[llvm-dev] [MSP430] Plans for MSP430 improvements (original) (raw)

Jozef Lawrynowicz via llvm-dev llvm-dev at lists.llvm.org
Mon Aug 16 01:07:21 PDT 2021

On Sun, Aug 15, 2021 at 10:33:38PM +0500, Anton Korobeynikov wrote:

Thanks, Josef!

Hi Anton,

Contributions to MSP430 are much appreciated and I will be happy to review them (was on vacations recently and taming the backlog of emails now).

Thanks for offering to review the MSP430 patches, it's much appreciated.

Jozef

On Sun, Aug 15, 2021 at 7:39 PM Jozef Lawrynowicz via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi, > > I thought I would notify the LLVM community about some improvements to > MSP430 support in LLVM/Clang that I'm planning to make. > > MCU support > ============= > - Update MCU data to the latest version > + Currently only 161 MCUs are supported, but the latest version of > TI device data describes 609 MCUs. > - Store the CPU version of each MCU > + Currently only the hardware multiply version of each MCU is > stored; knowledge of the CPU supported by each MCU is required for > future updates. > > Support MSP430X code generation (small memory model only) > =========================================================== > - Support the -mcpu=msp430x option in Clang > + This option is accepted by Clang, but doesn't do anything. > Plumbing is required so it enables the MSP430X feature in LLVM, > and passes the correct multilibs to the linker. > - Implement extended shift instructions > + MSP430X shift instructions such as RRAM and RRAX can shift by > more than one bit position in a single instruction. > + Currently, multiple shift instructions need to be emitted, each > shifting by one bit position. > - Implement extended PUSH/POP instructions > + PUSHM/POPM can push and pop multiple registers with a single > instruction. > + Currently, multiple PUSH/POP instructions need to be emitted, each > pushing or popping one register. > - Implement the RPT flag in the extension word > + The RPT flag describes how many times an instruction should be > repeated. Up to 16 repeats are supported, and the repeat count can > be hard-coded into the extension word, or stored in a register > described by the extension word. > + This is mainly used for encoding shifts by amounts not supported > by the more compact R**M instructions. > > Check correctness of code generation using the GCC testsuite > ============================================================== > - I've used the Embecosm "gcc-for-llvm-testing"[1] repository to run a > subset of GCC's execution tests on MSP430, using the Binutils/GDB > simulator. So far it doesn't seem like anything is critically > broken, but I need to do a full run of the suite and analyze the > results. > > In addition to above, I've also implemented ELF object attributes, > currently awaiting review here: <https://reviews.llvm.org/D107969> > > Thanks, > Jozef > > [1] <https://github.com/embecosm/gcc-for-llvm-testing> > _> ________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

-- With best regards, Anton Korobeynikov Department of Statistical Modelling, Saint Petersburg State University

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