delete function name from comment


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219443 91177308-0d34-0410-b5e6-96231b3b80d8
delete function names from comments


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219444 91177308-0d34-0410-b5e6-96231b3b80d8
Improve sqrt estimate algorithm (fast-math)

This patch changes the fast-math implementation for calculating sqrt(x) from:
y = 1 / (1 / sqrt(x))
to:
y = x * (1 / sqrt(x))

This has 2 benefits: less code / faster code and one less estimate instruction 
that may lose precision.

The only target that will be affected (until http://reviews.llvm.org/D5658 is approved)
is PPC. The difference in codegen for PPC is 2 less flops for a single-precision sqrtf
or vector sqrtf and 4 less flops for a double-precision sqrt. 
We also eliminate a constant load and extra register usage.

Differential Revision: http://reviews.llvm.org/D5682



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219445 91177308-0d34-0410-b5e6-96231b3b80d8
[ADT] Add basic operator overloads for arithmetic to APFloat to make
code using it more readable.

Also add a copySign static function that works more like the standard
function by accepting the value and sign-carying value as arguments.

No interesting logic here, but tests added to cover the basic API
additions and make sure they do something plausible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219453 91177308-0d34-0410-b5e6-96231b3b80d8
obj2yaml, COFF: Handle long section names

Long section names are represented as a slash followed by a numeric
ASCII string.  This number is an offset into a string table.

Print the appropriate entry in the string table instead of the less
enlightening /4.

N.B.  yaml2obj already does the right thing, this test exercises both
sides of the (de-)serialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219458 91177308-0d34-0410-b5e6-96231b3b80d8
Fix gcc warning in gold-plugin.cpp.

Patch by Markus Trippelsdorf!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219459 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyCFG: Don't convert phis into selects if we could remove undef behavior
instead

We used to transform this:

  define void @test6(i1 %cond, i8* %ptr) {
  entry:
    br i1 %cond, label %bb1, label %bb2

  bb1:
    br label %bb2

  bb2:
    %ptr.2 = phi i8* [ %ptr, %entry ], [ null, %bb1 ]
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

into this:

  define void @test6(i1 %cond, i8* %ptr) {
    %ptr.2 = select i1 %cond, i8* null, i8* %ptr
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

because the simplifycfg transformation into selects would happen to happen
before the simplifycfg transformation that removes unreachable control flow
(We have 'unreachable control flow' due to the store to null which is undefined
behavior).

The existing transformation that removes unreachable control flow in simplifycfg
is:

  /// If BB has an incoming value that will always trigger undefined behavior
  /// (eg. null pointer dereference), remove the branch leading here.
  static bool removeUndefIntroducingPredecessor(BasicBlock *BB)

Now we generate:

  define void @test6(i1 %cond, i8* %ptr) {
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

I did not see any impact on the test-suite + externals.

rdar://18596215

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219462 91177308-0d34-0410-b5e6-96231b3b80d8
Add isInfinity to ConstantFP

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219463 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid unnecessary map lookup/insertion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219466 91177308-0d34-0410-b5e6-96231b3b80d8
[LVI] Revert the remainder of "r218231 - Add two thresholds lvi-overdefined-BB-threshold and lvi-overdefined-threshold"

Some of r218231 was reverted with the code that used it in r218971, but not all
of it. This removes the rest (which is now dead).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219469 91177308-0d34-0410-b5e6-96231b3b80d8
[ADT] Implement the 'logb' functionality for APFloat. This is necessary
to implement complex division in the constant folder of Clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219471 91177308-0d34-0410-b5e6-96231b3b80d8
[ADT] Add the scalbn function for APFloat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219473 91177308-0d34-0410-b5e6-96231b3b80d8
[ADT] Replace the logb implementation with the simpler and much closer
to what we actually want ilogb implementation. This makes everything
*much* easier to deal with and is actually what we want when using it
anyways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219474 91177308-0d34-0410-b5e6-96231b3b80d8
Add minnum / maxnum to APFloat

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219475 91177308-0d34-0410-b5e6-96231b3b80d8
Sink most of DwarfDebug::constructAbstractSubprogramScopeDIE down into DwarfCompileUnit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219476 91177308-0d34-0410-b5e6-96231b3b80d8
Sink the per-CU part of DwarfDebug::finishSubprogramDefinitions into DwarfCompileUnit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219477 91177308-0d34-0410-b5e6-96231b3b80d8
Object, COFF: Relax aux symbols for section definitions

We, I suppose naïvely, believed the COFF specification with regard to
auxiliary symbol records which defined sections: they specified that the
symbol value should be zero.  However, dumpbin and MinGW's objdump do
not consider the symbol value as a restriction.  Relaxing this allows us
to properly dump MinGW linked executables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219479 91177308-0d34-0410-b5e6-96231b3b80d8
Add tests for r219479.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219480 91177308-0d34-0410-b5e6-96231b3b80d8
Don't use an unqualified 'abs' function call with a builtin type.

This is dangerous for numerous reasons. The primary risk here is with
floating point or double types where if the wrong header files are
included in a strange order this can implicitly convert to integers and
then call the C abs function on the integers. There is a secondary risk
that even impacts integers where if the namespace the code is written in
ever defines an abs overload for types within that namespace the global
abs will be hidden. The correct form is to call std::abs or write 'using
std::abs' for builtin types (and only the latter is correct in any
generic context).

I've also added the requisite header to be a bit more explicit here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219484 91177308-0d34-0410-b5e6-96231b3b80d8
[ADT] Add an (ADL-friendly) abs free function for APFloat that returns
by value having cleared the sign bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219485 91177308-0d34-0410-b5e6-96231b3b80d8