This function adds copies to be erased to DupCopies, avoid also adding
them to DeadCopies.

llvm-svn: 157147

Avoid looking at the operands of a potentially erased instruction.

llvm-svn: 157146

llvm-svn: 157145

llvm-svn: 157144

That struct ought to be a LiveInterval implementation detail.

llvm-svn: 157143

llvm-svn: 157142

This class is meant to be the primary interface for examining a live
range in the vicinity on a given instruction. It avoids all the messy
dealings with iterators and early clobbers.

This is a more abstract interface to live ranges, hiding the
implementation as a vector of segments.

llvm-svn: 157141

LoopUnswitch.  Fixes PR12887.

llvm-svn: 157140

llvm-svn: 157139

I'm pretty sure we are in fact doing the right thing here, but someone who knows the standard better should double-check that we are in fact supposed to zero out the member in the given testcase.

llvm-svn: 157138

llvm-svn: 157137

Make delegating initializers use a similar codepath to base initializers in dependent contexts.  PR12890.

llvm-svn: 157136

Dead code elimination during coalescing could cause a virtual register
to be split into connected components. The following rewriting would be
confused about the already joined copies present in the code, but
without a corresponding value number in the live range.

Erase all joined copies instantly when joining intervals such that the
MI and LiveInterval representations are always in sync.

llvm-svn: 157135

copied-in constant, as a subsequent user may rely on over alignment.
Fixes PR12885.

llvm-svn: 157134

The current code will generate a prologue which starts with something like:
        mflr 0
        stw 31, -4(1)
        stw 0, 4(1)
        stwu 1, -16(1)

But under the PPC32 SVR4 ABI, access to negative offsets from R1 is not allowed.

This was pointed out by Peter Bergner.

llvm-svn: 157133

Dead code and joined copies are now eliminated on the fly, and there is
no need for a post pass.

This makes the coalescer work like other modern register allocator
passes: Code is changed on the fly, there is no pending list of changes
to be committed.

llvm-svn: 157132

The late dead code elimination is no longer necessary.

The test changes are cause by a register hint that can be either %rdi or
%rax. The choice depends on the use list order, which this patch changes.

llvm-svn: 157131

Before rewriting uses of one value in A to register B, check that there
are no tied uses. That would require multiple A values to be rewritten.

This bug can't bite in the current version of the code for a fairly
subtle reason: A tied use would have caused 2-addr to insert a copy
before the use. If the copy has been coalesced, it will be found by the
same loop changed by this patch, and the optimization is aborted.

This was exposed by 400.perlbench and lua after applying a patch that
deletes joined copies aggressively.

llvm-svn: 157130

llvm-svn: 157129

Revert fix to http://llvm.org/bugs/show_bug.cgi?id=12867 for the reason now included in the code comment.

llvm-svn: 157128

llvm-svn: 157127

clang++ and msvc happily had no problem with it but g++ refuses to compile.

llvm-svn: 157126

There is no reason to defer the collection of virtual registers whose
register class may be replaced with a larger class.

llvm-svn: 157125

Otherwise just looking up a value in the map requires creating a VH, adding it to the use lists and destroying it again.

llvm-svn: 157124

Move CallbackVHs dtor inline, it can be devirtualized in many cases. Move the other virtual methods out of line as they are only called from within Value.cpp anyway.

llvm-svn: 157123

llvm-svn: 157122

and provide a 'fixit' to change 'readonly' to 'readwrite'. 'fixit'
part needs little more work. // rdar://11448209

llvm-svn: 157121

llvm-svn: 157120

llvm-svn: 157119

llvm-svn: 157118

llvm-svn: 157117

Simplify some users of DeclarationName::getNameKind. Fold getFETokenInfoAsVoid into its only caller.

llvm-svn: 157116

llvm-svn: 157114

This makes DenseMap<..., TinyPtrVector<...>> as cheap as it always should've been!

llvm-svn: 157113

llvm-svn: 157112

llvm-svn: 157111

Fixes the case where we created a dummy target, deleted it, and then tried to evaluate an expression with no target.

llvm-svn: 157110

llvm-svn: 157109

llvm-svn: 157108

llvm-svn: 157107