The issues was that AArch64 has additional restrictions on when local
relocations can be used. We have to take those into consideration when
deciding to put a L symbol in the symbol table or not.
Original message:
Remove doesSectionRequireSymbols.
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 225048
We are allowed to move the 'B' to the right hand side if we an prove
there is no signed overflow and if the comparison itself is signed.
llvm-svn: 225034
Too many different comment characters - instead of trying to account for
them all, instead disable the comments and just check for end-of-line
instead.
llvm-svn: 225020
GCC does this for non-zero discriminators and since GCC doesn't produce
column info, that was the only place it comes up there. For LLVM, since
we can emit discriminators and/or column info, it makes more sense to
invert the condition and just test for changes in line number.
This should resolve at least some of the GDB 7.5 test suite failures
created by recent Clang changes that increase the location fidelity
(which, since Clang defaults to including column info on Linux by
default created a bunch of cases that confused GDB).
In theory we could do this better/differently by grouping actual source
statements together in a similar manner to the way lexical scopes are
handled but given that GDB isn't really in a position to consume that (&
users are probably somewhat used to different lines being different
'statements') this seems the safest and cheapest change. (I'm concerned
that doing this 'right' would bloat the debugloc data even further -
something Duncan's working hard to address)
llvm-svn: 225011
Under the large code model, we cannot assume that __morestack lives within
2^31 bytes of the call site, so we cannot use pc-relative addressing. We
cannot perform the call via a temporary register, as the rax register may
be used to store the static chain, and all other suitable registers may be
either callee-save or used for parameter passing. We cannot use the stack
at this point either because __morestack manipulates the stack directly.
To avoid these issues, perform an indirect call via a read-only memory
location containing the address.
This solution is not perfect, as it assumes that the .rodata section
is laid out within 2^31 bytes of each function body, but this seems to
be sufficient for JIT.
Differential Revision: http://reviews.llvm.org/D6787
llvm-svn: 225003
If a linker directive is already quoted, don't try to quote it again, otherwise it creates a mess.
This pops up in places like:
#pragma comment(linker,"\"/foo bar'\"")
Differential Revision: http://reviews.llvm.org/D6792
llvm-svn: 224998
This function's implementation lives in libgcc, a static library, so we need
to expose it explicitly, like the other such functions.
Differential Revision: http://reviews.llvm.org/D6788
llvm-svn: 224993
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 224985
Nothing particularly interesting, just adding infrastructure for use by in tree users and out of tree users.
Note: These were extracted out of a working frontend, but they have not been well tested in isolation.
Differential Revision: http://reviews.llvm.org/D6807
llvm-svn: 224981
It looks like the original intent was to check which symbols were created.
With macho-dump the sections were being checked just to match which symbol
was in which section.
llvm-objdump prints the section a symbol is in.
llvm-svn: 224980
These are simply a collection of tests intended to show that information about the contents of gc references in the heap is lost at a statepoint. I've tried to write them so that they don't disallow correct transformations, while still being fairly easy to understand.
p.s. Ideas for additional tests are welcome.
Differential Revision: http://reviews.llvm.org/D6491
llvm-svn: 224971
This change implements four basic optimizations:
If a relocated value isn't used, it doesn't need to be relocated.
If the value being relocated is null, relocation doesn't change that. (Technically, this might be collector specific. I don't know of one which it doesn't work for though.)
If the value being relocated is undef, the relocation is meaningless.
If the value being relocated was known nonnull, the relocated pointer also isn't null. (Since it points to the same source language object.)
I outlined other planned work in comments.
Differential Revision: http://reviews.llvm.org/D6600
llvm-svn: 224968
In LICM, we have a check for an instruction which is guaranteed to execute and thus can't introduce any new faults if moved to the preheader. To handle a function which might unconditionally throw when first called, we check for any potentially throwing call in the loop and give up.
