Summary:
The v_movreld machine instruction is used with three operands that are
in a sense tied to each other (the explicit VGPR_32 def and the implicit
VGPR_NN def and use). There is no way to express that using the currently
available operand bits, and indeed there are cases where the Two Address
instructions pass does the wrong thing.
This patch introduces a new set of pseudo instructions that are identical
in intended semantics as v_movreld, but they only have two tied operands.
Having to add a new set of pseudo instructions is admittedly annoying, but
it's a fairly straightforward and solid approach. The only alternative I
see is to try to teach the Two Address instructions pass about Three Address
instructions, and I'm afraid that's trickier and is going to end up more
fragile.
Note that v_movrels does not suffer from this problem, and so this patch
does not touch it.
This fixes several GL45-CTS.shaders.indexing.* tests.
Reviewers: tstellarAMD, arsenm
Subscribers: kzhuravl, wdng, yaxunl, llvm-commits, tony-tye
Differential Revision: https://reviews.llvm.org/D25633
llvm-svn: 284980
Fix AsmParser lines to correctly handle end-of-line pre-processor
comments parsing when '#' is not the assembly line comment prefix.
Reviewers: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25567
llvm-svn: 284978
If we don't have futimens(), we fall back to futimes(), which only supports
microsecond timestamps. In that case, we need to explicitly cast away the extra
precision in setLastModificationAndAccessTime().
llvm-svn: 284977
Summary:
Most of the changes are very straight-forward. The only choice I had to make was
to use second-precision time points in the Archive classes. I did this because
the archive files use that precision in the on-disk representation anyway.
Reviewers: rafael, zturner
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25773
llvm-svn: 284974
Summary:
Add relocations for AArch64 ILP32. Includes:
- Addition of definitions for R_AARCH32_*
- Definition of new -target-abi: ilp32
- Definition of data layout string
- Tests for added relocations. Not comprehensive, but matches
existing tests for 64-bit. Renames "CHECK-OBJ" to "CHECK-OBJ-LP64".
- Tests for llvm-readobj
Reviewers: zatrazz, peter.smith, echristo, t.p.northover
Subscribers: aemerson, rengolin, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25159
llvm-svn: 284973
Summary:
These are good candidates for jump threading. This enables later opts
(such as InstCombine) to combine instructions from the selects with
instructions out of the selects. SimplifyCFG will fold the select
again if unfolding wasn't worth it.
Patch by James Molloy and Pablo Barrio.
Reviewers: reames, bkramer, mcrosier, gberry, haicheng, jmolloy, sebpop
Subscribers: jojo, rengolin, llvm-commits
Differential Revision: https://reviews.llvm.org/D25477
llvm-svn: 284971
Summary:
This is a follow-up to D25416. It removes all usages of TimeValue from
llvm/Support library (except for the actual TimeValue declaration), and replaces
them with appropriate usages of std::chrono. To facilitate this, I have added
small utility functions for converting time points and durations into appropriate
OS-specific types (FILETIME, struct timespec, ...).
Reviewers: zturner, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25730
llvm-svn: 284966
Add synci to the microMIPS instruction definitions, mark the MIPS sync & synci
as not being part of microMIPS. This does not cover the sync instruction alias,
as that will be handled with a different patch. Add sync to the valid tests for
microMIPS.
Reviewers: vkalintiris
Differential Revision: https://reviews.llvm.org/D25795
llvm-svn: 284962
Summary: With MSVC 2013 and GCC < 4.8 gone, we can use the "constexpr" keyword.
Reviewers: bkramer, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25901
llvm-svn: 284947
We were defaulting to SSE2 costs which weren't taking into account the availability of PBLENDW/PBLENDVB to improve merging of per-element shift results.
llvm-svn: 284939
Summary:
r283710 introduced two regressions, one to llvm-lit, and the other to
lit executables that were installed via setuptools. Add instructions on
how to test for these regressions in the future.
Reviewers: ddunbar, delcypher, beanz, chapuni, cmatthews, echristo
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25459
llvm-svn: 284919
In BasicAA GEP operand values get adjusted ("wrap-around") based on the
pointersize. Otherwise, in non-64b modes, AA could report false negatives.
