In some case the loop exit count computation can overflow. Extend the type to
prevent most of those cases.
The problem is loops like:
int main ()
{
int a = 1;
char b = 0;
lbl:
a &= 4;
b--;
if (b) goto lbl;
return a;
}
The backedge count is 255. The induction variable type is i8. If we add one to
255 to get the exit count we overflow to zero.
To work around this issue we extend the type of the induction variable to i32 in
the case of i8 and i16.
PR17532
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195008 91177308-0d34-0410-b5e6-96231b3b80d8
Fixed an inappropriate use of BuildPairF64 when compiling for MIPS32 with FP64
which resulted in an impossible constraint on the register allocation. It now
uses BuildPairF64_64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195007 91177308-0d34-0410-b5e6-96231b3b80d8
Generally speaking, control flow paths with error reporting calls are cold.
So far, error reporting calls are calls to perror and calls to fprintf,
fwrite, etc. with stderr as the stream. This can be extended in the future.
The primary motivation is to improve block placement (the cold attribute
affects the static branch prediction heuristics).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194943 91177308-0d34-0410-b5e6-96231b3b80d8
Implementing this on bigendian platforms could get strange. I added a
target hook, getStackSlotRange, per Jakob's recommendation to make
this as explicit as possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194942 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a loop rerolling pass: the opposite of (partial) loop unrolling. The
transformation aims to take loops like this:
for (int i = 0; i < 3200; i += 5) {
a[i] += alpha * b[i];
a[i + 1] += alpha * b[i + 1];
a[i + 2] += alpha * b[i + 2];
a[i + 3] += alpha * b[i + 3];
a[i + 4] += alpha * b[i + 4];
}
and turn them into this:
for (int i = 0; i < 3200; ++i) {
a[i] += alpha * b[i];
}
and loops like this:
for (int i = 0; i < 500; ++i) {
x[3*i] = foo(0);
x[3*i+1] = foo(0);
x[3*i+2] = foo(0);
}
and turn them into this:
for (int i = 0; i < 1500; ++i) {
x[i] = foo(0);
}
There are two motivations for this transformation:
1. Code-size reduction (especially relevant, obviously, when compiling for
code size).
2. Providing greater choice to the loop vectorizer (and generic unroller) to
choose the unrolling factor (and a better ability to vectorize). The loop
vectorizer can take vector lengths and register pressure into account when
choosing an unrolling factor, for example, and a pre-unrolled loop limits that
choice. This is especially problematic if the manual unrolling was optimized
for a machine different from the current target.
The current implementation is limited to single basic-block loops only. The
rerolling recognition should work regardless of how the loop iterations are
intermixed within the loop body (subject to dependency and side-effect
constraints), but the significant restriction is that the order of the
instructions in each iteration must be identical. This seems sufficient to
capture all current use cases.
This pass is not currently enabled by default at any optimization level.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194939 91177308-0d34-0410-b5e6-96231b3b80d8
InstCombine, in visitFPTrunc, applies the following optimization to sqrt calls:
(fptrunc (sqrt (fpext x))) -> (sqrtf x)
but does not apply the same optimization to llvm.sqrt. This is a problem
because, to enable vectorization, Clang generates llvm.sqrt instead of sqrt in
fast-math mode, and because this optimization is being applied to sqrt and not
applied to llvm.sqrt, sometimes the fast-math code is slower.
This change makes InstCombine apply this optimization to llvm.sqrt as well.
This fixes the specific problem in PR17758, although the same underlying issue
(optimizations applied to libcalls are not applied to intrinsics) exists for
other optimizations in SimplifyLibCalls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194935 91177308-0d34-0410-b5e6-96231b3b80d8
The tests just hit this with a different sized
address space since I haven't figured out how
to use this to break it.
I thought I committed this a long time ago,
and I'm not sure why missing this hasn't caused
any problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194903 91177308-0d34-0410-b5e6-96231b3b80d8
and update test cases accordingly.
This doesn't affect the output dumped using llvm-dwarfdump, but
readelf does now dump the debug_loc section.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194898 91177308-0d34-0410-b5e6-96231b3b80d8
When we vectorize a scalar access with no alignment specified, we have to set
the target's abi alignment of the scalar access on the vectorized access.
Using the same alignment of zero would be wrong because most targets will have a
bigger abi alignment for vector types.
