Summary:
This rewrites store expression/leader handling. We no longer use the
value operand as the leader, instead, we store it separately. We also
now store the stored value as part of the expression, and compare it
when comparing stores for equality. This enables us to get rid of a
bunch of our previous hacks and machinations, as the existing
machinery takes care of everything *except* updating the stored value
on classes. The only time we have to update it is if the storecount
goes to 0, and when we do, we destroy it.
Since we no longer use the value operand as the leader, during elimination, we have to use the value operand. Doing this also fixes a bunch of store forwarding cases we were missing.
Any value operand we use is guaranteed to either be updated by previous eliminations, or minimized by future ones.
(IE the fact that we don't use the most dominating value operand when it's not a constant does not affect anything).
Sadly, this change also exposes that we didn't pay attention to the
output of the pr31594.ll test, as it also very clearly exposes the
same store leader bug we are fixing here.
(I added pr31682.ll anyway, but maybe we think that's too large to be useful)
On the plus side, propagate-ir-flags.ll now passes due to the
corrected store forwarding.
This change was 3 stage'd on darwin and linux, with the full test-suite.
Reviewers:
davide
Subscribers:
llvm-commits
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292648 91177308-0d34-0410-b5e6-96231b3b80d8
This is the third attemp to recommit r292526.
The original summary:
Currently, a GEP is considered free only if its indices are all constant.
TTI::getGEPCost() can give target-specific more accurate analysis. TTI is
already used for the cost of many other instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292633 91177308-0d34-0410-b5e6-96231b3b80d8
This is the second attemp to recommit r292526.
The original summary:
Currently, a GEP is considered free only if its indices are all constant.
TTI::getGEPCost() can give target-specific more accurate analysis. TTI is
already used for the cost of many other instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292616 91177308-0d34-0410-b5e6-96231b3b80d8
Like several other loop passes (the vectorizer, etc) this pass doesn't
really fit the model of a loop pass. The critical distinction is that it
isn't intended to be pipelined together with other loop passes. I plan
to add some documentation to the loop pass manager to make this more
clear on that side.
LoopSink is also different because it doesn't really need a lot of the
infrastructure of our loop passes. For example, if there aren't loop
invariant instructions causing a preheader to exist, there is no need to
form a preheader. It also doesn't need LCSSA because this pass is
only involved in sinking invariant instructions from a preheader into
the loop, not reasoning about live-outs.
This allows some nice simplifications to the pass in the new PM where we
can directly walk the loops once without restructuring them.
Differential Revision: https://reviews.llvm.org/D28921
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292589 91177308-0d34-0410-b5e6-96231b3b80d8
Part of the assert has been left active for further debugging.
The other part has been turned into a stat for tracking for the
moment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292583 91177308-0d34-0410-b5e6-96231b3b80d8
This recommits r292526 which is reverted in r292529 after fixing the test case.
The original summary:
Currently, a GEP is considered free only if its indices are all constant.
TTI::getGEPCost() can give target-specific more accurate analysis. TTI is
already used for the cost of many other instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292570 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fence instructions are currently marked as `ModRef` for all memory locations.
We can improve this for constant memory locations (such as constant globals),
since fence instructions cannot modify these locations.
This helps us to forward constant loads across fences (added test case in GVN).
There were no changes in behaviour for similar test cases in early-cse and licm.
Reviewers: dberlin, sanjoy, reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28914
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292546 91177308-0d34-0410-b5e6-96231b3b80d8
This can prove that:
extern int f;
int g() {
int x = 0;
for (int i = 0; i < 365; ++i) {
x /= f;
}
return x;
}
always returns zero. Thanks to Sanjoy for confirming this
transformation actually made sense (bugs are mine).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292531 91177308-0d34-0410-b5e6-96231b3b80d8
Currently, a GEP is considered free only if its indices are all constant.
TTI::getGEPCost() can give target-specific more accurate analysis. TTI is
already used for the cost of many other instructions.
Differential Revision: https://reviews.llvm.org/D28693
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292526 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In case of non-alloca pointers, we check for whether it is a pointer
from malloc-like calls and it is not captured. In such case, we can
promote the pointer, as the caller will have no way to access this pointer
even if there is unwinding in middle of the loop.
Reviewers: hfinkel, sanjoy, reames, eli.friedman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28834
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292510 91177308-0d34-0410-b5e6-96231b3b80d8
Type identifiers are exported by:
- Adding coarse-grained information about how to test the type
identifier to the summary.
- Creating symbols in the object file (aliases and absolute symbols)
containing fine-grained information about the type identifier.
Differential Revision: https://reviews.llvm.org/D28424
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292462 91177308-0d34-0410-b5e6-96231b3b80d8
This changes the vectorizer to explicitly use the loopsimplify and lcssa utils,
instead of "requiring" the transformations as if they were analyses.
This is not NFC, since it changes the LCSSA behavior - we no longer run LCSSA
for all loops, but rather only for the loops we expect to modify.
Differential Revision: https://reviews.llvm.org/D28868
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292456 91177308-0d34-0410-b5e6-96231b3b80d8
We currently check whether a reduction has a single outside user. We don't
really need to require that - we just need to make sure a single value is
used externally. The number of external users of that value shouldn't actually
matter.
Differential Revision: https://reviews.llvm.org/D28830
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292424 91177308-0d34-0410-b5e6-96231b3b80d8
deleted.
I've expanded its test coverage a bit including adding one test that
will crash clearly without this change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292332 91177308-0d34-0410-b5e6-96231b3b80d8
claims to test.
LoopSimplify was unifying the multiple exits in this test case, making
it never even test the multiple exit handling of LoopDeletion. Doh.
Now it works (thanks to a great idea from mkuper) and will fail if we
ever change something to make it stop working.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292331 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Partial unrolling should have separate threshold with full unrolling.
Reviewers: efriedma, mzolotukhin
Reviewed By: efriedma, mzolotukhin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28831
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292293 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Add a test case for LICM when promoting locals that may be read after the throw within the loop.
Reviewers: eli.friedman, hfinkel, sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28822
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292261 91177308-0d34-0410-b5e6-96231b3b80d8
runnig LCSSA over them prior to running the loop pipeline.
This also teaches the loop PM to verify that LCSSA form is preserved
throughout the pipeline's run across the loop nest.
Most of the test updates just leverage this new functionality. One has to be
relaxed with the new PM as IVUsers is less powerful when it sees LCSSA input.
Differential Revision: https://reviews.llvm.org/D28743
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292241 91177308-0d34-0410-b5e6-96231b3b80d8