However, a wrap-around is valid only for a fully evaluated expression.
It had been introduced to fix an alias problem in
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160118/326163.html.
This commit restricts the wrap-around to constant gep operands only where the
value is known at compile-time.
llvm-svn: 284908
The assert() macro doesn't actually execute its body in Release builds, so using
it to check cache invariants requires that the insertion be outside of the
assert() statement. This change does that, and also makes sure to return the
actual map contents.
llvm-svn: 284898
The build was breaking on some platforms because we assumed that
CachedHashString("foo") would match the CachedHashString(StringRef)
constructor rather than the CachedHashString(char*) constructor.
To fix this, provide a CachedHashString(const char*) constructor, and
add a dummy argument to the old CachedHashString(char*) constructor.
llvm-svn: 284892
This will prevent following regression when enabling i16 support (D18049):
test/CodeGen/AMDGPU/cvt_f32_ubyte.ll
Differential Revision: https://reviews.llvm.org/D25805
llvm-svn: 284891
Summary:
SetVector already used DenseSet, but SmallSetVector used std::set. This
leads to surprising performance differences. Moreover, it means that
the set of key types accepted by SetVector and SmallSetVector are
quite different!
In order to make this change, we had to convert some callsites that used
SmallSetVector<std::string, N> to use SmallSetVector<CachedHashString, N>
instead.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25648
llvm-svn: 284887
Summary:
We already have the hashes in hand, and comparing hashes should be much
more discriminatory than comparing the StringRefs' sizes.
Reviewers: rafael
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25705
llvm-svn: 284872
Summary:
This is like CachedHashStringRef, but owns its data.
This lets us use strings inside of DenseMaps.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25645
llvm-svn: 284871
Summary:
A CallSite is basically an Instruction*, and you can put Instruction*s
into DenseMaps, so you should be able to do the same with CallSites.
This is used in a later patch.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25643
llvm-svn: 284870
Summary:
When SCEVRewriteVisitor traverses the SCEV DAG, it may visit the same SCEV
multiple times if this SCEV is referenced by multiple other SCEVs. This has
exponential time complexity in the worst case. Memoizing the results will
avoid re-visiting the same SCEV. Add a map to save the results, and override
the visit function of SCEVVisitor. Now SCEVRewriteVisitor only visit each
SCEV once and thus returns the same result for the same input SCEV.
This patch fixes PR18606, PR18607.
Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin
Differential Revision: https://reviews.llvm.org/D25810
llvm-svn: 284868
iterating over an archive with object and non-object members that
would cause an Abort because to was not calling consumeError()
when the code was wanting to ignore a non-object file.
Found by Justin Bogner!
llvm-svn: 284867
If a 64-bit value is tested against a bit which is known to be in the range
[0..31) (modulo 64), we can use the 32-bit BT instruction, which has a slightly
shorter encoding.
Differential Revision: https://reviews.llvm.org/D25862
llvm-svn: 284864
Summary: This adds support for dumping the globals stream from PDB files using llvm-pdbdump, similar to the support we have for the publics stream.
Reviewers: ruiu, zturner
Subscribers: beanz, mgorny, modocache
Differential Revision: https://reviews.llvm.org/D25801
llvm-svn: 284861
Summary:
Utility pass to remove gc.relocates created by rewrite statepoints for GC.
With respect to safepoint verification, the IR generated would be incorrect, and cannot run
as such.
This would be a single transformation on the final optimized IR.
The benefit of the pass is for easy analysis when the IRs are 'polluted' by too
many gc.relocates.
Added tests.
test run: All RS4GC tests with -verify option. Local downstream tests on large
IR files. This also works when the pointer being gc.relocated is another
gc.relocate.
Reviewers: sanjoy, reames
Subscribers: beanz, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D25096
llvm-svn: 284855
the ARM_THREAD_STATE in the same format as
otool-classic(1) on darwin.