This probably fixes PR17878.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194876 91177308-0d34-0410-b5e6-96231b3b80d8
We used to use std::map<IndicesVector, LoadInst*> for OriginalLoads, and when we
try to promote two arguments, they will both write to OriginalLoads causing
created loads for the two arguments to have the same original load. And the same
tbaa tag and alignment will be put to the created loads for the two arguments.
The fix is to use std::map<std::pair<Argument*, IndicesVector>, LoadInst*>
for OriginalLoads, so each Argument will write to different parts of the map.
PR17906
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194846 91177308-0d34-0410-b5e6-96231b3b80d8
Stop folding constant adds into GEP when the type size doesn't match.
Otherwise, the adds' operands are effectively being promoted, changing the
conditions of an overflow. Results are different when:
sext(a) + sext(b) != sext(a + b)
Problem originally found on x86-64, but also fixed issues with ARM and PPC,
which used similar code.
<rdar://problem/15292280>
Patch by Duncan Exon Smith!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194840 91177308-0d34-0410-b5e6-96231b3b80d8
Now that FileCheck supports multiple check prefixes, we don't need to keep the
little and big endian versions of this test separate anymore. Merge them back
together.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194826 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When getConstant() is called for an expanded vector type, it is split into
multiple scalar constants which are then combined using appropriate build_vector
and bitcast operations.
In addition to the usual big/little endian differences, the case where the
element-order of the vector does not have the same endianness as the elements
themselves is also accounted for. For example, for v4i32 on big-endian MIPS,
the byte-order of the vector is <3210,7654,BA98,FEDC>. For little-endian, it is
<0123,4567,89AB,CDEF>.
Handling this case turns out to be a nop since getConstant() returns a splatted
vector (so reversing the element order doesn't change the value)
This fixes a number of cases in MIPS MSA where calling getConstant() during
operation legalization introduces illegal types (e.g. to legalize v2i64 UNDEF
into a v2i64 BUILD_VECTOR of illegal i64 zeros). It should also handle bigger
differences between illegal and legal types such as legalizing v2i64 into v8i16.
lowerMSASplatImm() in the MIPS backend no longer needs to avoid calling
getConstant() so this function has been updated in the same patch.
For the sake of transparency, the steps I've taken since the review are:
* Added 'virtual' to isVectorEltOrderLittleEndian() as requested. This revealed
that the MIPS tests were falsely passing because a polymorphic function was
not actually polymorphic in the reviewed patch.
* Fixed the tests that were now failing. This involved deleting the code to
handle the MIPS MSA element-order (which was previously doing an byte-order
swap instead of an element-order swap). This left
isVectorEltOrderLittleEndian() unused and it was deleted.
* Fixed build failures caused by rebasing beyond r194467-r194472. These build
failures involved the bset, bneg, and bclr instructions added in these commits
using lowerMSASplatImm() in a way that was no longer valid after this patch.
Some of these were fixed by calling SelectionDAG::getConstant() instead,
others were fixed by a new function getBuildVectorSplat() that provided the
removed functionality of lowerMSASplatImm() in a more sensible way.
Reviewers: bkramer
Reviewed By: bkramer
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1973
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194811 91177308-0d34-0410-b5e6-96231b3b80d8
Using a special machine node is cleaner than an InlineAsm node, and fixes an assertion failure in InstrEmitter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194810 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch (correctly) breaks some MSA tests by exposing the cases when
SelectionDAG::getConstant() produces illegal types. These have been temporarily
marked XFAIL and the XFAIL flag will be removed when
SelectionDAG::getConstant() is fixed.
There are three categories of failure:
* Immediate instructions are not selected in one endian mode.
* Immediates used in ldi.[bhwd] must be different according to endianness.
(this only affects cases where the 'wrong' ldi is used to load the correct
bitpattern. E.g. (bitcast:v2i64 (build_vector:v4i32 ...)))
* Non-immediate instructions that rely on immediates affected by the
previous two categories as part of their match pattern.
For example, the bset match pattern is the vector equivalent of
'ws | (1 << wt)'.
One test needed correcting to expect different output depending on whether big
or little endian was in use. This test was
test/CodeGen/Mips/msa/basic_operations.ll and experiences the second category
of failure shown above. The little endian version of this test is named
basic_operations_little.ll and will be merged back into basic_operations.ll in
a follow up commit now that FileCheck supports multiple check prefixes.
