Commit Graph

24903 Commits

Author SHA1 Message Date
Matt Arsenault
a4c1394dea DAG: Handle extract_vector_elt in isKnownNeverNaN
llvm-svn: 341317
2018-09-03 14:01:03 +00:00
Sander de Smalen
1aab3dec99 Fix issue introduced by r341301 that broke buildbot.
A condition in isSpillInstruction() updates a small vector rather
than the 'FI' by-ref parameter, which was used in a subsequent
call to 'isSpillSlotObjectIndex()'. This patch fixes the condition
to check the FIs in the vector instead.

llvm-svn: 341305
2018-09-03 10:23:34 +00:00
Sander de Smalen
9de07a620d Extend hasStoreToStackSlot with list of FI accesses.
For instructions that spill/fill to and from multiple frame-indices
in a single instruction, hasStoreToStackSlot and hasLoadFromStackSlot
should return an array of accesses, rather than just the first encounter
of such an access.

This better describes FI accesses for AArch64 (paired) LDP/STP
instructions.

Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D51537

llvm-svn: 341301
2018-09-03 09:15:58 +00:00
Hsiangkai Wang
03ff0042c1 Revert "[DebugInfo] Fix bug in LiveDebugVariables."
This reverts commit 8f548ff2a1819e1bc051e8218584f1a3d2cf178a.

buildbot failure in LLVM on clang-ppc64be-linux
http://lab.llvm.org:8011/builders/clang-ppc64le-linux/builds/19765

llvm-svn: 341290
2018-09-02 16:35:42 +00:00
Hsiangkai Wang
45bb59e001 [DebugInfo] Fix bug in LiveDebugVariables.
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.

Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().

Differential Revision: https://reviews.llvm.org/D50621

llvm-svn: 341289
2018-09-02 15:57:22 +00:00
Roman Lebedev
713057a782 [DAGCombine] optimizeSetCCOfSignedTruncationCheck(): handle inverted pattern
Summary:
A follow-up for D49266 / rL337166 + D49497 / rL338044.

This is still the same pattern to check for the [lack of]
signed truncation, but in this case the constants and the predicate
are negated.

https://rise4fun.com/Alive/BDV
https://rise4fun.com/Alive/n7Z

Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma, dmgreen

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51532

llvm-svn: 341287
2018-09-02 13:56:22 +00:00
Vlad Tsyrklevich
5750100b55 SafeStack: Prevent OOB reads with mem intrinsics
Summary:
Currently, the SafeStack analysis disallows out-of-bounds writes but not
out-of-bounds reads for mem intrinsics like llvm.memcpy. This could
cause leaks of pointers to the safe stack by leaking spilled registers/
frame pointers. Check for allocas used as source or destination pointers
to mem intrinsics.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: pcc, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D51334

llvm-svn: 341116
2018-08-30 20:44:51 +00:00
Craig Topper
8577019430 [DAGCombiner] Fix bad identation. NFC
llvm-svn: 341103
2018-08-30 19:35:40 +00:00
Vladimir Stefanovic
4f40714aee Allow inconsistent offsets for 'noreturn' basic blocks when '-verify-cfiinstrs'
With r295105, some 'noreturn' blocks (those that don't return and have no
successors) may be merged.
If such blocks' predecessors have different outgoing offset or register, don't
report an error in CFIInstrInserter verify().

Thanks to Vlad Tsyrklevich for reporting the issue.

Differential Revision: https://reviews.llvm.org/D51161

llvm-svn: 341087
2018-08-30 17:31:38 +00:00
Nicolai Haehnle
5a64e70379 [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
Ties Stuij
43c46fbb66 [CodeGen] emit inline asm clobber list warnings for reserved (cont)
Summary:
This is a continuation of https://reviews.llvm.org/D49727
Below the original text, current changes in the comments:

Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.

For example:

  extern int bar(int[]);
  
  int foo(int i) {
    int a[i]; // VLA
    asm volatile(
        "mov r7, #1"
      :
      :
      : "r7"
    );
  
    return 1 + bar(a);
  }

Compiled for thumb, this gives:

  $ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
  ...
  foo:
          .fnstart
  @ %bb.0:                                @ %entry
          .save   {r4, r5, r6, r7, lr}
          push    {r4, r5, r6, r7, lr}
          .setfp  r7, sp, #12
          add     r7, sp, #12
          .pad    #4
          sub     sp, #4
          movs    r1, #7
          add.w   r0, r1, r0, lsl #2
          bic     r0, r0, #7
          sub.w   r0, sp, r0
          mov     sp, r0
          @APP
          mov.w   r7, #1
          @NO_APP
          bl      bar
          adds    r0, #1
          sub.w   r4, r7, #12
          mov     sp, r4
          pop     {r4, r5, r6, r7, pc}
  ...

r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.

