free.

To support this, add the EvictionCost struct that counts how many hints
are broken by an eviction. We don't want to break one hint just to
satisfy another.

Rename canEvict to shouldEvict, and add the first bit of eviction policy
that doesn't depend on spill weights: Always make room in the preferred
register as long as the evictees can be split and aren't already
assigned to their preferred register.

Also make the CSR avoidance more accurate. When looking for a cheaper
register it is OK to use a new volatile register. Only CSR aliases that
have never been used before should be avoided.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134735 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-08 20:46:18 +00:00
Jakob Stoklund Olesen
fd38917d4d This method belonged in VirtRegMap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126002 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-19 00:38:43 +00:00
Jakob Stoklund Olesen
e324f6e05f Use VirtRegMap's Virt2SplitMap to keep track of the original live range before splitting.
All new virtual registers created for spilling or splitting point back to their original.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125980 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 22:35:20 +00:00
Jakob Stoklund Olesen
ba05c01dab Add VirtRegMap::rewrite() and use it in the new register allocators.
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125967 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 22:03:18 +00:00
Jakob Stoklund Olesen
2cfa5b4934 Add a forgotten VireReg2IndexFunctor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123123 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 18:58:33 +00:00
Jakob Stoklund Olesen
c7d67f90d3 Fix VirtRegMap to use TRI::index2VirtReg and TRI::virtReg2Index instead of
depending on TRI::FirstVirtualRegister.

Also use TRI::printReg instead of printing virtual registers directly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123101 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 23:11:07 +00:00
Jakob Stoklund Olesen
c9672cb8be Add an AllocationOrder class that can iterate over the allocatable physical
registers for a given virtual register.

Reserved registers are filtered from the allocation order, and any valid hint is
returned as the first suggestion.

For target dependent hints, a number of arcane target hooks are invoked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121497 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-10 18:36:02 +00:00
Jakob Stoklund Olesen
b55e91e087 Remember to resize SpillSlotToUsesMap when allocating an emergency spill slot.
Use amazing new function call technology instead of writing identical code in
multiple places.

This fixes PR8604.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119306 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-16 00:41:01 +00:00
Owen Anderson
90c579de5a Reapply r110396, with fixes to appease the Linux buildbot gods.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 18:33:48 +00:00
Owen Anderson
1f74590e9d Revert r110396 to fix buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 00:23:35 +00:00
Owen Anderson
9ccaf53ada Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110396 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05 23:42:04 +00:00
Jakob Stoklund Olesen
f0179004e9 Add SplitEditor to SplitKit. This class will be used to edit live intervals and
rewrite instructions for live range splitting.

