The changes here are based on the corresponding diffs for allowing FMF on 'select':
D61917
As discussed there, we want to have fast-math-flags be a property of an FP value
because the alternative (having them on things like fcmp) leads to logical
inconsistency such as:
https://bugs.llvm.org/show_bug.cgi?id=38086
The earlier patch for select made almost no practical difference because most
unoptimized conditional code begins life as a phi (based on what I see in clang).
Similarly, I don't expect this patch to do much on its own either because
SimplifyCFG promptly drops the flags when converting to select on a minimal
example like:
https://bugs.llvm.org/show_bug.cgi?id=39535
But once we have this plumbing in place, we should be able to wire up the FMF
propagation and start solving cases like that.
The change to RecurrenceDescriptor::AddReductionVar() is required to prevent a
regression in a LoopVectorize test. We are intersecting the FMF of any
FPMathOperator there, so if a phi is not properly annotated, new math
instructions may not be either. Once we fix the propagation in SimplifyCFG, it
may be safe to remove that hack.
Differential Revision: https://reviews.llvm.org/D67564
llvm-svn: 372866
The static analyzer is warning about a potential null dereference, but we should be able to use cast<CallInst> directly and if not assert will fire for us.
llvm-svn: 372720
Summary:
The functions different in two ways:
- getLLVMRegNum could return both "eh" and "other" dwarf register
numbers, while getLLVMRegNumFromEH only returned the "eh" number.
- getLLVMRegNum asserted if the register was not found, while the second
function returned -1.
The second distinction was pretty important, but it was very hard to
infer that from the function name. Aditionally, for the use case of
dumping dwarf expressions, we needed a function which can work with both
kinds of number, but does not assert.
This patch solves both of these issues by merging the two functions into
one, returning an Optional<unsigned> value. While the same thing could
be achieved by adding an "IsEH" argument to the (renamed)
getLLVMRegNumFromEH function, it seemed better to avoid the confusion of
two functions and put the choice of asserting into the hands of the
caller -- if he checks the Optional value, he can safely process
"untrusted" input, and if he blindly dereferences the Optional, he gets
the assertion.
I've updated all call sites to the new API, choosing between the two
options according to the function they were calling originally, except
that I've updated the usage in DWARFExpression.cpp to use the "safe"
method instead, and added a test case which would have previously
triggered an assertion failure when processing (incorrect?) dwarf
expressions.
Reviewers: dsanders, arsenm, JDevlieghere
Subscribers: wdng, aprantl, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67154
llvm-svn: 372710
We were miscompiling switch value comparisons with the wrong signedness, which
shows up when we have things like switch case values with i1 types, which end up
being legalized incorrectly.
Fixes PR43383
llvm-svn: 372675
This came up in the x86-specific:
https://bugs.llvm.org/show_bug.cgi?id=43239
...but it is a general problem for the BreakFalseDeps pass.
Dependencies may be broken by adding some other instruction,
so that should be avoided if the overall goal is to minimize size.
Differential Revision: https://reviews.llvm.org/D67363
llvm-svn: 372628
This intrinsics should be shift by immediate, but gcc allows any
i32 scalar and clang needs to match that. So we try to detect the
non-constant case and move the data from an integer register to an
MMX register.
Previously this was done by creating a v2i32 build_vector and
bitcast in SelectionDAGBuilder. This had to be done early since
v2i32 isn't a legal type. The bitcast+build_vector would be DAG
combined to X86ISD::MMX_MOVW2D which isel will turn into a
GPR->MMX MOVD.
This commit just moves the whole thing to lowering and emits
the X86ISD::MMX_MOVW2D directly to avoid the illegal type. The
test changes just seem to be due to nodes being linearized in a
different order.
llvm-svn: 372535
Recommit: fix asan errors.
The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).
This patch introduces a new API:
/// Analyze loop L, which must be a single-basic-block loop, and if the
/// conditions can be understood enough produce a PipelinerLoopInfo object.
virtual std::unique_ptr<PipelinerLoopInfo>
analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;
The return value is expected to be an implementation of the abstract class:
/// Object returned by analyzeLoopForPipelining. Allows software pipelining
/// implementations to query attributes of the loop being pipelined.
class PipelinerLoopInfo {
public:
virtual ~PipelinerLoopInfo();
/// Return true if the given instruction should not be pipelined and should
/// be ignored. An example could be a loop comparison, or induction variable
/// update with no users being pipelined.
virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;
/// Create a condition to determine if the trip count of the loop is greater
/// than TC.