Reviewers: bkramer, jacksprat, dsanders
Reviewed By: dsanders
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194806 91177308-0d34-0410-b5e6-96231b3b80d8
I was able to successfully run a bootstrapped LTO build of clang with
r194701, so this change does not seem to be the cause of our failing
buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194789 91177308-0d34-0410-b5e6-96231b3b80d8
This is to avoid this transformation in some cases:
fold (conv (load x)) -> (load (conv*)x)
On architectures that don't natively support some vector
loads efficiently casting the load to a smaller vector of
larger types and loading is more efficient.
Patch by Micah Villmow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194783 91177308-0d34-0410-b5e6-96231b3b80d8
While the test would work with any compiled in target with object
emission support, it's nontrivial to formulate this condition in
lit, so a conservative restriction is used instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194781 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit 194701. Apple's bootstrapped LTO builds have been failing,
and this change (along with compiler-rt 194702-194704) is the only thing on
the blamelist. I will either reappy these changes or help debug the problem,
depending on whether this fixes the buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194780 91177308-0d34-0410-b5e6-96231b3b80d8
This commit brings the module structure, argument order and
primitive names in Llvm_target in order with the rest of the bindings,
in preparation for adding TargetMachine API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194773 91177308-0d34-0410-b5e6-96231b3b80d8
short form. Constant islands will expand them if they are out of range.
Since there is not direct object emitter at this time, it does not
have any material affect because the assembler sorts this out. But we
need to know for the actual constant island work. We track the difference
by putting # 16 inst in the comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194766 91177308-0d34-0410-b5e6-96231b3b80d8
The LDS output queue is accessed via the OQAP register. The OQAP
register cannot be live across clauses, so if value is written to the
output queue, it must be retrieved before the end of the clause.
With the machine scheduler, we cannot statisfy this constraint, because
it lacks proper alias analysis and it will mark some LDS accesses as
having a chain dependency on vertex fetches. Since vertex fetches
require a new clauses, the dependency may end up spiltting OQAP uses and
defs so the end up in different clauses. See the lds-output-queue.ll
test for a more detailed explanation.
To work around this issue, we now combine the LDS read and the OQAP
copy into one instruction and expand it after register allocation.
This patch also adds some checks to the EmitClauseMarker pass, so that
it doesn't end a clause with a value still in the output queue and
removes AR.X and OQAP handling from the scheduler (AR.X uses and defs
were already being expanded post-RA, so the scheduler will never see
them).
Reviewed-by: Vincent Lejeune <vljn at ovi.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194755 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Some machine-type-neutral object files containing only undefined symbols
actually do exist in the Windows standard library. Need to recognize them
as COFF files.
Reviewers: Bigcheese
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2164
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194734 91177308-0d34-0410-b5e6-96231b3b80d8
We used to perform an invalid operation on an MVT and crash, which wasn't much
fun.
Patch by Oliver Stannard.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194714 91177308-0d34-0410-b5e6-96231b3b80d8
In ELF and COFF an alias is just another offset in a section. There is no way
to represent an alias to something in another file.
In MachO, the spec has the N_INDR type which should allow for exactly that, but
is not currently implemented. Given that it is specified but not implemented,
we error in codegen to avoid miscompiling but don't reject aliases to
declarations in the verifier to leave the option open of implementing it.
In the past we have used alias to declarations as a way of implementing
weakref, which is why it exists in some old tests which this patch updates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194705 91177308-0d34-0410-b5e6-96231b3b80d8
Indirect call wrapping helps MSanDR (dynamic instrumentation companion tool
for MSan) to catch all cases where execution leaves a compiler-instrumented
module by allowing the tool to rewrite targets of indirect calls.
This change is an optimization that skips wrapping for calls when target is
inside the current module. This relies on the linker providing symbols at the
begin and end of the module code (or code + data, does not really matter).
Gold linker provides such symbols by default. GNU (BFD) linker needs a link
flag: -Wl,--defsym=__executable_start=0.
More info:
https://code.google.com/p/memory-sanitizer/wiki/MSanDR#Native_exec
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194697 91177308-0d34-0410-b5e6-96231b3b80d8
If a null call target is provided, don't emit a dummy call. This
allows the runtime to reserve as little nop space as it needs without
the requirement of emitting a call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194676 91177308-0d34-0410-b5e6-96231b3b80d8
There is nothing special about quotes and newlines from the object
file point of view, only the assembler has to worry about expanding
the \n and \".
This patch then removes the special handling from the Mangler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194667 91177308-0d34-0410-b5e6-96231b3b80d8
with and without -g.