Still work in progress.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109469 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-26 23:44:11 +00:00
Lang Hames
233a60ec40 The Indexes Patch.
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
2009-11-03 23:52:08 +00:00
Lang Hames
cc3b0650f1 Renamed MachineInstrIndex to LiveIndex.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83254 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-03 04:21:37 +00:00
Lang Hames
8651125d28 Replaces uses of unsigned for indexes in LiveInterval and VNInfo with
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
2009-09-04 20:41:11 +00:00
Chris Lattner
d9ea85ab01 remove some uses of llvm/Support/Streams.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79842 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 08:43:55 +00:00
Daniel Dunbar
1cd1d98232 Move more to raw_ostream, provide support for writing MachineBasicBlock,
LiveInterval, etc to raw_ostream.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76965 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 10:36:58 +00:00
Evan Cheng
90f95f88c6 Move register allocation preference (or hint) from LiveInterval to MachineRegisterInfo. This allows more passes to set them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73346 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 20:22:55 +00:00
Mike Stump
fe095f39e7 Restore minor deletion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70892 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 18:40:41 +00:00
Evan Cheng
c781a243a3 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70787 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-03 18:32:42 +00:00
Bill Wendling
e67f5e4273 Oy! When reverting r68073, I added in experimental code. Sorry...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68099 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-31 08:41:31 +00:00
Bill Wendling
8fe00540fc Revert r68073. It's causing a failure in the Apple-style builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68092 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-31 08:26:26 +00:00
Owen Anderson
49c8aa0d8b Convert VirtRegMap to a MachineFunctionPass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66870 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-13 05:55:11 +00:00
Owen Anderson
1ed5b714f1 Reorganization: Move the Spiller out of VirtRegMap.cpp into its own files. No (intended) functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66720 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-11 22:31:21 +00:00
Dan Gohman
d68a07650c Tidy up #includes, deleting a bunch of unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61715 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 17:59:02 +00:00
Evan Cheng
cb74266cdb Move #include to right place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51932 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-04 09:16:33 +00:00
Evan Cheng
4cce6b4c78 Use of implicit_def is not part of live interval. Create empty intervals for the uses when the live interval is being spilled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49542 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-11 17:53:36 +00:00
Dan Gohman
39e33acf0a Fix typos in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48297 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-12 20:50:04 +00:00
Evan Cheng
c1f53c7426 Transfer physical register spill info when load / store folding happens.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48246 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-11 21:34:46 +00:00
Evan Cheng
676dd7c80b When the register allocator runs out of registers, spill a physical register around the def's and use's of the interval being allocated to make it possible for the interval to target a register and spill it right away and restore a register for uses. This likely generates terrible code but is before than aborting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48218 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-11 07:19:34 +00:00
Evan Cheng
d36531249a Spiller now remove unused spill slots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47657 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-27 03:04:06 +00:00
Dan Gohman
6f0d024a53 Rename MRegisterInfo to TargetRegisterInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46930 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-10 18:45:23 +00:00
Chris Lattner
4ee451de36 Remove attribution from file headers, per discussion on llvmdev.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 20:36:04 +00:00
Evan Cheng
d120ffd26f MachineInstr can change. Store indexes instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44612 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 10:24:35 +00:00
Evan Cheng
adf8590690 If a split live interval is spilled again, remove the kill marker on its last use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44611 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 09:51:10 +00:00
Evan Cheng
b50bb8cf19 Fix kill info for split intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44609 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 08:16:32 +00:00
Evan Cheng
aee4af68ae Remove redundant foldMemoryOperand variants and other code clean up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44517 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-02 08:30:39 +00:00
Evan Cheng
0cbb1164b3 Fixed various live interval splitting bugs / compile time issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44428 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-29 01:06:25 +00:00
Evan Cheng
cada245d06 Recover compile time regression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44386 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-28 01:28:46 +00:00
Evan Cheng
81a0382181 Live interval splitting:
When a live interval is being spilled, rather than creating short, non-spillable
intervals for every def / use, split the interval at BB boundaries. That is, for
every BB where the live interval is defined or used, create a new interval that
covers all the defs and uses in the BB.

This is designed to eliminate one common problem: multiple reloads of the same
value in a single basic block. Note, it does *not* decrease the number of spills
since no copies are inserted so the split intervals are *connected* through
spill and reloads (or rematerialization). The newly created intervals can be
spilled again, in that case, since it does not span multiple basic blocks, it's
spilled in the usual manner. However, it can reuse the same stack slot as the
previously split interval.

This is currently controlled by -split-intervals-at-bb.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44198 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-17 00:40:40 +00:00
Evan Cheng
7f56625447 Local spiller optimization:
Turn this:
movswl  %ax, %eax
movl    %eax, -36(%ebp)
xorl    %edi, -36(%ebp)
into
movswl  %ax, %eax
xorl    %edi, %eax
movl    %eax, -36(%ebp)
by unfolding the load / store xorl into an xorl and a store when we know the
value in the spill slot is available in a register. This doesn't change the
number of instructions but reduce the number of times memory is accessed.

Also unfold some load folding instructions and reuse the value when similar
situation presents itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42947 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-13 02:50:24 +00:00
Evan Cheng
549f27d307 Re-implement trivial rematerialization. This allows def MIs whose live intervals that are coalesced to be rematerialized.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41060 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-13 23:45:17 +00:00
David Greene
7e23146ab9 Add a missing forward declaration.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40896 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-07 16:34:05 +00:00
Dan Gohman
61e729e2e9 More explicit keywords.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40757 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-02 21:21:54 +00:00
Evan Cheng
9193514e2e Re-materialize all loads from fixed stack slots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35660 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-04 07:40:01 +00:00
Evan Cheng
2638e1a6b9 First cut trivial re-materialization support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35208 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-20 08:13:50 +00:00