Also remove an extra space in printing the initprot to make
the output match otool-classic(1) on darwin.
rdar://28851457
llvm-svn: 284852
0 - X --> 0, if the sub is NUW
0 - X --> 0, if X is 0 or the minimum signed value and the sub is NSW
0 - X --> X, if X is 0 or the minimum signed value
This is the DAG equivalent of:
https://reviews.llvm.org/rL284649
plus the fold for the NUW case which already existed in InstSimplify.
Note that we miss a vector fold because of a deficiency in the DAG version of
computeKnownBits().
llvm-svn: 284844
These are the backend equivalents for the tests added in r284627.
The patterns may emerge late, so we should have folds for these in the DAG too.
llvm-svn: 284842
After register allocation it is possible to have a spill of a register
that is only partially defined. That in itself it fine, but creates a
problem for double vector registers. Stores of such registers are pseudo
instructions that are expanded into pairs of individual vector stores,
and in case of a partially defined source, one of the stores may use
an entirely undefined register. To avoid this, track the defined parts
and only generate actual stores for those.
llvm-svn: 284841
Summary:
Need to reorder the operands to have the callee as the last argument.
Adds a pseudo-instruction, and a pass to lower it into a real
call_indirect.
This is the first of two options for how to fix the problem.
Reviewers: dschuff, sunfish
Subscribers: jfb, beanz, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D25708
llvm-svn: 284840
Because we're just 'or-ing' these 2 variables later in the code, I
don't think there's a logical bug here, but of course the string with
"no size" is the one that should have the size suffix stripped off.
llvm-svn: 284826
As discussed in D24815, let's start the process of killing off the broken fast-math global
state housed in TargetOptions and eliminate the need for function-level fast-math attributes.
Here we enable two similar folds that are possible when we don't care about signed-zero:
fadd nsz x, 0 --> x
fsub nsz 0, x --> -x
Note that although the test cases include a 'sin' function call, I'm side-stepping the
FMF-on-calls question (and lack of support in the DAG) for now. It's not needed for these
tests - isNegatibleForFree/GetNegatedExpression just look through a ISD::FSIN node.
Also, when we create an FNEG node and propagate the Flags of the FSUB to it, this doesn't
actually do anything today because Flags are silently dropped for any node that is not a
binary operator.
Differential Revision: https://reviews.llvm.org/D25297
llvm-svn: 284824
When we have a loop with a known upper bound on the number of iterations, and
furthermore know that either the number of iterations will be either exactly
that upper bound or zero, then we can fully unroll up to that upper bound
keeping only the first loop test to check for the zero iteration case.
Most of the work here is in plumbing this 'max-or-zero' information from the
part of scalar evolution where it's detected through to loop unrolling. I've
also gone for the safe default of 'false' everywhere but howManyLessThans which
could probably be improved.
Differential Revision: https://reviews.llvm.org/D25682
llvm-svn: 284818
Summary:
The spill size was incorrectly set to 196 bits,
which isn't a multiple of 8. This problem was detected when
experimenting with asserts that the spill size should be a
multiple of the byte size.
New corrected value for the spill size is set to 192 bits.
Note that tablegen (RegisterInfoEmitter) will divide the
size set in the RegisterClass definition by 8. So this
change should not have any impact on the tablegen output
(trunc(192/8) == trunc(196/8) == 24 bytes).
Reviewers: t.p.northover
Subscribers: llvm-commits, aemerson, rengolin
Differential Revision: https://reviews.llvm.org/D25818
llvm-svn: 284814
On i386 alignof(double) = 8 is not the same as alignof(struct { double
}) = 4. This used to be not an issue because the old implementation
always measured alignment inside of structs. Wrap a dummy struct around
the test to avoid this issue.
llvm-svn: 284812
There's no agreement about this patch. I personally find the
PRE machinery of the current GVN hard enough to reason about
that I'm not sure I'll try to land this again, instead of working
on the rewrite).
llvm-svn: 284796
rL284780 fixed the PREL31 relocation and added a test for it. Being
the first such test for ARM relocations, it exposed incorrect endianness
assumptions (causing buildbot failures on big-endian hosts). Fix that by
using the same helpers used for the x86 case.
llvm-svn: 284789
This is to avoid inlining too many multiplication operands into a SCEV, which could
take exponential time in the worst case.
Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin
Differential Revision: https://reviews.llvm.org/D25794
llvm-svn: 284784
Summary:
This allows us to mark when uses have been optimized.
This lets us avoid rewalking (IE when people call getClobberingAccess on everything), and also
enables us to later relax the requirement of use optimization during updates with less cost.
Reviewers: george.burgess.iv
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25172
llvm-svn: 284771
load commands that use the MachO::twolevel_hints_command type
which includes only the LC_TWOLEVEL_HINTS load command.
This is not used in llvm libObject code or in llvm tool code. But
does appear in one of the binary test files. While this load command is
obsolete it is easier to add code for it in libObject than edit or change
the binary test case.
llvm-svn: 284769
This was all using ArrayRef<>s before which presents a problem
when you want to serialize to or deserialize from an actual
PDB stream. An ArrayRef<> is really just a special case of
what can be handled with StreamInterface though (e.g. by using
a ByteStream), so changing this to use StreamInterface allows
us to plug in a PDB stream and get all the record serialization
and deserialization for free on a MappedBlockStream.
Subsequent patches will try to remove TypeTableBuilder and
TypeRecordBuilder in favor of class that operate on
Streams as well, which should allow us to completely merge
the reading and writing codepaths for both types and symbols.
Differential Revision: https://reviews.llvm.org/D25831
llvm-svn: 284762
Summary:
The original heuristic to break critical edge during machine sink is relatively conservertive: when there is only one instruction sinkable to the critical edge, it is likely that the machine sink pass will not break the critical edge. This leads to many speculative instructions executed at runtime. However, with profile info, we could model the splitting benefits: if the critical edge has 50% taken rate, it would always be beneficial to split the critical edge to avoid the speculated runtime instructions. This patch uses profile to guide critical edge splitting in machine sink pass.
The performance impact on speccpu2006 on Intel sandybridge machines:
spec/2006/fp/C++/444.namd 25.3 +0.26%
spec/2006/fp/C++/447.dealII 45.96 -0.10%
spec/2006/fp/C++/450.soplex 41.97 +1.49%
spec/2006/fp/C++/453.povray 36.83 -0.96%
spec/2006/fp/C/433.milc 23.81 +0.32%
spec/2006/fp/C/470.lbm 41.17 +0.34%
spec/2006/fp/C/482.sphinx3 48.13 +0.69%
spec/2006/int/C++/471.omnetpp 22.45 +3.25%
spec/2006/int/C++/473.astar 21.35 -2.06%
spec/2006/int/C++/483.xalancbmk 36.02 -2.39%
spec/2006/int/C/400.perlbench 33.7 -0.17%
spec/2006/int/C/401.bzip2 22.9 +0.52%
spec/2006/int/C/403.gcc 32.42 -0.54%
spec/2006/int/C/429.mcf 39.59 +0.19%
spec/2006/int/C/445.gobmk 26.98 -0.00%
spec/2006/int/C/456.hmmer 24.52 -0.18%
spec/2006/int/C/458.sjeng 28.26 +0.02%
spec/2006/int/C/462.libquantum 55.44 +3.74%
spec/2006/int/C/464.h264ref 46.67 -0.39%
geometric mean +0.20%
Manually checked 473 and 471 to verify the diff is in the noise range.
Reviewers: rengolin, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24818
llvm-svn: 284757
Summary:
While promoting *_EXTEND_VECTOR_INREG nodes whose inputs are already
promoted, perform the appropriate sign extension for the promoted node
before doing the *_EXTEND_VECTOR_INREG operation. If not, the undefined
high-order bits of the promoted operand may (a) be garbage inc ase of
zext) or (b) contribute the wrong sign-bit (in case of sext)
Updated the promote-vec3.ll test after this change. The diff shows
explicit zeroing in case of zext and intermediate sign extension in case
of sext.
Reviewers: RKSimon
Subscribers: llvm-commits, srhines
Differential Revision: https://reviews.llvm.org/D25790
llvm-svn: 284752
This is a retry of r284495 which was reverted at r284513 due to use-after-scope bugs
caused by faulty usage of StringRef.