///
/// If the trip count is statically known to be greater than TC, return
/// true. If the trip count is statically known to be not greater than TC,
/// return false. Otherwise return nullopt and fill out Cond with the test
/// condition.
virtual Optional<bool>
createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
SmallVectorImpl<MachineOperand> &Cond) = 0;
/// Modify the loop such that the trip count is
/// OriginalTC + TripCountAdjust.
virtual void adjustTripCount(int TripCountAdjust) = 0;
/// Called when the loop's preheader has been modified to NewPreheader.
virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;
/// Called when the loop is being removed.
virtual void disposed() = 0;
};
The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.
llvm-svn: 372463
We currently always set the HasCalls on MFI during translation and legalization if
we're handling a call or legalizing to a libcall. However, if that call is later
optimized to a tail call then we don't need the flag. The flag being set to true
causes frame lowering to always save and restore FP/LR, which adds unnecessary code.
This change does the same thing as SelectionDAG and ports over some code that scans
instructions after selection, using TargetInstrInfo to determine if target opcodes
are known calls.
Code size geomean improvements on CTMark:
-O0 : 0.1%
-Os : 0.3%
Differential Revision: https://reviews.llvm.org/D67868
llvm-svn: 372443
This commit broke the ASan buildbot. See comments in rL372376 for more
information.
This reverts commit 15e27b0b6d9d51362fad85dbe95ac5b3fadf0a06.
llvm-svn: 372425
Summary:
After the switch in SimplifyDemandedBits, it tries to create a
constant when possible. If the original node is a TargetConstant
the default in the switch will call computeKnownBits on the
TargetConstant which will succeed. This results in the
TargetConstant becoming a Constant. But TargetConstant exists to
avoid being changed.
I've fixed the two cases that relied on this in tree by explicitly
making the nodes constant instead of target constant. The Sparc
case is an old bug. The Mips case was recently introduced now that
ImmArg on intrinsics gets turned into a TargetConstant when the
SelectionDAG is created. I've removed the ImmArg since it lowers
to generic code.
Reviewers: arsenm, RKSimon, spatel
Subscribers: jyknight, sdardis, wdng, arichardson, hiraditya, fedor.sergeev, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67802
llvm-svn: 372409
The insertion of an unconditional branch during FastISel can differ depending on
building with or without debug information. This happens because FastISel::fastEmitBranch
emits an unconditional branch depending on the size of the current basic block
without distinguishing between debug and non-debug instructions.
This patch fixes this issue by ignoring debug instructions when getting the size
of the basic block.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: ormris, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67703
llvm-svn: 372389
The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).
This patch introduces a new API:
/// Analyze loop L, which must be a single-basic-block loop, and if the
/// conditions can be understood enough produce a PipelinerLoopInfo object.
virtual std::unique_ptr<PipelinerLoopInfo>
analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;
The return value is expected to be an implementation of the abstract class:
/// Object returned by analyzeLoopForPipelining. Allows software pipelining
/// implementations to query attributes of the loop being pipelined.
class PipelinerLoopInfo {
public:
virtual ~PipelinerLoopInfo();
/// Return true if the given instruction should not be pipelined and should
/// be ignored. An example could be a loop comparison, or induction variable
/// update with no users being pipelined.
virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;
/// Create a condition to determine if the trip count of the loop is greater
/// than TC.
///
/// If the trip count is statically known to be greater than TC, return
/// true. If the trip count is statically known to be not greater than TC,
/// return false. Otherwise return nullopt and fill out Cond with the test
/// condition.
virtual Optional<bool>
createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
SmallVectorImpl<MachineOperand> &Cond) = 0;
/// Modify the loop such that the trip count is
/// OriginalTC + TripCountAdjust.
virtual void adjustTripCount(int TripCountAdjust) = 0;
/// Called when the loop's preheader has been modified to NewPreheader.
virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;
/// Called when the loop is being removed.
virtual void disposed() = 0;
};
The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.
llvm-svn: 372376
If an instruction had multiple subregister defs, and one of them was
undef, this would improperly conclude all other lanes are
killed. There could still be other defs of those read-undef lanes in
other operands. This would improperly remove register uses from
CurrentVRegUses, so the visitation of later operands would not find
the necessary register dependency. This would also mean this would
fail or not depending on how different subregister def operands were
ordered.
On an undef subregister def, scan the instruction for other
subregister defs and avoid killing those.
