This fixes what I consider to be an API flaw I've tripped over
multiple times. The point this is constructed isn't well defined, so
depending on where this is first called, you can conclude different
information based on the MachineFunction. For example, the AMDGPU
implementation inspected the MachineFrameInfo on construction for the
stack objects and if the frame has calls. This kind of worked in
SelectionDAG which visited all allocas up front, but broke in
GlobalISel which hasn't visited any of the IR when arguments are
lowered.

I've run into similar problems before with the MIR parser and trying
to make use of other MachineFunction fields, so I think it's best to
just categorically disallow dependency on the MachineFunction state in
the constructor and to always construct this at the same time as the
MachineFunction itself.

A missing feature I still could use is a way to access an custom
analysis pass on the IR here.

MIR support is totally unusable for AMDGPU without this, since the set
of reserved registers is set from fields here.

Add a clone method to MachineFunctionInfo. This is a subtle variant of
the copy constructor that is required if there are any MIR constructs
that use pointers. Specifically, at minimum fields that reference
MachineBasicBlocks or the MachineFunction need to be adjusted to the
values in the new function.

It will soon be disallowed to depend on MachineFunction state on
construction.

Force using Register.

One downside is the generated register enums require explicit
conversion.

llvm-svn: 364194

Handle position independent code for MIPS32.
When callee is global address, lower call will emit callee
as G_GLOBAL_VALUE and add target flag if needed.
Support $gp in getRegBankFromRegClass().
Select G_GLOBAL_VALUE, specially handle case when
there are target flags attached by lowerCall.

Differential Revision: https://reviews.llvm.org/D62589

llvm-svn: 362210

Move initGlobalBaseReg from MipsSEDAGToDAGISel to MipsFunctionInfo.
This way functions used for handling position independent code during
instruction selection, getGlobalBaseReg and initGlobalBaseReg,
end up in same class.

Differential Revision: https://reviews.llvm.org/D62586

llvm-svn: 362206

to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

llvm-svn: 293565

Summary:
[ls][bh] and [ls][bh]u cannot use sp-relative addresses and must therefore
lower frameindex nodes such that there is a copy to a CPU16Regs register. This
is now done consistently using a separate addressing mode that does not
permit frameindex nodes.

As part of this I've had to remove an optimization that reduced the number of
instructions needed to work around the lack of sp-relative addresses on [ls][bh]
and [ls][bh]u. This optimization used one of the eight CPU16Regs registers as
a copy of the stack pointer and it's implementation was the root cause of many
of the register vs register class mismatches.

lw/sw can use sp-relative addresses but we ought to ensure that we use the
correct version of lw/sw internally for things like IAS. This is not currently
the case and this change does not fix this. However, this change does clean it
up sufficiently well to fix the machine verifier failures.

Also removed irrelevant functions from stchar.ll.

Reviewers: sdardis

Subscribers: dsanders, sdardis, llvm-commits

Differential Revision: http://reviews.llvm.org/D21062

llvm-svn: 272882