llvm-6502/lib/Target/MSP430
Tim Northover ca7e0787f0 CodeGen: convert CCState interface to using ArrayRefs
Everyone except R600 was manually passing the length of a static array
at each callsite, calculated in a variety of interesting ways. Far
easier to let ArrayRef handle that.

There should be no functional change, but out of tree targets may have
to tweak their calls as with these examples.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230118 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-21 02:11:17 +00:00
..
InstPrinter
MCTargetDesc
TargetInfo
CMakeLists.txt
LLVMBuild.txt
Makefile
MSP430.h
MSP430.td
MSP430AsmPrinter.cpp
MSP430BranchSelector.cpp
MSP430CallingConv.td
MSP430FrameLowering.cpp
MSP430FrameLowering.h
MSP430InstrFormats.td
MSP430InstrInfo.cpp
MSP430InstrInfo.h
MSP430InstrInfo.td
MSP430ISelDAGToDAG.cpp Remove unnecessary calls to getSubtarget/getSubtargetImpl from the 2015-01-29 23:46:42 +00:00
MSP430ISelLowering.cpp CodeGen: convert CCState interface to using ArrayRefs 2015-02-21 02:11:17 +00:00
MSP430ISelLowering.h
MSP430MachineFunctionInfo.cpp
MSP430MachineFunctionInfo.h
MSP430MCInstLower.cpp Remove unused header. 2015-01-29 23:46:39 +00:00
MSP430MCInstLower.h
MSP430RegisterInfo.cpp
MSP430RegisterInfo.h
MSP430RegisterInfo.td
MSP430SelectionDAGInfo.cpp
MSP430SelectionDAGInfo.h
MSP430Subtarget.cpp Move DataLayout back to the TargetMachine from TargetSubtargetInfo 2015-01-26 19:03:15 +00:00
MSP430Subtarget.h Move DataLayout back to the TargetMachine from TargetSubtargetInfo 2015-01-26 19:03:15 +00:00
MSP430TargetMachine.cpp [PM] Remove the old 'PassManager.h' header file at the top level of 2015-02-13 10:01:29 +00:00
MSP430TargetMachine.h Move DataLayout back to the TargetMachine from TargetSubtargetInfo 2015-01-26 19:03:15 +00:00
README.txt Test commit to see if it triggers an email to llvm-commits. No change. 2015-02-06 21:33:08 +00:00

//===---------------------------------------------------------------------===//
// MSP430 backend.
//===---------------------------------------------------------------------===//

DISCLAIMER: Thid backend should be considered as highly experimental. I never
seen nor worked with this MCU, all information was gathered from datasheet
only. The original intention of making this backend was to write documentation
of form "How to write backend for dummies" :) Thes notes hopefully will be
available pretty soon.

Some things are incomplete / not implemented yet (this list surely is not
complete as well):

1. Verify, how stuff is handling implicit zext with 8 bit operands (this might
be modelled currently in improper way - should we need to mark the superreg as
def for every 8 bit instruction?).

2. Libcalls: multiplication, division, remainder. Note, that calling convention
for libcalls is incomptible with calling convention of libcalls of msp430-gcc
(these cannot be used though due to license restriction).

3. Implement multiplication / division by constant (dag combiner hook?).

4. Implement non-constant shifts.

5. Implement varargs stuff.

6. Verify and fix (if needed) how's stuff playing with i32 / i64.

7. Implement floating point stuff (softfp?)

8. Implement instruction encoding for (possible) direct code emission in the
future.

9. Since almost all instructions set flags - implement brcond / select in better
way (currently they emit explicit comparison).

10. Handle imm in comparisons in better way (see comment in MSP430InstrInfo.td)

11. Implement hooks for better memory op folding, etc.