Adding a test case to make sure that the threshold used in the memory
dependence analysis is respected. The test case also checks that debug
intrinsics are not counted towards this threshold.
Differential Revision: http://llvm-reviews.chandlerc.com/D2141
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194646 91177308-0d34-0410-b5e6-96231b3b80d8
According to the hazy gcov documentation, it appeared to be technically
possible for lines within a block to belong to different source files.
However, upon further investigation, gcov does not actually support
multiple source files for a single block.
This change removes a level of separation between blocks and lines by
replacing the StringMap of GCOVLines with a SmallVector of ints
representing line numbers. This also means that the GCOVLines class is
no longer needed.
This paves the way for supporting the "-a" option, which will output
block information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194637 91177308-0d34-0410-b5e6-96231b3b80d8
Unified the interface for read functions. They all return a boolean
indicating if the read from file succeeded. Functions that previously
returned the read value now store it into a variable that is passed in
by reference instead. Callers will need to check the return value to
detect if an error occurred.
Also added a new test which ensures that no assertions occur when file
contains invalid data. llvm-cov should return with error code 1 upon
failure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194635 91177308-0d34-0410-b5e6-96231b3b80d8
All shift operations will be selected as SALU instructions and then
if necessary lowered to VALU instructions in the SIFixSGPRCopies pass.
This allows us to do more operations on the SALU which will improve
performance and is also required for implementing private memory
using indirect addressing, since the private memory pointers must stay
in the scalar registers.
This patch includes some fixes from Matt Arsenault.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194625 91177308-0d34-0410-b5e6-96231b3b80d8
This test compares the output of llvm-cov against a coverage file
generated by gcov. Currently, llvm-cov does not work on certain
platforms (namely big-endian architectures such as PowerPC, among
others). These platforms are marked as XFAIL for now, but will be fixed
later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194616 91177308-0d34-0410-b5e6-96231b3b80d8
instructions. This patch does not include the shift right and accumulate
instructions. A number of non-overloaded intrinsics have been remove in favor
of their overloaded counterparts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194598 91177308-0d34-0410-b5e6-96231b3b80d8
By default, the behavior of IT block generation will be determinated
dynamically base on the arch (armv8 vs armv7). This patch adds backend
options: -arm-restrict-it and -arm-no-restrict-it. The former one
restricts the generation of IT blocks (the same behavior as thumbv8) for
both arches. The later one allows the generation of legacy IT block (the
same behavior as ARMv7 Thumb2) for both arches.
Clang will support -mrestrict-it and -mno-restrict-it, which is
compatible with GCC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194592 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fix a case when "FileCheck --check-prefix=CHECK --check-prefix=CHECKER"
would silently ignore check-lines of the form:
CHECKER: foo
Reviewers: dsanders
Reviewed By: dsanders
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2168
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194577 91177308-0d34-0410-b5e6-96231b3b80d8
Accepting quotes is a property of an assembler, not of an object file. For
example, ELF can support any names for sections and symbols, but the gnu
assembler only accepts quotes in some contexts and llvm-mc in a few more.
LLVM should not produce different symbols based on a guess about which assembler
will be reading the code it is printing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194575 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a new scalar pass that reads a file with samples generated
by 'perf' during runtime. The samples read from the profile are
incorporated and emmited as IR metadata reflecting that profile.
The profile file is assumed to have been generated by an external
profile source. The profile information is converted into IR metadata,
which is later used by the analysis routines to estimate block
frequencies, edge weights and other related data.
External profile information files have no fixed format, each profiler
is free to define its own. This includes both the on-disk representation
of the profile and the kind of profile information stored in the file.
A common kind of profile is based on sampling (e.g., perf), which
essentially counts how many times each line of the program has been
executed during the run.
The SampleProfileLoader pass is organized as a scalar transformation.
On startup, it reads the file given in -sample-profile-file to
determine what kind of profile it contains. This file is assumed to
contain profile information for the whole application. The profile
data in the file is read and incorporated into the internal state of
the corresponding profiler.
To facilitate testing, I've organized the profilers to support two file
formats: text and native. The native format is whatever on-disk
representation the profiler wants to support, I think this will mostly
be bitcode files, but it could be anything the profiler wants to
support. To do this, every profiler must implement the
SampleProfile::loadNative() function.
The text format is mostly meant for debugging. Records are separated by
newlines, but each profiler is free to interpret records as it sees fit.
