be of (dynamically) constant values, so races on it are immaterial. We just need
to ensure that at least one write has completed before return the pointer into it.
With this change, parllc exhibits essentially no overhead on 403.gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79708 91177308-0d34-0410-b5e6-96231b3b80d8
- Drop the Candidates argument and fix all callers. Now that RegScavenger
tracks available registers accurately, there is no need to restict the
search.
- Make sure that no aliases of the found register are in use. This was a potential bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79369 91177308-0d34-0410-b5e6-96231b3b80d8
remove RemoveDuplicateSuccessor, as it is no longer necessary, and because
it breaks assumptions made in
MachineBasicBlock::isOnlyReachableByFallthrough.
Convert test/CodeGen/X86/omit-label.ll to FileCheck and add a testcase
for PR4732.
test/CodeGen/Thumb2/thumb2-ifcvt2.ll sees a diff with this commit due to
it being bugpoint-reduced to the point where it doesn't matter what the
condition for the branch is.
Add some more interesting code to
test/CodeGen/X86/2009-08-06-branchfolder-crash.ll, which is the testcase
that originally motivated the RemoveDuplicateSuccessor code, to help
verify that the original problem isn't being re-broken.
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MCAsmStreamer. Based on this, eliminate the current section from AsmPrinter.
While I'm at it, clean up the last of the horrible "switch to null section" stuff
and add an assert. This change is in preparation for completely eliminating
asmprinter::switchtosection.
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more properly belong. This allows removing the front-end conditionalized
SJLJ code, and cleans up the generated IR considerably. All of the
infrastructure code (calling _Unwind_SjLj_Register/Unregister, etc) is
added by the SjLjEHPrepare pass.
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doing it directly. This requires const'izing a bunch of stuff that
took sections, but this seems like the right semantic thing to do:
emitting a label to a section shouldn't mutate the MCSection object
itself, for example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79227 91177308-0d34-0410-b5e6-96231b3b80d8
If two uses of a CopyFromReg want different regclasses, first try a common
sub-class, then fall back on the copy emitted in AddRegisterOperand. There is
no need for an assert here. The cross-class joiner usually cleans up nicely.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79193 91177308-0d34-0410-b5e6-96231b3b80d8
It is legal for an inline asm operand to use an earlyclobber register if the
use operand is tied to the earlyclobber operand. The issue is discussed here:
http://gcc.gnu.org/ml/gcc/1999-04n/msg00431.html
We should perhaps let only the machine code verifier worry about these finer
details. EarlyClobber operands are not really interesting to the scavenger.
This fixes PR4528 for the third time.
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In a naked function, the flag is never set and getPristineRegs() returns an
empty list. That means naked functions are able to clobber callee saved
registers, but that is the whole point of naked functions.
This fixes PR4716.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79096 91177308-0d34-0410-b5e6-96231b3b80d8
In the included test case, a stack load was not included in DistanceMap. That
caused TransferDeadness to ignore the instruction, leading to a scavenger
assert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79090 91177308-0d34-0410-b5e6-96231b3b80d8
libcall. Take advantage of this in the ARM backend to rectify broken
choice of CC when hard float is in effect. PIC16 may want to see if
it could be of use in MakePIC16Libcall, which works unchanged.
Patch by Sandeep!
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TargetAsmInfo. This eliminates a dependency on TargetMachine.h from
TargetRegistry.h, which technically was a layering violation.
- Clients probably can only sensibly pass in the same TargetAsmInfo as the
TargetMachine has, but there are only limited clients of this API.
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syntactically as a string, very similiar to what Chris did with MachO.
The parsing support and validation is not introduced yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78890 91177308-0d34-0410-b5e6-96231b3b80d8
the basic block label printing to check whether a block has a name
before printing a comment character and whitespace for it.
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pair instead of from a virtual method on TargetMachine. This cuts the final
ties of TargetAsmInfo to TargetMachine, meaning that MC can now use
TargetAsmInfo.
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"inlineasmstart/end" strings so that the contents of the directive
are separate from the comment character. This lets elf targets
get #APP/#NOAPP for free even if they don't use "#" as the comment
character. This also allows hoisting the darwin stuff up to the
shared TAI class.
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The register scavenger maintains a DistanceMap that maps MI pointers to their
distance from the top of the current MBB. The DistanceMap is built
incrementally in forward() and in bulk in findFirstUse(). It is used by
scavengeRegister() to determine which candidate register has the longest
unused interval.
Unfortunately the DistanceMap contents can become outdated. The first time
scavengeRegister() is called, the DistanceMap is filled to cover the MBB. If
then instructions are inserted in the MBB (as they always are following
scavengeRegister()), the recorded distances are too short. This causes bad
behaviour in the included test case where a register use /after/ the current
position is ignored because findFirstUse() thinks is is /before/ the current
position. A "using an undefined register" assertion follows promptly.
The fix is to build a fresh DistanceMap at the top of scavengeRegister(), and
discard it after use. This means that DistanceMap is no longer needed as a
RegScavenger member variable, and forward() doesn't need to update it.
