and don't assume that the call doesn't throw. It would be nice if there were a
way to determine which is the callee and which is a parameter. In practice, the
architecture we care about normally only have one operand for a call instruction
(x86 and arm).
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slots. The AsmPrinter will use this information to determine whether to
print a spill/reload comment.
Remove default argument values. It's too easy to pass a wrong argument
value when multiple arguments have default values. Make everything
explicit to trap bugs early.
Update all targets to adhere to the new interfaces..
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making it visible to clients and adding LLVM-style cast capability.
This will be used by AsmPrinter to determine when to emit spill comments
for an instruction.
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instead of typedefs for std::pair. This simplifies the type of
SameTails, which previously was std::vector<std::pair<std::vector<std::pair<unsigned, MachineBasicBlock *> >::iterator, MachineBasicBlock::iterator>
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tail merging support to handle more cases.
- Recognize several cases where tail merging is beneficial even when
the tail size is smaller than the generic threshold.
- Make use of MachineInstrDesc::isBarrier to help detect
non-fallthrough blocks.
- Check for and avoid disrupting fall-through edges in more cases.
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- 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.
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constant whose component type is not a legal type for the target.
(If the target ConstantPool cannot handle this type either, it has
an opportunity to merge elements. In practice any target with
8-bit bytes must support i8 *as data*). 7320806 (partial).
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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.
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This patch forbids implicit conversion of DenseMap::const_iterator to
DenseMap::iterator which was possible because DenseMapIterator inherited
(publicly) from DenseMapConstIterator. Conversion the other way around is now
allowed as one may expect.
The template DenseMapConstIterator is removed and the template parameter
IsConst which specifies whether the iterator is constant is added to
DenseMapIterator.
Actually IsConst parameter is not necessary since the constness can be
determined from KeyT but this is not relevant to the fix and can be addressed
later.
Patch by Victor Zverovich!
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except it doesn't care if the definitions' virtual registers differ. This is
used by machine LICM and other MI passes to perform CSE.
- Teach Thumb2InstrInfo::isIdentical() to check two t2LDRpci_pic are identical.
Since pc relative constantpool entries are always different, this requires it
it check if the values can actually the same.
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A non-identity copy cannot be coalesced when the phi join destination register
is live at the copy site.
Also verify the condition that the PHI join source register is only used in
the PHI join. Otherwise the coalescing is invalid.
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The KILL pseudo-instruction may survive to the asm printer pass, just like the IMPLICIT_DEF. Print the KILL as a comment instead of just leaving a blank line in the output.
With -asm-verbose=0, a blank line is printed, like IMPLICIT?DEF.
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and extract_subreg as a "copy" that defines a valno.
Also fixes a typo. These two issues prevent a simple subreg coalescing from
happening before.
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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.
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an unconditional branch (possibly from tail merging), this code is
trying to redirect all of its predecessors to go directly to the branch
target, but that isn't feasible for indirect branches. The other
predecessors (that don't end with indirect branches) could theoretically
still be handled, but that is not easily done right now.
The AnalyzeBranch interface doesn't currently let us distinguish jump table
branches from indirect branches, and this code is currently handling
jump tables. To avoid punting on address-taken blocks, we would have to give
up handling jump tables. That seems like a bad tradeoff.
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the loop preheader. Add instructions which are already in the preheader block that
may be common expressions of those that are hoisted out. These does get a few more
instructions CSE'ed.
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- Be consistent when referring to MachineBasicBlocks: BB#0.
- Be consistent when referring to virtual registers: %reg1024.
- Be consistent when referring to unknown physical registers: %physreg10.
- Be consistent when referring to known physical registers: %RAX
- Be consistent when referring to register 0: %reg0
- Be consistent when printing alignments: align=16
- Print jump table contents.
- Don't print host addresses, in general.
- and various other cleanups.
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previously running CodePlacementOpt. Also print headers before
each dump in -print-machineinstrs mode, so that it's clear which
dump is which.
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results. This works around a problem affecting targets which rely on
MVT::Flag to handle physical register defs.