Profilers must implement the SampleProfile::loadText() function.
Finally, the pass will call SampleProfile::emitAnnotations() for each
function in the current translation unit. This function needs to
translate the loaded profile into IR metadata, which the analyzer will
later be able to use.
This patch implements the first steps towards the above design. I've
implemented a sample-based flat profiler. The format of the profile is
fairly simplistic. Each sampled function contains a list of relative
line locations (from the start of the function) together with a count
representing how many samples were collected at that line during
execution. I generate this profile using perf and a separate converter
tool.
Currently, I have only implemented a text format for these profiles. I
am interested in initial feedback to the whole approach before I send
the other parts of the implementation for review.
This patch implements:
- The SampleProfileLoader pass.
- The base ExternalProfile class with the core interface.
- A SampleProfile sub-class using the above interface. The profiler
generates branch weight metadata on every branch instructions that
matches the profiles.
- A text loader class to assist the implementation of
SampleProfile::loadText().
- Basic unit tests for the pass.
Additionally, the patch uses profile information to compute branch
weights based on instruction samples.
This patch converts instruction samples into branch weights. It
does a fairly simplistic conversion:
Given a multi-way branch instruction, it calculates the weight of
each branch based on the maximum sample count gathered from each
target basic block.
Note that this assignment of branch weights is somewhat lossy and can be
misleading. If a basic block has more than one incoming branch, all the
incoming branches will get the same weight. In reality, it may be that
only one of them is the most heavily taken branch.
I will adjust this assignment in subsequent patches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194566 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This fixes a subtle bug in new FileCheck feature added
in r194343. When we search for the first satisfying check-prefix,
we should actually return the first encounter of some check-prefix as a
substring, even if it's not a part of valid check-line. Otherwise
"FileCheck --check-prefix=FOO --check-prefix=BAR" with check file:
FOO not a vaild check-line
FOO: foo
BAR: bar
incorrectly accepted file:
fog
bar
as it skipped the first two encounters of FOO, matching only BAR: line.
Reviewers: arsenm, dsanders
Reviewed By: dsanders
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2166
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194565 91177308-0d34-0410-b5e6-96231b3b80d8
They are failing on clang-native-arm-cortex-a9.
Please tweak MCJIT/lit.local.cfg, if this didn't satisfy bots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194561 91177308-0d34-0410-b5e6-96231b3b80d8
specifically about the .space directive. This allows us to force large
blocks of code to appear in test cases for things like constant islands
without having to make giant test cases to force things like long
branches to take effect.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194555 91177308-0d34-0410-b5e6-96231b3b80d8
This patch reapplies r193676 with an additional fix for the Hexagon backend. The
SystemZ backend has already been fixed by r194148.
The Type Legalizer recognizes that VSELECT needs to be split, because the type
is to wide for the given target. The same does not always apply to SETCC,
because less space is required to encode the result of a comparison. As a result
VSELECT is split and SETCC is unrolled into scalar comparisons.
This commit fixes the issue by checking for VSELECT-SETCC patterns in the DAG
Combiner. If a matching pattern is found, then the result mask of SETCC is
promoted to the expected vector mask type for the given target. Now the type
legalizer will split both VSELECT and SETCC.
This allows the following X86 DAG Combine code to sucessfully detect the MIN/MAX
pattern. This fixes PR16695, PR17002, and <rdar://problem/14594431>.
Reviewed by Nadav
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194542 91177308-0d34-0410-b5e6-96231b3b80d8
print the name of the function on which the dependence analysis is performed
such that changes to the testcase are easier to review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194528 91177308-0d34-0410-b5e6-96231b3b80d8
Add user-supplied C runtime and compiler-rt library functions to
llvm.compiler.used to protect them from premature optimization by
passes like -globalopt and -ipsccp. Calls to (seemingly unused)
runtime library functions can be added by -instcombine and instruction
lowering.
Patch by Duncan Exon Smith, thanks!
Fixes <rdar://problem/14740087>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194514 91177308-0d34-0410-b5e6-96231b3b80d8
The system LDM and STM instructions can't usually writeback to the base
register. The one exception is when an LDM is actually an exception-return
(i.e. contains PC in the register list).
(There's already a test that "ldm sp!, {r0-r3, pc}^" works, which is why there
is no positive test).
rdar://problem/15223374
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194512 91177308-0d34-0410-b5e6-96231b3b80d8