sdesmalen marked an inline comment as done. sdesmalen added inline comments.
================ Comment at: clang/lib/CodeGen/CGBuiltin.cpp:7880 + return Builder.CreateBitCast(Val, Ty); + } + ---------------- efriedma wrote: > sdesmalen wrote: > > efriedma wrote: > > > I'm vaguely suspicious this might be wrong for big-endian targets. I > > > mean, this isn't unreasonable, but users might be surprised if > > > svreinterpret isn't a no-op. > > For SVE the loads and stores (svld1 and svst1) are all endian safe, so no > > special consideration needs to be taken for big endian targets. > > > > The ACLE specifies that: > > > The svreinterpret functions simply reinterpret a vector of one type as a > > > vector of another type, without changing any of the bits. > "bitcast" is specified to mean "reinterpret the bits like a store+load". On > big-endian NEON (and, I assume, SVE), that isn't a no-op. See > http://llvm.org/docs/BigEndianNEON.html . > > I mean, if the answer here is "yes, svreinterpret is supposed to lower to a > REV", then that's fine. But I'd like to see some explciit acknowledgement > that that's intentional. Thanks for pointing out that page, but for SVE I don't think the svreinterpret should lower to a REV. This is probably where things are different from Neon. The ACLE SVE vectors such as `svint32_t` are opaque vector types and the only way to load/store them from/to memory is through the use of the svld1 and svst1 intrinsics which are endian safe (in that they use the ld1/st1 instructions that do endianess conversion on big endian targets). The ACLE does not expose any full-vector load/store (ldr/str) operations. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D78756/new/ https://reviews.llvm.org/D78756 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
