to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
When splitting musttail calls, the split blocks' original terminators
get removed; inform the DTU when this happens.
Also add a testcase that fails an assertion in the DTU without this fix.
Reviewers: fhahn, junbuml
Reviewed By: fhahn
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D55027
llvm-svn: 347872
This patch updates DuplicateInstructionsInSplitBetween to update a DTU
instead of applying updates to the DT directly.
Given that there only are 2 users, also updated them in this patch to
avoid churn.
I slightly moved the code in CallSiteSplitting around to reduce the
places where we have to pass in DTU. If necessary, I could split those
changes in a separate patch.
This fixes missing DT updates when dealing with musttail calls in
CallSiteSplitting, by using DTU->deleteBB.
Reviewers: junbuml, kuhar, NutshellySima, indutny, brzycki
Reviewed By: NutshellySima
llvm-svn: 346769
We can stop recording conditions once we reached the immediate dominator
for the block containing the call site. Conditions in predecessors of the
that node will be the same for all paths to the call site and splitting
is not beneficial.
This patch makes CallSiteSplitting dependent on the DT anlysis. because
the immediate dominators seem to be the easiest way of finding the node
to stop at.
I had to update some exiting tests, because they were checking for
conditions that were true/false on all paths to the call site. Those
should now be handled by instcombine/ipsccp.
Reviewers: davide, junbuml
Reviewed By: junbuml
Differential Revision: https://reviews.llvm.org/D44627
llvm-svn: 346483
by `getTerminator()` calls instead be declared as `Instruction`.
This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).
llvm-svn: 344502
There are 2 cases when we create PHI nodes:
* For the result of the call that was duplicated in the split blocks.
Those PHI nodes should have the debug location of the call.
* For values produced before the call. Those instructions need to be
duplicated in the split blocks and the PHI nodes should have the
debug locations of those instructions.
Fixes PR37962.
Reviewers: junbuml, gbedwell, vsk
Reviewed By: junbuml
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D51919
llvm-svn: 341970
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)
llvm-svn: 333954
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Summary: We do not need nonull attribute if we know an argument is going to be constant.
Reviewers: junbuml, davide, fhahn
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45608
llvm-svn: 330641
Summary:
If the callsite is inside landing pad, do not perform callsite splitting.
Callsite splitting uses utility function llvm::DuplicateInstructionsInSplitBetween, which eventually calls llvm::SplitEdge. llvm::SplitEdge calls llvm::SplitCriticalEdge with an assumption that the function returns nullptr only when the target edge is not a critical edge (and further assumes that if the return value was not nullptr, the predecessor of the original target edge always has a single successor because critical edge splitting was successful). However, this assumtion is not true because SplitCriticalEdge returns nullptr if the destination block is a landing pad. This invalid assumption results assertion failure.
Fundamental solution might be fixing llvm::SplitEdge to not to rely on the invalid assumption. However, it'll involve a lot of work because current API assumes that llvm::SplitEdge never fails. Instead, this patch makes callsite splitting to not to attempt splitting if the callsite is in a landing pad.
Attached test case will crash with assertion failure without the fix.
Reviewers: fhahn, junbuml, dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45130
llvm-svn: 329250
The dominator tree analysis can be preserved easily.
Some other kinds of analysis can probably be preserved
too.
Reviewers: junbuml, dberlin
Reviewed By: dberlin
Differential Revision: https://reviews.llvm.org/D43173
llvm-svn: 328206
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.
Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.
Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.
llvm-svn: 328165
getNumUses is a linear operation. It walks a linked list to get a count. So in this case its better to just ask if there are any users rather than how many.
llvm-svn: 327314
Change doCallSiteSplitting to iterate until we reach the terminator instruction.
tryToSplitCallSite can replace BB's terminator in case BB is a successor of
itself. Then IE will be invalidated and we also have to check the current
terminator.
Reviewers: junbuml, davidxl, davide, fhahn
Reviewed By: fhahn, junbuml
Differential Revision: https://reviews.llvm.org/D43824
llvm-svn: 326793
Iterating through predecessors of `TailBB` while removing their
terminators leads to use after-free, because the predecessor list is
changing on each removal.
llvm-svn: 326668
Summary:
`musttail` calls can't be naively splitted. The split blocks must
include not only the call instruction itself, but also (optional)
`bitcast` and `return` instructions that follow it.
Clone `bitcast` and `ret`, place them into the split blocks, and
remove the tail block when done.
Reviewers: junbuml, mcrosier, davidxl, davide, fhahn
Reviewed By: fhahn
Subscribers: JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D43729
llvm-svn: 326666
For basic blocks with instructions between the beginning of the block
and a call we have to duplicate the instructions before the call in all
split blocks and add PHI nodes for uses of the duplicated instructions
after the call.
Currently, the threshold for the number of instructions before a call
is quite low, to keep the impact on binary size low.
Reviewers: junbuml, mcrosier, davidxl, davide
Reviewed By: junbuml
Differential Revision: https://reviews.llvm.org/D41860
llvm-svn: 325126
For basic blocks with instructions between the beginning of the block
and a call we have to duplicate the instructions before the call in all
split blocks and add PHI nodes for uses of the duplicated instructions
after the call.
Currently, the threshold for the number of instructions before a call
is quite low, to keep the impact on binary size low.
Reviewers: junbuml, mcrosier, davidxl, davide
Reviewed By: junbuml
Differential Revision: https://reviews.llvm.org/D41860
llvm-svn: 325001
This removes some duplication from splitCallSite and makes it easier to
add additional code dealing with each predecessor. It also allows us to
split for more than 2 predecessors, although that is not enabled for
now.
Reviewers: junbuml, mcrosier, davidxl, davide
Reviewed By: junbuml
Differential Revision: https://reviews.llvm.org/D41858
llvm-svn: 322599
By following the single predecessors of the predecessors of the call
site, we do not need to restrict the control flow.
Reviewed By: junbuml, davide
Differential Revision: https://reviews.llvm.org/D40729
llvm-svn: 321413
Summary:
This change makes the call site creation more general if any of the
arguments is predicated on a condition in the call site's predecessors.
If we find a callsite, that potentially can be split, we collect the set
of conditions for the call site's predecessors (currently only 2
predecessors are allowed). To do that, we traverse each predecessor's
predecessors as long as it only has single predecessors and record the
condition, if it is relevant to the call site. For each condition, we
also check if the condition is taken or not. In case it is not taken,
we record the inverse predicate.
We use the recorded conditions to create the new call sites and split
the basic block.
This has 2 benefits: (1) it is slightly easier to see what is going on
(IMO) and (2) we can easily extend it to handle more complex control
flow.
Reviewers: davidxl, junbuml
Reviewed By: junbuml
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40728
llvm-svn: 320547
Summary:
This solves PR35616.
We don't want the compiler to generate different code when we compile
with/without -g, so we now ignore debug intrinsics when determining if
the optimization can trigger or not.
Reviewers: junbuml
Subscribers: davide, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D41068
llvm-svn: 320460
Summary:
With this patch I tried to reduce the complexity of the code sightly, by
removing some indirection. Please let me know what you think.
Reviewers: junbuml, mcrosier, davidxl
Reviewed By: junbuml
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40037
llvm-svn: 318593
This recommit r317351 after fixing a buildbot failure.
Original commit message:
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
llvm-svn: 317362
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
Reviewers: davidxl, huntergr, chandlerc, mcrosier, eraman, davide
Reviewed By: davidxl
Subscribers: sdesmalen, ashutosh.nema, fhahn, mssimpso, aemerson, mgorny, mehdi_amini, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D39137
llvm-svn: 317351
Chandler Carruth