LLVM has an @llvm.eh.dwarf.cfa intrinsic, used to lower the GCC-compatible
__builtin_dwarf_cfa() builtin. As pointed out in PR26761, this is currently
broken on PowerPC (and likely on ARM as well). Currently, @llvm.eh.dwarf.cfa is
lowered using:
ADD(FRAMEADDR, FRAME_TO_ARGS_OFFSET)
where FRAME_TO_ARGS_OFFSET defaults to the constant zero. On x86,
FRAME_TO_ARGS_OFFSET is lowered to 2*SlotSize. This setup, however, does not
work for PowerPC. Because of the way that the stack layout works, the canonical
frame address is not exactly (FRAMEADDR + FRAME_TO_ARGS_OFFSET) on PowerPC
(there is a lower save-area offset as well), so it is not just a matter of
implementing FRAME_TO_ARGS_OFFSET for PowerPC (unless we redefine its
semantics -- We can do that, since it is currently used only for
@llvm.eh.dwarf.cfa lowering, but the better to directly lower the CFA construct
itself (since it can be easily represented as a fixed-offset FrameIndex)). Mips
currently does this, but by using a custom lowering for ADD that specifically
recognizes the (FRAMEADDR, FRAME_TO_ARGS_OFFSET) pattern.
This change introduces a ISD::EH_DWARF_CFA node, which by default expands using
the existing logic, but can be directly lowered by the target. Mips is updated
to use this method (which simplifies its implementation, and I suspect makes it
more robust), and updates PowerPC to do the same.
Fixes PR26761.
Differential Revision: https://reviews.llvm.org/D24038
llvm-svn: 280350
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
When expanding FP constants, we attempt to shrink doubles to floats and perform an extending load.
However, on SystemZ, and possibly on other targets (I've only confirmed the problem on SystemZ), the FP extending load instruction may convert SNaN into QNaN, or may cause an exception. So in the general case, we would still like to shrink FP constants, but SNaNs should be left as doubles.
Differential Revision: https://reviews.llvm.org/D22685
llvm-svn: 277602
An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size.
After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts.
In doing so we can significantly reduce the number of operations required.
Differential Revision: https://reviews.llvm.org/D21578
llvm-svn: 276432
Summary:
Instead, we take a single flags arg (a bitset).
Also add a default 0 alignment, and change the order of arguments so the
alignment comes before the flags.
This greatly simplifies many callsites, and fixes a bug in
AMDGPUISelLowering, wherein the order of the args to getLoad was
inverted. It also greatly simplifies the process of adding another flag
to getLoad.
Reviewers: chandlerc, tstellarAMD
Subscribers: jholewinski, arsenm, jyknight, dsanders, nemanjai, llvm-commits
Differential Revision: http://reviews.llvm.org/D22249
llvm-svn: 275592
For the most part this simplifies all callers. There were two places in X86 that needed an explicit makeArrayRef to shorten a statically sized array.
llvm-svn: 274337
I think this converts all the simple cases that really just care about
the generated code being position independent or not. The remaining
uses are a bit more complicated and are checking things like "is this
a library or executable" or "can this symbol be preempted".
llvm-svn: 274055
Recommiting after correcting over-eager Debug Value transfer fixing PR28270.
[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.
Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.
This refixes PR9817 which was being incompletely checked in the
testsuite.
Reviewers: jyknight
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D21037
llvm-svn: 273585
Recommiting after fixing over-aggressive assertion
[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.
Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.
This refixes PR9817 which was being incompletely checked in the
testsuite.
Reviewers: jyknight
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D21037
llvm-svn: 273456
The setCallee function will set the number of fixed arguments based
on the size of the argument list. The FixedArgs parameter was often
explicitly set to 0, leading to a lack of consistent value for non-
vararg functions.
Differential Revision: http://reviews.llvm.org/D20376
llvm-svn: 273403
Summary:
canCombineSinCosLibcall() would previously combine sin+cos into sincos for
GNUX32/GNUEABI/GNUEABIHF regardless of whether UnsafeFPMath were set or not.
However, GNU would only combine them for UnsafeFPMath because sincos does not
set errno like sin and cos do. It seems likely that this is an oversight.
Reviewers: t.p.northover
Subscribers: t.p.northover, aemerson, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D21431
llvm-svn: 273259
[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.
Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.
This refixes PR9817 which was being incompletely checked in the
testsuite.
Reviewers: jyknight
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D21037
llvm-svn: 272792
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
llvm-svn: 272512
Currently, SelectionDAG assumes 8/16-bit cmpxchg returns either a sign
extended result, or a zero extended result. SystemZ takes a third
option by returning junk in the high bits (rotated contents of the other
bytes in the memory word). In that case, don't use Assert*ext, and
zero-extend the result ourselves if a comparison is needed.
