Commit Graph

90 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
dcfe5f30b5 Keep track of phi join registers explicitly in LiveVariables.
Previously, LiveIntervalAnalysis would infer phi joins by looking for multiply
defined registers. That doesn't work if the phi join is implicitly defined in
all but one of the predecessors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96994 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-23 22:43:58 +00:00
Jakob Stoklund Olesen
8f72235a77 Move PHIElimination::isLiveOut method to LiveVariables.
We want LiveVariables clients to use methods rather than accessing the
getVarInfo data structure directly. That way it will be possible to change the
LiveVariables representation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90240 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 17:13:31 +00:00
Evan Cheng
a4025df42d Fix PR5614: parts of a physical register def may be killed the rest.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90180 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 00:44:45 +00:00
Jakob Stoklund Olesen
323d8c3ed7 Be more clever about calculating live variables through new basic blocks.
When splitting a critical edge, the registers live through the edge are:

- Used in a PHI instruction, or
- Live out from the predecessor, and
- Live in to the successor.

This allows the coalescer to eliminate even more phi joins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89530 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-21 02:05:21 +00:00
Jakob Stoklund Olesen
3e20475fee Fix liveness calculation when splitting critical edges during PHI elimination.
- Edges are split before any phis are eliminated, so the code is SSA.

- Create a proper IR BasicBlock for the split edges.

- LiveVariables::addNewBlock now has same syntax as
  MachineDominatorTree::addNewBlock. Algorithm calculates predecessor live-out
  set rather than successor live-in set.

This feature still causes some miscompilations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86867 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 19:31:31 +00:00
Jakob Stoklund Olesen
f235f13931 Teach PHIElimination to split critical edges when -split-phi-edges is enabled.
Critical edges leading to a PHI node are split when the PHI source variable is
live out from the predecessor block. This help the coalescer eliminate more
PHI joins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86725 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 22:01:05 +00:00
Evan Cheng
ad934b821c Clean up LiveVariables and change how it deals with partial updates and kills. This also eliminate the horrible check which scan forward to the end of the basic block. It should be faster and more accurate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82676 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-24 02:15:22 +00:00
Evan Cheng
296925dc16 Fix PR5024. LiveVariables physical register defs should *commit* only after all
of the defs are processed.
Also fix a implicit_def propagation bug: a implicit_def of a physical register
should be applied to uses of the sub-registers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82616 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-23 06:28:31 +00:00
Evan Cheng
dace0ed8c7 Forgot this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82536 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-22 08:47:59 +00:00
Dan Gohman
75144f93eb Fix apostrophos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81856 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-15 15:08:33 +00:00
David Greene
3a190f5e5e Add missing includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79467 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-19 21:17:28 +00:00
Jeffrey Yasskin
493a3d015c LiveVariables::VarInfo contains an AliveBlocks BitVector, which has as many
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72426 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-26 18:27:15 +00:00
Evan Cheng
aed4a430f4 Eliminate VarInfo::UsedBlocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72411 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-26 06:25:46 +00:00
Evan Cheng
a894ae130b Fix PR3243: a LiveVariables bug. When HandlePhysRegKill is checking whether the last reference is also the last def (i.e. dead def), it should also check if last reference is the current machine instruction being processed. This can happen when it is processing a physical register use and setting the current machine instruction as sub-register's last ref.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62617 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-20 21:25:12 +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
Dan Gohman
7fc610f073 Revert the part of r59145 that changed the comment about
virtual registers possibly having multiple kills while still
being defined and killed in the same block. If LiveIntervals
is manually re-run after two-address lowering, it currently
does add extra kills to two-address instructions, but this
is considered a bug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59194 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-12 23:24:15 +00:00
Dan Gohman
e8f4ac2b10 Update VarInfo's comments to reflect the current code. LiveVar
no longer records a unique defining instruction, and virtual
registers may have multiple kills while still being defined
and killed in the same block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59145 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-12 17:02:24 +00:00
Dan Gohman
d735b8019b Switch the MachineOperand accessors back to the short names like
isReg, etc., from isRegister, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57006 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-03 15:45:36 +00:00
Dan Gohman
3bdf5fe71a Factor out code into HandleVirtRegDef, for consistency with
Handle{Virt,Phys}Reg{Def,Use}. Remove a redundant check
for register zero, and redundant checks for isPhysicalRegister.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56412 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-21 21:11:41 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Owen Anderson
bd3ba461eb - Fix SelectionDAG to generate correct CFGs.
- Add a basic machine-level dead block eliminator.