This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.

The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.

If we find a reserved register, we print a warning:

  repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
        "mov r7, #1"
        ^

Reviewers: efriedma, olista01, javed.absar

Reviewed By: efriedma

Subscribers: eraman, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D51165

llvm-svn: 341062
2018-08-30 12:52:35 +00:00
Matt Arsenault
9c6d728552 Don't count debug instructions towards neighborhood count
In computeRegisterLiveness, the max instructions to search
was counting dbg_value instructions, which could potentially
cause an observable codegen change from the presence of debug
info.

llvm-svn: 341028
2018-08-30 07:18:19 +00:00
Matt Arsenault
f28136694b CodeGen: Make computeRegisterLiveness search forward first
If there is an unused def, this would previously
report that the register was live. Check for uses
first so that it is reported as dead if never used.

llvm-svn: 341027
2018-08-30 07:18:10 +00:00
Matt Arsenault
55014dafc8 CodeGen: Make computeRegisterLiveness consider successors
If the end of the block is reached during the scan, check
the live ins of the successors. This was already done in the
other direction if the block entry was reached.

llvm-svn: 341026
2018-08-30 07:17:51 +00:00
Carlos Alberto Enciso
b3643235a3 [DWARF] Missing location debug information with -O2.
Check that Machine CSE correctly handles during the transformation, the
debug location information for local variables.

Differential Revision: https://reviews.llvm.org/D50887

llvm-svn: 341025
2018-08-30 07:17:41 +00:00
Matt Arsenault
b04c5924df DAG: Don't use ABI copies in some contexts
If an ABI-like value is used in a different block,
the type split used is not necessarily the same as
the call's ABI. The value is used through an intermediate
copy virtual registers from the other block. This
resulted in copies with inconsistent sizes later.

Fixes regressions since r338197 when AMDGPU started
splitting vector types for calls.

llvm-svn: 341018
2018-08-30 05:49:28 +00:00
Huihui Zhang
d0b6fb04cd [GlobalMerge] Fix GlobalMerge on bss external global variables.
Summary:
Global variables that are external and zero initialized are
supposed to be merged with global variables in the bss section
rather than the data section.

Reviewers: efriedma, rengolin, t.p.northover, javed.absar, asl, john.brawn, pcc

Reviewed By: efriedma

Subscribers: dmgreen, llvm-commits

Differential Revision: https://reviews.llvm.org/D51379

llvm-svn: 341008
2018-08-30 00:49:50 +00:00
Eli Friedman
f9565a1015 [NFC] Make getPreferredAlignment honor section markings.
This should more accurately reflect what the AsmPrinter will actually
do.

This is NFC, as far as I can tell; all the places that might be affected
already have an extra check to avoid using the result of
getPreferredAlignment in this situation.

Differential Revision: https://reviews.llvm.org/D51377

llvm-svn: 340999
2018-08-29 23:46:26 +00:00
Matthias Braun
a9707dee3c Reverse subregister saved loops in register usage info collector; NFC
On AMDGPU we have 70 register classes, so iterating over all 70
each time and exiting is costly on the CPU, this flips the loop
around so that it loops over the 70 register classes first,
and exits without doing the inner loop if needed.

On my test just starting radv this takes
RegUsageInfoCollector::runOnMachineFunction
from 6.0% of total time to 2.7% of total time,
and reduces the startup from 2.24s to 2.19s

Patch by David Airlie!

Differential Revision: https://reviews.llvm.org/D48582

llvm-svn: 340993
2018-08-29 23:12:42 +00:00
Martin Storsjo
94a46bec1d [MinGW] [X86] Add stubs for references to data variables that might end up imported from a dll
Variables declared with the dllimport attribute are accessed via a
stub variable named __imp_<var>. In MinGW configurations, variables that
aren't declared with a dllimport attribute might still end up imported
from another DLL with runtime pseudo relocs.

For x86_64, this avoids the risk that the target is out of range
for a 32 bit PC relative reference, in case the target DLL is loaded
further than 4 GB from the reference. It also avoids having to make the
text section writable at runtime when doing the runtime fixups, which
makes it worthwhile to do for i386 as well.

