order of slices of the alloca which have exactly the same size and other
properties. This was found by a perniciously unstable sort
implementation used to flush out buggy uses of the algorithm.
The fundamental idea is that findCommonType should return the best
common type it can find across all of the slices in the range. There
were two bugs here previously:
1) We would accept an integer type smaller than a byte-width multiple,
and if there were different bit-width integer types, we would accept
the first one. This caused an actual failure in the testcase updated
here when the sort order changed.
2) If we found a bad combination of types or a non-load, non-store use
before an integer typed load or store we would bail, but if we found
the integere typed load or store, we would use it. The correct
behavior is to always use an integer typed operation which covers the
partition if one exists.
While a clever debugging sort algorithm found problem #1 in our existing
test cases, I have no useful test case ideas for #2. I spotted in by
inspection when looking at this code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195118 91177308-0d34-0410-b5e6-96231b3b80d8
lowering only for load/stores to scalar allocas. The resulting values
confuse the backend and don't add anything because we can describe
array-allocas with a dbg.declare intrinsic just fine.
rdar://problem/15464571
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195052 91177308-0d34-0410-b5e6-96231b3b80d8
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
This adds a boolean member variable to the PassManagerBuilder to control loop
rerolling (just like we have for unrolling and the various vectorization
options). This is necessary for control by the frontend. Loop rerolling remains
disabled by default at all optimization levels.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194966 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
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
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
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 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
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
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
Constant merge can merge a constant with implicit alignment with one that has
explicit alignment. Before this change it was assuming that the explicit
alignment was higher than the implicit one, causing the result to be under
aligned in some cases.
Fixes pr17815.
Patch by Chris Smowton!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194506 91177308-0d34-0410-b5e6-96231b3b80d8
The symptom is that an assertion is triggered. The assertion was added by
me to detect the situation when value is propagated from dead blocks.
(We can certainly get rid of assertion; it is safe to do so, because propagating
value from dead block to alive join node is certainly ok.)
The root cause of this bug is : edge-splitting is conducted on the fly,
the edge being split could be a dead edge, therefore the block that
split the critial edge needs to be flagged "dead" as well.
There are 3 ways to fix this bug:
1) Get rid of the assertion as I mentioned eariler
2) When an dead edge is split, flag the inserted block "dead".
3) proactively split the critical edges connecting dead and live blocks when
new dead blocks are revealed.
This fix go for 3) with additional 2 LOC.
Testing case was added by Rafael the other day.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194424 91177308-0d34-0410-b5e6-96231b3b80d8
LoopUnswitch's code simplification routine has logic to convert conditional
branches into unconditional branches, after unswitching makes the condition
constant, and then remove any blocks that renders dead. Unfortunately, this
code is dead, currently broken, and furthermore, has never been alive (at least
as far back at 2006).
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194277 91177308-0d34-0410-b5e6-96231b3b80d8
Due to the previously added overflow checks, we can have a retain/release
relation that is one directional. This occurs specifically when we run into an
additive overflow causing us to drop state in only one direction. If that
occurs, we should bail and not optimize that retain/release instead of
asserting.
Apologies for the size of the testcase. It is necessary to cause the additive
cfg overflow to trigger.
rdar://15377890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194083 91177308-0d34-0410-b5e6-96231b3b80d8
As with the other loop unrolling parameters (the unrolling threshold, partial
unrolling, etc.) runtime unrolling can now also be controlled via the
constructor. This will be necessary for moving non-trivial unrolling late in
the pass manager (after loop vectorization).
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194027 91177308-0d34-0410-b5e6-96231b3b80d8
When the elements are extracted from a select on vectors
or a vector select, do the select on the extracted scalars
from the input if there is only one use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194013 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of doing a RPO traversal of the whole function remember the blocks
containing gathers (typically <= 2) and scan them in dominator-first order.
The actual CSE is still quadratic, but I'm not confident that adding a
scoped hash table here is worth it as we're only looking at the generated
instructions and not arbitrary code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193956 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r193356, it caused PR17781.
A reduced test case covering this regression has been added to the test suite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193955 91177308-0d34-0410-b5e6-96231b3b80d8
This adds an SimplifyLibCalls case which converts the special __sinpi and
__cospi (float & double variants) into a __sincospi_stret where appropriate to
remove duplicated work.
Patch by Tim Northover
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193943 91177308-0d34-0410-b5e6-96231b3b80d8
Doing this with a hash map doesn't change behavior and avoids calling
isIdenticalTo O(n^2) times. This should probably eventually move into a utility
class shared with EarlyCSE and the limited CSE in the SLPVectorizer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193926 91177308-0d34-0410-b5e6-96231b3b80d8
When the loop vectorizer was part of the SCC inliner pass manager gvn would
run after the loop vectorizer followed by instcombine. This way redundancy
(multiple uses) were removed and instcombine could perform scalarization on the
induction variables. Having moved the loop vectorizer to later we no longer run
any form of redundancy elimination before we perform instcombine. This caused
vectorized induction variables to survive that did not before.
On a recent iMac this helps linpack back from 6000Mflops to 7000Mflops.
This should also help lpbench and paq8p.
I ran a Release (without Asserts) build over the test-suite and did not see any
negative impact on compile time.
radar://15339680
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193891 91177308-0d34-0410-b5e6-96231b3b80d8
If we have a pointer to a single-element struct we can still build wide loads
and stores to it (if there is no padding).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193860 91177308-0d34-0410-b5e6-96231b3b80d8
When a dependence check fails we can still try to vectorize loops with runtime
array bounds checks.
This helps linpack to vectorize a loop in dgefa. And we are back to 2x of the
scalar performance on a corei7-avx.
radar://15339680
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193853 91177308-0d34-0410-b5e6-96231b3b80d8
Clear all data structures when resetting the RuntimeCheck data structure.