These two have to go together, since many other parts of the code generator are unable to handle the unreachable blocks otherwise created.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54333 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-04 23:54:43 +00:00
Evan Cheng
9f1c8317a4 - Remove calls to copyKillDeadInfo which is an N^2 function. Instead, propagate kill / dead markers as new instructions are constructed in foldMemoryOperand, convertToThressAddress, etc.
- Also remove LiveVariables::instructionChanged, etc. Replace all calls with cheaper calls which update VarInfo kill list.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53097 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-03 09:09:37 +00:00
Evan Cheng
be04dc1413 - Add LiveVariables::replaceKillInstruction. This does a subset of instructionChanged. That is, it only update the VarInfo.kills if the new instruction is known to have the correct dead and kill markers.
- CommuteInstruction copies kill / dead markers over to new instruction. So use replaceKillInstruction instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53061 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-03 00:07:19 +00:00
Evan Cheng
0d4bdde327 Rewrite LiveVariable liveness computation. The new implementation is much simplified. It eliminated the nasty recursive routines and removed the partial def / use bookkeeping. There is also potential for performance improvement by replacing the conservative handling of partial physical register definitions. The code is currently disabled until live interval analysis is taught of the name scheme.
This patch also fixed a couple of nasty corner cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49784 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-16 09:46:40 +00:00
Evan Cheng
ea1d9cdc4e Now that I am told MachineRegisterInfo also tracks physical register uses / defs, I can do away with the horribleness I introduced a while back. It's impossible to detect if there is any use of a physical register below an instruction (and before any def of the register) with some cheap book keeping.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49105 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-02 18:04:08 +00:00
Evan Cheng
1088317675 Remove #include<map> from LiveVariables.h. Not referenced.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49099 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-02 17:23:50 +00:00
Evan Cheng
94202018c5 Fix live variables issues:
1. If part of a register is re-defined, an implicit kill and an implicit def are added to denote read / mod / write. However, this should only be necessary if the register is actually read later. This is a performance issue.
2. If a sub-register is being defined, and it doesn't have a previous use, do not add a implicit kill to the last use of a super-register:
   = EAX, AX<imp-use,kill>
...
AX =
In this case, EAX is live but AX is killed, this is wrong and will cause the coalescer to do bad things.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48521 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-19 00:52:20 +00:00
Evan Cheng
fe666a3592 Improve VarInfo::removeKill() by using std::find instead of linear search.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48321 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-13 02:42:55 +00:00
Evan Cheng
6130f66eaa Refactor code. Remove duplicated functions that basically do the same thing as
findRegisterUseOperandIdx, findRegisterDefOperandIndx. Fix some naming inconsistencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47927 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-05 00:59:57 +00:00
Bill Wendling
5ec3ab7f67 Fixed typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47365 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20 09:14:09 +00:00
Bill Wendling
420cdebbcb More constification of things. More comments added. No functionality
changes. (Sorry for any formatting changes that creeped in.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47362 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20 07:36:31 +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
Dan Gohman
35e9f7d711 Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46588 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-31 00:44:33 +00:00
Dan Gohman
6326b0d0f8 Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46507 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 12:06:33 +00:00
Owen Anderson
b487e7215c Move some functionality for adding flags to MachineInstr's into methods on MachineInstr rather than LiveVariables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46295 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-24 01:10:07 +00:00
Owen Anderson
40a627ddf8 Move some calls to getVRegDef higher in the callgraph, so they don't get executed as frequently in performance sensitive code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46027 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-15 22:58:11 +00:00
Evan Cheng
426df7538d Unbreak the build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46021 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-15 22:19:35 +00:00
Chris Lattner
f73823000e More cleanups for MachineOperand:
- Eliminate the static "print" method for operands, moving it
    into MachineOperand::print.
  - Change various set* methods for register flags to take a bool
    for the value to set it to.  Remove unset* methods.
  - Group methods more logically by operand flavor in MachineOperand.h


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45461 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-30 21:56:09 +00:00
Chris Lattner
7ed47a1335 Don't attribute in file headers anymore. See llvmdev for the
discussion of this change.  Boy are my fingers tired. ;-)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45411 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 19:59:42 +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
Owen Anderson
fc8663dbe0 Oops, forgot to commit this file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43867 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-08 01:22:24 +00:00
Dan Gohman
92dfe2001e Remove isReg, isImm, and isMBB, and change all their users to use
isRegister, isImmediate, and isMachineBasicBlock, which are equivalent,
and more popular.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41958 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-14 20:33:02 +00:00
Dan Gohman
c674a924d4 Don't assume that only Uses can be kills. Defs are marked as kills initially
when there are no uses. This fixes a dangling-pointer bug, where pointers to
deleted instructions were not removed from kills lists. More info here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-July/009749.html


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40131 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-20 23:17:34 +00:00
Evan Cheng
4efe74129f Properly handle kills of a physical register which has sub-registers that are read by later instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37739 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-26 21:03:35 +00:00
Evan Cheng
56184904cd Eliminate MarkVirtRegAliveInBlock recursion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36943 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-08 19:00:00 +00:00
Nick Lewycky
ecd94c804a Fix typo in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36873 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-06 13:37:16 +00:00
Devang Patel
1997473cf7 Drop 'const'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36662 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-03 01:11:54 +00:00
Devang Patel
3e15bf33e0 Use 'static const char' instead of 'static const int'.
Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36652 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-02 21:39:20 +00:00
Devang Patel
794fd75c67 Do not use typeinfo to identify pass in pass manager.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36632 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-01 21:15:47 +00:00
Evan Cheng
05350288a6 Be careful when to add implicit kill / dead operands. Don't add them during / post reg-allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36458 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-26 01:40:09 +00:00