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unfolding loads for hoisting. getOpcodeAfterMemoryUnfold returns the
opcode of the original operation without the load, not the load
itself, MachineLICM needs to know the operand index in order to get
the correct register class. Extend getOpcodeAfterMemoryUnfold to
return this information.
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bunch of associated comments, because it doesn't have anything to do
with DAGs or scheduling. This is another step in decoupling MachineInstr
emitting from scheduling.
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indexed via the stack pointer, even if a frame pointer is present. Update the
heuristic to place it nearest the stack pointer in that case, rather than
nearest the frame pointer.
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the second (store) instruction in SpillSlotToUsesMap
consistently. I don't think this matters functionally,
but it's cleaner and Evan wants it this way.
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--- Reverse-merging r85338 into '.':
U lib/CodeGen/SimpleRegisterCoalescing.cpp
U lib/CodeGen/SimpleRegisterCoalescing.h
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to spill after all, we weren't handling 2-instruction
spill sequences correctly (PPC Altivec). We need to
remove the store in this case. Removing the other
instruction(s) would be goodness but is not needed for
correctness, and isn't done here. 7331562.
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use it to control tail merging when there is a tradeoff between performance
and code size. When there is only 1 instruction in the common tail, we have
been merging. That can be good for code size but is a definite loss for
performance. Now we will avoid tail merging in that case when the
optimization level is "Aggressive", i.e., "-O3". Radar 7338114.
Since the IfConversion pass invokes BranchFolding, it too needs to know
the optimization level. Note that I removed the RegisterPass instantiation
for IfConversion because it required a default constructor. If someone
wants to keep that for some reason, we can add a default constructor with
a hard-wired optimization level.
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Remove LowerAllocations pass.
Update some more passes to treate free calls just like they were treating FreeInst.
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machineinstr whether the aliased register is dead, rather than the original
register is dead. This allows it to get the correct answer when examining
an instruction like this:
CALLpcrel32 <ga:foo>, %AL<imp-def>, %EAX<imp-def,dead>
where EAX is dead but a subregister of it is still live. This fixes PR5294.
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bootstrapping. It's not safe to leave identity subreg_to_reg and insert_subreg
around.
- Relax register scavenging to allow use of partially "not-live" registers. It's
common for targets to operate on registers where the top bits are undef. e.g.
s0 =
d0 = insert_subreg d0<undef>, s0, 1
...
= d0
When the insert_subreg is eliminated by the coalescer, the scavenger used to
complain. The previous fix was to keep to insert_subreg around. But that's
brittle and it's overly conservative when we want to use the scavenger to
allocate registers. It's actually legal and desirable for other instructions
to use the "undef" part of d0. e.g.
s0 =
d0 = insert_subreg d0<undef>, s0, 1
...
s1 =
= s1
= d0
We probably need add a "partial-undef" marker on machine operand so the
machine verifier would not complain.
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Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.
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used elsewhere - an exit block is a block outside the loop branched to
from within the loop. An exiting block is a block inside the loop that
branches out.
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to break up CFG diamonds by banishing one of the blocks to the end of
the function, which is bad for code density and branch size.
This does pessimize MultiSource/Benchmarks/Ptrdist/yacr2, the
benchmark cited as the reason for the change, however I've examined
the code and it looks more like a case of gaming a particular
branch than of being generally applicable.
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tracked. Instead of trying to manually keep track of these locations
while doing complex modifications, just recompute them when they're needed.
This fixes a bug in which the TopMBB and BotMBB were not correctly updated,
leading to invalid transformations.
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appropriate restore location for the spill as well as perform the actual
save and restore.
The Thumb1 target uses this to make sure R12 is not clobbered while a spilled
scavenger register is live there.
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stack slots and giving them different PseudoSourceValue's did not fix the
problem of post-alloc scheduling miscompiling llvm itself.
- Apply Dan's conservative workaround by assuming any non fixed stack slots can
alias other memory locations. This means a load from spill slot #1 cannot
move above a store of spill slot #2.
- Enable post-alloc scheduling for x86 at optimization leverl Default and above.