No test case. This was exposed by an upcomming change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193852 91177308-0d34-0410-b5e6-96231b3b80d8
Given that backend does not handle "invoke asm" correctly ("invoke asm" will be
handled by SelectionDAGBuilder::visitInlineAsm, which does not have the right
setup for LPadToCallSiteMap) and we already made the assumption that inline asm
does not throw in InstCombiner::visitCallSite, we are going to make the same
assumption in Inliner to make sure we don't convert "call asm" to "invoke asm".
If it becomes necessary to add support for "invoke asm" later on, we will need
to modify the backend as well as remove the assumptions that inline asm does
not throw.
Fix rdar://15317907
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193808 91177308-0d34-0410-b5e6-96231b3b80d8
There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
files.
* The linker tells LLVM which symbols are not used from other object files,
but will be put in the dso symbol table if present.
GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.
LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.
This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193800 91177308-0d34-0410-b5e6-96231b3b80d8
By vectorizing a series of srl, or, ... instructions we have obfuscated the
intention so much that the backend does not know how to fold this code away.
radar://15336950
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193573 91177308-0d34-0410-b5e6-96231b3b80d8
No test case, because with the current cost model we don't see a difference.
An upcoming ARM memory cost model change will expose and test this bug.
radar://15332579
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193572 91177308-0d34-0410-b5e6-96231b3b80d8
Partial fix for PR17459: wrong code at -O3 on x86_64-linux-gnu
(affecting trunk and 3.3)
When SCEV expands a recurrence outside of a loop it attempts to scale
by the stride of the recurrence. Chained recurrences don't work that
way. We could compute binomial coefficients, but would hve to
guarantee that the chained AddRec's are in a perfectly reduced form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193438 91177308-0d34-0410-b5e6-96231b3b80d8
This patch teaches GlobalStatus to analyze a call that uses the global value as
a callee, not as an argument.
With this change internalize call handle the common use of linkonce_odr
functions. This reduces the number of linkonce_odr functions in a LTO build of
clang (checked with the emit-llvm gold plugin option) from 1730 to 60.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193436 91177308-0d34-0410-b5e6-96231b3b80d8
The loop vectorizer does not currently understand how to vectorize
extractelement instructions. The existing check, which excluded all
vector-valued instructions, did not catch extractelement instructions because
it checked only the return value. As a result, vectorization would proceed,
producing illegal instructions like this:
%58 = extractelement <2 x i32> %15, i32 0
%59 = extractelement i32 %58, i32 0
where the second extractelement is illegal because its first operand is not a vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193434 91177308-0d34-0410-b5e6-96231b3b80d8
Make sure we mark all loops (scalar and vector) when vectorizing,
so that we don't try to vectorize them anymore. Also, set unroll
to 1, since this is what we check for on early exit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193349 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM optimizers may widen accesses to packed structures that overflow the structure itself, but should be in bounds up to the alignment of the object
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193317 91177308-0d34-0410-b5e6-96231b3b80d8
Major steps include:
1). introduces a not-addr-taken bit-field in GlobalVariable
2). GlobalOpt pass sets "not-address-taken" if it proves a global varirable
dosen't have its address taken.
3). AA use this info for disambiguation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193251 91177308-0d34-0410-b5e6-96231b3b80d8
When a linkonce_odr value that is on the dso list is not unnamed_addr
we can still look to see if anything is actually using its address. If
not, it is safe to hide it.
This patch implements that by moving GlobalStatus to Transforms/Utils
and using it in Internalize.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193090 91177308-0d34-0410-b5e6-96231b3b80d8
A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.
PR17621
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193064 91177308-0d34-0410-b5e6-96231b3b80d8
One optimization simplify-cfg performs is the converting of switches to
lookup tables if the switch has > 4 cases. This is done by:
1. Finding the max/min case value and calculating the switch case range.
2. Create a lookup table basic block.
3. Perform a check in the switch's BB to see if the input value is in
the switch's case range. If the input value satisfies said predicate
branch to the lookup table BB, otherwise branch to the switch's default
destination BB using the default value as the result.
The conditional check consists of subtracting the min case value of the
table from any input iN value and then ensuring that said value is
unsigned less than the size of the lookup table represented as an iN
value.
If the lookup table is a covered lookup table, the size of the table will be N
which is 0 as an iN value. Thus the comparison will be an `icmp ult` of an iN
value against 0 which is always false yielding the incorrect result.
This patch fixes this problem by recognizing if we have a covered lookup table
and if we do, unconditionally jumps to the lookup table BB since the covering
property of the lookup table implies no input values could not be handled by
said BB.
rdar://15268442
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193045 91177308-0d34-0410-b5e6-96231b3b80d8
If the predecessor's being spliced into a landing pad, then we need the PHIs to
come first and the rest of the predecessor's code to come *after* the landing
pad instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193035 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Given a global array G[N], which is declared in this CU and has static initializer
avoid instrumenting accesses like G[i], where 'i' is a constant and 0<=i<N.
Also add a bit of stats.
This eliminates ~1% of instrumentations on SPEC2006
and also partially helps when asan is being run together with coverage.
Reviewers: samsonov
Reviewed By: samsonov
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1947
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192794 91177308-0d34-0410-b5e6-96231b3b80d8
Currently MSan checks that arguments of *cvt* intrinsics are fully initialized.
That's too much to ask: some of them only operate on lower half, or even
quarter, of the input register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192599 91177308-0d34-0410-b5e6-96231b3b80d8
Before this patch we relied on the order of phi nodes when we looked for phi
nodes of the same type. This could prevent vectorization of cases where there
was a phi node of a second type in between phi nodes of some type.
