On certain architectures we can support efficient vectorized version of
instructions if the operand value is uniform (splat) or a constant scalar.
An example of this is a vector shift on x86.
We can efficiently support
for (i = 0 ; i < ; i += 4)
w[0:3] = v[0:3] << <2, 2, 2, 2>
but not
for (i = 0; i < ; i += 4)
w[0:3] = v[0:3] << x[0:3]
This patch adds a parameter to getArithmeticInstrCost to further qualify operand
values as uniform or uniform constant.
Targets can then choose to return a different cost for instructions with such
operand values.
A follow-up commit will test this feature on x86.
radar://13576547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178807 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes PR15570: SEGV: SCEV back-edge info invalid after dead code removal.
Indvars creates a SCEV expression for the loop's back edge taken
count, then determines that the comparison is always true and
removes it.
When loop-unroll asks for the expression, it contains a NULL
SCEVUnknkown (as a CallbackVH).
forgetMemoizedResults should invalidate the loop back edges expression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177986 91177308-0d34-0410-b5e6-96231b3b80d8
This pass hasn't been touched in two years & would fail with assertions against
the current debug info metadata format (the only test case for it still uses a
many-versions old debug info metadata format)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176707 91177308-0d34-0410-b5e6-96231b3b80d8
The "invariant.load" metadata indicates the memory unit being accessed is immutable.
A load annotated with this metadata can be moved across any store.
As I am not sure if it is legal to move such loads across barrier/fence, this
change dose not allow such transformation.
rdar://11311484
Thank Arnold for code review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176562 91177308-0d34-0410-b5e6-96231b3b80d8
Clarify that we mean the object starting at the pointer to the end of the
underlying object and not the size of the whole allocated object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176491 91177308-0d34-0410-b5e6-96231b3b80d8
This adds minimalistic support for PHI nodes to llvm.objectsize() evaluation
fingers crossed so that it does break clang boostrap again..
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176408 91177308-0d34-0410-b5e6-96231b3b80d8
this is similar to getObjectSize(), but doesnt subtract the offset
tweak the BasicAA code accordingly (per PR14988)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176407 91177308-0d34-0410-b5e6-96231b3b80d8
Adds a function to target transform info to query for the cost of address
computation. The cost model analysis pass now also queries this interface.
The code in LoopVectorize adds the cost of address computation as part of the
memory instruction cost calculation. Only there, we know whether the instruction
will be scalarized or not.
Increase the penality for inserting in to D registers on swift. This becomes
necessary because we now always assume that address computation has a cost and
three is a closer value to the architecture.
radar://13097204
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174713 91177308-0d34-0410-b5e6-96231b3b80d8
it isn't really an AliasAnalysis concept, and ValueTracking has similar things
that it could plausibly share code with some day.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174027 91177308-0d34-0410-b5e6-96231b3b80d8
reference to a pointer, so that it can handle the case where DataLayout
is not available and behave conservatively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174024 91177308-0d34-0410-b5e6-96231b3b80d8
generic function calls and intrinsics. This is somewhat overlapping with
an existing intrinsic cost method, but that one seems targetted at
vector intrinsics. I'll merge them or separate their names and use cases
in a separate commit.
This sinks the test of 'callIsSmall' down into TTI where targets can
control it. The whole thing feels very hack-ish to me though. I've left
a FIXME comment about the fundamental design problem this presents. It
isn't yet clear to me what the users of this function *really* care
about. I'll have to do more analysis to figure that out. Putting this
here at least provides it access to proper analysis pass tools and other
such. It also allows us to more cleanly implement the baseline cost
interfaces in TTI.
With this commit, it is now theoretically possible to simplify much of
the inline cost analysis's handling of calls by calling through to this
interface. That conversion will have to happen in subsequent commits as
it requires more extensive restructuring of the inline cost analysis.
The CodeMetrics class is now really only in the business of running over
a block of code and aggregating the metrics on that block of code, with
the actual cost evaluation done entirely in terms of TTI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173148 91177308-0d34-0410-b5e6-96231b3b80d8
is free. The whole CodeMetrics API should probably be reworked more, but
this is enough to allow deleting the duplicate code there for computing
whether an instruction is free.
All of the passes using this have been updated to pull in TTI and hand
it to the CodeMetrics stuff. Further, a dead CodeMetrics API
(analyzeFunction) is nuked for lack of users.
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depend on and use other analyses (as long as they're either immutable
passes or CGSCC passes of course -- nothing in the pass manager has been
fixed here). Leverage this to thread TargetTransformInfo down through
the inline cost analysis.
No functionality changed here, this just threads things through.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173031 91177308-0d34-0410-b5e6-96231b3b80d8
a dynamic analysis done on each call to the routine. However, now it can
use the standard pass infrastructure to reference other analyses,
instead of a silly setter method. This will become more interesting as
I teach it about more analysis passes.
This updates the two inliner passes to use the inline cost analysis.
Doing so highlights how utterly redundant these two passes are. Either
we should find a cheaper way to do always inlining, or we should merge
the two and just fiddle with the thresholds to get the desired behavior.
I'm leaning increasingly toward the latter as it would also remove the
Inliner sub-class split.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173030 91177308-0d34-0410-b5e6-96231b3b80d8
lowered cost.
Currently, this is a direct port of the logic implementing
isInstructionFree in CodeMetrics. The hope is that the interface can be
improved (f.ex. supporting un-formed instruction queries) and the
implementation abstracted so that as we have test cases and target
knowledge we can expose increasingly accurate heuristics to clients.
I'll start switching existing consumers over and kill off the routine in
CodeMetrics in subsequent commits.
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Okay, here's how to reproduce the problem:
1) Build a Release (or Release+Asserts) version of clang in the normal way.
2) Using the clang & clang++ binaries from (1), build a Release (or
Release+Asserts) version of the same sources, but this time enable LTO ---
specify the `-flto' flag on the command line.
3) Run the ARC migrator tests:
$ arcmt-test --args -triple x86_64-apple-darwin10 -fsyntax-only -x objective-c++ ./src/tools/clang/test/ARCMT/cxx-rewrite.mm
You'll see that the output isn't correct (the whitespace is off).
The mis-compile is in the function `RewriteBuffer::RemoveText' in the
clang/lib/Rewrite/Core/Rewriter.cpp file. When that function and RewriteRope.cpp
are compiled with LTO and the `arcmt-test' executable is regenerated, you'll see
the error. When those files are not LTO'ed, then the output of the `arcmt-test'
is fine.
It is *really* hard to get a testcase out of this. I'll file a PR with what I
have currently.
--- Reverse-merging r172363 into '.':
U include/llvm/Analysis/MemoryBuiltins.h
U lib/Analysis/MemoryBuiltins.cpp
--- Reverse-merging r171325 into '.':
U test/Transforms/InstCombine/objsize.ll
G include/llvm/Analysis/MemoryBuiltins.h
G lib/Analysis/MemoryBuiltins.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172756 91177308-0d34-0410-b5e6-96231b3b80d8
Moving the X86CostTable to a common place, so that other back-ends
can share the code. Also simplifying it a bit and commoning up
tables with one and two types on operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172658 91177308-0d34-0410-b5e6-96231b3b80d8
Note that this bug is only exposed because LTO fails to use TTI.
Fixes self-LTO of clang. rdar://13007381.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172462 91177308-0d34-0410-b5e6-96231b3b80d8