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to be more general and understand more varieties of loops.
Teach CodePlacementOpt to reorganize the basic blocks of a loop so that
they are contiguous. This also includes a fair amount of logic for preserving
fall-through edges while doing so. This fixes a BranchFolding-ism where blocks
which can't be made to use a fall-through edge and don't conveniently fit
anywhere nearby get tossed out to the end of the function.
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header is just the entry block to the loop, and it needn't be at
the top of the loop in the code layout.
Remove the code that suppressed loop alignment for outer loops,
so that outer loops are aligned.
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so get rid of eh.selector.i64 and rename eh.selector.i32 to eh.selector.
Likewise for eh.typeid.for. This aligns us with gcc, which always uses a
32 bit value for the selector on all platforms. My understanding is that
the register allocator used to assert if the selector intrinsic size didn't
match the pointer size, and this was the reason for introducing the two
variants. However my testing shows that this is no longer the case (I
fixed some bugs in selector lowering yesterday, and some more today in the
fastisel path; these might have caused the original problems).
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to remat non-load instructions as loads, and the remat code now uses
the UnmodeledSideEffects flags, MachineMemOperands, and similar things
to decide which instructions are valid for rematerialization.
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truncating an SDValue (depending on whether the target
type is bigger or smaller than the value's type); or zero
extending or truncating it. Use it in a few places (this
seems to be a popular operation, but I only modified cases
of it in SelectionDAGBuild). In particular, the eh_selector
lowering was doing this wrong due to a repeated rather than
inverted test, fixed with this change.
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bootstrap of FSF-style PPC, so there is some
reason to believe the original bug (which was
never analyzed) has been fixed, probably by
82266.
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into MachineInstrs. This is mostly just moving the code from
ScheduleDAGSDNodesEmit.cpp into a new class. This decouples MachineInstr
emitting from scheduling.
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is trivially rematerializable and integrate it into
TargetInstrInfo::isTriviallyReMaterializable. This way, all places that
need to know whether an instruction is rematerializable will get the
same answer.
This enables the useful parts of the aggressive-remat option by
default -- using AliasAnalysis to determine whether a memory location
is invariant, and removes the questionable parts -- rematting operations
with virtual register inputs that may not be live everywhere.
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While recording beginning of a function, use scope info from the first location entry instead of just relying on first location entry itself.
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to declare that they preserve other passes without needing to pull in
additional header file or library dependencies. Convert MachineFunctionPass
and CodeGenLICM to make use of this.
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implementations with a new MachineInstr::isInvariantLoad, which uses
MachineMemOperands and is target-independent. This brings MachineLICM
and other functionality to targets which previously lacked an
isInvariantLoad implementation.
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a virtual register to eliminate a frame index, it can return that register
and the constant stored there to PEI to track. When scavenging to allocate
for those registers, PEI then tracks the last-used register and value, and
if it is still available and matches the value for the next index, reuses
the existing value rather and removes the re-materialization instructions.
Fancier tracking and adjustment of scavenger allocations to keep more
values live for longer is possible, but not yet implemented and would likely
be better done via a different, less special-purpose, approach to the
problem.
eliminateFrameIndex() is modified so the target implementations can return
the registers they wish to be tracked for reuse.
ARM Thumb1 implements and utilizes the new mechanism. All other targets are
simply modified to adjust for the changed eliminateFrameIndex() prototype.
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verbose-asm mode, print comments instead. This eliminates a non-comment
difference between verbose-asm mode and non-verbose-asm mode.
Also, factor out the relevant code out of all the targets and into
target-independent code.
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spill slot. When frame references are via the frame pointer, they will be
negative, but Thumb1 load/store instructions only allow positive immediate
offsets. Instead, Thumb1 will spill to R12.
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the new predicates I added) instead of going through a context and doing a
pointer comparison. Besides being cheaper, this allows a smart compiler
to turn the if sequence into a switch.
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MI->addOperand invalidates references to it's operands, avoid touching
the operand after a new one was added.