This is important for vectorization of an internal graphics kernel. On the test
suite + external on x86_64 (and on a run on armv7s) it showed no impact on
either performance or compile time.
radar://15024459
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192537 91177308-0d34-0410-b5e6-96231b3b80d8
If a function seen at compile time is not necessarily the one linked to
the binary being built, it is illegal to change the actual arguments
passing to it.
e.g.
--------------------------
void foo(int lol) {
// foo() has linkage satisifying isWeakForLinker()
// "lol" is not used at all.
}
void bar(int lo2) {
// xform to foo(undef) is illegal, as compiler dose not know which
// instance of foo() will be linked to the the binary being built.
foo(lol2);
}
-----------------------------
Such functions can be captured by isWeakForLinker(). NOTE that
mayBeOverridden() is insufficient for this purpose as it dosen't include
linkage types like AvailableExternallyLinkage and LinkOnceODRLinkage.
Take link_odr* as an example, it indicates a set of *EQUIVALENT* globals
that can be merged at link-time. However, the semantic of
*EQUIVALENT*-functions includes parameters. Changing parameters breaks
the assumption.
Thank John McCall for help, especially for the explanation of subtle
difference between linkage types.
rdar://11546243
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Otherwise, we don't perform operations that would have been performed on
the scalar version.
Fixes PR17498.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192133 91177308-0d34-0410-b5e6-96231b3b80d8
UpdatePHINodes has an optimization to reuse an existing PHI node, where it
first deletes all of its entries and then replaces them. Unfortunately, in the
case where we had duplicate predecessors (which are allowed so long as the
associated PHI entries have the same value), the loop removing the existing PHI
entries from the to-be-reused PHI would assert (if that PHI was not the one
which had the duplicates).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192001 91177308-0d34-0410-b5e6-96231b3b80d8
Sort the operands of the other entries in the current vectorization root
according to the first entry's operands opcodes.
%conv0 = uitofp ...
%load0 = load float ...
= fmul %conv0, %load0
= fmul %load0, %conv1
= fmul %load0, %conv2
Make sure that we recursively vectorize <%conv0, %conv1, %conv2> and <%load0,
%load0, %load0>.
This makes it more likely to obtain vectorizable trees. We have to be careful
when we sort that we don't destroy 'good' existing ordering implied by source
order.
radar://15080067
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Generalize the API so we can distinguish symbols that are needed just for a DSO
symbol table from those that are used from some native .o.
The symbols that are only wanted for the dso symbol table can be dropped if
llvm can prove every other dso has a copy (linkonce_odr) and the address is not
important (unnamed_addr).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191922 91177308-0d34-0410-b5e6-96231b3b80d8
Don't vectorize with a runtime check if it requires a
comparison between pointers with different address spaces.
The values can't be assumed to be directly comparable.
Previously it would create an illegal bitcast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191862 91177308-0d34-0410-b5e6-96231b3b80d8
This recursively strips all GEPs like the existing code. It also handles bitcasts and
other operations that do not change the pointer value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191847 91177308-0d34-0410-b5e6-96231b3b80d8
Switch instructions were crashing the StructurizeCFG pass, and it's
probably easier anyway if we don't need to handle them in this pass.
Reviewed-by: Christian König <christian.koenig@amd.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191841 91177308-0d34-0410-b5e6-96231b3b80d8
infrastructure.
This was essentially work toward PGO based on a design that had several
flaws, partially dating from a time when LLVM had a different
architecture, and with an effort to modernize it abandoned without being
completed. Since then, it has bitrotted for several years further. The
result is nearly unusable, and isn't helping any of the modern PGO
efforts. Instead, it is getting in the way, adding confusion about PGO
in LLVM and distracting everyone with maintenance on essentially dead
code. Removing it paves the way for modern efforts around PGO.
Among other effects, this removes the last of the runtime libraries from
LLVM. Those are being developed in the separate 'compiler-rt' project
now, with somewhat different licensing specifically more approriate for
runtimes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191835 91177308-0d34-0410-b5e6-96231b3b80d8
The test's output doesn't change, but this ensures
this is actually hit with a different address space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191701 91177308-0d34-0410-b5e6-96231b3b80d8
Defines away the issue where cast<Instruction> would fail because constant
folding happened. Also slightly cleaner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191674 91177308-0d34-0410-b5e6-96231b3b80d8
Inspired by the object from the SLPVectorizer. This found a minor bug in the
debug loc restoration in the vectorizer where the location of a following
instruction was attached instead of the location from the original instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191673 91177308-0d34-0410-b5e6-96231b3b80d8
when it was actually a Constant*.
There are quite a few other casts to Instruction that might have the same problem,
but this is the only one I have a test case for.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191668 91177308-0d34-0410-b5e6-96231b3b80d8
Currently foldSelectICmpAndOr asserts if the "or" involves a vector
containing several of the same power of two. We can easily avoid this by
only performing the fold on integer types, like foldSelectICmpAnd does.
Fixes <rdar://problem/15012516>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191552 91177308-0d34-0410-b5e6-96231b3b80d8
We were previously using getFirstInsertionPt to insert PHI
instructions when vectorizing, but getFirstInsertionPt also skips past
landingpads, causing this to generate invalid IR.
We can avoid this issue by using getFirstNonPHI instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191526 91177308-0d34-0410-b5e6-96231b3b80d8
Put them under a separate flag for experimentation. They are more likely to
interfere with loop vectorization which happens later in the pass pipeline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191371 91177308-0d34-0410-b5e6-96231b3b80d8
Revert 191122 - with extra checks we are allowed to vectorize math library
function calls.
