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Instead of awkwardly encoding calling-convention information with ISD::CALL, ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering provides three virtual functions for targets to override: LowerFormalArguments, LowerCall, and LowerRet, which replace the custom lowering done on the special nodes. They provide the same information, but in a more immediately usable format. This also reworks much of the target-independent tail call logic. The decision of whether or not to perform a tail call is now cleanly split between target-independent portions, and the target dependent portion in IsEligibleForTailCallOptimization. This also synchronizes all in-tree targets, to help enable future refactoring and feature work. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78142 91177308-0d34-0410-b5e6-96231b3b80d8 |
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.. | ||
TargetInfo | ||
CMakeLists.txt | ||
Makefile | ||
MSP430.h | ||
MSP430.td | ||
MSP430AsmPrinter.cpp | ||
MSP430CallingConv.td | ||
MSP430InstrFormats.td | ||
MSP430InstrInfo.cpp | ||
MSP430InstrInfo.h | ||
MSP430InstrInfo.td | ||
MSP430ISelDAGToDAG.cpp | ||
MSP430ISelLowering.cpp | ||
MSP430ISelLowering.h | ||
MSP430MachineFunctionInfo.h | ||
MSP430RegisterInfo.cpp | ||
MSP430RegisterInfo.h | ||
MSP430RegisterInfo.td | ||
MSP430Subtarget.cpp | ||
MSP430Subtarget.h | ||
MSP430TargetAsmInfo.cpp | ||
MSP430TargetAsmInfo.h | ||
MSP430TargetMachine.cpp | ||
MSP430TargetMachine.h | ||
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): 0. Implement asmprinting for variables :) 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.