This possibly should be deferring removing anything from
CurrentVRegUses until the entire instruction has been processed
instead.
llvm-svn: 372362
This reverts r372314, reapplying r372285 and the commits which depend
on it (r372286-r372293, and r372296-r372297)
This was missing one switch to getTargetConstant in an untested case.
llvm-svn: 372338
This patch converts the DAGCombine isNegatibleForFree/GetNegatedExpression into overridable TLI hooks and includes a demonstration X86 implementation.
The intention is to let us extend existing FNEG combines to work more generally with negatible float ops, allowing it work with target specific combines and opcodes (e.g. X86's FMA variants).
Unlike the SimplifyDemandedBits, we can't just handle target nodes through a Target callback, we need to do this as an override to allow targets to handle generic opcodes as well. This does mean that the target implementations has to duplicate some checks (recursion depth etc.).
I've only begun to replace X86's FNEG handling here, handling FMADDSUB/FMSUBADD negation and some low impact codegen changes (some FMA negatation propagation). We can build on this in future patches.
Differential Revision: https://reviews.llvm.org/D67557
llvm-svn: 372333
As commented on D67557 we have a lot of uses of depth checks all using magic numbers.
This patch adds the SelectionDAG::MaxRecursionDepth constant and moves over some general cases to use this explicitly.
Differential Revision: https://reviews.llvm.org/D67711
llvm-svn: 372315
This broke the Chromium build, causing it to fail with e.g.
fatal error: error in backend: Cannot select: t362: v4i32 = X86ISD::VSHLI t392, Constant:i8<15>
See llvm-commits thread of r372285 for details.
This also reverts r372286, r372287, r372288, r372289, r372290, r372291,
r372292, r372293, r372296, and r372297, which seemed to depend on the
main commit.
> Encode them directly as an imm argument to G_INTRINSIC*.
>
> Since now intrinsics can now define what parameters are required to be
> immediates, avoid using registers for them. Intrinsics could
> potentially want a constant that isn't a legal register type. Also,
> since G_CONSTANT is subject to CSE and legalization, transforms could
> potentially obscure the value (and create extra work for the
> selector). The register bank of a G_CONSTANT is also meaningful, so
> this could throw off future folding and legalization logic for AMDGPU.
>
> This will be much more convenient to work with than needing to call
> getConstantVRegVal and checking if it may have failed for every
> constant intrinsic parameter. AMDGPU has quite a lot of intrinsics wth
> immarg operands, many of which need inspection during lowering. Having
> to find the value in a register is going to add a lot of boilerplate
> and waste compile time.
>
> SelectionDAG has always provided TargetConstant for constants which
> should not be legalized or materialized in a register. The distinction
> between Constant and TargetConstant was somewhat fuzzy, and there was
> no automatic way to force usage of TargetConstant for certain
> intrinsic parameters. They were both ultimately ConstantSDNode, and it
> was inconsistently used. It was quite easy to mis-select an
> instruction requiring an immediate. For SelectionDAG, start emitting
> TargetConstant for these arguments, and using timm to match them.
>
> Most of the work here is to cleanup target handling of constants. Some
> targets process intrinsics through intermediate custom nodes, which
> need to preserve TargetConstant usage to match the intrinsic
> expectation. Pattern inputs now need to distinguish whether a constant
> is merely compatible with an operand or whether it is mandatory.
>
> The GlobalISelEmitter needs to treat timm as a special case of a leaf
> node, simlar to MachineBasicBlock operands. This should also enable
> handling of patterns for some G_* instructions with immediates, like
> G_FENCE or G_EXTRACT.
>
> This does include a workaround for a crash in GlobalISelEmitter when
> ARM tries to uses "imm" in an output with a "timm" pattern source.
llvm-svn: 372314
Encode them directly as an imm argument to G_INTRINSIC*.
Since now intrinsics can now define what parameters are required to be
immediates, avoid using registers for them. Intrinsics could
potentially want a constant that isn't a legal register type. Also,
since G_CONSTANT is subject to CSE and legalization, transforms could
potentially obscure the value (and create extra work for the
selector). The register bank of a G_CONSTANT is also meaningful, so
this could throw off future folding and legalization logic for AMDGPU.
This will be much more convenient to work with than needing to call
getConstantVRegVal and checking if it may have failed for every
constant intrinsic parameter. AMDGPU has quite a lot of intrinsics wth
immarg operands, many of which need inspection during lowering. Having
to find the value in a register is going to add a lot of boilerplate
and waste compile time.