Standard library indentifiers are reserved names so functions with external
linkage must not overrided them. However, functions with internal linkage can.
Therefore, we can vectorize calls to math library functions with a check for
external linkage and matching signature. This matches what we do during
SelectionDAG building.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191206 91177308-0d34-0410-b5e6-96231b3b80d8
This makes using array_pod_sort significantly safer. The implementation relies
on function pointer casting but that should be safe as we're dealing with void*
here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191175 91177308-0d34-0410-b5e6-96231b3b80d8
SROA wants to convert any types of equivalent widths but it's not possible to
convert vectors of pointers to an integer scalar with a single cast. As a
workaround we add a bitcast to the corresponding int ptr type first. This type
of cast used to be an edge case but has become common with SLP vectorization.
Fixes PR17271.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191143 91177308-0d34-0410-b5e6-96231b3b80d8
Reapply r191108 with a fix for a memory corruption error I introduced. Of
course, we can't reference the scalars that we replace by vectorizing and then
call their eraseFromParent method. I only 'needed' the scalars to get the
DebugLoc. Just store the DebugLoc before actually vectorizing instead. As a nice
side effect, this also simplifies the interface between BoUpSLP and the
HorizontalReduction class to returning a value pointer (the vectorized tree
root).
radar://14607682
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This reverts commit r191108.
The horizontal.ll test case fails under libgmalloc. Thanks Shuxin for pointing
this out to me.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191121 91177308-0d34-0410-b5e6-96231b3b80d8
The problem of r191017 is that when GVN fabricate a val-number for a dead instruction (in order
to make following expr-PRE happy), it forget to fabricate a leader-table entry for it as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191118 91177308-0d34-0410-b5e6-96231b3b80d8
Match reductions starting at binary operation feeding into a phi. The code
handles trees like
r += v1 + v2 + v3 ...
and
r += v1
r += v2
...
and
r *= v1 + v2 + ...
We currently only handle associative operations (add, fadd fast).
The code can now also handle reductions feeding into stores.
a[i] = v1 + v2 + v3 + ...
The code is currently disabled behind the flag "-slp-vectorize-hor". The cost
model for most architectures is not there yet.
I found one opportunity of a horizontal reduction feeding a phi in TSVC
(LoopRerolling-flt) and there are several opportunities where reductions feed
into stores.
radar://14607682
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191108 91177308-0d34-0410-b5e6-96231b3b80d8
The GEP pattern is what SCEV expander emits for "ugly geps". The latter is what
you get for pointer subtraction in C code. The rest of instcombine already
knows how to deal with that so just canonicalize on that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191090 91177308-0d34-0410-b5e6-96231b3b80d8
If "C1/X" were having multiple uses, the only benefit of this
transformation is to potentially shorten critical path. But it is at the
cost of instroducing additional div.
The additional div may or may not incur cost depending on how div is
implemented. If it is implemented using Newton–Raphson iteration, it dosen't
seem to incur any cost (FIXME). However, if the div blocks the entire
pipeline, that sounds to be pretty expensive. Let CodeGen to take care
this transformation.
This patch sees 6% on a benchmark.
rdar://15032743
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This is how it ignores the dead code:
1) When a dead branch target, say block B, is identified, all the
blocks dominated by B is dead as well.
2) The PHIs of those blocks in dominance-frontier(B) is updated such
that the operands corresponding to dead predecessors are replaced
by "UndefVal".
Using lattice's jargon, the "UndefVal" is the "Top" in essence.
Phi node like this "phi(v1 bb1, undef xx)" will be optimized into
"v1" if v1 is constant, or v1 is an instruction which dominate this
PHI node.
3) When analyzing the availability of a load L, all dead mem-ops which
L depends on disguise as a load which evaluate exactly same value as L.
4) The dead mem-ops will be materialized as "UndefVal" during code motion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191017 91177308-0d34-0410-b5e6-96231b3b80d8
Adds a flag to the MemorySanitizer pass that enables runtime rewriting of
indirect calls. This is part of MSanDR implementation and is needed to return
control to the DynamiRio-based helper tool on transition between instrumented
and non-instrumented modules. Disabled by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191006 91177308-0d34-0410-b5e6-96231b3b80d8
XCore target: Add XCoreTargetTransformInfo
This is where getNumberOfRegisters() resides, which in turn returns the
number of vector registers (=0).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190936 91177308-0d34-0410-b5e6-96231b3b80d8
To avoid regressions with bitfield optimizations, this slicing should take place
later, like ISel time.
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Some of this code is no longer necessary since int<->ptr casts are no
longer occur as of r187444.
This also fixes handling vectors of pointers, and adds a bunch of new
testcases for vectors and address spaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190885 91177308-0d34-0410-b5e6-96231b3b80d8
We can't insert an insertelement after an invoke. We would have to split a
critical edge. So when we see a phi node that uses an invoke we just give up.
radar://14990770
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other in memory.
The motivation was to get rid of truncate and shift right instructions that get
in the way of paired load or floating point load.
E.g.,
Consider the following example:
struct Complex {
float real;
float imm;
};
When accessing a complex, llvm was generating a 64-bits load and the imm field
was obtained by a trunc(lshr) sequence, resulting in poor code generation, at
least for x86.
The idea is to declare that two load instructions is the canonical form for
loading two arithmetic type, which are next to each other in memory.
Two scalar loads at a constant offset from each other are pretty
easy to detect for the sorts of passes that like to mess with loads.
<rdar://problem/14477220>
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If there are no legal integers, assume 1 byte.
This makes more sense than using the pointer size as
a guess for the maximum GPR width.
It is conceivable to want to use some 64-bit pointers
on a target where 64-bit integers aren't legal.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190817 91177308-0d34-0410-b5e6-96231b3b80d8
We would have to compute the pre increment value, either by computing it on
every loop iteration or by splitting the edge out of the loop and inserting a
computation for it there.
