which branch on undef to branch on a boolean constant for the edge
exiting the loop. This helps ScalarEvolution compute trip counts for
loops.
Teach ScalarEvolution to recognize single-value PHIs, when safe, and
ForgetSymbolicName to forget such single-value PHI nodes as apprpriate
in ForgetSymbolicName.
llvm-svn: 97126
argument is non-null, pass it along to PHITranslateSubExpr so that it can
prefer using existing values that dominate the PredBB, instead of just
blindly picking the first equivalent value that it finds on a uselist.
Also when the DominatorTree is specified, have PHITranslateValue filter
out any result that does not dominate the PredBB. This is basically just
refactoring the check that used to be in GetAvailablePHITranslatedSubExpr
and also in GVN.
Despite my initial expectations, this change does not affect the results
of GVN for any testcases that I could find, but it should help compile time.
Before this change, if PHITranslateSubExpr picked a value that does not
dominate, PHITranslateWithInsertion would then insert a new value, which GVN
would later determine to be redundant and would replace. By picking a good
value to begin with, we save GVN the extra work of inserting and then
replacing a new value.
llvm-svn: 97010
getelementptr. Despite only doing so in the case where x is a known
array object and c can be converted to an index within range, this
could still be invalid if c is actually the address of an object
allocated outside of LLVM. Also, SCEVExpander, the original motivation
for this code, has since been improved to avoid inttoptr+ptroint in
more cases.
llvm-svn: 96950
operators.
The test difference is just due to the multiplication operands
being commuted (and thus requiring a more elaborate match). In
optimized code, that expression would be folded.
llvm-svn: 96816
true or false as its exit condition. These are usually eliminated by
SimplifyCFG, but the may be left around during a pass which wishes
to preserve the CFG.
llvm-svn: 96683
a loop exit value, so that if a loop gets deleted, ScalarEvolution
isn't stick holding on to dangling SCEVAddRecExprs for that loop. This
fixes PR6339.
llvm-svn: 96626
case where there are loop-invariant instructions somehow left
inside the loop, and in a position where they won't dominate
the IV increment position.
llvm-svn: 96448
name, test whether the SCEV itself is that temporary symbolic name,
in addition to checking whether the symbolic name appears as a
possibly-indirect operand.
llvm-svn: 96216
insert location has become an "inserted" instruction since the time
it was saved. If so, advance to the first non-"inserted" instruction.
llvm-svn: 96203
current insertion point, advance the current insertion point.
This avoids a use-before-def situation in a testcase extracted
from clang which is difficult to reduce to a reasonable-sized
regression test.
llvm-svn: 96151
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.
This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.
llvm-svn: 95975
cases, and implement target-independent folding rules for alignof and
offsetof. Also, reassociate reassociative operators when it leads to
more folding.
Generalize ScalarEvolution's isOffsetOf to recognize offsetof on
arrays. Rename getAllocSizeExpr to getSizeOfExpr, and getFieldOffsetExpr
to getOffsetOfExpr, for consistency with analagous ConstantExpr routines.
Make the target-dependent folder promote GEP array indices to
pointer-sized integers, to make implicit casting explicit and exposed
to subsequent folding.
And add a bunch of testcases for this new functionality, and a bunch
of related existing functionality.
llvm-svn: 94987
use plain SCEVUnknowns with ConstantExpr::getSizeOf and
ConstantExpr::getOffsetOf constants. This eliminates a bunch of
special-case code.
Also add code for pattern-matching these expressions, for clients that
want to recognize them.
Move ScalarEvolution's logic for expanding array and vector sizeof
expressions into an element count times the element size, to expose
the multiplication to subsequent folding, into the regular constant
folder.
llvm-svn: 94737
After running a batch of measurements, it is clear that the inliner metrics
need some adjustments:
Own argument bonus: 20 -> 5
Outgoing argument penalty: 0 -> 5
Alloca bonus: 10 -> 5
Constant instr bonus: 7 -> 5
Dead successor bonus: 40 -> 5*(avg instrs/block)
The new cost metrics are generaly 25 points higher than before, so we may need
to move thresholds.
With this change, InlineConstants::CallPenalty becomes a political correction:
if (!isa<IntrinsicInst>(II) && !callIsSmall(CS.getCalledFunction()))
NumInsts += InlineConstants::CallPenalty + CS.arg_size();
The code size is accurately modelled by CS.arg_size(). CallPenalty is added
because calls tend to take a long time, so it may not be worth it to inline a
function with lots of calls.
All of the political corrections are in the InlineConstants namespace:
IndirectCallBonus, CallPenalty, LastCallToStaticBonus, ColdccPenalty,
NoreturnPenalty.
llvm-svn: 94615
A GEP with all constant indices is already considered free by
analyzeBasicBlock(), so don't give it an extra bonus in
CountCodeReductionForAlloca().
This patch should remove a small positive bias toward inlining functions with
variable-index GEPs, and remove a smaller negative bias from functions with
all-constant index GEPs.
llvm-svn: 94591
Functions containing indirectbr are marked NeverInline by analyzeBasicBlock(),
so there is no point in giving indirectbr special treatment in
CountCodeReductionForConstant. It is never called.
No functional change intended.
llvm-svn: 94590
have trouble with an intermediate add overflowing. Also, be more conservative
about the case where the induction variable in an SLT loop exit can step past
the RHS of the SLT and overflow in a single step.
Make getSignedRange more aggressive, to recover for some common cases which
the above fixes pessimized.
This addresses rdar://7561161.
llvm-svn: 94512
missing ones are libsupport, libsystem and libvmcore. libvmcore is
currently blocked on bugpoint, which uses EH. Once it stops using
EH, we can switch it off.
This #if 0's out 3 unit tests, because gtest requires RTTI information.
Suggestions welcome on how to fix this.
llvm-svn: 94164
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.
It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.
llvm-svn: 94061
form of an expression. This is the expression without the
post-increment adjustment made, which is useful in determining
which registers will be used by the expansion.
llvm-svn: 93921
Move the DOTGraphTraits dotty printer/viewer templates, that were developed for
the dominance tree into their own header file. This will allow reuse in future
passes.
llvm-svn: 93632
This patch also cleans up code that expects there to be a bitcast in the first argument and testcases that call llvm.dbg.declare.
It also strips old llvm.dbg.declare intrinsics that did not pass metadata as the first argument.
llvm-svn: 93531
memcpy, memset and other intrinsics that only access their arguments
to be readnone if the intrinsic's arguments all point to local memory.
This improves the testcase in the README to readonly, but it could in
theory be made readnone, however this would involve more sophisticated
analysis that looks through the memcpy.
llvm-svn: 92829
after the MDNode in memory. This eliminates the operands
pointer and saves a new[] per node.
Note that the code in DIDerivedType::replaceAllUsesWith is wrong
and quite scary. A MDNode should not be RAUW'd with something
else: this changes all uses of the mdnode, which may not be debug
info related! Debug info should use something non-mdnode for
declarations.
llvm-svn: 92321
getMDKindID/getMDKindNames methods to LLVMContext (and add
convenience methods to Module), eliminating MetadataContext.
Move the state that it maintains out to LLVMContext.
llvm-svn: 92259
I asked Devang to do back on Sep 27. Instead of going through the
MetadataContext class with methods like getMD() and getMDs(), just
ask the instruction directly for its metadata with getMetadata()
and getAllMetadata().
This includes a variety of other fixes and improvements: previously
all Value*'s were bloated because the HasMetadata bit was thrown into
value, adding a 9th bit to a byte. Now this is properly sunk down to
the Instruction class (the only place where it makes sense) and it
will be folded away somewhere soon.
This also fixes some confusion in getMDs and its clients about
whether the returned list is indexed by the MDID or densely packed.
This is now returned sorted and densely packed and the comments make
this clear.
This introduces a number of fixme's which I'll follow up on.
llvm-svn: 92235
instead of stored. This reduces memdep memory usage, and also eliminates a bunch of
weakvh's. This speeds up gvn on gcc.c-torture/20001226-1.c from 23.9s to 8.45s (2.8x)
on a different machine than earlier.
llvm-svn: 91885
cache a pointer as being unavailable due to phi trans in the
wrong place. This would cause later queries to fail even when
they didn't involve phi trans.
llvm-svn: 91787
contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.
llvm-svn: 91654
of 91296 that caused trouble -- the Processed list needs to be
preserved for the livetime of the pass, as AddUsersIfInteresting
is called from other passes.
llvm-svn: 91641
isPodLike type trait. This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.
llvm-svn: 91421
add, there is no need to scan the world to find the same add again.
This invalidates the previous testcase, which wasn't wonderful anyway,
because it needed a run of instcombine to permute the use-lists in
just the right way to before GVN was run (so it was really fragile).
Not a big loss.
llvm-svn: 90973
phi translation of complex expressions like &A[i+1]. This has the
following benefits:
1. The phi translation logic is all contained in its own class with
a strong interface and verification that it is self consistent.
2. The logic is more correct than before. Previously, if intermediate
expressions got PHI translated, we'd miss the update and scan for
the wrong pointers in predecessor blocks. @phi_trans2 is a testcase
for this.
3. We have a lot less code in memdep.
We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).
This patch should fix the miscompiles of 255.vortex, and I tested it
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.
llvm-svn: 90926
examines; fall back to a conservative answer if there are
more. This works around some several compile time problems
resulting from BasicAliasAnalysis calling PointerMayBeCaptured.
The value has been chosen arbitrarily.
This fixes rdar://7438917 and may partially address PR5708.
llvm-svn: 90905
The semantics of llvm.dbg.value are that starting from where it is executed, an offset into the specified user source variable is specified to get a new value.
An example:
call void @llvm.dbg.value(metadata !{ i32 7 }, i64 0, metadata !2)
Here the user source variable associated with metadata #2 gets the value "i32 7" at offset 0.
llvm-svn: 90788
Devang Patel