Commit Graph

144 Commits

Author SHA1 Message Date
Evan Cheng
f2090008be 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.
llvm-svn: 82676
2009-09-24 02:15:22 +00:00
Evan Cheng
863ed2677b 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.

llvm-svn: 82616
2009-09-23 06:28:31 +00:00
Evan Cheng
97c8597450 Fix PR5024. LiveVariables::FindLastPartialDef should return a set of sub-registers that were defined by the last partial def, not just a single sub-register.
llvm-svn: 82535
2009-09-22 08:34:46 +00:00
Chris Lattner
11f509336c remove the last uses of Config/alloca.h
llvm-svn: 79873
2009-08-23 22:57:38 +00:00
Chris Lattner
db2965c71f remove various std::ostream version of printing methods from
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
2009-08-23 03:41:05 +00:00
Dan Gohman
f28b3bb262 Reapply r77654 with a fix: MachineFunctionPass's getAnalysisUsage
shouldn't do AU.setPreservesCFG(), because even though CodeGen passes
don't modify the LLVM IR CFG, they may modify the MachineFunction CFG,
and passes like MachineLoop are registered with isCFGOnly set to true.

llvm-svn: 77691
2009-07-31 18:16:33 +00:00
Daniel Dunbar
60d71a790c Revert r77654, it appears to be causing llvm-gcc bootstrap failures, and many
failures when building assorted projects with clang.

--- Reverse-merging r77654 into '.':
U    include/llvm/CodeGen/Passes.h
U    include/llvm/CodeGen/MachineFunctionPass.h
U    include/llvm/CodeGen/MachineFunction.h
U    include/llvm/CodeGen/LazyLiveness.h
U    include/llvm/CodeGen/SelectionDAGISel.h
D    include/llvm/CodeGen/MachineFunctionAnalysis.h
U    include/llvm/Function.h
U    lib/Target/CellSPU/SPUISelDAGToDAG.cpp
U    lib/Target/PowerPC/PPCISelDAGToDAG.cpp
U    lib/CodeGen/LLVMTargetMachine.cpp
U    lib/CodeGen/MachineVerifier.cpp
U    lib/CodeGen/MachineFunction.cpp
U    lib/CodeGen/PrologEpilogInserter.cpp
U    lib/CodeGen/MachineLoopInfo.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
D    lib/CodeGen/MachineFunctionAnalysis.cpp
D    lib/CodeGen/MachineFunctionPass.cpp
U    lib/CodeGen/LiveVariables.cpp

llvm-svn: 77661
2009-07-31 03:02:41 +00:00
Dan Gohman
645f1122c0 Manage MachineFunctions with an analysis Pass instead of the Annotable
mechanism. To support this, make MachineFunctionPass a little more
complete.

llvm-svn: 77654
2009-07-31 01:52:50 +00:00
Evan Cheng
29ce3bfbb8 Avoid adding a duplicate def. This fixes PR4478.
llvm-svn: 74857
2009-07-06 21:34:05 +00:00
Evan Cheng
b45918e5bb Fix PR4419: handle defs of partial uses.
llvm-svn: 73816
2009-06-20 04:34:51 +00:00
Evan Cheng
085beccfb5 If there is a def of a super-register followed by a use of a sub-register, do *not* add an implicit def of the sub-register. e.g.
EAX = ..., AX<imp-def>
...
    = AX

This creates a double-def. Apparently this used to be necessary but is no longer needed.

Thanks to Anton for pointing this out. Anton, I cannot create a test case without your uncommitted ARM patches. Please check in a test case for me.

llvm-svn: 72755
2009-06-03 05:15:46 +00:00
Jeffrey Yasskin
14f27c22aa 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.

llvm-svn: 72426
2009-05-26 18:27:15 +00:00
Evan Cheng
28673c9554 Eliminate VarInfo::UsedBlocks.
llvm-svn: 72411
2009-05-26 06:25:46 +00:00
Evan Cheng
5bea79c062 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.
llvm-svn: 62617
2009-01-20 21:25:12 +00:00
Devang Patel
a2ccbea45a Silence unused variable warnings.
llvm-svn: 59841
2008-11-21 20:00:59 +00:00
Dan Gohman
f63a02ae6c Use find_first/find_next to iterate through all the set bits in a
BitVector, instead of manually testing each bit.

llvm-svn: 59246
2008-11-13 16:31:27 +00:00
Dan Gohman
30c5ce1b7d Switch the MachineOperand accessors back to the short names like
isReg, etc., from isRegister, etc.

llvm-svn: 57006
2008-10-03 15:45:36 +00:00
Dan Gohman
98a22f8a8f 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.

llvm-svn: 56412
2008-09-21 21:11:41 +00:00
Owen Anderson
d3c6cbed61 Use SmallSet instead of std::set to save allocations.
llvm-svn: 54810
2008-08-14 23:41:38 +00:00
Owen Anderson
84fbc312d4 - 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.

llvm-svn: 54333
2008-08-04 23:54:43 +00:00
Evan Cheng
1f6148a84c - 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.

llvm-svn: 53097
2008-07-03 09:09:37 +00:00
Evan Cheng
67ab36cb9d Use std::replace instead of std::find and push_back.
llvm-svn: 53063
2008-07-03 00:28:27 +00:00
Evan Cheng
7c3920e692 - 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.

llvm-svn: 53061
2008-07-03 00:07:19 +00:00
Owen Anderson
e0604d46c2 Use a SmallSet when we can to reduce memory allocations.
This speeds up a particular testcase from 0.0302s to 0.0222s in LiveVariables.