For now, just give up vectorizing such loops.
Fixes PR17179.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190790 91177308-0d34-0410-b5e6-96231b3b80d8
This pass was based on the previous (essentially unused) profiling
infrastructure and the assumption that by ordering the basic blocks at
the IR level in a particular way, the correct layout would happen in the
end. This sometimes worked, and mostly didn't. It also was a really
naive implementation of the classical paper that dates from when branch
predictors were primarily directional and when loop structure wasn't
commonly available. It also didn't factor into the equation
non-fallthrough branches and other machine level details.
Anyways, for all of these reasons and more, I wrote
MachineBlockPlacement, which completely supercedes this pass. It both
uses modern profile information infrastructure, and actually works. =]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190748 91177308-0d34-0410-b5e6-96231b3b80d8
Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190542 91177308-0d34-0410-b5e6-96231b3b80d8
It works with clang, but GCC has different rules so we can't make all of those
hidden. This reverts commit r190534.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190536 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM IR doesn't currently allow atomic bool load/store operations, and the
transformation is dubious anyway because it isn't profitable on all platforms.
PR17163.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190357 91177308-0d34-0410-b5e6-96231b3b80d8
Several architectures use the same instruction to perform both a comparison and
a subtract. The instruction selection framework does not allow to consider
different basic blocks to expose such fusion opportunities.
Therefore, these instructions are “merged” by CSE at MI IR level.
To increase the likelihood of CSE to apply in such situation, we reorder the
operands of the comparison, when they have the same complexity, so that they
matches the order of the most frequent subtract.
E.g.,
icmp A, B
...
sub B, A
<rdar://problem/14514580>
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The work on this project was left in an unfinished and inconsistent state.
Hopefully someone will eventually get a chance to implement this feature, but
in the meantime, it is better to put things back the way the were. I have
left support in the bitcode reader to handle the case-range bitcode format,
so that we do not lose bitcode compatibility with the llvm 3.3 release.
This reverts the following commits: 155464, 156374, 156377, 156613, 156704,
156757, 156804 156808, 156985, 157046, 157112, 157183, 157315, 157384, 157575,
157576, 157586, 157612, 157810, 157814, 157815, 157880, 157881, 157882, 157884,
157887, 157901, 158979, 157987, 157989, 158986, 158997, 159076, 159101, 159100,
159200, 159201, 159207, 159527, 159532, 159540, 159583, 159618, 159658, 159659,
159660, 159661, 159703, 159704, 160076, 167356, 172025, 186736
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190328 91177308-0d34-0410-b5e6-96231b3b80d8
instead of having its own implementation.
The implementation of isTBAAVtableAccess is in TypeBasedAliasAnalysis.cpp
since it is related to the format of TBAA metadata.
The path for struct-path tbaa will be exercised by
test/Instrumentation/ThreadSanitizer/read_from_global.ll, vptr_read.ll, and
vptr_update.ll when struct-path tbaa is on by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190216 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r189886.
I found a corner case where this optimization is not valid:
Say we have a "linkonce_odr unnamed_addr" in two translation units:
* In TU 1 this optimization kicks in and makes it hidden.
* In TU 2 it gets const merged with a constant that is *not* unnamed_addr,
resulting in a non unnamed_addr constant with default visibility.
* The static linker rules for combining visibility them produce a hidden
symbol, which is incorrect from the point of view of the non unnamed_addr
constant.
The one place we can do this is when we know that the symbol is not used from
another TU in the same shared object, i.e., during LTO. I will move it there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189954 91177308-0d34-0410-b5e6-96231b3b80d8
"(icmp op i8 A, B)" is equivalent to "(icmp op i8 (A & 0xff), B)" as a
degenerate case. Allowing this as a "masked" comparison when analysing "(icmp)
&/| (icmp)" allows us to combine them in more cases.
rdar://problem/7625728
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189931 91177308-0d34-0410-b5e6-96231b3b80d8
Even in cases which aren't universally optimisable like "(A & B) != 0 && (A &
C) != 0", the masks can make one of the comparisons completely redundant. In
this case, since we've gone to the effort of spotting masked comparisons we
should combine them.
rdar://problem/7625728
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189930 91177308-0d34-0410-b5e6-96231b3b80d8
Original message:
If a constant or a function has linkonce_odr linkage and unnamed_addr, mark
hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189886 91177308-0d34-0410-b5e6-96231b3b80d8
The reason that I am turning off this optimization is that there is an
additional case where a block can escape that has come up. Specifically, this
occurs when a block is used in a scope outside of its current scope.
This can cause a captured retainable object pointer whose life is preserved by
the objc_retainBlock to be deallocated before the block is invoked.
An example of the code needed to trigger the bug is:
----
\#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
void (^somethingToDoLater)();
{
NSObject *obj = [NSObject new];
somethingToDoLater = ^{
[obj self]; // Crashes here
};
}
NSLog(@"test.");
somethingToDoLater();
return 0;
}
----
In the next commit, I remove all the dead code that results from this.
Once I put in the fixing commit I will bring back the tests that I deleted in
this commit.
rdar://14802782.
rdar://14868830.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189869 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes the default setting for the LateVectorization flag that controls where the loop-vectorizer is ran.
Perf gains:
SingleSource/Benchmarks/Shootout/matrix -37.33%
MultiSource/Benchmarks/PAQ8p/paq8p -22.83%
SingleSource/Benchmarks/Linpack/linpack-pc -16.22%
SingleSource/Benchmarks/Shootout-C++/ary3 -15.16%
MultiSource/Benchmarks/TSVC/NodeSplitting-flt/NodeSplitting-flt -10.34%
MultiSource/Benchmarks/TSVC/NodeSplitting-dbl/NodeSplitting-dbl -7.12%
Regressions:
SingleSource/Benchmarks/Misc/lowercase 15.10%
MultiSource/Benchmarks/TSVC/Equivalencing-flt/Equivalencing-flt 13.18%
SingleSource/Benchmarks/Shootout-C++/matrix 8.27%
SingleSource/Benchmarks/CoyoteBench/lpbench 7.30%
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189858 91177308-0d34-0410-b5e6-96231b3b80d8
1) If the width of vectorization list candidate is bigger than vector reg width, we will break it down to fit the vector reg.
2) We do not vectorize the width which is not power of two.
The performance result shows it will help some spec benchmarks. mesa improved 6.97% and ammp improved 1.54%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189830 91177308-0d34-0410-b5e6-96231b3b80d8
Select condition shadow was being ignored resulting in false negatives.
This change OR-s sign-extended condition shadow into the result shadow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189785 91177308-0d34-0410-b5e6-96231b3b80d8
The existing code missed some edge cases when e.g. we're going to emit sqrtf but
only the availability of sqrt was checked. This happens on odd platforms like
windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189724 91177308-0d34-0410-b5e6-96231b3b80d8
PR17026. Also avoid undefined shifts and shift amounts larger than 64 bits
(those are always undef because we can't represent integer types that large).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189672 91177308-0d34-0410-b5e6-96231b3b80d8
Revert unintentional commit (of an unreviewed change).
Original commit message:
Add getUnrollingPreferences to TTI
Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189566 91177308-0d34-0410-b5e6-96231b3b80d8
Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189565 91177308-0d34-0410-b5e6-96231b3b80d8
1. They are a kind of cannonicalization.
2. The performance measurements show that it is better to keep them in.
There should be no functional change if you are not enabling the LateVectorization mode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189539 91177308-0d34-0410-b5e6-96231b3b80d8
When unrolling is disabled in the pass manager, the loop vectorizer should also
not unroll loops. This will allow the -fno-unroll-loops option in Clang to
behave as expected (even for vectorizable loops). The loop vectorizer's
-force-vector-unroll option will (continue to) override the pass-manager
setting (including -force-vector-unroll=0 to force use of the internal
auto-selection logic).
In order to test this, I added a flag to opt (-disable-loop-unrolling) to force
disable unrolling through opt (the analog of -fno-unroll-loops in Clang). Also,
this fixes a small bug in opt where the loop vectorizer was enabled only after
the pass manager populated the queue of passes (the global_alias.ll test needed
a slight update to the RUN line as a result of this fix).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189499 91177308-0d34-0410-b5e6-96231b3b80d8
This patch merges LoopVectorize of InnerLoopVectorizer and InnerLoopUnroller by adding checks for VF=1. This helps in erasing the Unroller code that is almost identical to the InnerLoopVectorizer code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189391 91177308-0d34-0410-b5e6-96231b3b80d8
The builder inserts from before the insert point,
not after, so this would insert before the last
instruction in the bundle instead of after it.
I'm not sure if this can actually be a problem
with any of the current insertions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189285 91177308-0d34-0410-b5e6-96231b3b80d8
This patch enables unrolling of loops when vectorization is legal but not profitable.
We add a new class InnerLoopUnroller, that extends InnerLoopVectorizer and replaces some of the vector-specific logic with scalars.
This patch does not introduce any runtime regressions and improves the following workloads:
SingleSource/Benchmarks/Shootout/matrix -22.64%
SingleSource/Benchmarks/Shootout-C++/matrix -13.06%
External/SPEC/CINT2006/464_h264ref/464_h264ref -3.99%
SingleSource/Benchmarks/Adobe-C++/simple_types_constant_folding -1.95%
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189281 91177308-0d34-0410-b5e6-96231b3b80d8
The code was erroneously reading overflow area shadow from the TLS slot,
bypassing the local copy. Reading shadow directly from TLS is wrong, because
it can be overwritten by a nested vararg call, if that happens before va_start.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189104 91177308-0d34-0410-b5e6-96231b3b80d8
...so that it can be used for z too. Most of the code is the same.
The only real change is to use TargetTransformInfo to test when a sqrt
instruction is available.
The pass is opt-in because at the moment it only handles sqrt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189097 91177308-0d34-0410-b5e6-96231b3b80d8
The current version of StripDeadDebugInfo became stale and no longer actually
worked since it was expecting an older version of debug info.
This patch updates it to use DebugInfoFinder and the modern DebugInfo classes as
much as possible to make it more redundent to such changes. Additionally, the
only place where that was avoided (the code where we replace the old sets with
the new), I call verify on the DIContextUnit implying that if the format changes
and my live set changes no longer make sense an assert will be hit. In order to
ensure that that occurs I have included a test case.
The actual stripping of the dead debug info follows the same strategy as was
used before in this class: find the live set and replace the old set in the
given compile unit (which may contain dead global variables/functions) with the
new live one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189078 91177308-0d34-0410-b5e6-96231b3b80d8
DFSan changes the ABI of each function in the module. This makes it possible
for a function with the native ABI to be called with the instrumented ABI,
or vice versa, thus possibly invoking undefined behavior. A simple way
of statically detecting instances of this problem is to prepend the prefix
"dfs$" to the name of each instrumented-ABI function.
This will not catch every such problem; in particular function pointers passed
across the instrumented-native barrier cannot be used on the other side.
These problems could potentially be caught dynamically.
