Commit Graph

79 Commits

Author SHA1 Message Date
Ahmed Bougacha 8a41319d8d [CodeGen] Further simplify returned call operand logic. NFC.
As Pete points out in r290905, CallSite lets us avoid duplicating this!

llvm-svn: 290909
2017-01-03 21:42:43 +00:00
Ahmed Bougacha 6aff744e7c [CodeGen] Simplify logic that looks for returned call operands. NFC-ish.
Use getReturnedArgOperand() instead of rolling our own.  Note that it's
equivalent because there can only be one 'returned' operand.

The existing code was also incorrect: there already was awkward logic to
ignore callee/EH blocks, but operands can now also be operand bundles,
in which case we'll look for non-existent parameter attributes.

Unfortunately, this isn't observable in-tree, as it only crashes when
exercising the regular call lowering logic with operand bundles.
Still, this is a nice small cleanup anyway.

llvm-svn: 290905
2017-01-03 20:33:22 +00:00
Matthias Braun d0ee66c2e9 Move most EH from MachineModuleInfo to MachineFunction
Recommitting r288293 with some extra fixes for GlobalISel code.

Most of the exception handling members in MachineModuleInfo is actually
per function data (talks about the "current function") so it is better
to keep it at the function instead of the module.

This is a necessary step to have machine module passes work properly.

Also:
- Rename TidyLandingPads() to tidyLandingPads()
- Use doxygen member groups instead of "//===- EH ---"... so it is clear
  where a group ends.
- I had to add an ugly const_cast at two places in the AsmPrinter
  because the available MachineFunction pointers are const, but the code
  wants to call tidyLandingPads() in between
  (markFunctionEnd()/endFunction()).

Differential Revision: https://reviews.llvm.org/D27227

llvm-svn: 288405
2016-12-01 19:32:15 +00:00
Eric Christopher e70b7c3dfb Temporarily Revert "Move most EH from MachineModuleInfo to MachineFunction"
This apprears to have broken the global isel bot:
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-globalisel_build/5174/console

This reverts commit r288293.

llvm-svn: 288322
2016-12-01 07:50:12 +00:00
Matthias Braun ed14cb0604 Move most EH from MachineModuleInfo to MachineFunction
Most of the exception handling members in MachineModuleInfo is actually
per function data (talks about the "current function") so it is better
to keep it at the function instead of the module.

This is a necessary step to have machine module passes work properly.

Also:
- Rename TidyLandingPads() to tidyLandingPads()
- Use doxygen member groups instead of "//===- EH ---"... so it is clear
  where a group ends.
- I had to add an ugly const_cast at two places in the AsmPrinter
  because the available MachineFunction pointers are const, but the code
  wants to call tidyLandingPads() in between
  (markFunctionEnd()/endFunction()).

Differential Revision: https://reviews.llvm.org/D27227

llvm-svn: 288293
2016-11-30 23:49:01 +00:00
Bjorn Pettersson 807f732ce8 Fix memory issue in AttrBuilder::removeAttribute uses.
Summary:
Found when running Valgrind.

This removes two unnecessary assignments when using
AttrBuilder::removeAttribute.

AttrBuilder::removeAttribute returns a reference to the object.
As the LHSes were the same as the callees, the assignments
resulted in memcpy calls where dst = src.

Commited on behalf-of: dstenb (David Stenberg)

Reviewers: mkuper, rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25460

llvm-svn: 285298
2016-10-27 14:48:09 +00:00
Michael Kuperstein f79af6f8c4 [CGP] Be less conservative about tail-duplicating a ret to allow tail calls
CGP tail-duplicates rets into blocks that end with a call that feed the ret.
This puts the call in tail position, potentially allowing the DAG builder to
lower it as a tail call. To avoid tail duplication in cases where we won't
form the tail call, CGP tried to predict whether this is going to be possible,
and avoids doing it when lowering as a tail call will definitely fail.
However, it was being too conservative by always throwing away calls to
functions with a signext/zeroext attribute on the return type.

Instead, we can use the same logic the builder uses to determine whether the
attributes work out.