This is unfortunate when the potentially throwing condition is down a rare path. It prevents essentially all LICM of potentially faulting instructions where the faulting condition is checked outside the loop. It also greatly diminishes the utility of loop unswitching since control dependent instructions - which are now likely in the loops header block - will not be lifted by subsequent LICM runs.
define void @nothrow_header(i64 %x, i64 %y, i1 %cond) {
; CHECK-LABEL: nothrow_header
; CHECK-LABEL: entry
; CHECK: %div = udiv i64 %x, %y
; CHECK-LABEL: loop
; CHECK: call void @use(i64 %div)
entry:
br label %loop
loop: ; preds = %entry, %for.inc
%div = udiv i64 %x, %y
br i1 %cond, label %loop-if, label %exit
loop-if:
call void @use(i64 %div)
br label %loop
exit:
ret void
}
The current patch really only helps with non-memory instructions (i.e. divs, etc..) since the maythrow call down the rare path will be considered to alias an otherwise hoistable load. The one exception is that it does kick in for loads which are known to be invariant without regard to other possible stores, i.e. those marked with either !invarant.load metadata of tbaa 'is constant memory' metadata.
Differential Revision: http://reviews.llvm.org/D6725
llvm-svn: 224965
Summary:
This in turn allows us to use #includes with cgo that rely on CMake
provided include directories which is particularly useful for handling
generated headers that aren't reasonable to put in an "installable"
location.
Differential Revision: http://reviews.llvm.org/D6798
llvm-svn: 224962
This patches fixes a miscompile where we were assuming that loading from null is undefined and thus we could assume it doesn't happen. This transform is perfectly legal in address space 0, but is not neccessarily legal in other address spaces.
We really should introduce a hook to control this property on a per target per address space basis. We may be loosing valuable optimizations in some address spaces by being too conservative.
Original patch by Thomas P Raoux (submitted to llvm-commits), tests and formatting fixes by me.
llvm-svn: 224961
a CLANG_LIBDIR_SUFFIX variable. This is necessary before I can add
support for using that variable to CMake and the C++ code in Clang, and
the autoconf build system does all substitutions in the LLVM tree.
As mentioned before, I'm not planning to add actual multilib support to
the autoconf build, just enough stubs for it to keep playing nicely with
the CMake build once that one has support.
llvm-svn: 224922
For this to work, we have to encode it in the build variables and use it
from llvm-config.cpp. I've tried to do this reasonably cleanly, but the
code for llvm-config.cpp is pretty strange. However, with this,
llvm-config stops giving the wrong answer when using LLVM_LIBDIR_SUFFIX.
Note that the configure+make build just sets this to an empty string as
that build system has zero support for multilib of any form. I'm not
planning to add support there either, but this should leave a path for
anyone that wanted to.
llvm-svn: 224921
that is used by other projects to build against LLVM. This will allow
subsequent patches to them to use LLVM_LIBDIR_SUFFIX, both when built as
part of the larger LLVM build an as part of a standalone build against
an installed set of LLVM libraries.
llvm-svn: 224920
*numerous* places where it was missing in the CMake build. The primary
change here is that the suffix is now actually used for all of the lib
directories in the LLVM project's CMake. The various subprojects still
need similar treatment.
This is the first of a series of commits to try to make LLVM's cmake
effective in a multilib Linux installation. I don't think many people
are seriously using this variable so I'm hoping the fallout will be
minimal. A somewhat unfortunate consequence of the nature of these
commits is that until I land all of them, they will in part make the
brokenness of our multilib support more apparant. At the end, things
should actually work.
llvm-svn: 224919
The else case ResultReg was not checked for validity.
To my surprise, this case was not hit in any of the
existing test cases. This includes a new test cases
that tests this path.
Also drop the `target triple` declaration from the
original test as suggested by H.J. Lu, because
apparently with it the test won't be run on Linux
llvm-svn: 224901
If the control flow is modelling an if-statement where the only instruction in
the 'then' basic block (excluding the terminator) is a call to cttz/ctlz,
CodeGenPrepare can try to speculate the cttz/ctlz call and simplify the control
flow graph.
Example:
\code
entry:
%cmp = icmp eq i64 %val, 0
br i1 %cmp, label %end.bb, label %then.bb
then.bb:
%c = tail call i64 @llvm.cttz.i64(i64 %val, i1 true)
br label %end.bb
end.bb:
%cond = phi i64 [ %c, %then.bb ], [ 64, %entry]
\code
In this example, basic block %then.bb is taken if value %val is not zero.
Also, the phi node in %end.bb would propagate the size-of in bits of %val
only if %val is equal to zero.
With this patch, CodeGenPrepare will try to hoist the call to cttz from %then.bb
into basic block %entry only if cttz is cheap to speculate for the target.