Differential Revision: http://llvm-reviews.chandlerc.com/D1373
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189052 91177308-0d34-0410-b5e6-96231b3b80d8
using GEPs. Previously, it used a number of different heuristics for
analyzing the GEPs. Several of these were conservatively correct, but
failed to fall back to SCEV even when SCEV might have given a reasonable
answer. One was simply incorrect in how it was formulated.
There was good code already to recursively evaluate the constant offsets
in GEPs, look through pointer casts, etc. I gathered this into a form
code like the SLP code can use in a previous commit, which allows all of
this code to become quite simple.
There is some performance (compile time) concern here at first glance as
we're directly attempting to walk both pointers constant GEP chains.
However, a couple of thoughts:
1) The very common cases where there is a dynamic pointer, and a second
pointer at a constant offset (usually a stride) from it, this code
will actually not do any unnecessary work.
2) InstCombine and other passes work very hard to collapse constant
GEPs, so it will be rare that we iterate here for a long time.
That said, if there remain performance problems here, there are some
obvious things that can improve the situation immensely. Doing
a vectorizer-pass-wide memoizer for each individual layer of pointer
values, their base values, and the constant offset is likely to be able
to completely remove redundant work and strictly limit the scaling of
the work to scrape these GEPs. Since this optimization was not done on
the prior version (which would still benefit from it), I've not done it
here. But if folks have benchmarks that slow down it should be straight
forward for them to add.
I've added a test case, but I'm not really confident of the amount of
testing done for different access patterns, strides, and pointer
manipulation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189007 91177308-0d34-0410-b5e6-96231b3b80d8
There are situations which can affect the correctness (or at least expectation)
of the gcov output. For instance, if a call to __gcov_flush() occurs within a
block before the execution count is registered and then the program aborts in
some way, then that block will not be marked as executed. This is not normally
what the user expects.
If we move the code that's registering when a block is executed to the
beginning, we can catch these types of situations.
PR16893
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188849 91177308-0d34-0410-b5e6-96231b3b80d8
Update iterator when the SLP vectorizer changes the instructions in the basic
block by restarting the traversal of the basic block.
Patch by Yi Jiang!
Fixes PR 16899.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188832 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a llvm.copysign intrinsic; We already have Libfunc recognition for
copysign (which is turned into the FCOPYSIGN SDAG node). In order to
autovectorize calls to copysign in the loop vectorizer, we need a corresponding
intrinsic as well.
In addition to the expected changes to the language reference, the loop
vectorizer, BasicTTI, and the SDAG builder (the intrinsic is transformed into
an FCOPYSIGN node, just like the function call), this also adds FCOPYSIGN to a
few lists in LegalizeVector{Ops,Types} so that vector copysigns can be
expanded.
In TargetLoweringBase::initActions, I've made the default action for FCOPYSIGN
be Expand for vector types. This seems correct for all in-tree targets, and I
think is the right thing to do because, previously, there was no way to generate
vector-values FCOPYSIGN nodes (and most targets don't specify an action for
vector-typed FCOPYSIGN).
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When both constants are positive or both constants are negative,
InstCombine already simplifies comparisons like this, but when
it's exactly zero and -1, the operand sorting ends up reversed
and the pattern fails to match. Handle that special case.
Follow up for rdar://14689217
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This path wasn't tested before without a datalayout,
so add some more tests and re-run with and without one.
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Summary:
When the -dfsan-debug-nonzero-labels parameter is supplied, the code
is instrumented such that when a call parameter, return value or load
produces a nonzero label, the function __dfsan_nonzero_label is called.
The idea is that a debugger breakpoint can be set on this function
in a nominally label-free program to help identify any bugs in the
instrumentation pass causing labels to be introduced.
Reviewers: eugenis
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1405
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This replaces the old incomplete greylist functionality with an ABI
list, which can provide more detailed information about the ABI and
semantics of specific functions. The pass treats every function in
the "uninstrumented" category in the ABI list file as conforming to
the "native" (i.e. unsanitized) ABI. Unless the ABI list contains
additional categories for those functions, a call to one of those
functions will produce a warning message, as the labelling behaviour
of the function is unknown. The other supported categories are
"functional", "discard" and "custom".
- "discard" -- This function does not write to (user-accessible) memory,
and its return value is unlabelled.
- "functional" -- This function does not write to (user-accessible)
memory, and the label of its return value is the union of the label of
its arguments.
- "custom" -- Instead of calling the function, a custom wrapper __dfsw_F
is called, where F is the name of the function. This function may wrap
the original function or provide its own implementation.
Differential Revision: http://llvm-reviews.chandlerc.com/D1345
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188402 91177308-0d34-0410-b5e6-96231b3b80d8
extremely subtle miscompilations (such as a load getting replaced with
the value stored *below* the load within a basic block) related to
promoting an alloca to an SSA value, there is the dim possibility that
you hit this. Please let me know if you won this unfortunate lottery.
The first half of mem2reg's core logic (as it is used both in the
standalone mem2reg pass and in SROA) builds up a mapping from
'Instruction *' to the index of that instruction within its basic block.
This allows quickly establishing which store dominate a particular load
even for large basic blocks. We cache this information throughout the
run of mem2reg over a function in order to amortize the cost of
computing it.
This is not in and of itself a strange pattern in LLVM. However, it
introduces a very important constraint: absolutely no instruction can be
deleted from the program without updating the mapping. Otherwise a newly
allocated instruction might get the same pointer address, and then end
up with a wrong index. Yes, LLVM routinely suffers from a *single
threaded* variant of the ABA problem. Most places in LLVM don't find
avoiding this an imposition because they don't both delete and create
new instructions iteratively, but mem2reg *loves* to do this... All the
time. Fortunately, the mem2reg code was really careful about updating
this cache to handle this eventuallity... except when it comes to the
debug declare intrinsic. Oops. The fix is to invalidate that pointer in
the cache when we delete it, the same as we do when deleting alloca
instructions and other instructions.
