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.
llvm-svn: 78093
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.
llvm-svn: 78090
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.
llvm-svn: 78072
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.
llvm-svn: 78023
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.
llvm-svn: 77989
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.
llvm-svn: 77904
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.
llvm-svn: 77896
getLSDASection() to be more specific. This makes it pretty obvious
that the ELF LSDA section is being specified wrong in PIC mode. We're
probably getting a lot of startup-time relocations to a readonly page,
which is expensive and bad.
Someone who cares about ELF C++ should investigate this.
llvm-svn: 77847
compute it based on what it knows. As part of this, rename getSectionForMergeableConstant
to getSectionForConstant because it works for non-mergable constants also.
The only functionality change from this is that Xcore will start dropping
its jump tables into readonly section instead of data section in -static mode.
This should be fine as the linker resolves the relocations. If this is a
problem, let me know and we'll come up with another solution.
llvm-svn: 77833
to:
.quad X
even on a 32-bit system, where X is not 64-bits. There isn't much that
we can do here, so we just print:
.quad ((X) & 4294967295)
instead.
llvm-svn: 77818
should have no state that is specific to particular globals in the
section. In this case, it means the removal of the "isWeak" and
"ExplicitSection" bits. MCSection uses the new form of SectionKind.
To handle isWeak, I introduced a new SectionInfo class, which is
SectionKind + isWeak, and it is used by the part of the code generator
that does classification of a specific global.
The ExplicitSection disappears. It is moved onto MCSection as a new
"IsDirective" bit. Since the Name of a section is either a section
or directive, it makes sense to keep this bit in MCSection. Ultimately
the creator of MCSection should canonicalize (e.g.) .text to whatever
the actual section is.
llvm-svn: 77803
in SelectionDAGLowering::visitTargetIntrinsic.
This removes a bit of special-case code for vector types. After staring
at it for a while, I managed to convince myself that it is not necessary.
The only case where TLI.getValueType() differs from MVT::getMVT is for iPTR,
so this code could potentially make a difference for a vector of pointers.
But, it looks like that is not supported. Calling TLI.getValueType() on
a vector of pointers leads to the following sequence of calls:
TargetLowering::getValueType
MVT::getMVT
MVT::getVectorVT(iPTR, num elements)
MVT::getExtendedVectorVT
MVT::getTypeForMVT for iPTR
assertion fails "Type is not extended!"
So, unless I'm really missing something, this bit of code is irrelevant to
the current version of LLVM, which is consistent with the fact that I don't
see this code in other similar places.
llvm-svn: 77747
padding is disabled, tabs get replaced by spaces except in the case of
the first operand, where the tab is output to line up the operands after
the mnemonics.
Add some better comments and eliminate redundant code.
Fix some testcases to not assume tabs.
llvm-svn: 77740
thing is #if0'd out anyway. Just simplify the code by reducing the interface.
Not deleting this is essential for Bill's continuing happiness.
llvm-svn: 77736
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
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
When the return value is not used (i.e. only care about the value in the memory), x86 does not have to use add to implement these. Instead, it can use add, sub, inc, dec instructions with the "lock" prefix.
This is currently implemented using a bit of instruction selection trick. The issue is the target independent pattern produces one output and a chain and we want to map it into one that just output a chain. The current trick is to select it into a merge_values with the first definition being an implicit_def. The proper solution is to add new ISD opcodes for the no-output variant. DAG combiner can then transform the node before it gets to target node selection.
Problem #2 is we are adding a whole bunch of x86 atomic instructions when in fact these instructions are identical to the non-lock versions. We need a way to add target specific information to target nodes and have this information carried over to machine instructions. Asm printer (or JIT) can use this information to add the "lock" prefix.
llvm-svn: 77582
and convert code to using it, instead of having lots of things
poke the isLookupPtrRegClass() method directly.