The fix then discloses issue number two in the same test case: The candidate
search in scavengeRegister() finds a CSR that has been saved in the prologue,
but is currently unused. It would be both inefficient and wrong to spill such
a register in the emergency spill slot. In the present case, the emergency
slot restore is placed immediately before the normal epilogue restore, leading
to a "Redefining a live register" assertion.
Fix number two: When scavengerRegister() stumbles upon an unused register that
is overwritten later in the MBB, return that register early. It is important
to verify that the register is defined later in the MBB, otherwise it might be
an unspilled CSR.
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and short. Well, it's kinda short. Definitely nasty and brutish.
The front-end generates the register/unregister calls into the SjLj runtime,
call-site indices and landing pad dispatch. The back end fills in the LSDA
with the call-site information provided by the front end. Catch blocks are
not yet implemented.
Built on Darwin and verified no llvm-core "make check" regressions.
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MERGE_VALUES nodes. Replacing the result values with the
operands in one MERGE_VALUES node may cause another
MERGE_VALUES node be CSE'd with the first one, and bring
its uses along, so that the first one isn't dead, as this
code expects. Fix this by iterating until the node is
really dead. This fixes PR4699.
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This definitely slows down asm output so put it under an -asm-exuberant
flag.
This information is useful when doing static analysis of performance
issues.
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2. Move section switch printing to MCSection virtual method which takes a
TAI. This eliminates textual formatting stuff from TLOF.
3. Eliminate SwitchToSectionDirective, getSectionFlagsAsString, and
TLOFELF::AtIsCommentChar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78510 91177308-0d34-0410-b5e6-96231b3b80d8
A TAI hook is appropriate in this case because this is just an
asm syntax issue, not a semantic difference. TLOF should model
the semantics of the section.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78498 91177308-0d34-0410-b5e6-96231b3b80d8
Blackfin supports and/or/xor on i32 but not on i16. Teach
DAGCombiner::SimplifyBinOpWithSameOpcodeHands to not produce illegal nodes
after legalize ops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78497 91177308-0d34-0410-b5e6-96231b3b80d8
Handle large integers, x86_fp80, ConstantAggregateZero, and two more ConstantExpr:
GetElementPtr and IntToPtr
Set SHF_MERGE bit for mergeable strings
Avoid zero initialized strings to be classified as a bss symbol
Don't allow common symbols to be classified as STB_WEAK
Add a constant to be used as a global value offset in data relocations
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78476 91177308-0d34-0410-b5e6-96231b3b80d8
Also don't dereference old pointers after they have been deleted causing
random crashes when enabling the machine code verifier.
Ahem...
I have not included a test case for the crash. It hapened when enabling the
verifier on CodeGen/X86/2009-08-06-branchfolder-crash.ll.
The crash depends on an MBB being allocated at the same address as a
previously deleted MBB. I don't think that can be reproduced reliably.
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Now there is no special treatment of instructions that redefine part of a
super-register. Instead, the super-register is marked with <imp-use,kill> and
<imp-def>. For instance, from LowerSubregs on ARM:
subreg: CONVERTING: %Q1<def> = INSERT_SUBREG %Q1<undef>, %D1<kill>, 5
subreg: %D2<def> = FCPYD %D1<kill>, 14, %reg0, %Q1<imp-def>
subreg: CONVERTING: %Q1<def> = INSERT_SUBREG %Q1, %D0<kill>, 6
subreg: %D3<def> = FCPYD %D0<kill>, 14, %reg0, %Q1<imp-use,kill>, %Q1<imp-def>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78466 91177308-0d34-0410-b5e6-96231b3b80d8
Verify that early clobber registers and their aliases are not used.
All changes to RegsAvailable are now done as a transaction so the order of
operands makes no difference.
The included test case is from PR4686. It has behaviour that was dependent on the order of operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78465 91177308-0d34-0410-b5e6-96231b3b80d8
- start support for new PEI w/reg alloc, allow running RS from emit{Pro,Epi}logue() target hooks.
- fix minor issue with recursion detection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78318 91177308-0d34-0410-b5e6-96231b3b80d8
and high-bits values in ways that weren't correct for integer
types wider than 64 bits. This fixes a miscompile in
PPMacroExpansion.cpp in clang on x86-64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78295 91177308-0d34-0410-b5e6-96231b3b80d8
a dirty hack and isn't need anymore since the last x86 code emitter patch)
- Add a target-dependent modifier to addend calculation
- Use R_X86_64_32S relocation for X86::reloc_absolute_word_sext
- Use getELFSectionFlags whenever possible
- fix getTextSection to use TLOF and emit the right text section
- Handle global emission for static ctors, dtors and Type::PointerTyID
- Some minor fixes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78176 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of awkwardly encoding calling-convention information with ISD::CALL,
ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering
provides three virtual functions for targets to override:
LowerFormalArguments, LowerCall, and LowerRet, which replace the custom
lowering done on the special nodes. They provide the same information, but
in a more immediately usable format.
This also reworks much of the target-independent tail call logic. The
decision of whether or not to perform a tail call is now cleanly split
between target-independent portions, and the target dependent portion
in IsEligibleForTailCallOptimization.