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to emit target-specific things at the beginning of the asm output. This
fixes a problem for PPC, where the text sections are not being kept together
as expected. The base class doInitialization code calls DW->BeginModule()
which emits a bunch of DWARF section directives. The PPC doInitialization
code then emits all the TEXT section directives, with the intention that they
will be kept together. But as I understand it, the Darwin assembler treats
the default TEXT section as a special case and moves it to the beginning of
the file, which means that all those DWARF sections are in the middle of
the text. With this change, the EmitStartOfAsmFile hook is called before
the DWARF section directives are emitted, so that all the PPC text section
directives come out right at the beginning of the file.
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basic blocks that are so long that their size overflows a short.
Also assert that overflow does not happen in the future, as requested by Evan.
This fixes PR4401.
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information. This allows arbitrary code involving DW_OP_plus_uconst
and DW_OP_deref. The scheme allows for easy extention to include,
any, or all of the DW_OP_ opcodes. I thought about just exposing all
of them, but, wasn't sure if people wanted the dwarf opcodes exposed
in the api. Is that a layering violation?
With this scheme, the entire existing block scheme used by llvm-gcc
can be switched over to the new scheme. I think that would be
cleaner, as then the compiler specific bits are not present in llvm
proper. Before the old code can be yanked however, similar code in
clang would have to be removed.
Next up, more testing.
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so a simple "current register" will suffice. Also add some additional
sanity-checking assertions to make sure things are as we expect.
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the instruction we're scavenging for. The scavenger needs to know to avoid
them when analyzing register usage.
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physical registers. This is especially critical for the later two since they
start the live interval of a super-register. e.g.
%DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1
If this instruction is eliminated, the register scavenger will not be happy as
D0 is not defined previously.
This fixes PR5055.
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allocatable. Even if it doesn't appear to have any defs, it may latter
on after register allocation.
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which have no defs anywhere in the function. In particular, this fixes sinking
of instructions that reference RIP on x86-64, which is currently being modeled
as a register.
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- Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
This eliminates MachineInstr's std::list member and allows the data to be
created by isel and live for the remainder of codegen, avoiding a lot of
copying and unnecessary translation. This also shrinks MemSDNode.
- Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
fields for MachineMemOperands.
- Change MemSDNode to have a MachineMemOperand member instead of its own
fields with the same information. This introduces some redundancy, but
it's more consistent with what MachineInstr will eventually want.
- Ignore alignment when searching for redundant loads for CSE, but remember
the greatest alignment.
Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.
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naming scheme used in SelectionDAG, where there are multiple kinds
of "target" nodes, but "machine" nodes are nodes which represent
a MachineInstr.
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before producing FSIN, FCOS, FSQRT. If they aren't
so marked we have to assume they might set errno.
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allows appropriate backends to generate a sqrt instruction.
On x86, this isn't done at -O0 because we go through
FastISel instead. This is a behavior change from before
this series of sqrt patches started. I think this is OK
considering that compile speed is most important at -O0, but
could be convinced otherwise.
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For the AAPCS ABI, SP must always be 4-byte aligned, and at any "public
interface" it must be 8-byte aligned. For the older ARM APCS ABI, the stack
alignment is just always 4 bytes. For X86, we currently align SP at
entry to a function (e.g., to 16 bytes for Darwin), but no stack alignment
is needed at other times, such as for a leaf function.
After discussing this with Dan, I decided to go with the approach of adding
a new "TransientStackAlignment" field to TargetFrameInfo. This value
specifies the stack alignment that must be maintained even in between calls.
It defaults to 1 except for ARM, where it is 4. (Some other targets may
also want to set this if they have similar stack requirements. It's not
currently required for PPC because it sets targetHandlesStackFrameRounding
and handles the alignment in target-specific code.) The existing StackAlignment
value specifies the alignment upon entry to a function, which is how we've
been using it anyway.
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interest for this, as it currently reserves a register rather than using
the scavenger for matierializing constants as needed.
Instead of scavenging registers on the fly while eliminating frame indices,
new virtual registers are created, and then a scavenged collectively in a
post-pass over the function. This isolates the bits that need to interact
with the scavenger, and sets the stage for more intelligent use, and reuse,
of scavenged registers.