2. Make PointerLikeRegClass contain a 'kind' int, and store it in
the existing regclass field of TargetOperandInfo when the
isLookupPtrRegClass() predicate is set. Make getRegClass pass
this into TargetRegisterInfo::getPointerRegClass(), allowing
targets to have multiple ptr_rc things.
llvm-svn: 77504
it is highly specific to the object file that will be generated in the end,
this introduces a new TargetLoweringObjectFile interface that is implemented
for each of ELF/MachO/COFF/Alpha/PIC16 and XCore.
Though still is still a brutal and ugly refactoring, this is a major step
towards goodness.
This patch also:
1. fixes a bunch of dangling pointer problems in the PIC16 backend.
2. disables the TargetLowering copy ctor which PIC16 was accidentally using.
3. gets us closer to xcore having its own crazy target section flags and
pic16 not having to shadow sections with its own objects.
4. fixes wierdness where ELF targets would set CStringSection but not
CStringSection_. Factor the code better.
5. fixes some bugs in string lowering on ELF targets.
llvm-svn: 77294
1. Spell SectionFlags::Writeable as "Writable".
2. Add predicates for deriving SectionFlags from SectionKinds.
3. Sink ELF-specific getSectionPrefixForUniqueGlobal impl into
ELFTargetAsmInfo.
4. Fix SectionFlagsForGlobal to know that BSS/ThreadBSS has the
BSS bit set (the real fix for PR4619).
5. Fix isSuitableForBSS to not put globals with explicit sections
set in BSS (which was the reason #4 wasn't fixed earlier).
6. Remove my previous hack for PR4619.
llvm-svn: 77085
- Some clients which used DOUT have moved to DEBUG. We are deprecating the
"magic" DOUT behavior which avoided calling printing functions when the
statement was disabled. In addition to being unnecessary magic, it had the
downside of leaving code in -Asserts builds, and of hiding potentially
unnecessary computations.
llvm-svn: 77019
%0 = malloc [3758096384 x i32]
The "malloc" instruction doesn't support 64-bits correctly (see PR715),
and should be removed. Victor is actively working on fixing this, in
the meantime just don't crash.
llvm-svn: 76899
- Yay for '-'s and simplifications!
- I kept StringMap::GetOrCreateValue for compatibility purposes, this can
eventually go away. Likewise the StringMapEntry Create functions still follow
the old style.
- NIFC.
llvm-svn: 76888
a new getSectionForMergableConstant hook. This removes one dependence
of TAI on Type, and provides the hook with enough info to make the
right decision based on whether the global has relocations etc.
llvm-svn: 76705
This is considered a workaround. The problem is some targets are not modeling side effects correctly. PPC is apparently one of those. This patch allows ppc llvm-gcc to bootstrap on Darwin. Once we find out which instruction definitions are wrong, we can remove the PPCInstrInfo workaround.
llvm-svn: 76703
Constant::getRelocationInfo(), which has a much simpler
to use API. It still should not be part of libvmcore, but
is better than it was. Also teach it to be smart about
hidden visibility.
llvm-svn: 76700
range's weight properly. This is turned off right now in the sense that
you'll get an assert if you get into a situation that can only be caused
by an iterative coalescer. All other code paths operate exactly as
before so there is no functional change with this patch. The asserts
should be disabled if/when an iterative coalescer gets added to trunk.
llvm-svn: 76680
pool entry will require relocations against it. I implemented this
conservatively for ARM, someone who is knowledgable about it should
see if this can be improved.
llvm-svn: 76678
their appropriate sections before the code itself. They need to be emitted
before the function because on some targets (x86 but not x86_64) the later
may reference a JT or CP entry address
llvm-svn: 76672
be useful, and it's currently unused. (Some issues: it isn't actually
rich enough to capture the semantics on many architectures, and
semantics can vary depending on the type being shifted.)
llvm-svn: 76633
"LinkerPrivatePrefix". It seems to have been used in only one place before I
started this "linker_private" business. I'm thinking that a rename is in
order...
llvm-svn: 76479