Added two new hooks in TargetLowering.h to let targets customize the behavior
(i.e. decide whether it is cheap or not to speculate calls to cttz/ctlz). The
two new methods are 'isCheapToSpeculateCtlz' and 'isCheapToSpeculateCttz'.
By default, both methods return 'false'.
On X86, method 'isCheapToSpeculateCtlz' returns true only if the target has
LZCNT. Method 'isCheapToSpeculateCttz' only returns true if the target has BMI.
Differential Revision: http://reviews.llvm.org/D6728
llvm-svn: 224899
Masked vector intrinsics are a part of common LLVM IR, but they are really supported on AVX2 and AVX-512 targets. I added a code that translates masked intrinsic for all other targets. The masked vector intrinsic is converted to a chain of scalar operations inside conditional basic blocks.
http://reviews.llvm.org/D6436
llvm-svn: 224897
Determining the address of a TLS variable results in a function call in
certain TLS models. This means that a simple ICmpInst might actually
result in invalidating the CTR register.
In such cases, do not attempt to rely on the CTR register for loop
optimization purposes.
This fixes PR22034.
Differential Revision: http://reviews.llvm.org/D6786
llvm-svn: 224890
Summary:
Consider the following IR:
%3 = load i8* undef
%4 = trunc i8 %3 to i1
%5 = call %jl_value_t.0* @foo(..., i1 %4, ...)
ret %jl_value_t.0* %5
Bools (that are the result of direct truncs) are lowered as whatever
the argument to the trunc was and a "and 1", causing the part of the
MBB responsible for this argument to look something like this:
%vreg8<def,tied1> = AND8ri %vreg7<kill,tied0>, 1, %EFLAGS<imp-def>; GR8:%vreg8,%vreg7
Later, when the load is lowered, it will insert
%vreg15<def> = MOV8rm %vreg14, 1, %noreg, 0, %noreg; mem:LD1[undef] GR8:%vreg15 GR64:%vreg14
but remember to (at the end of isel) replace vreg7 by vreg15. Now for
the bug. In fast isel lowering, we mistakenly mark vreg8 as the result
of the load instead of the trunc. This adds a fixup to have
vreg8 replaced by whatever the result of the load is as well, so
we end up with
%vreg15<def,tied1> = AND8ri %vreg15<kill,tied0>, 1, %EFLAGS<imp-def>; GR8:%vreg15
which is an SSA violation and causes problems later down the road.
This fixes PR21557.
Test Plan: Test test case from PR21557 is added to the test suite.
Reviewers: ributzka
Reviewed By: ributzka
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6245
llvm-svn: 224884
When materializing constant i1 values, they must be zero extended. We represent
i1 values as [0, 1], not [0, -1], in i32 registers. As it turns out, this code
path was dead for i1 values prior to r216006 (which is why this did not manifest in
miscompiles until recently).
Fixes -O0 self-hosting on PPC64/Linux.
llvm-svn: 224842
Bob Wilson pointed out the unnecessary checks that had been committed to the
instruction check predicates. The check was meant to ensure that the check was
not accidentally applied to non-ARM instructions. This is better served as an
assertion rather than a condition check.
llvm-svn: 224825
Correct the line information generation for preprocessed assembly. Although we
tracked the source information for the macro instantiation, we failed to account
for the fact that we were instantiating a macro, which is populated into a new
buffer and that the line information would be relative to the definition rather
than the actual instantiation location. This could cause the line number
associated with the statement to be very high due to wrapping of the difference
calculated for the preprocessor line information emitted into the stream.
Properly calculate the line for the macro instantiation, referencing the line
where the macro is actually used as GCC/gas do.
The test case uses x86, though the same problem exists on any other target using
the LLVM IAS.
llvm-svn: 224810
This removes a hardcoded list of instructions in the CodeEmitter. Eventually I intend to remove the predicates on the affected instructions since in any given mode two of them are valid if we supported addr32/addr16 prefixes in the assembler.
llvm-svn: 224809
This function constructs the main liverange by merging all subranges if
subregister liveness tracking is available. This should be slightly
faster to compute instead of performing the liveness calculation again
for the main range. More importantly it avoids cases where the main
liverange would cover positions where no subrange was live. These cases
happened for partial definitions where the actual defined part was dead
and only the undefined parts used later.