For the time being, this is disabled by default. Once the bugs are worked out,
the current scavenging calls in replaceFrameIndices() will be removed and
the post-pass scavenging will be the default. Until then,
-enable-frame-index-scavenging enables the new code. Currently, only the
Thumb1 back end is set up to use it.
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LocalAreaOffset. (We don't have any of those right now.)
PEI::calculateFrameObjectOffsets includes the absolute value of the
LocalAreaOffset in the cumulative offset value used to calculate the
stack frame size. It then adds the raw value of the LocalAreaOffset
to the stack size. For a StackGrowsDown target, that raw value is negative
and has the effect of cancelling out the absolute value that was added
earlier, but that obviously won't work for a StackGrowsUp target. Change
to subtract the absolute value of the LocalAreaOffset.
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LiveVariables add implicit kills to correctly track partial register kills. This works well enough and is fairly accurate. But coalescer can make it impossible to maintain these markers. e.g.
BL <ga:sss1>, %R0<kill,undef>, %S0<kill>, %R0<imp-def>, %R1<imp-def,dead>, %R2<imp-def,dead>, %R3<imp-def,dead>, %R12<imp-def,dead>, %LR<imp-def,dead>, %D0<imp-def>, ...
...
%reg1031<def> = FLDS <cp#1>, 0, 14, %reg0, Mem:LD4[ConstantPool]
...
%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>
When reg1031 and S0 are coalesced, the copy (FCPYS) will be eliminated the the implicit-kill of D0 is lost. In this case it's possible to move the marker to the FLDS. But in many cases, this is not possible. Suppose
%reg1031<def> = FOO <cp#1>, %D0<imp-def>
...
%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>
When FCPYS goes away, the definition of S0 is the "FOO" instruction. However, transferring the D0 implicit-kill to FOO doesn't work since it is the def of D0 itself. We need to fix this in another time by introducing a "kill" pseudo instruction to track liveness.
Disabling the assertion is not ideal, but machine verifier is doing that job now. It's important to know double-def is not a miscomputation since it means a register should be free but it's not tracked as free. It's a performance issue instead.
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The machine code verifier did not check for explicit operands correctly. It
used MachineInstr::getNumExplicitOperands, but that method may cheat and use
the declared count in the TargetInstrDesc.
Now we check the explicit operands one at a time in visitMachineOperand.
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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.
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two different places for printing MachineMemOperands.
Drop the virtual from Value::dump and instead give Value a
protected virtual hook that can be overridden by subclasses
to implement custom printing. This lets printing be more
consistent, and simplifies printing of PseudoSourceValue
values.
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%S0<def> = EXTRACT_SUBREG %Q0<kill>, 1
to
%S0<def> = IMPLICIT_DEF %Q0<imp-use,kill>
Implicit_def does not *read* any register so the operand should be marked "implicit". The missing "implicit" marker on the operand is wrong, but it doesn't actually break anything.
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variable increment / decrement slighter high priority.
This has major impact on some micro-benchmarks. On MultiSource/Applications
and spec tests, it's a minor win. It also reduce 256.bzip instruction count
by 8%, 55 on 164.gzip on i386 / Darwin.
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the base pointer, without the offset. This matches MemSDNode's
new alignment behavior, and holds more interesting information.
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The machine code verifier no longer tolerates phi instructions with noop
operands. All MBBs on a phi instruction must be in the CFG.
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feature, either build the JIT in debug mode to enable it by default or pass
-jit-emit-debug to lli.
Right now, the only debug information that this communicates to GDB is call
frame information, since it's already being generated to support exceptions in
the JIT. Eventually, when DWARF generation isn't tied so tightly to AsmPrinter,
it will be easy to push that information to GDB through this interface.
Here's a step-by-step breakdown of how the feature works:
- The JIT generates the machine code and DWARF call frame info
(.eh_frame/.debug_frame) for a function into memory.
- The JIT copies that info into an in-memory ELF file with a symbol for the
function.
