Commit Graph

8 Commits

Author SHA1 Message Date
Alex Bradbury dc31c61b18 [RISCV] Add custom CC_RISCV calling convention and improved call support
The TableGen-based calling convention definitions are inflexible, while
writing a function to implement the calling convention is very
straight-forward, and allows difficult cases to be handled more easily. With
this patch adds support for:
* Passing large scalars according to the RV32I calling convention
* Byval arguments
* Passing values on the stack when the argument registers are exhausted

The custom CC_RISCV calling convention is also used for returns.

This patch also documents the ABI lowering that a language frontend is 
expected to perform. I would like to work to simplify these requirements over 
time, but this will require further discussion within the LLVM community.

We add PendingArgFlags CCState, as a companion to PendingLocs.

The PendingLocs vector is used by a number of backends to handle arguments 
that are split during legalisation. However CCValAssign doesn't keep track of 
the original argument alignment. Therefore, add a PendingArgFlags vector which 
can be used to keep track of the ISD::ArgFlagsTy for every value added to 
PendingLocs.

Differential Revision: https://reviews.llvm.org/D39898

llvm-svn: 320359
2017-12-11 12:49:02 +00:00
Alex Bradbury 8971842f43 [RISCV] Initial codegen support for ALU operations
This adds the minimum necessary to support codegen for simple ALU operations
on RV32. Prolog and epilog insertion, support for memory operations etc etc 
follow in future patches.

Leave guessInstructionProperties=1 until https://reviews.llvm.org/D37065 is 
reviewed and lands.

Differential Revision: https://reviews.llvm.org/D29933

llvm-svn: 316188
2017-10-19 21:37:38 +00:00
Alex Bradbury 8ab4a9696a [RISCV] Add support for disassembly
This Disassembly support allows for 'round-trip' testing, and rv32i-valid.s
has been updated appropriately.

Differential Revision: https://reviews.llvm.org/D23567

llvm-svn: 313486
2017-09-17 14:36:28 +00:00
Alex Bradbury 2fee9ead7e [RISCV] Add RISCVInstPrinter and basic MC assembler tests
With the addition of RISCVInstPrinter, it is now possible to test the basic 
operation of the RISCV MC layer.

Differential Revision: https://reviews.llvm.org/D23564

llvm-svn: 310917
2017-08-15 13:08:29 +00:00
Alex Bradbury 1a4272914d [RISCV] Add basic RISCVAsmParser
This doesn't yet support parsing things like %pcrel_hi(foo), but will handle
basic instructions with register or immediate operands.

Differential Revision: https://reviews.llvm.org/D23563

llvm-svn: 310361
2017-08-08 14:32:35 +00:00
Alex Bradbury 6b2cca7f8f [RISCV] Add bare-bones RISC-V MCTargetDesc
This is enough to compile and link but doesn't yet do anything particularly 
useful. Once an ASM parser and printer are added in the next two patches, the 
whole thing can be usefully tested.

Differential Revision: https://reviews.llvm.org/D23562

llvm-svn: 285770
2016-11-01 23:47:30 +00:00
Alex Bradbury 24d9b13b36 [RISCV 4/10] Add basic RISCV{InstrFormats,InstrInfo,RegisterInfo,}.td
For now, only add instruction definitions for basic ALU operations. Our 
initial target is a working MC layer rather than codegen, so appropriate 
SelectionDAG patterns will come later.

Differential Revision: https://reviews.llvm.org/D23561

llvm-svn: 285769
2016-11-01 23:40:28 +00:00
Alex Bradbury b2e5472d85 [RISCV] Add stub backend
This contains just enough for lib/Target/RISCV to compile. Notably a basic 
RISCVTargetMachine and RISCVTargetInfo. At this point you can attempt llc 
-march=riscv32 myinput.ll and will find it fails due to the lack of 
MCAsmInfo.

See http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.html for 
further discussion

Differential Revision: https://reviews.llvm.org/D23560

llvm-svn: 285712
2016-11-01 17:27:54 +00:00