Fix a random missed optimization by making InstCombine more aggressive when determining which bits are demanded by
a comparison against a constant.

llvm-svn: 123203

llvm-svn: 123202

restore the stack pointer from the frame pointer on thumbv6.

Fixes rdar://8819685

llvm-svn: 123196

llvm-svn: 123193

There's an inherent tension in DAGCombine between assuming
that things will be put in canonical form, and the Depth
mechanism that disables transformations when recursion gets
too deep.  It would not surprise me if there's a lot of little
bugs like this one waiting to be discovered.  The mechanism
seems fragile and I'd suggest looking at it from a design viewpoint.

llvm-svn: 123191

operation in some cases.

llvm-svn: 123190

llvm-svn: 123189

instructions but are restricted pseudo forms.

llvm-svn: 123177

instructions but are restricted pseudo forms.

llvm-svn: 123176

llvm-svn: 123175

llvm-svn: 123174

llvm-svn: 123172

llvm-svn: 123171

Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.

llvm-svn: 123170

llvm-svn: 123169

IDs when available rather than using a mixture of IDs and textual name
comparisons.

llvm-svn: 123165

rolled std::find.

llvm-svn: 123164

intrinsics element dependencies. Reviewed by Nick.

llvm-svn: 123161

These functions not longer assert when passed 0, but simply return false instead.

No functional change intended.

llvm-svn: 123155

them to FileCheck as well.

llvm-svn: 123154

llvm-svn: 123153

llvm-svn: 123152

llvm-svn: 123151

llvm-svn: 123149

llvm-svn: 123148

back to life.

llvm-svn: 123146

llvm-svn: 123145

llvm-svn: 123144

llvm-svn: 123143

llvm-svn: 123142

llvm-svn: 123141

Fix the TargetRegisterInfo::NoRegister places where someone preferred
typing 'TargetRegisterInfo::NoRegister' instead of typing '0'.

Note that TableGen is already emitting xx::NoRegister in xxGenRegisterNames.inc.

llvm-svn: 123140

llvm-svn: 123139

NUW AddRec's much more aggressively.  We now get a trip count
for @test2 in nsw.ll

llvm-svn: 123138

The numbering plan is now:

0           NoRegister.
[1;2^30)    Physical registers.
[2^30;2^31) Stack slots.
[2^31;2^32) Virtual registers. (With -1u and -2u used by DenseMapInfo.)

Each segment is filled from the left, so any mistaken interpretation should
quickly cause crashes.

FirstVirtualRegister has been removed. TargetRegisterInfo provides predicates
conversion functions that should be used instead of interpreting register
numbers manually.

It is now legal to pass NoRegister to isPhysicalRegister() and
isVirtualRegister(). The result is false in both cases.

It is quite rare to represent stack slots in this way, so isPhysicalRegister()
and isVirtualRegister() require that isStackSlot() be checked first if it can
possibly return true. This allows a very fast implementation of the common
predicates.

llvm-svn: 123137

llvm-svn: 123136

perform rounding other than truncation in the IR. Common C code for this
turns into really an LLVM intrinsic call that blocks a lot of further
optimizations.

llvm-svn: 123135

a + {b,+,stride} into {a+b,+,stride}  (because a is LIV),
then the resultant AddRec is NUW/NSW if the client says it
is.

llvm-svn: 123133

void f(int* begin, int* end) { std::fill(begin, end, 0); }

which turns into a != exit expression where one pointer is
strided and (thanks to step #1) known to not overflow, and 
the other is loop invariant.

The observation here is that, though the IV is strided by
4 in this case, that the IV *has* to become equal to the
end value.  It cannot "miss" the end value by stepping over
it, because if it did, the strided IV expression would
eventually wrap around.

Handle this by turning A != B into "A-B != 0" where the A-B
part is known to be NUW.

llvm-svn: 123131

when no virtual registers have been allocated.

It was only used to resize IndexedMaps, so provide an IndexedMap::resize()
method such that

 Map.grow(MRI.getLastVirtReg());

can be replaced with the simpler

 Map.resize(MRI.getNumVirtRegs());

This works correctly when no virtuals are allocated, and it bypasses the to/from
index conversions.

llvm-svn: 123130