Differential Revision: http://reviews.llvm.org/D19800
llvm-svn: 269075
When custom lowered, this is not called if the store is custom
lowered. Move it to be a utility function so targets can
easily expand unaligned accesses when custom lowering.
llvm-svn: 267029
For the same reason as the corresponding load change.
Note that ExpandStore is completely broken for non-byte sized element
vector stores, but preserve the current broken behavior which has tests
for it. The behavior should be the same, but now introduces a new typed
store that is incorrectly split later rather than doing it directly.
llvm-svn: 264928
On AMDGPU we want to be able to promote i64/f64 loads to v2i32.
If the access is unaligned, this would conclude that since i64 is legal,
it would convert it back to i64 and there is an endless legalization
loop.
Extract the logic for scalarizing the load into a new TargetLowering
function, where this can also replace the custom function AMDGPU
has for this.
llvm-svn: 264927
When merging stores in DAGCombiner, add check to ensure that no
dependenices exist that would cause the construction of a cycle in our
DAG. This may happen if one store has a data dependence on another
instruction (e.g. a load) which itself has a (chain) dependence on
another store being merged. These stores cannot be merged safely and
doing so results in a cycle that is discovered in LegalizeDAG.
This test is only done in cases where Antialias analysis is used (UseAA)
as non-AA store merge candidates will be merged logically after all
loads which have been checked to not alias.
Reviewers: ahatanak, spatel, niravd, arsenm, hfinkel, tstellarAMD, jyknight
Subscribers: llvm-commits, tberghammer, danalbert, srhines
Differential Revision: http://reviews.llvm.org/D18336
llvm-svn: 264461
If the operation's type has been promoted during type legalization, we
need to account for the fact that the high bits of the comparison
operand are likely unspecified.
The LHS is usually zero-extended, but MIPS sign extends it, so we have
to be slightly careful.
Patch by Simon Dardis.
llvm-svn: 264296
We were just completely ignoring the types when determining whether we could
safely emit a libcall as a tail call. This is clearly wrong.
Theoretically, we could dig deeper looking for incidental matches (much like
the generic code in Analysis.cpp does), but it's probably not worth it for the
few libcalls that exist.
llvm-svn: 264084
- Rename getATOMIC to getSYNC, as llvm will soon be able to emit both
'__sync' libcalls and '__atomic' libcalls, and this function is for
the '__sync' ones.
- getInsertFencesForAtomic() has been replaced with
shouldInsertFencesForAtomic(Instruction), so that the decision can be
made per-instruction. This functionality will be used soon.
- emitLeadingFence/emitTrailingFence are no longer called if
shouldInsertFencesForAtomic returns false, and thus don't need to
check the condition themselves.
llvm-svn: 263665
Since r230276, we support an improved legalization for f64->f16,
which goes through a temporary f32, improving codegen when
f32->f16 is legal but not f64->f16. This requires unsafe-fp-math.
However, that legalization assumed that the second step, producing
a pseudo-softened f16, had type i16. That's not true on targets
with illegal i16, such as ARM.
Use the initial f64->f16 result type instead.
llvm-svn: 257794
During selection DAG legalization, extractelement is replaced with a load
instruction. To do this, a temporary store to the stack is used unless an
existing store is found that can be re-used.
If re-using a store, the chain going out of the store must be replaced by
the one going out of the new load (this ensures that any stores that must
take place after the store happens after the load, else the value might
be overwritten before it is loaded).
The problem is, if the extractelement index is dependent on the store
replacing the chain will introduce a cycle in the selection DAG (the load
uses the index, and by replacing the chain we will make the index dependent
on the load).
To fix this, if the index is dependent on the store, the store is skipped.
This is conservative as we may end up creating an unnecessary extra store
to the stack. However, the situation is not expected to occur very often.
Differential Revision: http://reviews.llvm.org/D15330
llvm-svn: 255114
Almost all these changes are conditioned and only apply to the new
x86-64 f128 type configuration, which will be enabled in a follow up
patch. They are required together to make new f128 work. If there is
any error, we should fix or revert them as a whole.
These changes should have no impact to current configurations.
* Relax type legalization checks to accept new f128 type configuration,
whose TypeAction is TypeSoftenFloat, not TypeLegal, but also has
TLI.isTypeLegal true.
* Relax GetSoftenedFloat to return in some cases f128 type SDValue,
which is TLI.isTypeLegal but not "softened" to i128 node.
* Allow customized FABS, FNEG, FCOPYSIGN on new f128 type configuration,
to generate optimized bitwise operators for libm functions.
