Remove NoOperation.

parseCommandLine prints and error and exists if no operation is specified, so
it never returns NoOperation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185691 91177308-0d34-0410-b5e6-96231b3b80d8

[PowerPC] Support @tls in the asm parser

This adds support for the last missing construct to parse TLS-related
assembler code:
   add 3, 4, symbol@tls

The ADD8TLS currently hard-codes the @tls into the assembler string.
This cannot be handled by the asm parser, since @tls is parsed as
a symbol variant.  This patch changes ADD8TLS to have the @tls suffix
printed as symbol variant on output too, which allows us to remove
the isCodeGenOnly marker from ADD8TLS.  This in turn means that we
can add a AsmOperand to accept @tls marked symbols on input.

As a side effect, this means that the fixup_ppc_tlsreg fixup type
is no longer necessary and can be merged into fixup_ppc_nofixup.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185692 91177308-0d34-0410-b5e6-96231b3b80d8

[PowerPC] Make test case buildable with GNU as

The ppc64-fixups.s test currently fails to build with GNU as, since it
does not support plain symbols as arguments to li/lis.  Rewrite the test
for R_PPC64_ADDR16 and R_PPC64_REL16 to use lwz instead.

Allowing the test case to be built with both LLVM and GNU as makes it
easier to spot unwanted difference in the output.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185694 91177308-0d34-0410-b5e6-96231b3b80d8
Use simpler version of exists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185695 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Clean up register scavenging code

SystemZ wants normal register scavenging slots, as close to the stack or
frame pointer as possible.  The only reason it was using custom code was
because PrologEpilogInserter assumed an x86-like layout, where the frame
pointer is at the opposite end of the frame from the stack pointer.
This meant that when frame pointer elimination was disabled,
the slots ended up being as close as possible to the incoming
stack pointer, which is the opposite of what we want on SystemZ.

This patch adds a new knob to say which layout is used and converts
SystemZ to use target-independent scavenging slots.  It's one of the pieces
needed to support frame-to-frame MVCs, where two slots might be required.

The ABI requires us to allocate 160 bytes for calls, so one approach
would be to use that area as temporary spill space instead.  It would need
some surgery to make sure that the slot isn't live across a call though.

I stuck to the "isFPCloseToIncomingSP - ..." style comment on the
"do what the surrounding code does" principle.  The FP case is already
covered by several Systemz/frame-* tests, which fail without the
PrologueEpilogueInserter change, so no new ones are needed.

No behavioural change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185696 91177308-0d34-0410-b5e6-96231b3b80d8