Add stub variables for all dso local data references where a definition
of the variable isn't visible within the module, since the DLL data
autoimporting might make them imported even though they are marked as
dso local within LLVM.

Don't do this for variables that actually are defined within the same
module, since we then know for sure that it actually is dso local.

Don't do this for references to functions, since there's no need for
runtime pseudo relocations for autoimporting them; if a function from
a different DLL is called without the appropriate dllimport attribute,
the call just gets routed via a thunk instead.

GCC does something similar since 4.9 (when compiling with -mcmodel=medium
or large; from that version, medium is the default code model for x86_64
mingw), but only for x86_64.

Differential Revision: https://reviews.llvm.org/D51288

llvm-svn: 340942
2018-08-29 17:28:34 +00:00
Simon Pilgrim
6c5cf13b34 [DAGCombiner] Add X / X -> 1 & X % X -> 0 folds
Adds more divrem folds to try and get in sync with InstructionSimplify

Differential Revision: https://reviews.llvm.org/D50636

llvm-svn: 340919
2018-08-29 11:30:16 +00:00
George Rimar
7bb3635513 Revert r340904 "[llvm-mc] - Allow to set custom flags for debug sections."
It broke PPC64 BB:
http://lab.llvm.org:8011/builders/clang-ppc64be-linux/builds/23252

llvm-svn: 340906
2018-08-29 09:04:52 +00:00
George Rimar
a71c290608 [llvm-mc] - Allow to set custom flags for debug sections.
I am experimenting with a single split dwarf (.dwo sections in .o files).
I want to make linker to ignore .dwo sections in .o, for that I am trying to add
SHF_EXCLUDE flag ("E") for them in my asm sample.

I found that currently, it is impossible to add any flag for debug sections using llvm-mc.

That happens because we have a set of predefined unique sections created early with default flags:
https://github.com/llvm-mirror/llvm/blob/master/lib/MC/MCObjectFileInfo.cpp#L391

This patch allows a user to add any flags he wants.

I had to edit TargetLoweringObjectFileImpl.cpp to set MetaData type for debug sections.
Their kind was Data by default (so they were allocatable) and so after changes introduced by
this patch the SHF_ALLOC flag was applied for them, what does not make sense for debug sections.
One of OrcJITTests tests failed because of that.

Differential revision: https://reviews.llvm.org/D51361

llvm-svn: 340904
2018-08-29 08:42:02 +00:00
Aditya Nandakumar
0aefa6c214 [GISel]: Add legalization support for Widening UADDO/USUBO
https://reviews.llvm.org/D51384

Added code in LegalizerHelper to widen UADDO/USUBO along with unit
tests.

Reviewed by volkan.

llvm-svn: 340892
2018-08-29 03:17:08 +00:00
Craig Topper
04b2a1ec7d [X86] Support v2i32 gather/scatter indices with -x86-experimental-vector-widening-legalization
Summary: This is split out from D41062 to cover the code in LegalVectorTypes.cpp

Reviewers: RKSimon, spatel, efriedma

Reviewed By: efriedma

Subscribers: sdardis, jvesely, nhaehnle, jrtc27, atanasyan, llvm-commits

Differential Revision: https://reviews.llvm.org/D51337

llvm-svn: 340891
2018-08-29 02:12:49 +00:00
Aditya Nandakumar
4e615a2119 [GISel]: Add missing opcodes for overflow intrinsics
https://reviews.llvm.org/D51197

Currently, IRTranslator (and GISel) seems to be arbitrarily picking
which overflow intrinsics get mapped into opcodes which either have a
carry as an input or not.
For intrinsics such as Intrinsic::uadd_with_overflow, translate it to an
opcode (G_UADDO) which doesn't have any carry inputs (similar to LLVM
IR).