- The JIT creates a code entry pointing to the ELF buffer and adds it to a
linked list hanging off of a global descriptor at a special symbol that GDB
knows about.
- The JIT calls a function marked noinline that GDB knows about and has put an
internal breakpoint in.
- GDB catches the breakpoint and reads the global descriptor to look for new
code.
- When sees there is new code, it reads the ELF from the inferior's memory and
adds it to itself as an object file.
- The JIT continues, and the next time we stop the program, we are able to
produce a proper backtrace.
Consider running the following program through the JIT:
#include <stdio.h>
void baz(short z) {
long w = z + 1;
printf("%d, %x\n", w, *((int*)NULL)); // SEGFAULT here
}
void bar(short y) {
int z = y + 1;
baz(z);
}
void foo(char x) {
short y = x + 1;
bar(y);
}
int main(int argc, char** argv) {
char x = 1;
foo(x);
}
Here is a backtrace before this patch:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x2aaaabdfbd10 (LWP 25476)]
0x00002aaaabe7d1a8 in ?? ()
(gdb) bt
#0 0x00002aaaabe7d1a8 in ?? ()
#1 0x0000000000000003 in ?? ()
#2 0x0000000000000004 in ?? ()
#3 0x00032aaaabe7cfd0 in ?? ()
#4 0x00002aaaabe7d12c in ?? ()
#5 0x00022aaa00000003 in ?? ()
#6 0x00002aaaabe7d0aa in ?? ()
#7 0x01000002abe7cff0 in ?? ()
#8 0x00002aaaabe7d02c in ?? ()
#9 0x0100000000000001 in ?? ()
#10 0x00000000014388e0 in ?? ()
#11 0x00007fff00000001 in ?? ()
#12 0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=@0x7fffffffe050)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#13 0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=@0x13f06f8, envp=0x7fffffffe3b0)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#14 0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe398,
envp=0x7fffffffe3b0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208
And a backtrace after this patch:
Program received signal SIGSEGV, Segmentation fault.
0x00002aaaabe7d1a8 in baz ()
(gdb) bt
#0 0x00002aaaabe7d1a8 in baz ()
#1 0x00002aaaabe7d12c in bar ()
#2 0x00002aaaabe7d0aa in foo ()
#3 0x00002aaaabe7d02c in main ()
#4 0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=...)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#5 0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=..., envp=0x7fffffffe3c0)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#6 0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe3a8,
envp=0x7fffffffe3c0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82418 91177308-0d34-0410-b5e6-96231b3b80d8
U lib/CodeGen/AsmPrinter/DwarfException.cpp
U lib/CodeGen/AsmPrinter/DwarfException.h
--- Reverse-merging r82274 into '.':
U lib/Target/TargetLoweringObjectFile.cpp
G lib/CodeGen/AsmPrinter/DwarfException.cpp
These revisions were breaking everything.
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internal, they shouldn't use the indirect pointer stuff. In the case of
throw_rethrow_test, it was marked as 'internal' and calculated its own offset to
its contents.
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we pushed the beginning of the interval back 1, so the
interval would overlap with inputs that die. We were
also pushing the end of the interval back 1, though,
which means the earlyclobber didn't overlap with other
output operands. Don't do this. PR 4964.
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into the __DATA section. At launch time, dyld has to update most of the section
to fix up the type info pointers. It's better to place it into the __TEXT
section and use pc-rel indirect pointer encodings. Similar to the personality
routine.
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This can be seen on CodeGen/Generic/2006-09-06-SwitchLowering.ll. But it's not known to cause any real regression (but I have added an assertion for it now).
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constants out of loops. These aren't covered by the regular LICM
pass, because in LLVM IR constants don't require separate
instructions. They're not always covered by the MachineLICM pass
either, because it doesn't know how to unfold folded constant-pool
loads. This is somewhat experimental at this point, and off by
default.
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Eliminate the PersonalityPrefix/Suffix & NeedsIndirectEncoding
fields from MAI: they aren't part of the asm syntax, they are
related to the structure of the object file.
To replace their functionality, add a new
TLOF::getSymbolForDwarfGlobalReference method which asks targets
to decide how to reference a global from EH in a pc-relative way.