This version also renames a pair of functions:
getRecipEstimateDivEnabled()
getRecipEstimateSqrtEnabled()
as suggested by Eric Christopher.
original commit msg:
[Target] remove TargetRecip class; move reciprocal estimate isel functionality to TargetLowering
This is a follow-up to https://reviews.llvm.org/D24816 - where we changed reciprocal estimates to be function attributes
rather than TargetOptions.
This patch is intended to be a structural, but not functional change. By moving all of the
TargetRecip functionality into TargetLowering, we can remove all of the reciprocal estimate
state, shield the callers from the string format implementation, and simplify/localize the
logic needed for a target to enable this.
If a function has a "reciprocal-estimates" attribute, those settings may override the target's
default reciprocal preferences for whatever operation and data type we're trying to optimize.
If there's no attribute string or specific setting for the op/type pair, just use the target
default settings.
As noted earlier, a better solution would be to move the reciprocal estimate settings to IR
instructions and SDNodes rather than function attributes, but that's a multi-step job that
requires infrastructure improvements. I intend to work on that, but it's not clear how long
it will take to get all the pieces in place.
Differential Revision: https://reviews.llvm.org/D25440
llvm-svn: 284746
We weren't accounting for legal types on every subtarget, meaning that many of the costs were using defaults.
We still don't correctly cost (or test) the 512-bit sdiv/udiv by uniform const cases, nor the power-of-2 cases.
llvm-svn: 284744
Also clean up the legacy hacks for AlignedCharArray. I'm keeping
LLVM_ALIGNAS alive for a bit longer because GCC 4.8.0 (which we still
support apparently) shipped a buggy alignas(). All other supported
compilers have a working alignas.
llvm-svn: 284736
All of these existed because MSVC 2013 was unable to synthesize default
move ctors. We recently dropped support for it so all that error-prone
boilerplate can go.
No functionality change intended.
llvm-svn: 284721
This is a resubmission of r284590. The mingw build should be fixed now. The
problem was we were matching time_t with _localtime_64s, which was incorrect on
_USE_32BIT_TIME_T systems. Instead I use localtime_s, which should always
evaluate to the correct function.
llvm-svn: 284720
Post-RA sched strategy and scheduling instruction annotations for z196, zEC12
and z13.
This scheduler optimizes decoder grouping and balances processor resources
(including side steering the FPd unit instructions).
The SystemZHazardRecognizer keeps track of the scheduling state, which can
be dumped with -debug-only=misched.
Reviers: Ulrich Weigand, Andrew Trick.
https://reviews.llvm.org/D17260
llvm-svn: 284704
Without this check LLD crashes when SHT_GROUP section has invalid symbol index
because of next code:
template <class ELFT>
StringRef elf::ObjectFile<ELFT>::getShtGroupSignature(const Elf_Shdr &Sec) {
..
const Elf_Sym *Sym = Obj.getSymbol(Symtab, Sec.sh_info);
..
}
If sh_info is too large, &Symbols[Index] just asserts.
No testcases provided because llvm-objdump/llvm-readelf does
not use getSymbol() function.
I`ll commit testcase for LLD separatelly.
Differential revision: https://reviews.llvm.org/D25516
llvm-svn: 284702
- Add alignment attribute to DIVariable family
- Modify bitcode format to match new DIVariable representation
- Update tests to match these changes (also add bitcode upgrade test)
- Expect that frontend passes non-zero align value only when it is not default
(was forcibly aligned by alignas()/_Alignas()/__atribute__(aligned())
Differential Revision: https://reviews.llvm.org/D25073
llvm-svn: 284678
load commands that use the MachO::thread_command type
but are not used in llvm libObject code but used in llvm tool code.
This includes the LC_UNIXTHREAD and LC_THREAD
load commands.
A quick note about the philosophy of the error checking in
libObject for Mach-O files, the idea behind the checking is
that we never will return a Mach-O file out of libObject that
contains unknown things in the load commands.
To do this the 32-bit ARM and PPC general tread states
needed to be defined as two test case binaries contained
them. If other thread states for other CPUs need to be
added we will do that as needed.