llvm-svn: 52819
2008-06-27 07:05:59 +00:00
Dan Gohman
d1467012f5 Fix the text in an assert string.
llvm-svn: 52744
2008-06-25 22:14:43 +00:00
Bill Wendling
2501066409 This situation can occur:
,------.
    |      |
    |      v
    |   t2 = phi ... t1 ...
    |      |
    |      v
    |   t1 = ...
    |  ... = ... t1 ...
    |      |
    `------'

where there is a use in a PHI node that's a predecessor to the defining
block. We don't want to mark all predecessors as having the value "alive" in
this case. Also, the assert was too restrictive and didn't handle this case.

llvm-svn: 52655
2008-06-23 23:41:14 +00:00
Evan Cheng
6d05ce493b 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.

llvm-svn: 49784
2008-04-16 09:46:40 +00:00
Evan Cheng
748a0c9215 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.
llvm-svn: 49105
2008-04-02 18:04:08 +00:00
Evan Cheng
3d9309c11d 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.

llvm-svn: 48521
2008-03-19 00:52:20 +00:00
Evan Cheng
18064ddb5b Refactor code. Remove duplicated functions that basically do the same thing as
findRegisterUseOperandIdx, findRegisterDefOperandIndx. Fix some naming inconsistencies.

llvm-svn: 47927
2008-03-05 00:59:57 +00:00
Bill Wendling
27dcf967b0 Clear PhysRegPartUse for the sub register as well.
llvm-svn: 47453
2008-02-21 19:35:27 +00:00
Bill Wendling
aaf11abe28 Remove one of the fixmes that I put in there. From Evan:
No need to go up more levels. A def of a register also sets its sub-registers
(so if PhysRegInfo[SuperReg] is NULL, it means SuperReg's super registers are
not previously defined).

llvm-svn: 47399
2008-02-20 20:56:45 +00:00
Bill Wendling
df5f19c449 Improve some comments explaining the "handle kills" stuff better.
llvm-svn: 47395
2008-02-20 19:35:34 +00:00
Bill Wendling
753db180da Fix comment.
llvm-svn: 47389
2008-02-20 19:09:14 +00:00
Bill Wendling
54bd12bc49 Added some comments and reformatted others. No functionality change.
Added two "FIXMEs" for code that looks dubious to me (but I could be
wrong).

llvm-svn: 47366
2008-02-20 09:15:16 +00:00
Bill Wendling
9a2a1ddf6e More constification of things. More comments added. No functionality
changes. (Sorry for any formatting changes that creeped in.)

llvm-svn: 47362
2008-02-20 07:36:31 +00:00
Bill Wendling
723b09a29d No functionality change:
- Constified some MachineOperand values.
 - Added/Modified some comments.

llvm-svn: 47358
2008-02-20 06:10:21 +00:00
Dan Gohman
cabaec582f Rename MRegisterInfo to TargetRegisterInfo.
llvm-svn: 46930
2008-02-10 18:45:23 +00:00
Evan Cheng
69d5e0fc0f If a vr is already marked alive in a bb, then it has PHI uses that are visited earlier, then it is not killed in the def block (i.e. not dead).
llvm-svn: 46763
2008-02-05 20:04:18 +00:00
Owen Anderson
4d78ff86ae Move some functionality for adding flags to MachineInstr's into methods on MachineInstr rather than LiveVariables.
llvm-svn: 46295
2008-01-24 01:10:07 +00:00
Owen Anderson
214c1c3461 Move some calls to getVRegDef higher in the callgraph, so they don't get executed as frequently in performance sensitive code.
llvm-svn: 46027
2008-01-15 22:58:11 +00:00
Owen Anderson
946d55e773 Remove DefInst from LiveVariables::VarInfo. Use the facilities on MachineRegisterInfo instead.
llvm-svn: 46016
2008-01-15 22:02:46 +00:00
Chris Lattner
f83aae613c rename TargetInstrDescriptor -> TargetInstrDesc.
Make MachineInstr::getDesc return a reference instead
of a pointer, since it can never be null.

llvm-svn: 45695
2008-01-07 07:27:27 +00:00
Chris Lattner
9d38dfa4a5 Move a bunch more accessors from TargetInstrInfo to TargetInstrDescriptor
llvm-svn: 45680
2008-01-07 03:13:06 +00:00
Chris Lattner
96167aa93c Rename SSARegMap -> MachineRegisterInfo in keeping with the idea
that "machine" classes are used to represent the current state of
the code being compiled.  Given this expanded name, we can start 
moving other stuff into it.  For now, move the UsedPhysRegs and
LiveIn/LoveOuts vectors from MachineFunction into it.

Update all the clients to match.

This also reduces some needless #includes, such as MachineModuleInfo
from MachineFunction.

llvm-svn: 45467
2007-12-31 04:13:23 +00:00
Chris Lattner
9e5cc35593 Add new shorter predicates for testing machine operands for various types:
e.g. MO.isMBB() instead of MO.isMachineBasicBlock().  I don't plan on 
switching everything over, so new clients should just start using the 
shorter names.

Remove old long accessors, switching everything over to use the short
accessor: getMachineBasicBlock() -> getMBB(), 
getConstantPoolIndex() -> getIndex(), setMachineBasicBlock -> setMBB(), etc.

llvm-svn: 45464
2007-12-30 23:10:15 +00:00
Chris Lattner
7504adbd72 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

llvm-svn: 45461
2007-12-30 21:56:09 +00:00
Chris Lattner
19dd6c4eac Start using the simplified methods for adding operands.
llvm-svn: 45432
2007-12-30 00:41:17 +00:00
Chris Lattner
ad9a6ccb83 Remove attribution from file headers, per discussion on llvmdev.
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
Evan Cheng
5c96771102 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.

llvm-svn: 44198
2007-11-17 00:40:40 +00:00