SelectionDAG has always provided TargetConstant for constants which
should not be legalized or materialized in a register. The distinction
between Constant and TargetConstant was somewhat fuzzy, and there was
no automatic way to force usage of TargetConstant for certain
intrinsic parameters. They were both ultimately ConstantSDNode, and it
was inconsistently used. It was quite easy to mis-select an
instruction requiring an immediate. For SelectionDAG, start emitting
TargetConstant for these arguments, and using timm to match them.
Most of the work here is to cleanup target handling of constants. Some
targets process intrinsics through intermediate custom nodes, which
need to preserve TargetConstant usage to match the intrinsic
expectation. Pattern inputs now need to distinguish whether a constant
is merely compatible with an operand or whether it is mandatory.
The GlobalISelEmitter needs to treat timm as a special case of a leaf
node, simlar to MachineBasicBlock operands. This should also enable
handling of patterns for some G_* instructions with immediates, like
G_FENCE or G_EXTRACT.
This does include a workaround for a crash in GlobalISelEmitter when
ARM tries to uses "imm" in an output with a "timm" pattern source.
llvm-svn: 372285
DIFlagBlockByRefStruct is an unused DIFlag that originally was used by
clang to express (Objective-)C block captures in debug info. For the
last year Clang has been emitting complex DIExpressions to describe
block captures instead, which makes all the code supporting this flag
redundant.
This patch removes the flag and all supporting "dead" code, so we can
reuse the bit for something else in the future.
Since this only affects debug info generated by Clang with the block
extension this mostly affects Apple platforms and I don't have any
bitcode compatibility concerns for removing this. The Verifier will
reject debug info that uses the bit and thus degrade gracefully when
LTO'ing older bitcode with a newer compiler.
rdar://problem/44304813
Differential Revision: https://reviews.llvm.org/D67453
llvm-svn: 372272
Summary:
`DAGCombiner::visitADDLikeCommutative()` already has a sibling fold:
`(add X, Carry) -> (addcarry X, 0, Carry)`
This fold, as suggested by @efriedma, helps recover from //some//
of the regressions of D62266
Reviewers: efriedma, deadalnix
Subscribers: javed.absar, kristof.beyls, llvm-commits, efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62392
llvm-svn: 372259
This patch fixes a bug exposed by D65653 where a subsequent invocation
of `determineCalleeSaves` ends up with a different size for the callee
save area, leading to different frame-offsets in debug information.
In the invocation by PEI, `determineCalleeSaves` tries to determine
whether it needs to spill an extra callee-saved register to get an
emergency spill slot. To do this, it calls 'estimateStackSize' and
manually adds the size of the callee-saves to this. PEI then allocates
the spill objects for the callee saves and the remaining frame layout
is calculated accordingly.
A second invocation in LiveDebugValues causes estimateStackSize to return
the size of the stack frame including the callee-saves. Given that the
size of the callee-saves is added to this, these callee-saves are counted
twice, which leads `determineCalleeSaves` to believe the stack has
become big enough to require spilling an extra callee-save as emergency
spillslot. It then updates CalleeSavedStackSize with a larger value.
Since CalleeSavedStackSize is used in the calculation of the frame
offset in getFrameIndexReference, this leads to incorrect offsets for
variables/locals when this information is recalculated after PEI.
Reviewers: omjavaid, eli.friedman, thegameg, efriedma
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D66935
llvm-svn: 372204
The filename in the RemarkStreamer should be optional to allow clients
to stream remarks to memory or to existing streams.
This introduces a new overload of `setupOptimizationRemarks`, and avoids
enforcing the presence of a filename at different places.
llvm-svn: 372195
* Reordered MVT simple types to group scalable vector types
together.
* New range functions in MachineValueType.h to only iterate over
the fixed-length int/fp vector types.
* Stopped backends which don't support scalable vector types from
iterating over scalable types.
Reviewers: sdesmalen, greened
Reviewed By: greened
Differential Revision: https://reviews.llvm.org/D66339
llvm-svn: 372099
r371901 was overeager and widenScalarDst() and the like in the legalizer
attempt to increment the insert point given in order to add new instructions
after the currently legalizing inst. In cases where the insertion point is not
exactly the current instruction, then callers need to de-compensate for the
behaviour by decrementing the insertion iterator before calling them. It's not
a nice state of affairs, for now just undo the problematic parts of the change.
llvm-svn: 372050
For some reason we sometimes insert new instructions one instruction before
the first non-PHI when legalizing. This can result in having non-PHI
instructions before PHIs, which mean that PHI elimination doesn't catch them.
Differential Revision: https://reviews.llvm.org/D67570
llvm-svn: 371901
