llvm-svn: 213045

not properly handle the case where the predecessor block was the entry block to
the function.  The only in-tree client of this is JumpThreading, which worked
around the issue in its own code.  This patch moves the solution into the helper
so that JumpThreading (and other clients) do not have to replicate the same fix
everywhere.

llvm-svn: 212875

This commit fixes bug http://llvm.org/bugs/show_bug.cgi?id=20103.

Thanks to Qwertyuiop for the report and the proposed fix.

llvm-svn: 212802

Partially fix PR20058: reduce compile time for loop unrolling with very high count by reducing calls to SE->forgetLoop

llvm-svn: 212782

isSafeToSpeculativelyExecute can optionally take a DataLayout pointer. In the
past, this was mainly used to make better decisions regarding divisions known
not to trap, and so was not all that important for users concerned with "cheap"
instructions. However, now it also helps look through bitcasts for
dereferencable loads, and will also be important if/when we add a
dereferencable pointer attribute.

This is some initial work to feed a DataLayout pointer through to callers of
isSafeToSpeculativelyExecute, generally where one was already available.

llvm-svn: 212720

Turn llvm::SpecialCaseList into a simple class that parses text files in
a specified format and knows nothing about LLVM IR. Move this class into
LLVMSupport library. Implement two users of this class:
  * DFSanABIList in DFSan instrumentation pass.
  * SanitizerBlacklist in Clang CodeGen library.
The latter will be modified to use actual source-level information from frontend
(source file names) instead of unstable LLVM IR things (LLVM Module identifier).

Remove dependency edge from ClangCodeGen/ClangDriver to LLVMTransformUtils.

No functionality change.

llvm-svn: 212643

Two of those are use after frees. Found by clang-tidy, fixed by me.

llvm-svn: 212537

Fix for PR17073 ( http://llvm.org/pr17073 ), simplifycfg illegally hoists an operation in a phi node that can trap.

This patch adds to an existing loop over phi nodes in SimplifyCondBranchToCondBranch() to check for trapping ops and bails out of the optimization if we find one of those.

The test cases verify that trapping ops are not hoisted and non-trapping ops are still optimized as expected.

llvm-svn: 212490

llvm-svn: 212423

llvm-svn: 212405

llvm-svn: 212259

DebugInfo: Preserve debug location information when transforming a call into an invoke during inlining.

This both improves basic debug info quality, but also fixes a larger
hole whenever we inline a call/invoke without a location (debug info for
the entire inlining is lost and other badness that the debug info
emission code is currently working around but shouldn't have to).

llvm-svn: 212065

Temporarily back out commits r211749, r211752 and r211754.

llvm-svn: 211814

This is a follow-up to r211331, which failed to notice that we were
returning early from ValidLookupTableConstant for GEPs.

llvm-svn: 211753

string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.

small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.

This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.

The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.

llvm-svn: 211749

Fixes PR19823.

llvm-svn: 211436

We would previously put dllimport variables in switch lookup tables, which
doesn't work because the address cannot be used in a constant initializer.
This is basically the same problem that we have in PR19955.

Putting TLS variables in switch tables also desn't work, because the
address of such a variable is not constant.

Differential Revision: http://reviews.llvm.org/D4220

llvm-svn: 211331

When LowerSwitch transforms a switch instruction into a tree of ifs it
is actually performing a binary search into the various case ranges, to
see if the current value falls into one cases range of values.

So, if we have a program with something like this:

switch (a) {
case 0:
  do0();
  break;
case 1:
  do1();
  break;
case 2:
  do2();
  break;
default:
  break;
}

the code produced is something like this:

  if (a < 1) {
    if (a == 0) {
      do0();
    }
  } else {
    if (a < 2) {
      if (a == 1) {
        do1();
      }
    } else {
      if (a == 2) {
        do2();
      }
    }
  }

This code is inefficient because the check (a == 1) to execute do1() is
not needed.

The reason is that because we already checked that (a >= 1) initially by
checking that also  (a < 2) we basically already inferred that (a == 1)
without the need of an extra basic block spawned to check if actually (a
== 1).

The patch addresses this problem by keeping track of already
checked bounds in the LowerSwitch algorithm, so that when the time
arrives to produce a Leaf Block that checks the equality with the case
value / range the algorithm can decide if that block is really needed
depending on the already checked bounds .

For example, the above with "a = 1" would work like this:

the bounds start as LB: NONE , UB: NONE
as (a < 1) is emitted the bounds for the else path become LB: 1 UB:
NONE. This happens because by failing the test (a < 1) we know that the
value "a" cannot be smaller than 1 if we enter the else branch.
After the emitting the check (a < 2) the bounds in the if branch become
LB: 1 UB: 1. This is because by checking that "a" is smaller than 2 then
the upper bound becomes 2 - 1 = 1.

When it is time to emit the leaf block for "case 1:" we notice that 1
can be squeezed exactly in between the LB and UB, which means that if we
arrived to that block there is no need to emit a block that checks if (a
== 1).

