Add a simple initial heuristic to control importing based on the number
of instructions recorded in the function's summary. Add option to
control the limit, and test using option.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254036 91177308-0d34-0410-b5e6-96231b3b80d8
When the original binary is executed and sampled, the resulting profile
contains information on the original inline stack. We currently follow
the original inline plan if we notice that the inlined callsite has more
than 0 samples to it.
A better way is to determine whether the callsite is actually worth
inlining. If the callsite accumulates a small fraction of the samples
spent in the parent function, then we don't want to bother inlining it
(as it means that the callsite is actually cold).
This patch introduces a threshold expressed in percentage of samples
in relation to the parent function. If the callsite uses less than N%
of the total samples used by its parent, the original inline decision is
not re-applied.
I've set the threshold to the very arbitrary value of 5%. I'm yet to do
any actual experiments to see what's a good value. I wanted to separate
the basic mechanism from the tuning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254034 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a minimum spanning tree (MST) based instrumentation for
PGO. The use of MST guarantees minimum number of CFG edges getting
instrumented. An addition optimization is to instrument the less executed
edges to further reduce the instrumentation overhead. The patch contains both the
instrumentation and the use of the profile to set the branch weights.
Differential Revision: http://reviews.llvm.org/D12781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254021 91177308-0d34-0410-b5e6-96231b3b80d8
Analyze imported function bodies and add any new external calls to
the worklist for importing. Currently no controls on the importing
so this will end up importing everything possible in the call tree
below the importing module. Basic profitability checks coming next.
Update test to check for iteratively inlined functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254011 91177308-0d34-0410-b5e6-96231b3b80d8
Skip imports for weak_any aliases as well. Fix the test to check
non-import of weak aliases and functions, and import of normal alias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253991 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is a helper to perform cross-module import for ThinLTO. Right now
it is importing naively every possible called functions.
Reviewers: tejohnson
Subscribers: dexonsmith, llvm-commits
Differential Revision: http://reviews.llvm.org/D14914
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253954 91177308-0d34-0410-b5e6-96231b3b80d8
The existing coverage tracker counts the number of records that were used
from the input profile. An alternative view of coverage is to check how
many available samples were applied.
This way, if the profile contains several records with few samples, it
doesn't really matter much that they were not applied. The more
interesting records to apply are the ones that contribute many samples.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253912 91177308-0d34-0410-b5e6-96231b3b80d8
In profile runtime implementation for Darwin, Linux and FreeBSD, the
names of sections holding profile control/counter/naming data need
to be known by the runtime in order to locate the start/end of the
data. Moving the name definitions to the common file to specify the
connection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253814 91177308-0d34-0410-b5e6-96231b3b80d8
If a function was originally inlined but not actually hot at runtime,
its samples will not be counted inside the parent function. This throws
off the coverage calculation because it expects to find more used
records than it should.
Fixed by ignoring functions that will not be inlined into the parent.
Currently, this is inlined functions with 0 samples. In subsequent
patches, I'll change this to mean "cold" functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253716 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r253661.
Turns out that the assignment is not redundant (despite the Clang static analyzer claiming the opposite).
The variable is being used by the lambda function AddUsersToWorklistIfCapturing().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253696 91177308-0d34-0410-b5e6-96231b3b80d8
While debugging some sampling coverage problems, I found this useful:
When applying samples from a profile, it helps to also know what line
offset and discriminator the sample belongs to. This makes it easy to
correlate against the input profile.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253670 91177308-0d34-0410-b5e6-96231b3b80d8
Terrifyingly, one of them is a mishandling of floating point vectors
in Constant::isZero(). How exactly this issue survived this long
is beyond me.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253655 91177308-0d34-0410-b5e6-96231b3b80d8
The change exposed a bug in IndVarSimplify (PR25578), which led to a
failure (PR25538). When the bug is fixed, this patch can be reapplied.
The tests are kept in tree, as they're useful anyway, and will not break
with this revert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253596 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The new algorithm is more efficient (O(n), n is number of basic blocks). And it is guaranteed to cover all cases of multiple BB mapped to same line.
Reviewers: dblaikie, davidxl, dnovillo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14738
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253594 91177308-0d34-0410-b5e6-96231b3b80d8
The purpose of this change is help delineate the memset and memcpy
optimizations with the overall goal of resolving PR25520.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253585 91177308-0d34-0410-b5e6-96231b3b80d8
We currently bail out of global localization if the global has non-instruction users. However, often these can be simple bitcasts or constant-GEPs, which we can easily turn into instructions before localizing. Be a bit more aggressive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253584 91177308-0d34-0410-b5e6-96231b3b80d8
This provides a way to force a function to have certain attributes from the command line. This can be useful when debugging or doing workload exploration, where manually editing IR is tedious or not possible (due to build systems etc).
The syntax is -force-attribute=function_name:attribute_name
All function attributes are parsed except alignstack as it requires an argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253550 91177308-0d34-0410-b5e6-96231b3b80d8
Optimizations like LoadPRE in GVN will insert new instructions.
If the insertion point is in a already processed BB, they should
get a value number explicitly. If the insertion point is after
current instruction, then just leave it. However, current GVN framework
has no support for it.
In this patch, we just bail out if a VN can't be found.
Dfferential Revision: http://reviews.llvm.org/D14670
A test/Transforms/GVN/pr25440.ll
M lib/Transforms/Scalar/GVN.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253536 91177308-0d34-0410-b5e6-96231b3b80d8