Going forward the LC_MAIN load command is used to
set the entry point in Mach-O executables these days
instead of an LC_UNIXTHREAD as was done in the past.
So today only in core files are LC_THREAD load commands
and thread states usually found.
Other thread states have not yet been defined in
include/Support/MachO.h at this time. But that can be
added as needed with their corresponding checking also
added.
llvm-svn: 284668
Profile runtime can generate an empty raw profile (when there is no function in
the shared library). This empty profile is treated as a text format profile. A
test format profile without the flag of "#IR" is thought to be a clang
generated profile. So in llvm profile merging, we will get a bogus warning of
"Merge IR generated profile with Clang generated profile."
The fix here is to skip the empty profile (when the buffer size is 0) for
profile merge.
Reviewers: vsk, davidxl
Differential Revision: http://reviews.llvm.org/D25687
llvm-svn: 284659
Chapter 5.
Chapter 5 demonstrates remote JITing: code is executed on the remote, not the
machine running the REPL, so it's the remote's triple (and TargetMachine) that
we need.
llvm-svn: 284657
These tests rely on two sections being allocated with a limited displacement
from one to the other to work. We've never guaranteed this, and consequently
these tests usually fail. That led to them being XFAILed, but now they XPASS
whenever the sections do happen to be allocated nearby in memory. So I'm
removing these for now to get rid of the noise. We can re-instate them if/when
we take the time to implement a displacement-respecting allocator.
llvm-svn: 284654
This patch builds on clang r284648, and allows the runtime directory to make the bootstrap builds depend on the builtin libraries.
This patch also make the bootstrap build depend on configuring the other runtimes because the libcxx headers are copied during configuration. I have left a TODO in the code to remove that once I come up with a better solution.
llvm-svn: 284650
0 - X --> X, if X is 0 or the minimum signed value
0 - X --> 0, if X is 0 or the minimum signed value and the sub is NSW
I noticed this pattern might be created in the backend after the change from D25485,
so we'll want to add a similar fold for the DAG.
The use of computeKnownBits in InstSimplify may be something to investigate if the
compile time of InstSimplify is noticeable. We could replace computeKnownBits with
specific pattern matchers or limit the recursion.
Differential Revision: https://reviews.llvm.org/D25785
llvm-svn: 284649
This code crashed on funclet-style EH instructions such as catchpad,
catchswitch, and cleanuppad. Just treat all EH pad instructions
equivalently and avoid merging the globals they reference through any
use.
llvm-svn: 284633
Some instructions from the original loop, when vectorized, can become trivially
dead. This happens because of the way we structure the new loop. For example,
we create new induction variables and induction variable "steps" in the new
loop. Thus, when we go to vectorize the original induction variable update, it
may no longer be needed due to the instructions we've already created. This
patch prevents us from creating these redundant instructions. This reduces code
size before simplification and allows greater flexibility in code generation
since we have fewer unnecessary instruction uses.
Differential Revision: https://reviews.llvm.org/D25631
llvm-svn: 284631
This change is motivated by the case when IndVarSimplify doesn't widen a comparison of IV increment because it can't prove IV increment being non-negative. We end up with a redundant trunc of the widened increment on this example.
for.body:
%i = phi i32 [ %start, %for.body.lr.ph ], [ %i.inc, %for.inc ]
%within_limits = icmp ult i32 %i, 64
br i1 %within_limits, label %continue, label %for.end
continue:
%i.i64 = zext i32 %i to i64
%arrayidx = getelementptr inbounds i32, i32* %base, i64 %i.i64
%val = load i32, i32* %arrayidx, align 4
br label %for.inc
for.inc:
%i.inc = add nsw nuw i32 %i, 1
%cmp = icmp slt i32 %i.inc, %limit
br i1 %cmp, label %for.body, label %for.end
There is a range check inside of the loop which guarantees the IV to be non-negative. NSW on the increment guarantees that the increment is also non-negative. Teach IndVarSimplify to use the range check to prove non-negativity of loop increments.
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D25738
llvm-svn: 284629
Nicolai Haehnle