Differential Revision: https://reviews.llvm.org/D24315

llvm-svn: 280894
2016-09-08 00:48:37 +00:00
Reid Kleckner 26f9e9ebc3 Remove FIXME about asserting on the end iterator
After machine block placement, MBBs may not have terminators, and it is
appropriate to check for the end iterator here. We can fold the check
into the next if, as well. This look is really just looking for BBs that
end in CATCHRET.

llvm-svn: 278350
2016-08-11 16:00:43 +00:00
Duncan P. N. Exon Smith 2e7af979b9 CodeGen: Check for a terminator in llvm::getFuncletMembership
Check for an end iterator from MachineBasicBlock::getFirstTerminator in
llvm::getFuncletMembership.  If this is turned into an assertion, it
fires in 48 X86 testcases (for example,
CodeGen/X86/regalloc-spill-at-ehpad.ll).

Since this is likely a latent bug (shouldn't all basic blocks end with a
terminator?) I've filed PR28938.

llvm-svn: 278344
2016-08-11 15:29:02 +00:00
Rafael Espindola 3beef8d6db Move shouldAssumeDSOLocal to Target.
Should fix the shared library build.

llvm-svn: 273958
2016-06-27 23:15:57 +00:00
Rafael Espindola 8121becac3 Teach shouldAssumeDSOLocal about tls.
Fixes a fixme about handling other visibilities.

llvm-svn: 273921
2016-06-27 20:19:14 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Rafael Espindola a224de06bc Use shouldAssumeDSOLocal on AArch64.
This reduces code duplication and now AArch64 also handles PIE.

llvm-svn: 270844
2016-05-26 12:42:55 +00:00
Benjamin Kramer 391be792f2 One more batch of self-containing headers.
llvm-svn: 258974
2016-01-27 19:29:56 +00:00
David Majnemer 734d7c3272 [WinEH] Make collectFuncletMembers non-recursive
Use a worklist for the pre-order DFS instead of using recursion.
No functionality change is intended.

llvm-svn: 258521
2016-01-22 18:49:50 +00:00
Rafael Espindola 79db917139 Don't try to check all uses if lazy loading.
This means that LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN will not be set
in a few cases.

This should have no impact in ld64 since it doesn't use lazy loading
when merging modules and that is when it checks
LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN.

llvm-svn: 257915
2016-01-15 18:23:46 +00:00
David Blaikie 7b54b525cd Remove assert(false) in favor of asserting the if conditional it is contained within.
Also adjust the code to avoid 3 redundant map lookups.

llvm-svn: 251327
2015-10-26 18:41:13 +00:00
Duncan P. N. Exon Smith 980f8f2639 CodeGen: Remove implicit conversions from Analysis and BranchFolding
Remove a few more implicit ilist iterator conversions, this time from
Analysis.cpp and BranchFolding.cpp.

I added a few overloads for `remove()` and `erase()`, which quite
naturally take pointers as well as iterators as parameters.  This will
reduce the churn at least in the short term, but I don't really have a
problem with these existing for longer.

llvm-svn: 249867
2015-10-09 18:23:49 +00:00
David Majnemer e4f9b09b51 [WinEH] Update CATCHRET's operand to match its successor
The CATCHRET operand did not match the MachineFunction's CFG.  This
mismatch happened because FrameLowering created a new MachineBasicBlock
and updated the CFG but forgot to update the CATCHRET operand.

Let's make sure this doesn't happen again by strengthing the funclet
membership analysis: it can now reason about the membership of all basic
blocks, not just those inside of funclets.

llvm-svn: 249344
2015-10-05 20:09:16 +00:00
David Majnemer 161935520d [WinEH] Permit branch folding in the face of funclets
Track which basic blocks belong to which funclets.  Permit branch
folding to fire but only if it can prove that doing so will not cause
code in one funclet to be reused in another.

llvm-svn: 249257
2015-10-04 02:22:52 +00:00
David Majnemer 0a92f86fe6 Revert r246232 and r246304.
This reverts isSafeToSpeculativelyExecute's use of ReadNone until we
split ReadNone into two pieces: one attribute which reasons about how
the function reasons about memory and another attribute which determines
how it may be speculated, CSE'd, trap, etc.

llvm-svn: 246331
2015-08-28 21:13:39 +00:00
David Majnemer a787de3227 [CodeGen] isInTailCallPosition didn't consider readnone tailcalls
A readnone tailcall may still have a chain of computation which follows
it that would invalidate a tailcall lowering.  Don't skip the analysis
in such cases.

