sammccall added a comment. In D75443#1916761 <https://reviews.llvm.org/D75443#1916761>, @mibintc wrote:
> I'm working on a patch that will move FPOptions to Trailing storage, part of > https://reviews.llvm.org/D72841 ; hope to have another revision uploaded > today or tomorrow. I got feedback that moving the field to BinaryOperator > isn't adequate. Great! Moving FPOptions to trailing storage (which I guess allows it to only be present for floating point ops?) is much better than making it a member, and frees up a lot of bits. To unblock adding the extra "error" bit that we need (which really does apply to all Exprs), we could do any of: 1. wait for D72841 <https://reviews.llvm.org/D72841> to land, including the trailingstorage 2. move the trailing-storage parts out of that patch, and do it first as a smaller separate change 3. find some other way to save the bit for now (e.g. by encoding rounding + exceptions together), and undo that once saving 1 bit doesn't matter Any objections if we do 3 and take care of rolling it back later? ================ Comment at: clang/include/clang/Basic/LangOptions.h:200 /// Rounding to nearest, corresponds to "round.tonearest". - FPR_ToNearest, + FPR_ToNearest = 0, /// Rounding toward -Inf, corresponds to "round.downward". ---------------- this is implied and unneccesary ================ Comment at: clang/include/clang/Basic/LangOptions.h:361 fenv_access(LangOptions::FEA_Off), - rounding(LangOptions::FPR_ToNearest), - exceptions(LangOptions::FPE_Ignore) + packed(0) {} ---------------- Making use of the encoding of `packed` in lots of places is fragile and hard to maintain. I'd suggest the private primitives: `setRoundingAndExceptionMode(FPRoundingModeKind, FPExceptionModeKind)` `getRoundingAndExceptionMode() -> pair<FPRoundingModeKind, FPExceptionModeKind>` and implementing everything in terms of them. ================ Comment at: clang/include/clang/Basic/LangOptions.h:445 + // A packed field for encoding rounding and exceptions. + // packed = MaxExceptionValue * rounding + exceptions. + constexpr static unsigned MaxExceptionValue = 3; ---------------- FIXME: unpack this once saving one bit isn't critical here. ================ Comment at: clang/include/clang/Basic/LangOptions.h:447 + constexpr static unsigned MaxExceptionValue = 3; + unsigned packed: 4; }; ---------------- rounding_and_exceptions? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D75443/new/ https://reviews.llvm.org/D75443 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