This patch adds 4 missing opcodes for completeness - G_UADDO, G_USUBO,
G_SSUBE and G_SADDE.

llvm-svn: 340865
2018-08-28 18:54:10 +00:00
Nirav Dave
2914a691b3 [DAGCombine] Rework MERGE_VALUES to inline in single pass. NFCI.
Avoid hyperlinear cost of inlining MERGE_VALUE node by constructing
temporary vector and doing a single replacement.

llvm-svn: 340853
2018-08-28 18:13:26 +00:00
Nirav Dave
741515d89c [DAG] Avoid recomputing Divergence checks. NFCI.
When making multiple updates to the same SDNode, recompute node
divergence only once after all changes have been made.

llvm-svn: 340852
2018-08-28 18:13:00 +00:00
Nirav Dave
52a17527a0 [DAG] Fix updateDivergence calculation
Check correct SDNode when deciding if we should update the divergence
property.

llvm-svn: 340851
2018-08-28 18:12:35 +00:00
Craig Topper
707737eef4 [DAGCombiner][AMDGPU][Mips] Fold bitcast with volatile loads if the resulting load is legal for the target.
Summary:
I'm not sure if this patch is correct or if it needs more qualifying somehow. Bitcast shouldn't change the size of the load so it should be ok? We already do something similar for stores. We'll change the type of a volatile store if the resulting store is Legal or Custom. I'm not sure we should be allowing Custom there...

I was playing around with converting X86 atomic loads/stores(except seq_cst) into regular volatile loads and stores during lowering. This would allow some special RMW isel patterns in X86InstrCompiler.td to be removed. But there's some floating point patterns in there that didn't work because we don't fold (f64 (bitconvert (i64 volatile load))) or (f32 (bitconvert (i32 volatile load))).

Reviewers: efriedma, atanasyan, arsenm

Reviewed By: efriedma

Subscribers: jvesely, arsenm, sdardis, kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, arichardson, jrtc27, atanasyan, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D50491

llvm-svn: 340797
2018-08-28 03:47:20 +00:00
David Blaikie
cfd04c50e1 Revert "[CodeGenPrepare] Scan past debug intrinsics to find select candidates (NFC)"
This causes crashes due to the interleaved dbg.value intrinsics being
left at the end of basic blocks, causing the actual terminators (br,
etc) to be not where they should be (not at the end of the block),
leading to later crashes.

Further discussion on the original commit thread.

This reverts commit r340368.

llvm-svn: 340794
2018-08-28 00:55:19 +00:00
Brendon Cahoon
887911c8b0 [Pipeliner] Fix incorrect phi values in the epilog and kernel
The code that generates the loop definition operand for phis
in the epilog and kernel is incorrect in some cases.

In the kernel, when a phi refers to another phi, the code that
updates PhiOp2 needs to include the stage difference between
the two phis.

In the epilog, the check for using the loop definition instead
of the phi definition uses the StageDiffAdj value (the difference
between the phi stage and the loop definition stage), but the
adjustment is not needed to determine if the current stage
contains an iteration with the loop definition.

Differential Revision: https://reviews.llvm.org/D51167

llvm-svn: 340782
2018-08-27 22:04:50 +00:00
Matt Arsenault
3442f70fe6 DAG: Check transformed type for forming fminnum/fmaxnum from vselect
Follow up to r340655 to fix vector types which are split.

llvm-svn: 340766
2018-08-27 18:11:31 +00:00
Matt Arsenault
385d2085b8 MachineVerifier: Fix assert on implicit virtreg use
If the liveness of a physical register was invalid, this
was attempting to iterate the subregisters of all register
uses of the instruction, which would assert when it
encountered an implicit virtual register operand.

llvm-svn: 340763
2018-08-27 17:40:09 +00:00
Sanjay Patel
a63fc05170 [SelectionDAG] add helper query for binops; NFC
We will also use this in a planned enhancement for vector insertelement.

llvm-svn: 340741
2018-08-27 14:20:15 +00:00
Sanjay Patel
bcd538983f [SelectionDAG][x86] turn insertelement into undef with variable index into splat
I noticed this along with the patterns in D51125, but when the index is variable, 
we don't convert insertelement into a build_vector.

For x86, that means these get expanded at legalization time into the loading/spilling 
code that we see in the tests. I think it's always better to avoid going to memory on 
these, and we get the optimal 'broadcast' if it's available.

I suspect other targets may want to look at enabling the hook. AArch64 and AMDGPU have 
regression tests that would be affected (although I did not check what would happen in 
those cases). In the most basic cases shown here, AArch64 would probably do much 
better with a splat.

Differential Revision: https://reviews.llvm.org/D51186

llvm-svn: 340705
2018-08-26 18:20:41 +00:00
Chandler Carruth
5fa7afa32f [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
7f564cda33 [IR] Begin removal of TerminatorInst by removing successor manipulation.
The core get and set routines move to the `Instruction` class. These
routines are only valid to call on instructions which are terminators.