This fixes PR24613.

llvm-svn: 246304
2015-08-28 16:44:09 +00:00
Mehdi Amini 44ede33a69 Make TargetLowering::getPointerTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, ted, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11028

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241775
2015-07-09 02:09:04 +00:00
Mehdi Amini 56228dabfa Redirect DataLayout from TargetMachine to Module in ComputeValueVTs()
Summary:
Avoid using the TargetMachine owned DataLayout and use the Module owned
one instead. This requires passing the DataLayout up the stack to
ComputeValueVTs().

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11019

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241773
2015-07-09 01:57:34 +00:00
Tim Northover e4310fe946 CodeGen: move over-zealous assert into actual if statement.
It's quite possible to encounter an insertvalue instruction that's more deeply
nested than the value we're looking for, but when that happens we really
mustn't compare beyond the end of the index array.

Since I couldn't see any guarantees about what comparisons std::equal makes, we
probably need to directly check the size beforehand. In practice, I suspect
most std::equal implementations would probably bail early, which would be OK.
But just in case...

rdar://20834485

llvm-svn: 236635
2015-05-06 20:07:38 +00:00
Tim Northover 851ff69b42 CodeGen: match up correct insertvalue indices when assessing tail calls.
When deciding whether a value comes from the aggregate or inserted value of an
insertvalue instruction, we compare the indices against those of the location
we're interested in. One of the lists needs reversing because the input data is
backwards (so that modifications take place at the end of the SmallVector), but
we were reversing both before leading to incorrect results.

Should fix PR23408

llvm-svn: 236457
2015-05-04 20:41:51 +00:00
Benjamin Kramer 4f6ac16292 Replace std::copy with a back inserter with vector append where feasible
All of the cases were just appending from random access iterators to a
vector. Using insert/append can grow the vector to the perfect size
directly and moves the growing out of the loop. No intended functionalty
change.

llvm-svn: 230845
2015-02-28 10:11:12 +00:00
Eric Christopher f734a8bae7 Get the function specific subtarget.
llvm-svn: 230038
2015-02-20 18:44:17 +00:00
Mehdi Amini 7b068f6ba4 Add assertions for out of bound index in ComputeLinearIndex
llvm-svn: 225951
2015-01-14 05:38:48 +00:00
Mehdi Amini 8923cc5470 Fold a loop for array processing in ComputeLinearIndex
When processing an array, every Elt has the same layout, it is
useless to recursively call each ComputeLinearIndex on each element.
Just do it once and multiply by the number of elements.
    
Differential Revision: http://reviews.llvm.org/D6832

llvm-svn: 225949
2015-01-14 05:33:01 +00:00
Reid Kleckner 283bc2ed28 Allow the use of functions as typeinfo in landingpad clauses
This is one step towards supporting SEH filter functions in LLVM.

llvm-svn: 221954
2014-11-14 00:35:50 +00:00
Eric Christopher d913448b38 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

llvm-svn: 214781
2014-08-04 21:25:23 +00:00
Rafael Espindola f21434ccb0 Refactor duplicated code.
llvm-svn: 214328
2014-07-30 19:42:16 +00:00
Juergen Ributzka 480872b4ce Remove TLI from isInTailCallPosition's arguments. NFC.
There is no need to pass on TLI separately to the function. As Eric pointed out
the Target Machine already provides everything we need.

llvm-svn: 213108
2014-07-16 00:01:22 +00:00
Juergen Ributzka 4ce9863d0b [FastISel] Make isInTailCallPosition independent of SelectionDAG.
Break out the arguemnts required from SelectionDAG, so that this function can
also be used by FastISel.

llvm-svn: 212844
2014-07-11 20:50:47 +00:00
Eric Christopher dda00098bc The includes were sorted. Revert r210578.
llvm-svn: 211737
2014-06-25 22:36:37 +00:00
Eric Christopher 576d36ae05 Have isInTailCallPosition take the DAG so that we can use the
version of TargetLowering/Machine from there on the way to avoiding
TargetMachine in TargetLowering.