This also synchronizes all in-tree targets, to help enable future
refactoring and feature work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78142 91177308-0d34-0410-b5e6-96231b3b80d8
Imp-def is *not* allowed to redefine a live register.
Imp-use is *not* allowed to use a dead register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78106 91177308-0d34-0410-b5e6-96231b3b80d8
the masm backend. If anyone cares about masm in the future,
we'll have semantic sections it can hang off of.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78096 91177308-0d34-0410-b5e6-96231b3b80d8
For an undef operand, MO.getReg() is meaningless and we should not use it.
Undef operands should be skipped entirely.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78095 91177308-0d34-0410-b5e6-96231b3b80d8
When LowerExtract eliminates an EXTRACT_SUBREG with a kill flag, it moves the
kill flag to the place where the sub-register is killed. This can accidentally
overlap with the use of a sibling sub-register, and we have trouble.
In the test case we have this code:
Live Ins: %R0 %R1 %R2
%R2L<def> = EXTRACT_SUBREG %R2<kill>, 1
%R2H<def> = LOAD16fi <fi#-1>, 0, Mem:LD(2,4) [FixedStack-1 + 0]
%R1L<def> = EXTRACT_SUBREG %R1<kill>, 1
%R0L<def> = EXTRACT_SUBREG %R0<kill>, 1
%R0H<def> = ADD16 %R2H<kill>, %R2L<kill>, %AZ<imp-def>, %AN<imp-def>, %AC0<imp-def>, %V<imp-def>, %VS<imp-def>
subreg: CONVERTING: %R2L<def> = EXTRACT_SUBREG %R2<kill>, 1
subreg: eliminated!
subreg: killed here: %R0H<def> = ADD16 %R2H, %R2L, %R2<imp-use,kill>, %AZ<imp-def>, %AN<imp-def>, %AC0<imp-def>, %V<imp-def>, %VS<imp-def>
The kill flag on %R2 is moved to the last instruction, and the live range overlaps with the definition of %R2H:
*** Bad machine code: Redefining a live physical register ***
- function: f
- basic block: 0x18358c0 (#0)
- instruction: %R2H<def> = LOAD16fi <fi#-1>, 0, Mem:LD(2,4) [FixedStack-1 + 0]
Register R2H was defined but already live.
The fix is to replace EXTRACT_SUBREG with IMPLICIT_DEF instead of eliminating
it completely:
subreg: CONVERTING: %R2L<def> = EXTRACT_SUBREG %R2<kill>, 1
subreg: replace by: %R2L<def> = IMPLICIT_DEF %R2<kill>
Note that these IMPLICIT_DEF instructions survive to the asm output. It is
necessary to fix the stack-color-with-reg test case because of that.
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Implicit operands no longer get a free pass: Imp-use requires a live register
and imp-def requires a dead register.
There is also no special rule allowing redefinition of a sub-register when the
super-register is live. The super register must have imp-kill+imp-def operands
instead.
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killed by another operand.
There is probably a better fix. Either 1) scavenger can look at other operands, or
2) livevariables can be smarter about kill markers. Patches welcome.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78072 91177308-0d34-0410-b5e6-96231b3b80d8
TLI.computeMaskedBitsForTargetNode from ComputeMaskedBits, since
the former may call back into the latter. This fixes a major
compile time problem on a testcase that happnened to hit this
in a particularly bad way, PR4643.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78023 91177308-0d34-0410-b5e6-96231b3b80d8
When LowerSubregsInstructionPass::LowerInsert eliminates an INSERT_SUBREG
instriction because it is an identity copy, make sure that the same registers
are alive before and after the elimination.
When the super-register is marked <undef> this requires inserting an
IMPLICIT_DEF instruction to make sure the super register is live.
Fix a related bug where a kill flag on the inserted sub-register was not transferred properly.
Finally, clear the undef flag in MachineInstr::addRegisterKilled. Undef implies dead and kill implies live, so they cant both be valid.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77989 91177308-0d34-0410-b5e6-96231b3b80d8
Allow imp-def and imp-use of anything in the scavenger asserts, just like the machine code verifier.
Allow redefinition of a sub-register of a live register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77904 91177308-0d34-0410-b5e6-96231b3b80d8
support. This isn't immediately interesting, because Legalize
ends up lowering SELECT_CC if the target doesn't support it,
but this simplifies the process.
Also, if the SELECT_CC would be expanded in Legalize, it
can potentially end up with two copies of the condition
expression. By leaving it as SELECT+SETCC, the SELECT can be
expanded into two SELECTs that use a single SETCC.
The two comparisons are usually CSE'd, but depending on
when various expressions get legalized, the comparison
expression could involve calls to library functions, such
that the comparison expression may not be able to be CSE'd.
This will be needed by a future patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77896 91177308-0d34-0410-b5e6-96231b3b80d8
Use of an <undef> register is treated like an <imp-use>. It is not an error to use a dead <undef> register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77890 91177308-0d34-0410-b5e6-96231b3b80d8