I've also caused the same bug in new code while working on a fix to
PR16867, so this seems to be a really unfortunate pattern. Hopefully in
subsequent patches the deletion of dead instructions can be consolidated
sufficiently to make it less likely that we'll see future occurences of
this bug.
Sorry for not having a test case, but I have literally no idea how to
reliably trigger this kind of thing. It may be single-threaded, but it
remains an ABA problem. It would require a really amazing number of
stars to align.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188367 91177308-0d34-0410-b5e6-96231b3b80d8
Use the pointer size if datalayout is available.
Use i64 if it's not, which is consistent with what other
places do when the pointer size is unknown.
The test doesn't really test this in a useful way
since it will be transformed to that later anyway,
but this now tests it for non-zero arrays and when
datalayout isn't available. The cases in
visitGetElementPtrInst should save an extra re-visit to
the newly created GEP since it won't need to cleanup after
itself.
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When computing the use set of a store, we need to add the store to the write
set prior to iterating over later instructions. Otherwise, if there is a later
aliasing load of that store, that load will not be tagged as a use, and bad
things will happen.
trackUsesOfI still adds later dependent stores of an instruction to that
instruction's write set, but it never sees the original instruction, and so
when tracking uses of a store, the store must be added to the write set by the
caller.
Fixes PR16834.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188329 91177308-0d34-0410-b5e6-96231b3b80d8
However, opt -O2 doesn't run mem2reg directly so nobody noticed until r188146
when SROA started sending more things directly down the PromoteMemToReg path.
In order to revert r187191, I also revert dependent revisions r187296, r187322
and r188146. Fixes PR16867. Does not add the testcases from that PR, but both
of them should get added for both mem2reg and sroa when this revert gets
unreverted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188327 91177308-0d34-0410-b5e6-96231b3b80d8
Do not generate new vector values for the same entries because we know that the incoming values
from the same block must be identical.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188185 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Doing work in constructors is bad: this change suggests to
call SpecialCaseList::create(Path, Error) instead of
"new SpecialCaseList(Path)". Currently the latter may crash with
report_fatal_error, which is undesirable - sometimes we want to report
the error to user gracefully - for example, if he provides an incorrect
file as an argument of Clang's -fsanitize-blacklist flag.
Reviewers: pcc
Reviewed By: pcc
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1327
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These functions used to assume that the lsb of an integer corresponds
to vector element 0, whereas for big-endian it's the other way around:
the msb is in the first element and the lsb is in the last element.
Fixes MultiSource/Benchmarks/mediabench/gsm/toast for z.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188155 91177308-0d34-0410-b5e6-96231b3b80d8
SROA-based analysis has enough information. This should work now that
both mem2reg *and* the SSAUpdater-based AllocaPromoter have been updated
to be able to promote the types of allocas that the SROA analysis
detects.
I've included tests for the AllocaPromoter that were only possible to
write once we fast-tracked promotable allocas without rewriting them.
This includes a test both for r187347 and r188145.
Original commit log for r187323:
"""
Now that mem2reg understands how to cope with a slightly wider set of uses of
an alloca, we can pre-compute promotability while analyzing an alloca for
splitting in SROA. That lets us short-circuit the common case of a bunch of
trivially promotable allocas. This cuts 20% to 30% off the run time of SROA for
typical frontend-generated IR sequneces I'm seeing. It gets the new SROA to
within 20% of ScalarRepl for such code. My current benchmark for these numbers
is PR15412, but it fits the general pattern of IR emitted by Clang so it should
be widely applicable.
"""
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188146 91177308-0d34-0410-b5e6-96231b3b80d8
the more general set of patterns that are now handled by mem2reg and that we
can detect quickly while doing SROA's initial analysis. Notably, this allows it
to promote through no-op bitcast and GEP sequences. A core part of the
SSAUpdater approach is the ability to test whether a particular instruction is
part of the set being promoted. Testing this becomes significantly more complex
in the world where the operand to every load and store isn't the alloca itself.
I ended up using the approach of walking up the def-chain until we find the
alloca. I benchmarked this against keeping a set of pointer operands and
keeping a set of the loads and stores we care about, and this one seemed faster
although the difference was very small.
No test case yet because currently the rewriting always "fixes" the inputs to
not require this. The next patch which re-enables early promotion of easy cases
in SROA will include a test case that specifically exercises this aspect of the
alloca promoter.
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our visiting datastructures in the AllocaPromoter/SSAUpdater path of
SROA. Also shift the order if clears around to be more consistent.
No functionality changed here, this is just a cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188144 91177308-0d34-0410-b5e6-96231b3b80d8
It is breaking builbots with libgmalloc enabled on Mac OS X.
$ cd llvm ; mkdir release ; cd release
$ ../configure --enable-optimized —prefix=$PWD/install
$ make
$ make check
$ Release+Asserts/bin/llvm-lit -v --param use_gmalloc=1 --param \
gmalloc_path=/usr/lib/libgmalloc.dylib \
../test/Instrumentation/DataFlowSanitizer/args-unreachable-bb.ll
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I fixed the aforementioned problems that came up on some of the linux boxes.
Major thanks to Nick Lewycky for his help debugging!
rdar://14590914
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188122 91177308-0d34-0410-b5e6-96231b3b80d8
This moves removeUnreachableBlocksFromFn from SimplifyCFGPass.cpp
to Utils/Local.cpp and uses it to replace the implementation of
llvm::removeUnreachableBlocks, which appears to do a strict subset
of what removeUnreachableBlocksFromFn does.
Differential Revision: http://llvm-reviews.chandlerc.com/D1334
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