Shao-Ce Sun via llvm-dev
2021-Jul-09 02:23 UTC
[llvm-dev] [RISC-V V] How to read each bit of vbool8_t individually
Hi All, I have a question about RISC-V V, that is how to read each bit of vbool8_t individually, for example: vbool8_t A; bool B[8] = A; Thanks! -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210709/d0857fbb/attachment.html>
Craig Topper via llvm-dev
2021-Jul-09 03:41 UTC
[llvm-dev] [RISC-V V] How to read each bit of vbool8_t individually
There aren't really any instructions for doing this in the ISA. Solutions I can think of are rounding vl to the next multiple of 8 and storing it to a uint8_t using vse8. Then reading it back by looping over the array and looking at all 8 bits of each uint8_t. Or you could use vmerge to turn into a vuint8m1_t vector of 1 and 0. Perhaps if you shared your use case I might be able to come up with something else. ~Craig On Thu, Jul 8, 2021 at 7:23 PM Shao-Ce Sun via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Hi All, > I have a question about RISC-V V, that is how to read each bit of > vbool8_t individually, for example: > vbool8_t A; > bool B[8] = A; > Thanks! > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210708/cf377adf/attachment.html>