API gardening: Rename FindAllocaDbgValue to findDbgValue (NFC)
and use have it use SmallVectorImpl.

There is nothing specific about allocas in this function.

llvm-svn: 297643

NewGVN: Rewrite DCE during elimination so we do it as well as old GVN did.

llvm-svn: 297428

[Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)

Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including li

[Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)

Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including libc implementations, where
function names are actually macros (musl uses "#define fopen64 fopen", for
example; any other transitively visible macro would have similar effects).

Strictly speaking, a conforming C++ Standard Library should provide any such
macros as functions instead (via <cstdio>). However, there are some "library"
functions which are not part of the standard, and thus not subject to this
rule (fopen64, for example). So, in order to be both portable and consistent,
the enum should not use the bare function names.

The old enum naming used a namespace LibFunc and an enum Func, with bare
enumerators. This patch changes LibFunc to be an enum with enumerators prefixed
with "LibFFunc_". (Unfortunately, a scoped enum is not sufficient to override
macros.)

There are additional changes required in clang.

Reviewers: rsmith

Subscribers: mehdi_amini, mzolotukhin, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D28476

llvm-svn: 292848

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Refactor the DIExpression fragment query interface (NFC)
... so it becomes available to DIExpressionCursor.

llvm-svn: 290322

Revert @llvm.assume with operator bundles (r289755-r289757)

This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086

Remove the AssumptionCache

After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is mo

Remove the AssumptionCache

After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756

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[DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/piper

[DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

llvm-svn: 288683

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[LoopSimplify] Preserve LCSSA when removing edges from unreachable blocks.

This fixes PR30454.

llvm-svn: 287379

[simplifycfg][loop-simplify] Preserve loop metadata in 2 transformations.

insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the a

[simplifycfg][loop-simplify] Preserve loop metadata in 2 transformations.

insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the added backedge.

llvm::TryToSimplifyUncondBranchFromEmptyBlock in lib/Transforms/Utils/Local.cpp
now propagates existing llvm.loop metadata to the branch instructions in the
predecessor blocks of the empty block that is removed.

Differential Revision: https://reviews.llvm.org/D26495

llvm-svn: 287341

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[tsan] Add support for C++ exceptions into TSan (call __tsan_func_exit during unwinding), LLVM part

This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func

[tsan] Add support for C++ exceptions into TSan (call __tsan_func_exit during unwinding), LLVM part

This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.

Differential Revision: https://reviews.llvm.org/D26177

llvm-svn: 286893

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DCE math library calls with a constant operand.

On platforms which use -fmath-errno, math libcalls without any uses
require some extra checks to figure out if they are actually dead.

Fixes https://

DCE math library calls with a constant operand.

On platforms which use -fmath-errno, math libcalls without any uses
require some extra checks to figure out if they are actually dead.

Fixes https://llvm.org/bugs/show_bug.cgi?id=30464 .

Differential Revision: https://reviews.llvm.org/D25970

llvm-svn: 285857

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[DebugInfo] Add comments to phi dbg.value tracking code, NFC

LLVM developers might be surprised to learn that there are blocks
without valid insertion points (catchswitch), so it seems worth calling

[DebugInfo] Add comments to phi dbg.value tracking code, NFC

LLVM developers might be surprised to learn that there are blocks
without valid insertion points (catchswitch), so it seems worth calling
that out explicitly. Also add a FIXME about what we should really be
doing if we ever need to make optimized Windows EH code debuggable.

While I'm here, make auto usage more consistent with LLVM standards and
avoid an unecessary call to insertBefore.

llvm-svn: 282521

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Reapplying r281895 (and follow-up r281964) after fixing pr30468.

The additional fix is:

When adding debug information to a lowered phi node in mem2reg
check that we have a valid insertion point af

Reapplying r281895 (and follow-up r281964) after fixing pr30468.

The additional fix is:

When adding debug information to a lowered phi node in mem2reg
check that we have a valid insertion point after the phi for adding
the debug information.