The iterator and *generic* range based access move to `CFG.h` where all
the other generic successor and predecessor access lives. While moving
the iterator here, simplify it using the iterator utilities LLVM
provides and updates coding style as much as reasonable. The APIs remain
pointer-heavy when they could better use references, and retain the odd
behavior of `operator*` and `operator->` that is common in LLVM
iterators. Adjusting this API, if desired, should be a follow-up step.

Non-generic range iteration is added for the two instructions where
there is an especially easy mechanism and where there was code
attempting to use the range accessor from a specific subclass:
`indirectbr` and `br`. In both cases, the successors are contiguous
operands and can be easily iterated via the operand list.

This is the first major patch in removing the `TerminatorInst` type from
the IR's instruction type hierarchy. This change was discussed in an RFC
here and was pretty clearly positive:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123407.html

There will be a series of much more mechanical changes following this
one to complete this move.

Differential Revision: https://reviews.llvm.org/D47467

llvm-svn: 340698
2018-08-26 08:41:15 +00:00
Craig Topper
f92ce9e064 [SelectionDAG][X86] Reorder the operands the MaskedStoreSDNode to put the value first.
Summary:
Previously the value being stored is the last operand in SDNode. This causes the type legalizer to visit the mask operand before the value operand. The type legalizer was more complicated because of this since we want the type of the value to drive the decisions.

This patch moves the value to be the first operand so we visit it first during type legalization. It also simplifies the type legalization code accordingly.

X86 is currently the only in tree target that uses this SDNode. Not sure if there are any users out of tree.

Reviewers: RKSimon, delena, hfinkel, eli.friedman

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50402

llvm-svn: 340689
2018-08-25 17:48:17 +00:00
Bjorn Pettersson
d405dff40d [CodeGen] Set FrameSetup/FrameDestroy on BUNDLE instructions
Summary:
If any of the bundled instructions are marked as FrameSetup
or FrameDestroy, then that property is set on the BUNDLE
instruction as well.

As long as the scheduler/packetizer aren't mixing
prologue/epilogue instructions (i.e. all the bundled
instructions have the same property) then this simply gives
the bundle the correct property (so when using a bundle
iterator in late passes a bundle will be correctly identified
as FrameSetup/FrameDestroy).

When for example bundling a mix of FrameSetup instructions
with non-FrameSetup instructions it could be discussed if
the bundle should have the property or not. The choice here
has been to set these properties on the BUNDLE instruction if
any of the bundled instructions have the property set.

Reviewers: #debug-info, kparzysz

Reviewed By: kparzysz

Subscribers: vsk, thegameg, llvm-commits

Differential Revision: https://reviews.llvm.org/D50637

llvm-svn: 340680
2018-08-25 11:26:17 +00:00
Bjorn Pettersson
098cfbb1a5 [LiveDebugVariables] Avoid faulty addDefsFromCopies in computeIntervals
Summary:
When computeIntervals is looking through COPY instruction to
extend the location mapping for a debug variable it did not
handle subregisters correctly.

For example
    DBG_VALUE debug-use %0.sub_8bit_hi, ...
    %1:gr16 = COPY %0
was transformed into
    DBG_VALUE debug-use %0.sub_8bit_hi, ...
    %1:gr16 = COPY %0
    DBG_VALUE debug-use %1, ...
So the subregister index was missing in the added DBG_VALUE.

As long as the subreg refered to the least significant bits
of the superreg, then I guess we could get the correct
result in a debugger even when referring to the superreg.
But as in the example above when the subreg refers to other
parts of the superreg, then debuginfo would be incorrect.

I'm not sure exactly how to fix this properly, so this patch
just avoids looking through the COPY when there is a subreg
involved (for more info, see the FIXME added in the code).

Reviewers: rnk, aprantl

Reviewed By: aprantl

Subscribers: JDevlieghere, llvm-commits

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D50788

llvm-svn: 340679
2018-08-25 10:02:03 +00:00
Matt Arsenault
bddc128f74 DAG: Allow matching fminnum/fmaxnum from vselect
llvm-svn: 340655
2018-08-24 21:24:18 +00:00
Eli Friedman
3be32ec89b [SafeStack] Set debug location for calls to __safestack_pointer_address.
Otherwise, the debug info is incorrect.  On its own, this is mostly
harmless, but the safe-stack also later inlines the call to
__safestack_pointer_address, which leads to debug info with the wrong
scope, which eventually causes an assertion failure (and incorrect debug
info in release mode).

