Revert r325001: [CallSiteSplitting] Support splitting of blocks with instrs before call.

Due to memsan not being happy with the array of ValueToValue maps.

llvm-svn: 325009

[CallSiteSplitting] Clear ValueToValue maps.

llvm-svn: 325006

[CallSiteSplitting] Dereference pointer earlier.

This should make the sanitizers happy.

llvm-svn: 325004

[CallSiteSplitting] Support splitting of blocks with instrs before call.

For basic blocks with instructions between the beginning of the block
and a call we have to duplicate the instructions before

[CallSiteSplitting] Support splitting of blocks with instrs before call.

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

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[CallSiteSplitting] Fix infinite loop when recording conditions.

Fix infinite loop when recording conditions by correctly marking basic
blocks as visited.

Fixes https://bugs.llvm.org/show_bug.cgi?i

[CallSiteSplitting] Fix infinite loop when recording conditions.

Fix infinite loop when recording conditions by correctly marking basic
blocks as visited.

Fixes https://bugs.llvm.org/show_bug.cgi?id=36105

llvm-svn: 323515

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[CallSiteSplitting] Pass list of (BB, Conditions) pairs to splitCallSite.

This removes some duplication from splitCallSite and makes it easier to
add additional code dealing with each predecessor. I

[CallSiteSplitting] Pass list of (BB, Conditions) pairs to splitCallSite.

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

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Use phi ranges to simplify code. No functionality change intended.

llvm-svn: 321585

[CallSiteSplitting] Remove isOrHeader restriction.

By following the single predecessors of the predecessors of the call
site, we do not need to restrict the control flow.

Reviewed By: junbuml, davi

[CallSiteSplitting] Remove isOrHeader restriction.

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

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[CallSiteSplitting] Refactor creating callsites.

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.

[CallSiteSplitting] Refactor creating callsites.

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

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[CallSiteSplitting] Don't let debug intrinsics affect optimizations

Summary:
This solves PR35616.

We don't want the compiler to generate different code when we compile
with/without -g, so we now ig

[CallSiteSplitting] Don't let debug intrinsics affect optimizations

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

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[CallSiteSplitting] Remove some indirection (NFC).

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.

Re

[CallSiteSplitting] Remove some indirection (NFC).

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

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[CallSiteSplitting] clang-format my last commit. NFCI.

Thanks to Rui for pointing out.

llvm-svn: 317393

[CallSiteSplitting] Silence GCC's -Wparentheses. NFCI.

llvm-svn: 317385

Recommit r317351 : Add CallSiteSplitting pass

This recommit r317351 after fixing a buildbot failure.

Original commit message:

Summary:
This change add a pass which tries to split a call-si

Recommit r317351 : Add CallSiteSplitting pass

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

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Add CallSiteSplitting pass

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

Add CallSiteSplitting pass

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

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