I have a question regarding ARM support. It was mentioned in mails below that LLVM supports ARM v6 but a lot of ARM v6 instructions are actually missing from ARM ISA description files( e.g. Media Instructions). Is there any documentation mentioning the unsupported parts of v6 version Thanks --Kapil On Thu, Sep 18, 2008 at 2:14 PM, Evan Cheng <evan.cheng at apple.com> wrote:> > On Sep 17, 2008, at 3:00 PM, Tyler Wilson wrote: > > Good day, > > I have looked around for this information, but I have not been able to gain > a clear understanding: what is the status of the LLVM ARM backend? That is, > do the following work: > > > > > 1. Generating Thumb code: I saw a video online where they describe > an issue with using the ARM Thumb back-end > > > Thumb works. But it generate poor code. > > 2. Generating code for ARM9 (ARMv5?) or ARM7 (ARMv4): again, the > same presentation mentioned that it only generated ARMv6 or 7. Does the back > end work on older ARM processors today? > > > ARM v6 is known to work well. I am not sure about v4 and v5. They should > mostly work, but I don't test them. There is no support for v7. > > > I have seen the notes on the Apple provided bits to the project, but those > were form early-mid 2007, and I have not seen a clear declaration on what is > marked as working or not. > > > There hasn't been a lot of activities in ARM target. Patches welcome! > > Evan > > > Thank you, > Tyler > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20081009/de6aea04/attachment.html>
Can you give some examples of missing instructions? Evan On Oct 9, 2008, at 4:58 PM, kapil anand wrote:> I have a question regarding ARM support. It was mentioned in mails > below that LLVM supports ARM v6 but a lot of ARM v6 instructions are > actually missing from ARM ISA description files( e.g. Media > Instructions). Is there any documentation mentioning the unsupported > parts of v6 version > > Thanks > > --Kapil > > > On Thu, Sep 18, 2008 at 2:14 PM, Evan Cheng <evan.cheng at apple.com> > wrote: > > On Sep 17, 2008, at 3:00 PM, Tyler Wilson wrote: > >> Good day, >> >> I have looked around for this information, but I have not been able >> to gain a clear understanding: what is the status of the LLVM ARM >> backend? That is, do the following work: >> > > >> 1. Generating Thumb code: I saw a video online where they >> describe an issue with using the ARM Thumb back-end > > Thumb works. But it generate poor code. > >> 2. Generating code for ARM9 (ARMv5?) or ARM7 (ARMv4): again, >> the same presentation mentioned that it only generated ARMv6 or 7. >> Does the back end work on older ARM processors today? > > ARM v6 is known to work well. I am not sure about v4 and v5. They > should mostly work, but I don't test them. There is no support for v7. > >> >> I have seen the notes on the Apple provided bits to the project, >> but those were form early-mid 2007, and I have not seen a clear >> declaration on what is marked as working or not. > > There hasn't been a lot of activities in ARM target. Patches welcome! > > Evan > >> >> Thank you, >> Tyler >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20081010/6da7b343/attachment.html>
Media instructions like - parallel add and subtract, Sign/Zero Extend and Add instructions seem to be missing from ARM target support. These instructions are not listed in GenInstrNames.inc Kapil On Fri, Oct 10, 2008 at 11:54 AM, Evan Cheng <evan.cheng at apple.com> wrote:> > Can you give some examples of missing instructions? > > Evan > > On Oct 9, 2008, at 4:58 PM, kapil anand wrote: > >> I have a question regarding ARM support. It was mentioned in mails below that LLVM supports ARM v6 but a lot of ARM v6 instructions are actually missing from ARM ISA description files( e.g. Media Instructions). Is there any documentation mentioning the unsupported parts of v6 version >> >> Thanks >> >> --Kapil >> >> >> On Thu, Sep 18, 2008 at 2:14 PM, Evan Cheng <evan.cheng at apple.com> wrote: >>> >>> >>> On Sep 17, 2008, at 3:00 PM, Tyler Wilson wrote: >>> >>>> Good day, >>>> >>>> I have looked around for this information, but I have not been able to gain a clear understanding: what is the status of the LLVM ARM backend? That is, do the following work: >>>> >>> >>> >>> >>>> 1. Generating Thumb code: I saw a video online where they describe an issue with using the ARM Thumb back-end >>> >>> >>> Thumb works. But it generate poor code. >>> >>>> 2. Generating code for ARM9 (ARMv5?) or ARM7 (ARMv4): again, the same presentation mentioned that it only generated ARMv6 or 7. Does the back end work on older ARM processors today? >>> >>> >>> ARM v6 is known to work well. I am not sure about v4 and v5. They should mostly work, but I don't test them. There is no support for v7. >>> >>>> >>>> I have seen the notes on the Apple provided bits to the project, but those were form early-mid 2007, and I have not seen a clear declaration on what is marked as working or not. >>> >>> >>> There hasn't been a lot of activities in ARM target. Patches welcome! >>> >>> Evan >>> >>>> >>>> Thank you, >>>> Tyler >>>> _______________________________________________ >>>> LLVM Developers mailing list >>>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >>> >>> >>> >>> _______________________________________________ >>> LLVM Developers mailing list >>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >>> >> >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >