Commit Graph

1547 Commits

Author SHA1 Message Date
Nick Desaulniers f086941765 [SelectionDAGISel] small cleanup to INLINEASM_BR selection. NFC
Summary:
This code was throwing away the opcode for a boolean, which was then
reconstructing the opcode from that boolean.  Just pass the opcode, and
forget the boolean.

Reviewers: srhines

Reviewed By: srhines

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77100
2020-03-30 15:32:06 -07:00
Juneyoung Lee 7802be4a3d [SelDag] Add FREEZE
Summary:
- Add FREEZE node to SelDag
- Lower FreezeInst (in IR) to FREEZE node
- Add Legalization for FREEZE node

Reviewers: qcolombet, bogner, efriedma, lebedev.ri, nlopes, craig.topper, arsenm

Reviewed By: lebedev.ri

Subscribers: wdng, xbolva00, Petar.Avramovic, liuz, lkail, dylanmckay, hiraditya, Jim, arsenm, craig.topper, RKSimon, spatel, lebedev.ri, regehr, trentxintong, nlopes, mkuper, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D29014
2020-03-24 23:04:58 +09:00
Vedant Kumar 3091049446 Add dbgs() output to help track down missing DW_AT_location bugs, NFC 2020-02-13 14:38:44 -08:00
Simon Pilgrim 3dd688a9ee [DAG] OptLevelChanger - fix uninitialized variable analyzer warning (PR44471)
Ensure that OptLevelChanger::SavedFastISel is initialized in the constructor.

This should be NFC - as the equivalent 'same opt level' early-out is used in the destructor as well, so SavedFastISel is only actually referenced in the general case.

Differential Revision: https://reviews.llvm.org/D73875
2020-02-04 10:54:33 +00:00
Matt Arsenault f33f3d98e9 DAG: Don't use unchecked dyn_cast 2020-01-09 17:37:52 -05:00
Matt Arsenault 255cc5a760 CodeGen: Use LLT instead of EVT in getRegisterByName
Only PPC seems to be using it, and only checks some simple cases and
doesn't distinguish between FP. Just switch to using LLT to simplify
use from GlobalISel.
2020-01-09 17:37:52 -05:00
Ulrich Weigand 63336795f0 [FPEnv] Default NoFPExcept SDNodeFlag to false
The NoFPExcept bit in SDNodeFlags currently defaults to true, unlike all
other such flags. This is a problem, because it implies that all code that
transforms SDNodes without copying flags can introduce a correctness bug,
not just a missed optimization.

This patch changes the default to false. This makes it necessary to move
setting the (No)FPExcept flag for constrained intrinsics from the
visitConstrainedIntrinsic routine to the generic visit routine at the
place where the other flags are set, or else the intersectFlagsWith
call would erase the NoFPExcept flag again.

In order to avoid making non-strict FP code worse, whenever
SelectionDAGISel::SelectCodeCommon matches on a set of orignal nodes
none of which can raise FP exceptions, it will preserve this property
on all results nodes generated, by setting the NoFPExcept flag on
those result nodes that would otherwise be considered as raising
an FP exception.

To check whether or not an SD node should be considered as raising
an FP exception, the following logic applies:

- For machine nodes, check the mayRaiseFPException property of
  the underlying MI instruction
- For regular nodes, check isStrictFPOpcode
- For target nodes, check a newly introduced isTargetStrictFPOpcode

The latter is implemented by reserving a range of target opcodes,
similarly to how memory opcodes are identified. (Note that there a
bit of a quirk in identifying target nodes that are both memory nodes
and strict FP nodes. To simplify the logic, right now all target memory
nodes are automatically also considered strict FP nodes -- this could
be fixed by adding one more range.)

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D71841
2020-01-02 16:59:45 +01:00
Fangrui Song e0d855b399 [SelectionDAG] Change SelectionDAGISel::{funcInfo,SDB} to use unique_ptr
CurDAG is referenced more than 2000 times and used in many gerated .cpp
files. Don't touch it for now.
2019-12-23 22:41:05 -08:00
Fangrui Song 01b98e6fd5 [SelectionDAG] Don't repeatedly add a node to the worklist in ComputeLiveOutVRegInfo. NFC
For sqlite3 amalgram, this decreases the number of Worklist.push_back calls (603084) by 10%.
2019-12-23 22:04:14 -08:00
Ulrich Weigand 0d3f782e41 [FPEnv][X86] More strict int <-> FP conversion fixes
Fix several several additional problems with the int <-> FP conversion
logic both in common code and in the X86 target. In particular:

- The STRICT_FP_TO_UINT expansion emits a floating-point compare. This
  compare can raise exceptions and therefore needs to be a strict compare.
  I've made it signaling (even though quiet would also be correct) as
  signaling is the more usual default for an LT. This code exists both
  in common code and in the X86 target.

- The STRICT_UINT_TO_FP expansion algorithm was incorrect for strict mode:
  it emitted two STRICT_SINT_TO_FP nodes and then used a select to choose one
  of the results. This can cause spurious exceptions by the STRICT_SINT_TO_FP
  that ends up not chosen. I've fixed the algorithm to use only a single
  STRICT_SINT_TO_FP instead.

- The !isStrictFPEnabled logic in DoInstructionSelection would sometimes do
  the wrong thing because it calls getOperationAction using the result VT.
  But for some opcodes, incuding [SU]INT_TO_FP, getOperationAction needs to
  be called using the operand VT.

- Remove some (obsolete) code in X86DAGToDAGISel::Select that would mutate
  STRICT_FP_TO_[SU]INT to non-strict versions unnecessarily.

Reviewed by: craig.topper

Differential Revision: https://reviews.llvm.org/D71840
2019-12-23 21:11:45 +01:00
Reid Kleckner 5d986953c8 [IR] Split out target specific intrinsic enums into separate headers
This has two main effects:
- Optimizes debug info size by saving 221.86 MB of obj file size in a
  Windows optimized+debug build of 'all'. This is 3.03% of 7,332.7MB of
  object file size.
- Incremental step towards decoupling target intrinsics.

The enums are still compact, so adding and removing a single
target-specific intrinsic will trigger a rebuild of all of LLVM.
Assigning distinct target id spaces is potential future work.

Part of PR34259

Reviewers: efriedma, echristo, MaskRay

Reviewed By: echristo, MaskRay

Differential Revision: https://reviews.llvm.org/D71320
2019-12-11 18:02:14 -08:00
Hiroshi Yamauchi d9ae493937 [PGO][PGSO] Instrument the code gen / target passes.
Summary:
Split off of D67120.

Add the profile guided size optimization instrumentation / queries in the code
gen or target passes. This doesn't enable the size optimizations in those passes
yet as they are currently disabled in shouldOptimizeForSize (for non-IR pass
queries).

A second try after reverted D71072.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71149
2019-12-09 12:42:59 -08:00
Hiroshi Yamauchi 2eb30fafa5 Revert "[PGO][PGSO] Instrument the code gen / target passes."
This reverts commit 9a0b5e1407.

This seems to break buildbots.
2019-12-06 12:17:32 -08:00
Hiroshi Yamauchi 9a0b5e1407 [PGO][PGSO] Instrument the code gen / target passes.
Summary:
Split off of D67120.

Add the profile guided size optimization instrumentation / queries in the code
gen or target passes. This doesn't enable the size optimizations in those passes
yet as they are currently disabled in shouldOptimizeForSize (for non-IR pass
queries).

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71072
2019-12-06 10:43:39 -08:00
Ulrich Weigand daee549b17 [FPEnv][SelectionDAG] Relax chain requirements
This patch implements the following changes:

1) SelectionDAGBuilder::visitConstrainedFPIntrinsic currently treats
each constrained intrinsic like a global barrier (e.g. a function call)
and fully serializes all pending chains. This is actually not required;
it is allowed for constrained intrinsics to be reordered w.r.t one
another or (nonvolatile) memory accesses. The MI-level scheduler already
allows for that flexibility, so it makes sense to allow it at the DAG
level as well.

This patch therefore changes the way chains for constrained intrisincs
are created, and handles them basically like load operations are handled.
This has the effect that constrained intrinsics are no longer serialized
against one another or (nonvolatile) loads. They are still serialized
against stores, but that seems hard to change with the current DAG chain
setup, and it also doesn't seem to be a big problem preventing DAG

2) The OPC_CheckFoldableChainNode check requires that each of the
intermediate nodes in a multi-node pattern match only has a single use.
This check tends to fail if those intermediate nodes are strict operations
as those have a chain output that typically indeed has another use.
However, we don't really need to consider chains here at all, since they
will all be rewritten anyway by UpdateChains later. Other parts of the
matcher therefore already ignore chains, but this hasOneUse check doesn't.

This patch replaces hasOneUse by a custom test that verifies there is no
more than one use of any non-chain output value.

In theory, this change could affect code unrelated to strict FP nodes,
but at least on SystemZ I could not find any single instance of that
happening

3) The SystemZ back-end currently does not allow matching multiply-and-
extend operations (32x32 -> 64bit or 64x64 -> 128bit FP multiply) for
strict FP operations.  This was not possible in the past due to the
problems described under 1) and 2) above.

With those issues fixed, it is now possible to fully support those
instructions in strict mode as well, and this patch does so.

Differential Revision: https://reviews.llvm.org/D70913
2019-12-06 11:02:11 +01:00
Amaury Séchet b4980f7781 [SelectionDAG] Reoder ViewXXXDAGs declarations to match execution order. NFC 2019-12-03 16:26:12 +01:00
Pengfei Wang 22a0edd070 [FPEnv] Add an option to disable strict float node mutating to an normal
float node

This patch add an option 'disable-strictnode-mutation' to prevent strict
node mutating to an normal node.
So we can make sure that the patch which sets strict-node as legal works
correctly.

Patch by Chen Liu(LiuChen3)

Differential Revision: https://reviews.llvm.org/D70226
2019-11-21 18:07:11 -08:00
Hiroshi Yamauchi 52e377497d [PGO][PGSO] DAG.shouldOptForSize part.
Summary:
(Split of off D67120)

SelectionDAG::shouldOptForSize changes for profile guided size optimization.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70095
2019-11-21 14:16:00 -08:00
Craig Topper c9e8e808cf [SelectionDAG][X86] Mutate strictFP nodes to non-strict in DoInstructionSelection when the node is marked Expand rather than when it is not Legal.
This allows operations that are marked Custom, but have some type
combinations that are legal to get past this code.

Add custom mutation code to X86's Select function for the nodes
that don't have isel patterns yet.
2019-11-20 10:36:02 -08:00
Reid Kleckner 5fe3f00ae2 Replace wrongly deleted header banner, fix formatting
I reviewed the diff hunks of 05da2fe521 that don't contain
'#include' lines, and found two unintended changes. I deleted a header
banner inadvertently while inserting a header, and changed the
indentation of a constructor in an odd way. Add back the banner, and
reformat the constructor.
2019-11-14 10:21:42 -08:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Dávid Bolvanský a18a8db0d4 [SelectionDAG] Fixed null check after dereferencing warning. NFCI. 2019-11-03 19:34:03 +01:00
Reid Kleckner 904cd3e06b Prune a LegacyDivergenceAnalysis and MachineLoopInfo include each
Now X86ISelLowering doesn't depend on many IR analyses.

llvm-svn: 375320
2019-10-19 01:31:09 +00:00
Matt Arsenault f24ac13aaa TLI: Remove DAG argument from getRegisterByName
Replace with the MachineFunction. X86 is the only user, and only uses
it for the function. This removes one obstacle from using this in
GlobalISel. The other is the more tolerable EVT argument.

The X86 use of the function seems questionable to me. It checks hasFP,
before frame lowering.

llvm-svn: 373292
2019-10-01 01:44:39 +00:00
Teresa Johnson 9c27b59cec Change TargetLibraryInfo analysis passes to always require Function
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.

This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.

Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.

There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.

Reviewers: chandlerc, hfinkel

Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66428

llvm-svn: 371284
2019-09-07 03:09:36 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Matt Arsenault 542720b2bc TableGen: Support physical register inputs > 255
This was truncating register value that didn't fit in unsigned char.
Switch AMDGPU sendmsg intrinsics to using a tablegen pattern.

llvm-svn: 366695
2019-07-22 15:02:34 +00:00
Reid Kleckner 2f07c2e9d9 Standardize on MSVC behavior for triples with no environment
Summary:
This makes it so that IR files using triples without an environment work
out of the box, without normalizing them.

Typically, the MSVC behavior is more desirable. For example, it tends to
enable things like constant merging, use of associative comdats, etc.

Addresses PR42491

Reviewers: compnerd

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64109

llvm-svn: 365387
2019-07-08 21:05:20 +00:00
Matt Arsenault e3a676e9ad CodeGen: Introduce a class for registers
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().

llvm-svn: 364191
2019-06-24 15:50:29 +00:00
Matt Arsenault 9cac4e6d14 Rename ExpandISelPseudo->FinalizeISel, delay register reservation
This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.

Patch by Matthias Braun

llvm-svn: 363757
2019-06-19 00:25:39 +00:00
Francis Visoiu Mistrih a438432acc [FastISel] Skip creating unnecessary vregs for arguments
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.

This re-enables it for FastISel with the corresponding fix.

This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.

FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.

This fix moves the replacement of registers before the emission of
copies for the live-ins.

The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).

A few tests are affected by this:

* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed

Differential Revision: https://reviews.llvm.org/D62361

llvm-svn: 362963
2019-06-10 16:53:37 +00:00
Amara Emerson 829037a914 Factor out SelectionDAG's switch analysis and lowering into a separate component.
In order for GlobalISel to re-use the significant amount of analysis and
optimization code in SDAG's switch lowering, we first have to extract it and
create an interface to be used by both frameworks.

No test changes as it's NFC.

Differential Revision: https://reviews.llvm.org/D62745

llvm-svn: 362857
2019-06-08 00:05:17 +00:00
Ulrich Weigand 6c5d5ce551 Allow target to handle STRICT floating-point nodes
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).

This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.

To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:

- A new MCID flag "mayRaiseFPException" that the target should set on any
  instruction that possibly can raise FP exception according to the
  architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
  instruction resulting from expansion of any constrained FP intrinsic.

Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).

Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.

The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.

This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.

Reviewed By: andrew.w.kaylor

Differential Revision: https://reviews.llvm.org/D55506

llvm-svn: 362663
2019-06-05 22:33:10 +00:00
Alexander Timofeev ba447bae74 [AMDGPU] Divergence driven ISel. Assign register class for cross block values according to the divergence.
Details: To make instruction selection really divergence driven it is necessary to assign
             the correct register classes to the cross block values beforehand. For the divergent targets
             same value type requires different register classes dependent on the value divergence.

    Reviewers: rampitec, nhaehnle

    Differential Revision: https://reviews.llvm.org/D59990

    This commit was reverted because of the build failure.
    The reason was mlformed patch.
    Build failure fixed.

llvm-svn: 361741
2019-05-26 20:33:26 +00:00
Peter Collingbourne 3b93737446 Revert r361644, "[AMDGPU] Divergence driven ISel. Assign register class for cross block values according to the divergence."
Broke sanitizer bots:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/21694/steps/bootstrap%20clang/logs/stdio
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/32478/steps/check-llvm%20asan/logs/stdio

llvm-svn: 361688
2019-05-25 01:52:38 +00:00
Alexander Timofeev dffedea014 [AMDGPU] Divergence driven ISel. Assign register class for cross block values according to the divergence.
Details: To make instruction selection really divergence driven it is necessary to assign
         the correct register classes to the cross block values beforehand. For the divergent targets
         same value type requires different register classes dependent on the value divergence.

Reviewers: rampitec, nhaehnle

Differential Revision: https://reviews.llvm.org/D59990

llvm-svn: 361644
2019-05-24 15:32:18 +00:00
Tim Northover 3d7a057b0d CodeGen: factor out swifterror value tracking.
llvm-svn: 361607
2019-05-24 08:39:43 +00:00
Petar Jovanovic e85bbf564d [DebugInfoMetadata] Refactor DIExpression::prepend constants (NFC)
Refactor DIExpression::With* into a flag enum in order to be less
error-prone to use (as discussed on D60866).

Patch by Djordje Todorovic.

Differential Revision: https://reviews.llvm.org/D61943

llvm-svn: 361137
2019-05-20 10:35:57 +00:00
Simon Pilgrim aeed0a30c0 SelectionDAGISel::CodeGenAndEmitDAG - remove unused variable. NFCI.
llvm-svn: 360514
2019-05-11 11:00:37 +00:00
Serguei Katkov fb44846e37 [FastISel] Fix the crash in gc.result lowering
The Fast ISel has a fallback to SelectionDAGISel in case it cannot handle the instruction.
This works as follows:
Using reverse order, try to select instruction using Fast ISel, if it cannot handle instruction it fallbacks to SelectionDAGISel
for these instructions if it is a call and continue fast instruction selections.

However if unhandled instruction is not a call or statepoint related instruction it fallbacks to SelectionDAGISel for all remaining
instructions in basic block.

However gc.result instruction is missed and as a result it is possible that gc.result is processed earlier than statepoint
causing breakage invariant the gc.results should be handled after statepoint.

Test is updated because in the current form fast-isel cannot handle ret instruction (due to i1 ret type without explicit ext)
and as a result test does not check fast-isel at all.

Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D60182

llvm-svn: 357672
2019-04-04 04:19:56 +00:00
Craig Topper 1a872f2b15 Recommit r355224 "[TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary."
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.

Original commit message:

Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.

By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.

This removes something like 40,000 bytes from the X86 isel table.

Differential Revision: https://reviews.llvm.org/D58595

llvm-svn: 355784
2019-03-10 05:21:52 +00:00
Craig Topper 57fd733140 Revert r355224 "[TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary."
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.

llvm-svn: 355433
2019-03-05 19:18:16 +00:00
Craig Topper 4cfc39179e [TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary.
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.

By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.

This removes something like 40,000 bytes from the X86 isel table.

Differential Revision: https://reviews.llvm.org/D58595

llvm-svn: 355224
2019-03-01 20:18:38 +00:00
Craig Topper 8c9724ea4f [SelectionDAG] Add a OPC_CheckChild2CondCode to SelectionDAGISel to remove a MoveChild and MoveParent pair.
OPC_CheckCondCode is always used as operand 2 of a setcc. And its always surrounded by a MoveChild2 and a MoveParent. By having a dedicated opcode for this case we can reduce the number of bytes needed for this pattern from 4 bytes to 2.

This saves ~3000 bytes in the X86 table.

llvm-svn: 354763
2019-02-25 03:11:44 +00:00
Jeremy Morse 291713a596 [DebugInfo][DAG] Either salvage dangling debug info or emit Undef DBG_VALUEs
In this patch SelectionDAG tries to salvage any dbg.values that are going to be
dropped, in case they can be recovered from Values in the current BB. It also
strengthens SelectionDAGs handling of dangling debug data, so that dbg.values
are *always* emitted (as Undef or otherwise) instead of dangling forever.

The motivation behind this patch exists in the new test case: a memory address
(here a bitcast and GEP) exist in one basic block, and a dbg.value referring to
the address is left in the 'next' block. The base pointer is live across all
basic blocks. In current llvm trunk the dbg.value cannot be encoded, and it
isn't even emitted as an Undef DBG_VALUE.

The change is simply: if we're definitely going to drop a dbg.value, repeatedly
apply salvageDebugInfo to its operand until either we find something that can
be encoded, or we can't salvage any further in which case we produce an Undef
DBG_VALUE. To know when we're "definitely going to drop a dbg.value",
SelectionDAG signals SelectionDAGBuilder when all IR instructions have been
encoded to force salvaging. This ensures that any dbg.value that's dangling
after DAG creation will have a corresponding DBG_VALUE encoded. 

Differential Revision: https://reviews.llvm.org/D57694

llvm-svn: 353954
2019-02-13 16:33:05 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
James Y Knight 2c36240a82 Fix emission of _fltused for MSVC.
It should be emitted when any floating-point operations (including
calls) are present in the object, not just when calls to printf/scanf
with floating point args are made.

The difference caused by this is very subtle: in static (/MT) builds,
on x86-32, in a program that uses floating point but doesn't print it,
the default x87 rounding mode may not be set properly upon
initialization.

This commit also removes the walk of the types pointed to by pointer
arguments in calls. (To assist in opaque pointer types migration --
eventually the pointee type won't be available.)

That latter implies that it will no longer consider a call like
`scanf("%f", &floatvar)` as sufficient to emit _fltused on its
own. And without _fltused, `scanf("%f")` will abort with error R6002. This
new behavior is unlikely to bite anyone in practice (you'd have to
read a float, and do nothing with it!), and also, is consistent with
MSVC.

Differential Revision: https://reviews.llvm.org/D56548

llvm-svn: 352076
2019-01-24 18:34:00 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Simon Pilgrim 911dce2f30 [SelectionDAG] Always use the version of computeKnownBits that returns a value. NFCI.
Continues the work started by @bogner in rL340594 to remove uses of the KnownBits output paramater version.

llvm-svn: 349907
2018-12-21 14:56:18 +00:00
Nicolai Haehnle 445b0b6260 TableGen/ISel: Allow PatFrag predicate code to access captured operands
Summary:
This simplifies writing predicates for pattern fragments that are
automatically re-associated or commuted.

For example, a followup patch adds patterns for fragments of the form
(add (shl $x, $y), $z) to the AMDGPU backend. Such patterns are
automatically commuted to (add $z, (shl $x, $y)), which makes it basically
impossible to refer to $x, $y, and $z generically in the PredicateCode.

With this change, the PredicateCode can refer to $x, $y, and $z simply
as `Operands[i]`.

Test confirmed that there are no changes to any of the generated files
when building all (non-experimental) targets.

Change-Id: I61c00ace7eed42c1d4edc4c5351174b56b77a79c

Reviewers: arsenm, rampitec, RKSimon, craig.topper, hfinkel, uweigand

Subscribers: wdng, tpr, llvm-commits

Differential Revision: https://reviews.llvm.org/D51994

llvm-svn: 347992
2018-11-30 14:15:13 +00:00
Craig Topper 4954c66430 [SelectionDAG] Compute known bits and num sign bits for live out vector registers. Use it to add AssertZExt/AssertSExt in the live in basic blocks
Summary:
We already support this for scalars, but it was explicitly disabled for vectors. In the updated test cases this allows us to see the upper bits are zero to use less multiply instructions to emulate a 64 bit multiply.

This should help with this ispc issue that a coworker pointed me to https://github.com/ispc/ispc/issues/1362

Reviewers: spatel, efriedma, RKSimon, arsenm

Reviewed By: spatel

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D54725

llvm-svn: 347287
2018-11-20 04:30:26 +00:00
Serge Guelton 86f8b70f1b Type safe version of MachinePassRegistry
Previous version used type erasure through a `void* (*)()` pointer,
which triggered gcc warning and implied a lot of reinterpret_cast.

This version should make it harder to hit ourselves in the foot.

Differential revision: https://reviews.llvm.org/D54203

llvm-svn: 346522
2018-11-09 17:19:45 +00:00
Craig Topper eeac12af6d [SelectionDAGISel] Suppress a -Wunused-but-set-variable warning in release builds. NFC
llvm-svn: 345761
2018-10-31 18:46:15 +00:00
Heejin Ahn 24faf859e5 Reland "[WebAssembly] LSDA info generation"
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 345345
2018-10-25 23:55:10 +00:00
Krasimir Georgiev 547d824da6 Revert "[WebAssembly] LSDA info generation"
This reverts commit r344575.
Newly introduced test eh-lsda.ll.test fails with use-after-free under
ASAN build.

llvm-svn: 344639
2018-10-16 18:50:09 +00:00
Heejin Ahn 0981eaab47 [WebAssembly] LSDA info generation
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 344575
2018-10-16 00:09:12 +00:00
Chandler Carruth edb12a838a [TI removal] Make variables declared as `TerminatorInst` and initialized
by `getTerminator()` calls instead be declared as `Instruction`.

This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).

llvm-svn: 344502
2018-10-15 10:04:59 +00:00
Mikael Nilsson 9c8e35174e Run VerifyDAGDiverence in debug only
VerifyDAGDiverence costs compilation time, avoid running it in non-debug
builds.

Differential Revision: https://reviews.llvm.org/D52454

llvm-svn: 343086
2018-09-26 09:25:45 +00:00
Nicolai Haehnle 35617ed4cb [NFC] Rename the DivergenceAnalysis to LegacyDivergenceAnalysis
Summary:
This is patch 1 of the new DivergenceAnalysis (https://reviews.llvm.org/D50433).

The purpose of this patch is to free up the name DivergenceAnalysis for the new generic
implementation. The generic implementation class will be shared by specialized
divergence analysis classes.

Patch by: Simon Moll

Reviewed By: nhaehnle

Subscribers: jvesely, jholewinski, arsenm, nhaehnle, mgorny, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D50434

Change-Id: Ie8146b11be2c50d5312f30e11c7a3036a15b48cb
llvm-svn: 341071
2018-08-30 14:21:36 +00:00
Chandler Carruth 9ae926b973 [IR] Replace `isa<TerminatorInst>` with `isTerminator()`.
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

llvm-svn: 340701
2018-08-26 09:51:22 +00:00
Chandler Carruth 66654b72c9 [SDAG] Remove the reliance on MI's allocation strategy for
`MachineMemOperand` pointers attached to `MachineSDNodes` and instead
have the `SelectionDAG` fully manage the memory for this array.

Prior to this change, the memory management was deeply confusing here --
The way the MI was built relied on the `SelectionDAG` allocating memory
for these arrays of pointers using the `MachineFunction`'s allocator so
that the raw pointer to the array could be blindly copied into an
eventual `MachineInstr`. This creates a hard coupling between how
`MachineInstr`s allocate their array of `MachineMemOperand` pointers and
how the `MachineSDNode` does.

This change is motivated in large part by a change I am making to how
`MachineFunction` allocates these pointers, but it seems like a layering
improvement as well.

This would run the risk of increasing allocations overall, but I've
implemented an optimization that should avoid that by storing a single
`MachineMemOperand` pointer directly instead of allocating anything.
This is expected to be a net win because the vast majority of uses of
these only need a single pointer.

As a side-effect, this makes the API for updating a `MachineSDNode` and
a `MachineInstr` reasonably different which seems nice to avoid
unexpected coupling of these two layers. We can map between them, but we
shouldn't be *surprised* at where that occurs. =]

Differential Revision: https://reviews.llvm.org/D50680

llvm-svn: 339740
2018-08-14 23:30:32 +00:00
Matt Arsenault 611dff423c DAG: Remove unnecessary .str()
llvm-svn: 338112
2018-07-27 09:04:41 +00:00
Matthias Braun 90ad6835dd CodeGen: Remove pipeline dependencies on StackProtector; NFC
This re-applies r336929 with a fix to accomodate for the Mips target
scheduling multiple SelectionDAG instances into the pass pipeline.

PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336964
2018-07-13 00:08:38 +00:00
Matthias Braun f03f32d478 Revert "(HEAD -> master, origin/master, arcpatch-D37582) CodeGen: Remove pipeline dependencies on StackProtector; NFC"
This was triggering pass scheduling failures.

This reverts commit r336929.

llvm-svn: 336934
2018-07-12 19:27:01 +00:00
Matthias Braun 9436570cbd CodeGen: Remove pipeline dependencies on StackProtector; NFC
PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336929
2018-07-12 18:33:32 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Craig Topper 781aa181ab Fix a bunch of places where operator-> was used directly on the return from dyn_cast.
Inspired by r331508, I did a grep and found these.

Mostly just change from dyn_cast to cast. Some cases also showed a dyn_cast result being converted to bool, so those I changed to isa.

llvm-svn: 331577
2018-05-05 01:57:00 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Craig Topper 4e644b38d7 [X86] Use APInt::isSubsetof instead of APInt::intersects to avoid a negation of an APInt value. NFC
llvm-svn: 330105
2018-04-15 19:11:25 +00:00
Fangrui Song 956ee79795 Fix a bunch of typoes. NFC
llvm-svn: 328907
2018-03-30 22:22:31 +00:00
Craig Topper 2fa1436206 [IR][CodeGen] Remove dependency on EVT from IR/Function.cpp. Move EVT to CodeGen layer.
Currently EVT is in the IR layer only because of Function.cpp needing a very small piece of the functionality of EVT::getEVTString(). The rest of EVT is used in codegen making CodeGen a better place for it.

The previous code converted a Type* to EVT and then called getEVTString. This was only expected to handle the primitive types from Type*. Since there only a few primitive types, we can just print them as strings directly.

Differential Revision: https://reviews.llvm.org/D45017

llvm-svn: 328806
2018-03-29 17:21:10 +00:00
David Blaikie 36a0f226b1 Fix layering by moving ValueTypes.h from CodeGen to IR
ValueTypes.h is implemented in IR already.

llvm-svn: 328397
2018-03-23 23:58:31 +00:00
David Blaikie 13e77db2df Fix layering of MachineValueType.h by moving it from CodeGen to Support
This is used by llvm tblgen as well as by LLVM Targets, so the only
common place is Support for now. (maybe we need another target for these
sorts of things - but for now I'm at least making them correct & we can
make them better if/when people have strong feelings)

llvm-svn: 328395
2018-03-23 23:58:25 +00:00
Nirav Dave 5b3e8791b4 [DAG] Fix node id invalidation in Instruction Selection.
Invalidation should be bit negation. Add missing negation.

llvm-svn: 328287
2018-03-23 01:22:39 +00:00
Nirav Dave 8c5f47ac40 [DAG, X86] Fix ISel-time node insertion ids
As in SystemZ backend, correctly propagate node ids when inserting new
unselected nodes into the DAG during instruction Seleciton for X86
target.

Fixes PR36865.

Reviewers: jyknight, craig.topper

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D44797

llvm-svn: 328233
2018-03-22 19:32:07 +00:00
Nirav Dave 3264c1bdf6 [DAG, X86] Revert r327197 "Revert r327170, r327171, r327172"
Reland ISel cycle checking improvements after simplifying node id
invariant traversal and correcting typo.

llvm-svn: 327898
2018-03-19 20:19:46 +00:00
Nirav Dave 5f0ab71b62 Revert "[DAG, X86] Revert r327197 "Revert r327170, r327171, r327172""
as it times out building test-suite on PPC.

llvm-svn: 327778
2018-03-17 19:24:54 +00:00
Nirav Dave 982d3a56ea [DAG, X86] Revert r327197 "Revert r327170, r327171, r327172"
Reland ISel cycle checking improvements after simplifying and reducing
node id invariant traversal.

llvm-svn: 327777
2018-03-17 17:42:10 +00:00
Reid Kleckner 3a7a2e4a0a [FastISel] Sink local value materializations to first use
Summary:
Local values are constants, global addresses, and stack addresses that
can't be folded into the instruction that uses them. For example, when
storing the address of a global variable into memory, we need to
materialize that address into a register.

FastISel doesn't want to materialize any given local value more than
once, so it generates all local value materialization code at
EmitStartPt, which always dominates the current insertion point. This
allows it to maintain a map of local value registers, and it knows that
the local value area will always dominate the current insertion point.

The downside is that local value instructions are always emitted without
a source location. This is done to prevent jumpy line tables, but it
means that the local value area will be considered part of the previous
statement. Consider this C code:
  call1();      // line 1
  ++global;     // line 2
  ++global;     // line 3
  call2(&global, &local); // line 4

Today we end up with assembly and line tables like this:
  .loc 1 1
  callq call1
  leaq global(%rip), %rdi
  leaq local(%rsp), %rsi
  .loc 1 2
  addq $1, global(%rip)
  .loc 1 3
  addq $1, global(%rip)
  .loc 1 4
  callq call2

The LEA instructions in the local value area have no source location and
are treated as being on line 1. Stepping through the code in a debugger
and correlating it with the assembly won't make much sense, because
these materializations are only required for line 4.

This is actually problematic for the VS debugger "set next statement"
feature, which effectively assumes that there are no registers live
across statement boundaries. By sinking the local value code into the
statement and fixing up the source location, we can make that feature
work. This was filed as https://bugs.llvm.org/show_bug.cgi?id=35975 and
https://crbug.com/793819.

This change is obviously not enough to make this feature work reliably
in all cases, but I felt that it was worth doing anyway because it
usually generates smaller, more comprehensible -O0 code. I measured a
0.12% regression in code generation time with LLC on the sqlite3
amalgamation, so I think this is worth doing.

There are some special cases worth calling out in the commit message:
1. local values materialized for phis
2. local values used by no-op casts
3. dead local value code

Local values can be materialized for phis, and this does not show up as
a vreg use in MachineRegisterInfo. In this case, if there are no other
uses, this patch sinks the value to the first terminator, EH label, or
the end of the BB if nothing else exists.

Local values may also be used by no-op casts, which adds the register to
the RegFixups table. Without reversing the RegFixups map direction, we
don't have enough information to sink these instructions.

Lastly, if the local value register has no other uses, we can delete it.
This comes up when fastisel tries two instruction selection approaches
and the first materializes the value but fails and the second succeeds
without using the local value.

Reviewers: aprantl, dblaikie, qcolombet, MatzeB, vsk, echristo

Subscribers: dotdash, chandlerc, hans, sdardis, amccarth, javed.absar, zturner, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D43093

llvm-svn: 327581
2018-03-14 21:54:21 +00:00
Nirav Dave 042678bd55 Revert: r327172 "Correct load-op-store cycle detection analysis"
r327171 "Improve Dependency analysis when doing multi-node Instruction Selection"
        r328170 "[DAG] Enforce stricter NodeId invariant during Instruction selection"

Reverting patch as NodeId invariant change is causing pathological
increases in compile time on PPC

llvm-svn: 327197
2018-03-10 02:16:15 +00:00
Nirav Dave d668f69ee7 Improve Dependency analysis when doing multi-node Instruction Selection
Relanding after fixing NodeId Invariant.

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 327171
2018-03-09 20:57:42 +00:00
Nirav Dave 071699bf82 [DAG] Enforce stricter NodeId invariant during Instruction selection
Instruction Selection makes use of the topological ordering of nodes
by node id (a node's operands have smaller node id than it) when doing
cycle detection.  During selection we may violate this property as a
selection of multiple nodes may induce a use dependence (and thus a
node id restriction) between two unrelated nodes. If a selected node
has an unselected successor this may allow us to miss a cycle in
detection an invalid selection.

This patch fixes this by marking all unselected successors of a
selected node have negated node id.  We avoid pruning on such negative
ids but still can reconstruct the original id for pruning.

In-tree targets have been updated to replace DAG-level replacements
with ISel-level ones which enforce this property.

This preemptively fixes PR36312 before triggering commit r324359 relands

Reviewers: craig.topper, bogner, jyknight

Subscribers: arsenm, nhaehnle, javed.absar, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D43198

llvm-svn: 327170
2018-03-09 20:57:15 +00:00
Alexander Timofeev 2e5eeceeb7 Pass Divergence Analysis data to Selection DAG to drive divergence
dependent instruction selection.

Differential revision: https://reviews.llvm.org/D35267

llvm-svn: 326703
2018-03-05 15:12:21 +00:00
Chandler Carruth a1d6107b14 [DAG, X86] Revert r324797, r324491, and r324359.
Sadly, r324359 caused at least PR36312. There is a patch out for review
but it seems to be taking a bit and we've already had these crashers in
tree for too long. We're hitting this PR in real code now and are
blocked on shipping new compilers as a consequence so I'm reverting us
back to green.

Sorry for the churn due to the stacked changes that I had to revert. =/

llvm-svn: 325420
2018-02-17 02:26:25 +00:00
Nirav Dave c8c9d4fe35 [DAG] Make early exit hasPredecessorHelper return true. NFCI.
All uses conservatively assume in early exit case that it will be a
predecessor. Changing default removes checking code in all uses.

llvm-svn: 324797
2018-02-10 02:41:22 +00:00
Nirav Dave efed656873 [SelectionDAG] More Aggressibly prune nodes in AddChains. NFCI.
Travel all chains paths to first non-tokenfactor node can be
exponential work. Add simple redundency check to avoid this.
Fixes PR36264.

llvm-svn: 324491
2018-02-07 17:12:34 +00:00
Nirav Dave 27721e8617 [DAG, X86] Improve Dependency analysis when doing multi-node
Instruction Selection

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 324359
2018-02-06 16:14:29 +00:00
Nirav Dave 18f7f60e17 [SelectionDAG] Fix UpdateChains handling of TokenFactors
Summary:
In Instruction Selection UpdateChains replaces all matched Nodes'
chain references including interior token factors and deletes them.
This may allow nodes which depend on these interior nodes but are not
part of the set of matched nodes to be left with a dangling dependence.
Avoid this by doing the replacement for matched non-TokenFactor nodes.

Fixes PR36164.

Reviewers: jonpa, RKSimon, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D42754

llvm-svn: 323977
2018-02-01 16:11:59 +00:00
Nirav Dave c3a1e16db1 [DAG] Prevent NodeId pruning of TokenFactors in Instruction Selection.
Summary:
Instruction Selection preserves relative orders of all nodes save
TokenFactors which we treat specially. As a result Node Ids for
TokenFactors may violate the topological ordering and should not be
considered as valid pruning candidates in predecessor search.

Fixes PR35316.

Reviewers: RKSimon, hfinkel

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D42701

llvm-svn: 323880
2018-01-31 15:23:17 +00:00
Craig Topper 8f324bb1a4 [SelectionDAGISel] Add a debug print before call to Select. Adjust where blank lines are printed during isel process to make things more sensibly grouped.
Previously some targets printed their own message at the start of Select to indicate what they were selecting. For the targets that didn't, it means there was no print of the root node before any custom handling in the target executed. So if the target did something custom and never called SelectNodeCommon, no print would be made. For the targets that did print a message in Select, if they didn't custom handle a node SelectNodeCommon would reprint the root node before walking the isel table.

It seems better to just print the message before the call to Select so all targets behave the same. And then remove the root node printing from SelectNodeCommon and just leave a message that says we're starting the table search.

There were also some oddities in blank line behavior. Usually due to a \n after a call to SelectionDAGNode::dump which already inserted a new line.

llvm-svn: 323551
2018-01-26 19:34:20 +00:00
Amara Emerson f386e2b081 [GlobalISel] Don't fall back to FastISel.
Apparently checking the pass structure isn't enough to ensure that we don't fall
back to FastISel, as it's set up as part of the SelectionDAGISel.

llvm-svn: 323369
2018-01-24 19:59:29 +00:00
Sanjay Patel 37e28e40cb [SelectionDAG] lower math intrinsics to finite version of libcalls when possible (PR35672)
Ingredients in this patch:
1. Add HANDLE_LIBCALL defs for finite mathlib functions that correspond to LLVM intrinsics.
2. Plumbing to send TargetLibraryInfo down to SelectionDAGLegalize.
3. Relaxed math and library checking in SelectionDAGLegalize::ConvertNodeToLibcall() to choose finite libcalls.

There was a bug about determining the availability of the finite calls that should be fixed with:
rL322010

Not in this patch:
This doesn't resolve the question/bug of clang creating the intrinsic IR in the first place.
There's likely follow-up work needed to support the long double variants better.
There's room for improvement to reduce the code duplication.
Create finite calls that don't originate from a corresponding intrinsic or DAG node?

Differential Revision: https://reviews.llvm.org/D41338

llvm-svn: 322087
2018-01-09 15:41:00 +00:00
Benjamin Kramer c7fc81e659 Use phi ranges to simplify code. No functionality change intended.
llvm-svn: 321585
2017-12-30 15:27:33 +00:00
Matt Arsenault d60951f469 DAG: Tolerate non-MemSDNodes for OPC_RecordMemRef
When intrinsics are allowed to have mem operands, there
are two ways this can happen. First is an intrinsic
that is marked has having a mem operand, but is not handled
by getTgtMemIntrinsic.

The second way can occur even for intrinsics which do not
have a mem operand. It seems the selector table does
some kind of sorting based on the opcode, and the
mem ref recording can happen in the same scope for
intrinsics that both do and do not have mem refs.
I haven't been able to figure out exactly why this happens
(although it happens even with the matcher optimizations disabled).
I'm not sure if it's worth trying to avoid hitting this for
these nodes since I think it's still reasonable to handle
this in case getTgtMemIntrinic is not implemented.

llvm-svn: 321208
2017-12-20 19:11:59 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Alex Bradbury 660bcceccf [RISCV] Support lowering FrameIndex
Introduces the AddrFI "addressing mode", which is necessary simply because 
it's not possible to write a pattern that directly matches a frameindex.

Ensure callee-saved registers are accessed relative to the stackpointer. This
is necessary as callee-saved register spills are performed before the frame
pointer is set.

Move HexagonDAGToDAGISel::isOrEquivalentToAdd to SelectionDAGISel, so we can 
make use of it in the RISC-V backend.

Differential Revision: https://reviews.llvm.org/D39848

llvm-svn: 320353
2017-12-11 11:53:54 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Matt Morehouse 9e658c974b Revert "[X86] Improvement in CodeGen instruction selection for LEAs."
This reverts r319543, due to ASan bot breakage.

llvm-svn: 319591
2017-12-01 22:20:26 +00:00
Jatin Bhateja 328199ec26 [X86] Improvement in CodeGen instruction selection for LEAs.
Summary:
1/  Operand folding during complex pattern matching for LEAs has been extended, such that it promotes Scale to
     accommodate similar operand appearing in the DAG  e.g.
                 T1 = A + B
                 T2 = T1 + 10
                 T3 = T2 + A
    For above DAG rooted at T3, X86AddressMode will now look like
                Base = B , Index = A , Scale = 2 , Disp = 10

2/  During OptimizeLEAPass down the pipeline factorization is now performed over LEAs so that if there is an opportunity
     then complex LEAs (having 3 operands) could be factored out  e.g.
                 leal 1(%rax,%rcx,1), %rdx
                 leal 1(%rax,%rcx,2), %rcx
     will be factored as following
                 leal 1(%rax,%rcx,1), %rdx
                 leal (%rdx,%rcx)   , %edx

3/ Aggressive operand folding for AM based selection for LEAs is sensitive to loops, thus avoiding creation of any complex LEAs within a loop.

4/ Simplify LEA converts (lea (BASE,1,INDEX,0)  --> add (BASE, INDEX) which offers better through put.

PR32755 will be taken care of by this pathc.

Previous patch revisions : r313343 , r314886

Reviewers: lsaba, RKSimon, craig.topper, qcolombet, jmolloy, jbhateja

Reviewed By: lsaba, RKSimon, jbhateja

Subscribers: jmolloy, spatel, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D35014

llvm-svn: 319543
2017-12-01 14:07:38 +00:00