llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-06 05:06:45 +00:00

History

Rafael Espindola 7d7d99622f Replace PROLOG_LABEL with a new CFI_INSTRUCTION. The old system was fairly convoluted: * A temporary label was created. * A single PROLOG_LABEL was created with it. * A few MCCFIInstructions were created with the same label. The semantics were that the cfi instructions were mapped to the PROLOG_LABEL via the temporary label. The output position was that of the PROLOG_LABEL. The temporary label itself was used only for doing the mapping. The new CFI_INSTRUCTION has a 1:1 mapping to MCCFIInstructions and points to one by holding an index into the CFI instructions of this function. I did consider removing MMI.getFrameInstructions completelly and having CFI_INSTRUCTION own a MCCFIInstruction, but MCCFIInstructions have non trivial constructors and destructors and are somewhat big, so the this setup is probably better. The net result is that we don't create temporary labels that are never used. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203204 91177308-0d34-0410-b5e6-96231b3b80d8		2014-03-07 06:08:31 +00:00
..
InstPrinter	[CMake] Let add_public_tablegen_target responsible to provide dependency to CommonTableGen.	2013-11-28 17:04:04 +00:00
MCTargetDesc	Prune redundant dependencies in LLVMBuild.txt.	2013-12-11 00:30:57 +00:00
TargetInfo	Prune redundant dependencies in LLVMBuild.txt.	2013-12-11 00:30:57 +00:00
CMakeLists.txt	[CMake] Let add_public_tablegen_target() provide intrinsics_gen, too.	2013-11-28 17:04:31 +00:00
LLVMBuild.txt
Makefile
MSP430.h
MSP430.td	Change the default of AsmWriterClassName and isMCAsmWriter.	2013-12-02 04:55:42 +00:00
MSP430AsmPrinter.cpp	Change MCStreamer EmitInstruction interface to take subtarget info	2014-01-28 23:12:42 +00:00
MSP430BranchSelector.cpp
MSP430CallingConv.td
MSP430FrameLowering.cpp	[C++11] Replace llvm::next and llvm::prior with std::next and std::prev.	2014-03-02 12:27:27 +00:00
MSP430FrameLowering.h
MSP430InstrFormats.td
MSP430InstrInfo.cpp	Replace PROLOG_LABEL with a new CFI_INSTRUCTION.	2014-03-07 06:08:31 +00:00
MSP430InstrInfo.h	[weak vtables] Remove a bunch of weak vtables	2013-11-19 00:57:56 +00:00
MSP430InstrInfo.td
MSP430ISelDAGToDAG.cpp
MSP430ISelLowering.cpp	[C++11] Replace llvm::next and llvm::prior with std::next and std::prev.	2014-03-02 12:27:27 +00:00
MSP430ISelLowering.h
MSP430MachineFunctionInfo.cpp
MSP430MachineFunctionInfo.h
MSP430MCInstLower.cpp	Move the llvm mangler to lib/IR.	2014-01-07 21:19:40 +00:00
MSP430MCInstLower.h
MSP430RegisterInfo.cpp	[C++11] Replace llvm::next and llvm::prior with std::next and std::prev.	2014-03-02 12:27:27 +00:00
MSP430RegisterInfo.h
MSP430RegisterInfo.td
MSP430SelectionDAGInfo.cpp
MSP430SelectionDAGInfo.h
MSP430Subtarget.cpp
MSP430Subtarget.h
MSP430TargetMachine.cpp	Make the llvm mangler depend only on DataLayout.	2014-01-03 19:21:54 +00:00
MSP430TargetMachine.h
README.txt

README.txt

//===---------------------------------------------------------------------===//
// 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.