Differential Revision: https://reviews.llvm.org/D51075

llvm-svn: 340651
2018-08-24 20:42:32 +00:00
Peter Collingbourne
02fb976bb0 CodeGen: Add two more conditions for adding symbols to the address-significance table.
Firstly, require the symbol to be used within the module. If a
symbol is unused within a module, then by definition it cannot be
address-significant within that module. This condition is useful on all
platforms because it could make symbol tables smaller -- without this
change, emitting an address-significance table could cause otherwise
unused undefined symbols to be added to the object file.

But this change is necessary with COFF specifically in order to
preserve the property that an unreferenced undefined symbol in an IR
module does not result in a link failure. This is already the case for
ELF because ELF linkers only reject links with unresolved symbols if
there is a relocation to that symbol, but COFF linkers require all
undefined symbols to be resolved regardless of relocations. So if
a module contains an unreferenced undefined symbol, we need to make
sure not to add it to the address-significance table (and thus the
symbol table) in case it doesn't end up resolved at link time.

Secondly, do not add dllimport symbols to the table. These symbols
won't be able to be resolved because their definitions live in another
module and are accessed via the IAT, and the address-significance
table has no effect on other modules anyway. It wouldn't make sense
to add the IAT entry symbol to the address-significance table either
because the IAT entry isn't address-significant -- the generated code
never takes its address.

Differential Revision: https://reviews.llvm.org/D51199

llvm-svn: 340648
2018-08-24 20:37:09 +00:00
David Blaikie
0f21649780 DebugInfo: Fix skipping CUs in DWARFv5 debug_names table
My previoust test case had skipped CUs from one TU out of a two-TU LTO
scenario, which meant the CU index wasn't needed (as it was unambiguous
which CU a table entry applied to) - expanding the test to use 3 TUs,
skipping one (so long as it's not the last one) shows the indexes are
miscomputed. Fix that with a little indirection for the index.

llvm-svn: 340646
2018-08-24 20:31:05 +00:00
Craig Topper
ae241aa02f [DAGCombiner][Mips] Don't combine bitcast+store after LegalOperations when the store is volatile, if the resulting store isn't Legal
Previously we allowed the store to be Custom. But without knowing for sure that the Custom handling won't split the store, we shouldn't convert a volatile store. We also probably shouldn't be creating a store the requires custom handling after LegalizeOps. This could lead to an infinite loop if the custom handling was to insert a bitcast. Though I guess isStoreBitCastBeneficial could be used to block such a loop.

The test changes here are due to the volatile part of this. The stores in the test are all volatile and i32 stores are marked custom, So we are no longer converting them

This is related to D50491 where I was trying to allow some bitcasting of volatile loads

Differential Revision: https://reviews.llvm.org/D50578

llvm-svn: 340626
2018-08-24 17:48:25 +00:00
Justin Bogner
c1f40d10bf [SDAG] Add versions of computeKnownBits that return a value
Having the KnownBits as an output parameter is kind of awkward to use
and a holdover from when it was two separate APInts. Instead, just
return a KnownBits object.

I'm leaving the existing interface in place for now, since updating
the callers all at once would be thousands of lines of diff.

llvm-svn: 340594
2018-08-24 02:42:24 +00:00
Tim Renouf
aa23123d32 [RegisterCoalescer] Fix for assert in removePartialRedundancy
Summary:
I got "Use not jointly dominated by defs" when removePartialRedundancy
attempted to prune then re-extend a subrange whose only liveness was a
dead def at the copy being removed.

V2: Removed junk from test. Improved comment.
V3: Addressed minor review comments.

Subscribers: MatzeB, qcolombet, nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D50914

Change-Id: I6f894e9f517f71e921e0c6d81d28c5f344db8dad
llvm-svn: 340549
2018-08-23 17:28:33 +00:00
Chandler Carruth
a4cb0d60d9 Revert r340508: [DebugInfo] Fix bug in LiveDebugVariables.
This patch's test case relies on debug prints which isn't generally an
OK way to test stuff in LLVM and fails whenever asserts aren't enabled.
I've send a heads-up to the commit and detailed comments on the review.

llvm-svn: 340513
2018-08-23 05:39:02 +00:00
Hsiangkai Wang
a6319a1529 [DebugInfo] Fix bug in LiveDebugVariables.
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.

Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().

Differential Revision: https://reviews.llvm.org/D50621

llvm-svn: 340508
2018-08-23 03:28:24 +00:00