This change addresses the issue in pr30468 where a lowered phi was
added before a catchswitch and no debug information should be added
after the phi in this case.

Differential Revision: https://reviews.llvm.org/D24797

llvm-svn: 282155

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Revert r281895 "Add @llvm.dbg.value entries for the phi node created by -mem2reg"

(And follow-up r281964.)

It caused PR30468.

llvm-svn: 282077

Make llvm::ConvertDebugDeclareToDebugValue() be a void function (NFC)

The routines llvm::ConvertDebugDeclareToDebugValue() always returned
a true value which was never checked at the call site; chan

Make llvm::ConvertDebugDeclareToDebugValue() be a void function (NFC)

The routines llvm::ConvertDebugDeclareToDebugValue() always returned
a true value which was never checked at the call site; change the
function return type to void.

This NFC cleanup was approved in the review https://reviews.llvm.org/D23715

llvm-svn: 281964

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Add @llvm.dbg.value entries for the phi node created by -mem2reg

When phi nodes are created in the -mem2reg phase, the @llvm.dbg.declare
entries are converted to @llvm.dbg.value entries at the place

Add @llvm.dbg.value entries for the phi node created by -mem2reg

When phi nodes are created in the -mem2reg phase, the @llvm.dbg.declare
entries are converted to @llvm.dbg.value entries at the place where the
store instructions existed. However no entry is created to describe
the resulting value of the phi node.

The effect of this is especially noticeable in for loops which have a
constant for the intial value; the loop control variable's location
would be described as the intial constant value in the loop body once
the -mem2reg optimization phase was run.

This change adds the creation of the @llvm.dbg.value entries to describe
variables whose location is the result of a phi node created in -mem2reg.

Also when the phi node is finally lowered to a machine instruction it
is important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.

Differential Revision: https://reviews.llvm.org/D23715

llvm-svn: 281895

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Fix misleading comment for getOrEnforceKnownAlignment

It does not return 0 to indicate failure, and returns the known
alignment.

llvm-svn: 281350

revert r280427

Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWi

revert r280427

Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update after sinking.
llvm-svn: 280949

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Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update aft

Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update after sinking.

Reviewers: chandlerc, davidxl, danielcdh

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24170

llvm-svn: 280427

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[JumpThreading] Fix handling of aliasing metadata.

Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the

[JumpThreading] Fix handling of aliasing metadata.

Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the
behavior of other passes, like instcombine and GVN.

There's also a minor optimization improvement here: for load PRE, the
aliasing metadata on the inserted load should be the same as the
metadata on the original load. Not sure why the old code was throwing
it away.

Issue found by inspection.

Differential Revision: http://reviews.llvm.org/D21460

llvm-svn: 277977

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Move helpers into anonymous namespaces. NFC.

llvm-svn: 277916

[sanitizer] Simplify and future-proof maybeMarkSanitizerLibraryCallNoBuiltin().

Sanitizers set nobuiltin attribute on certain library functions to
avoid a situation where such function is neither in

[sanitizer] Simplify and future-proof maybeMarkSanitizerLibraryCallNoBuiltin().

Sanitizers set nobuiltin attribute on certain library functions to
avoid a situation where such function is neither instrumented nor
intercepted.

At the moment the list of interesting functions is hardcoded. This
change replaces it with logic based on
TargetLibraryInfo::hasOptimizedCodegen and the presense of readnone
function attribute (sanitizers are generally interested in memory
behavior of library functions).

This is expected to be a no-op change: the new logic matches exactly
the same set of functions.

r276771 (currently reverted) added mempcpy() to the list, breaking
MSan tests. With this change, r276771 can be safely re-landed.

llvm-svn: 277086

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[Utils] Simplify combineMetadata

Use a range-based for loop, no functional change is intended.

llvm-svn: 276600

Just a small cleanup

No functional change is intended

llvm-svn: 273780

Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"

This reverts commit r273778, it seems to break UBSan :/

llvm-svn: 273779