The default implementation just returns the symbol. The default
darwin implementation references the symbol through an indirect
$non_lazy_ptr stub. The bizarro x86-64 darwin specialization
handles the weird "foo@GOTPCREL+4" hack.
DwarfException.cpp now uses this to emit the reference to the
symbol in the right way, and this also eliminates another
horrible hack from DwarfException.cpp:
- if (strcmp(MAI->getPersonalitySuffix(), "+4@GOTPCREL"))
- O << "-" << MAI->getPCSymbol();
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one implementation into its one caller. This eliminates a totally
awesome and gratuitous hack where we casted a Function* to
GlobalVariable*.
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1. Switch from an std::set to a SmallPtrSet for visited chain nodes.
2. Do not force the recursive flattening of token factor nodes, regardless of
use count.
3. Immediately process newly created TokenFactor nodes.
Also, improve combiner-aa by teaching it that loads to non-overlapping offsets
of relatively aligned objects cannot alias.
These changes result in a >5x speedup for combiner-aa on most testcases.
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DAG Combiner to disambiguate chains for loads and stores of types which are
broken up by the Legalizer into smaller pieces.
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The gist of this is if source of some of the copies that feed into a phi join is defined by the phi join, we'd like to eliminate them. However, if any of the non-identity source overlaps the live interval of the phi join then the coalescer won't be able to coalesce them. The early coalescer's job is to eliminate the identity copies by partially-coalescing the two live intervals.
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created once, so shouldn't be stuck in the middle of the loop. Also early exit
if there are no uses of UnwindInst in the function.
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full AsmPrinter, and change TargetRegistry to keep track
of registered MCInstPrinters.
llvm-mc is still linking in the entire
target foo to get the code emitter stuff, but this is an
important step in the right direction.
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now that printBasicBlockLabel is only used for starting
a MBB. This allows elimination of a bunch of arguments.
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Move GetMBBSymbol up to AsmPrinter and make printBasicBlockLabel use it so that
we only have one place that decides what to name bb labels. Hopefully various
clients of printBasicBlockLabel can start using GetMBBSymbol instead.
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object, the timer it creates was not being deleted. Since the
timer belonged to a static timer group, the timer group would
be destroyed on shutdown, and would notice and complain that
not all timers it contained were destroyed.
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from the exception tables. However, Duncan explained why it's a can of worms to
do it the GCC way. I went back to doing it the LLVM way and added Duncan's
explanation so that I don't do this again in the future.
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like what GCC outputs. The mysterious code to insert padding wasn't in GCC at
all. I modified the TType base offset code to calculate the offset like GCC
does, though.
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code within it was the same inside and out. There's still a problem of the
TypeInfoSize should be the size of the TType format encoding (at least that's
what GCC thinks it should be).
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Basically, this patch is working towards removing the hard-coded values that are
output for the CIE. In particular, the CIE augmentation and the CIE augmentation
size. Both of these should be calculated. In the process, I was able to make a
bunch of code simpler.
The encodings for the personality, LSDA, and FDE in the CIE are still not
correct. They should be generated either from target-specific callbacks (blech!)
or grokked from first-principles.
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the MCInst path of the asmprinter. Instead, pull comment printing
out of the autogenerated asmprinter into each target that uses the
autogenerated asmprinter. This causes code duplication into each
target, but in a way that will be easier to clean up later when more
asmprinter stuff is commonized into the base AsmPrinter class.
This also fixes an xcore strangeness where it inserted two tabs
before every instruction.
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to instructions instead of zero extended ones. This makes the asmprinter
print signed values more consistently. This apparently only really affects
the X86 backend.
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instruction to insert before can be end(). getDebugLoc on
end() returns an invalid value, therefore use the debug
loc of the call instruction, and give it to InsertLabel.
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from floating-point to integer first, and bitcast the result
back to floating-point. Previously, this test was passing by
falling back to SelectionDAG lowering. The resulting code isn't
as nice, but it's correct and CodeGen now stays on the fast path.
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