llvm-svn: 210579
2014-06-10 20:39:38 +00:00
Eric Christopher 09fc276d08 Reorder includes to be sorted.
llvm-svn: 210578
2014-06-10 20:39:35 +00:00
Eric Christopher db5028bd5b Fix typos.
llvm-svn: 210571
2014-06-10 20:07:29 +00:00
Craig Topper c0196b1b40 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206142
2014-04-14 00:51:57 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Michael Gottesman ce0e4c263b [stackprotector] Refactor out the end of isInTailCallPosition into the function returnTypeIsEligibleForTailCall.
This allows me to use returnTypeIsEligibleForTailCall in the stack protector pass.

rdar://13935163

llvm-svn: 188765
2013-08-20 08:36:50 +00:00
Tim Northover 707d68f082 Allow compatible extension attributes for tail calls
If the tail-callee and caller give the same bits via the same signext/zeroext
attribute then a tail-call should be allowed, since the extension has already
been done by the callee.

llvm-svn: 188159
2013-08-12 09:45:46 +00:00
Benjamin Kramer df03449a0a Make helper static and fix formatting.
llvm-svn: 188074
2013-08-09 14:44:41 +00:00
Tim Northover a4415854db Refactor isInTailCallPosition handling
This change came about primarily because of two issues in the existing code.
Niether of:

define i64 @test1(i64 %val) {
  %in = trunc i64 %val to i32
  tail call i32 @ret32(i32 returned %in)
  ret i64 %val
}

define i64 @test2(i64 %val) {
  tail call i32 @ret32(i32 returned undef)
  ret i32 42
}

should be tail calls, and the function sameNoopInput is responsible. The main
problem is that it is completely symmetric in the "tail call" and "ret" value,
but in reality different things are allowed on each side.

For these cases:
1. Any truncation should lead to a larger value being generated by "tail call"
   than needed by "ret".
2. Undef should only be allowed as a source for ret, not as a result of the
   call.

Along the way I noticed that a mismatch between what this function treats as a
valid truncation and what the backends see can lead to invalid calls as well
(see x86-32 test case).

This patch refactors the code so that instead of being based primarily on
values which it recurses into when necessary, it starts by inspecting the type
and considers each fundamental slot that the backend will see in turn. For
example, given a pathological function that returned {{}, {{}, i32, {}}, i32}
we would consider each "real" i32 in turn, and ask if it passes through
unchanged. This is much closer to what the backend sees as a result of
ComputeValueVTs.

Aside from the bug fixes, this eliminates the recursion that's going on and, I
believe, makes the bulk of the code significantly easier to understand. The
trade-off is the nasty iterators needed to find the real types inside a
returned value.

llvm-svn: 187787
2013-08-06 09:12:35 +00:00
Michael Gottesman c0659fad7f [stackprotector] Changed isNoopBitcast/sameNoopInput to take TargetLoweringBase instead of TargetLowering.
Both functions only use functionality from TargetLoweringBase.

rdar://13935163

llvm-svn: 186874
2013-07-22 21:05:47 +00:00
Stephen Lin 699808ceb2 Only pass 'returned' to target-specific lowering code when the value of entire register is guaranteed to be preserved.
llvm-svn: 180825
2013-04-30 22:49:28 +00:00
Stephen Lin 6c70dc7842 Add some constraints to use of 'returned':
1) Disallow 'returned' on parameter that is also 'sret' (no sensible semantics, as far as I can tell).
2) Conservatively disallow tail calls through 'returned' parameters that also are 'zext' or 'sext' (for consistency with treatment of other zero-extending and sign-extending operations in tail call position detection...can be revised later to handle situations that can be determined to be safe).

This is a new attribute that is not yet used, so there is no impact.

llvm-svn: 180118
2013-04-23 16:31:56 +00:00
Stephen Lin b8bd232a3d Add CodeGen support for functions that always return arguments via a new parameter attribute 'returned', which is taken advantage of in target-independent tail call opportunity detection and in ARM call lowering (when placed on an integral first parameter).
llvm-svn: 179925
2013-04-20 05:14:40 +00:00
Stephen Lin ffc445492c Allow tail call opportunity detection through nested and/or multiple iterations of extractelement/insertelement indirection
llvm-svn: 179924
2013-04-20 04:27:51 +00:00