* Enhance related Lower* functions to handle f128 type.
* Enhance DAGTypeLegalizer::run, SoftenFloatResult, and related functions
to keep new f128 type in register, and convert f128 operators to library calls.
* Fix Combiner, Emitter, Legalizer routines that did not handle f128 type.
* Add ExpandConstant to handle i128 constants, ExpandNode
to handle ISD::Constant node.
* Add one more parameter to getCommonSubClass and firstCommonClass,
to guarantee that returned common sub class will contain the specified
simple value type.
This extra parameter is used by EmitCopyFromReg in InstrEmitter.cpp.
* Fix infinite loop in getTypeLegalizationCost when f128 is the value type.
* Fix printOperand to handle null operand.
* Enhance ISD::BITCAST node to handle f128 constant.
* Expand new f128 type for BR_CC, SELECT_CC, SELECT, SETCC nodes.
* Enhance X86AsmPrinter to emit f128 values in comments.
Differential Revision: http://reviews.llvm.org/D15134
llvm-svn: 254653
The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.
Patch by Max Ostapenko.
Differential Revision: http://reviews.llvm.org/D14983
llvm-svn: 254404
to a simple type when lowering a truncating store of a vector type. In this
case for an EVT we'll return Expand as we should in all of the cases anyhow.
The testcase triggered at the one in VectorLegalizer::LegalizeOp, inspection
found the rest.
llvm-svn: 254061
Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash.
What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size.
Use an APInt for the shift and VT.getScalarSizeInBits().
llvm-svn: 253023
Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target.
This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support.
The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently).
llvm-svn: 252878
- Factor out code to query and modify the sign bit of a floatingpoint
value as an integer. This also works if none of the targets integer
types is big enough to hold all bits of the floatingpoint value.
- Legalize FABS(x) as FCOPYSIGN(x, 0.0) if FCOPYSIGN is available,
otherwise perform bit manipulation on the sign bit. The previous code
used "x >u 0 ? x : -x" which is incorrect for x being -0.0! It also
takes 34 instructions on ARM Cortex-M4. With this patch we only
require 5:
vldr d0, LCPI0_0
vmov r2, r3, d0
lsrs r2, r3, #31
bfi r1, r2, #31, #1
bx lr
(This could be further improved if the compiler would recognize that
r2, r3 is zero).
- Only lower FCOPYSIGN(x, y) = sign(x) ? -FABS(x) : FABS(x) if FABS is
available otherwise perform bit manipulation on the sign bit.
- Perform the sign(x) test by masking out the sign bit and comparing
with 0 rather than shifting the sign bit to the highest position and
testing for "<s 0". For x86 copysignl (on 80bit values) this gets us:
testl $32768, %eax
rather than:
shlq $48, %rax
sets %al
testb %al, %al
Differential Revision: http://reviews.llvm.org/D11172
llvm-svn: 252839
This allows avoiding the default Expand behavior which
introduces stack usage. Bitcast the scalar and replace
the missing elements with undef.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252632
This is for AMDGPU to implement v2i64 extract as extract of
half of a v4i32.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252630
This will be used in future commits for AMDGPU to promote
operations on i64 vectors into operations on 32-bit vector
components.
This will be used / tested in future AMDGPU commits.
llvm-svn: 250945
Summary:
TargetLoweringBase::Expand is defined as "Try to expand this to other ops,
otherwise use a libcall." For ISD::UDIV and ISD::SDIV, the choice between
the two possibilities was defined in a rather convoluted way:
- if DIVREM is legal, expand to DIVREM
- if DIVREM has a custom lowering, expand to DIVREM
- if DIVREM libcall is defined and a remainder from the same division is
computed elsewhere, expand to a DIVREM libcall
- else, expand to a DIV libcall
This had the undesirable effect that if both DIV and DIVREM are implemented
as libcalls, then ISD::UDIV and ISD::SDIV are expanded to the heavier DIVREM
libcall, even when the remainder isn't used.
The new code adds a new LegalizeAction, TargetLoweringBase::LibCall, so that
backends can directly control whether they prefer an expansion or a conversion
to a libcall. This makes the generic lowering code even more generic,
allowing its reuse in a wider range of target-specific configurations.
The useful effect is that ARM backend will now generate a call
to __aeabi_{i,u}div rather than __aeabi_{i,u}divmod in cases where
it doesn't need the remainder. There's no functional change outside
the ARM backend.
Reviewers: t.p.northover, rengolin
Subscribers: t.p.northover, llvm-commits, aemerson
Differential Revision: http://reviews.llvm.org/D13862
llvm-svn: 250826
