llvm-6502/lib/Target/MSP430
Daniel Sanders 547ba56bd0 Recommit r232027 with PR22883 fixed: Add infrastructure for support of multiple memory constraints.
The operand flag word for ISD::INLINEASM nodes now contains a 15-bit
memory constraint ID when the operand kind is Kind_Mem. This constraint
ID is a numeric equivalent to the constraint code string and is converted
with a target specific hook in TargetLowering.

This patch maps all memory constraints to InlineAsm::Constraint_m so there
is no functional change at this point. It just proves that using these
previously unused bits in the encoding of the flag word doesn't break
anything.

The next patch will make each target preserve the current mapping of
everything to Constraint_m for itself while changing the target independent
implementation of the hook to return Constraint_Unknown appropriately. Each
target will then be adapted in separate patches to use appropriate
Constraint_* values.

PR22883 was caused the matching operands copying the whole of the operand flags
for the matched operand. This included the constraint id which needed to be
replaced with the operand number. This has been fixed with a conversion
function. Following on from this, matching operands also used the operand
number as the constraint id. This has been fixed by looking up the matched
operand and taking it from there. 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232165 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-13 12:45:09 +00:00
..
InstPrinter Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MCTargetDesc TableGen: Use 'enum : uint64_t' for feature flags to fix -Wmicrosoft 2015-03-09 20:23:14 +00:00
TargetInfo
CMakeLists.txt
LLVMBuild.txt
Makefile
MSP430.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430.td
MSP430AsmPrinter.cpp std::unique_ptrify the MCStreamer argument to createAsmPrinter 2015-01-18 20:29:04 +00:00
MSP430BranchSelector.cpp Have MachineFunction cache a pointer to the subtarget to make lookups 2014-08-05 02:39:49 +00:00
MSP430CallingConv.td Drop the W postfix on the 16-bit registers. 2014-09-10 06:58:14 +00:00
MSP430FrameLowering.cpp Drop the W postfix on the 16-bit registers. 2014-09-10 06:58:14 +00:00
MSP430FrameLowering.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430InstrFormats.td
MSP430InstrInfo.cpp Have MachineFunction cache a pointer to the subtarget to make lookups 2014-08-05 02:39:49 +00:00
MSP430InstrInfo.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430InstrInfo.td Replace neverHasSideEffects=1 with hasSideEffects=0 in all .td files. 2014-11-26 00:46:26 +00:00
MSP430ISelDAGToDAG.cpp Recommit r232027 with PR22883 fixed: Add infrastructure for support of multiple memory constraints. 2015-03-13 12:45:09 +00:00
MSP430ISelLowering.cpp getRegForInlineAsmConstraint wants to use TargetRegisterInfo for 2015-02-26 22:38:43 +00:00
MSP430ISelLowering.h getRegForInlineAsmConstraint wants to use TargetRegisterInfo for 2015-02-26 22:38:43 +00:00
MSP430MachineFunctionInfo.cpp
MSP430MachineFunctionInfo.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430MCInstLower.cpp Remove unused header. 2015-01-29 23:46:39 +00:00
MSP430MCInstLower.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430RegisterInfo.cpp Drop the W postfix on the 16-bit registers. 2014-09-10 06:58:14 +00:00
MSP430RegisterInfo.h Have getCalleeSavedRegs take a non-null MachineFunction all the 2015-03-11 21:41:28 +00:00
MSP430RegisterInfo.td Drop the W postfix on the 16-bit registers. 2014-09-10 06:58:14 +00:00
MSP430SelectionDAGInfo.cpp
MSP430SelectionDAGInfo.h Canonicalize header guards into a common format. 2014-08-13 16:26:38 +00:00
MSP430Subtarget.cpp 80-column fixup. 2015-03-03 17:54:39 +00:00
MSP430Subtarget.h Move DataLayout back to the TargetMachine from TargetSubtargetInfo 2015-01-26 19:03:15 +00:00
MSP430TargetMachine.cpp Move the DataLayout to the generic TargetMachine, making it mandatory. 2015-03-12 00:07:24 +00:00
MSP430TargetMachine.h Move the DataLayout to the generic TargetMachine, making it mandatory. 2015-03-12 00:07:24 +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.