Patch by: Marcello Maggioni <hayarms@gmail.com>

llvm-svn: 211038

llvm-svn: 210871

This should make sure that most new uses use the std prefix.

llvm-svn: 210835

This is a minimal change to remove the header. I will remove the occurrences
of "using std::error_code" in a followup patch.

llvm-svn: 210803

Instructions from __nodebug__ functions don't have file:line
information even when inlined into no-nodebug functions. As a result,
intrinsics (SSE and other) from <*intrin.h> clang headers _never_
have file:line information.

With this change, an instruction without !dbg metadata gets one from
the call instruction when inlined.

Fixes PR19001.

llvm-svn: 210459

This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

llvm-svn: 210062

This helps more branches into selects. On R600,
vectors are cheap and anything that helps
remove branches is very good.

llvm-svn: 209914

During loop-unroll, loop exits from the current loop may end up in in different
outer loop. This requires to re-form LCSSA recursively for one level down from
the outer most loop where loop exits are landed during unroll. This fixes PR18861.

Differential Revision: http://reviews.llvm.org/D2976

llvm-svn: 209796

Summary:
This adds two new diagnostics: -pass-remarks-missed and
-pass-remarks-analysis. They take the same values as -pass-remarks but
are intended to be triggered in different contexts.

-pass-remarks-missed is used by LLVMContext::emitOptimizationRemarkMissed,
which passes call when they tried to apply a transformation but
couldn't.

-pass-remarks-analysis is used by LLVMContext::emitOptimizationRemarkAnalysis,
which passes call when they want to inform the user about analysis
results.

The patch also:

1- Adds support in the inliner for the two new remarks and a
   test case.

2- Moves emitOptimizationRemark* functions to the llvm namespace.

3- Adds an LLVMContext argument instead of making them member functions
   of LLVMContext.

Reviewers: qcolombet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3682

llvm-svn: 209442

as it was causing build failures in ruby.

This reverts commit r207713.

llvm-svn: 209135

llvm-svn: 209076

This is in preparation for adding an optional offset.

llvm-svn: 209073

This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized.  This is necessary for MSVC
ABI compatibility.  Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.

Reviewers: nlewycky

Differential Revision: http://reviews.llvm.org/D3499

llvm-svn: 209015

This patch changes the design of GlobalAlias so that it doesn't take a
ConstantExpr anymore. It now points directly to a GlobalObject, but its type is
independent of the aliasee type.

To avoid changing all alias related tests in this patches, I kept the common
syntax

@foo = alias i32* @bar

to mean the same as now. The cases that used to use cast now use the more
general syntax

@foo = alias i16, i32* @bar.

Note that GlobalAlias now behaves a bit more like GlobalVariable. We
know that its type is always a pointer, so we omit the '*'.

For the bitcode, a nice surprise is that we were writing both identical types
already, so the format change is minimal. Auto upgrade is handled by looking
through the casts and no new fields are needed for now. New bitcode will
simply have different types for Alias and Aliasee.

One last interesting point in the patch is that replaceAllUsesWith becomes
smart enough to avoid putting a ConstantExpr in the aliasee. This seems better
than checking and updating every caller.

A followup patch will delete getAliasedGlobal now that it is redundant. Another
patch will add support for an explicit offset.

llvm-svn: 209007

This is part of the fix for pr10367. A GlobalAlias always has a pointer type,
so just have the constructor build the type.

llvm-svn: 208983

The allocas going out of scope are immediately killed by the return
instruction.

This is a resend of r208912, which was committed accidentally.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3792

llvm-svn: 208920

This reverts commit r208912.

It was committed accidentally without review.

llvm-svn: 208914

We have to iterate over all the calls that were inlined to find out if
any were musttail.

Sink another variable down to where its used.

llvm-svn: 208913

The allocas going out of scope are immediately killed by the return
instruction.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3630

llvm-svn: 208912

The interesting case is what happens when you inline a musttail call
through a musttail call site.  In this case, we can't break perfect
forwarding or allow any stack growth.

Instead of merging control flow from the inlined return instruction
after a musttail call into the body of the caller, leave the inlined
return instruction in the caller so that the musttail call stays in the
tail position.

More work is required in http://reviews.llvm.org/D3630 to handle the
case where the inlined function has dynamic allocas or byval arguments.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3491

llvm-svn: 208910

inappropriate since it lost its Mask parameter in r154011.

llvm-svn: 208811

This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.

llvm-svn: 208716

Since ExtractValue is not included in ComputeSpeculationCost CFGs containing
ExtractValueInsts cannot be simplified. In particular this interacts with
InstCombineCompare's tendency to insert add.with.overflow intrinsics for
certain idiomatic math operations, preventing optimization.

This patch adds ExtractValue to the ComputeSpeculationCost. Test case included

rdar://14853450

llvm-svn: 208434