The register coalescing requires that every part covered by the main
live range has at least one subrange live.
I also expect this function to become usefull later for places where the
subranges are modified in a way that it is hard to correctly fix the
main liverange in the machine scheduler, we can simply reconstruct it
from subranges then.
llvm-svn: 224806
Without a reference the code did not remember when moving the iterators
of the subranges/registerunit ranges forward and instead would scan from
the beginning again at the next position.
llvm-svn: 224803
Patch by Ramkumar Ramachandra <artagnon@gmail.com>.
Also remove Llvm_executionengine.get_pointer_to_global, as it
is actually deprecated and didn't appear in a stable release.
llvm-svn: 224801
within a partition of an alloca in SROA.
This reflects the fact that the organization of the slices isn't really
ideal for analysis, but is the naive way in which the slices are
available while we're processing them in the core partitioning
algorithm.
It is possible we could improve matters, and I've left a FIXME with
one of my ideas for how to do this, but it is a lot of work, the benefit
is somewhat minor, and it isn't clear that it would be strictly better.
=/ Not really satisfying, but I'm out of really good ideas.
This also improves one place where the debug logging failed to mark some
split partitions. Now we log in one place, slightly later, and with
accurate information about whether the slice is split by the partition
being rewritten.
llvm-svn: 224800
operate in terms of the new Partition class, and generally have a more
clear set of arguments. No functionality changed.
The most notable improvements here are consistently using the
terminology of 'partition' for a collection of slices that will be
rewritten together and 'slice' for a region of an alloca that is used by
a particular instruction.
This also makes it more clear that the split things are actually slices
as well, just ones that will be split by the proposed partition.
This doesn't yet address the confusing aspects of the partition's
interface where slices that will be split by the partition and start
prior to the partition are accesssed via Partition::splitSlices() while
the core range of slices exposed by a Partition includes both unsplit
slices and slices which will be split by the end, but started within the
offset range of the partition. This is particularly hard to address
because the algorithm which computes partitions quite literally doesn't
know which slices these will end up being until too late. I'm looking at
whether I can fix that or not, but I'm not optimistic. I'll update the
comments and/or names to further explain this either way. I've also
added one FIXME in this patch relating to this confusion so that I don't
forget about it.
llvm-svn: 224798
On non-Darwin PPC64, the TOC reload needs to come directly after the bctrl
instruction (for indirect calls) because the 'bctrl/ld 2, 40(1)' instruction
sequence is interpreted by the unwinding code in libgcc. To make sure these
occur as a pair, as with other pairings interpreted by the linker, fuse the two
instructions into one instruction (for code generation only).
In the future, we might wish to do this by emitting CFI directives instead,
but this solution is simpler, and mirrors what GCC does. Additional discussion
on this point is contained in the PR.
Fixes PR22015.
llvm-svn: 224788
a size and alignment. Several assertions in DwarfDebug rely on all variable
types to report back a size, or to be derived from a type with a size.
Tested in CFE.
llvm-svn: 224780
Right now in DAG Combine check the validity of the returned type
only when -debug is given on the command line. However usually
the test cases in the validation does not use -debug.
An Assert build should always check this.
llvm-svn: 224779
GlobalAlias handling used to be after GlobalValue handling, which meant it was, in practice, dead code. r220165 moved GlobalAlias handling to be before GlobalValue handling, but also moved it to be before the max depth check, causing an assert due to a recursion depth limit violation.
This moves GlobalAlias handling forward to where it's safe, and changes the GlobalValue handling to only look at GlobalObjects.
Differential Revision: http://reviews.llvm.org/D6758
llvm-svn: 224765
It is tempting to mark the fixed stack slot used to store the return address as
immutable when lowering @llvm.returnaddress(i32 0). Unfortunately, within the
function, it is not completely immutable: it is written during the function
prologue. When using post-RA instruction scheduling, the prologue instructions
are available for scheduling, and we're not free to interchange the order of a
particular store in the prologue with loads from that stack location.
Fixes PR21976.
llvm-svn: 224761
In r224033, in moving the signed power-of-2 division expansion into
BuildSDIVPow2, I accidentally made it possible to attempt the lowering for a
64-bit division on PPC32. This later asserts.
Fixes PR21928.
llvm-svn: 224758
Michael Gottesman