bruno marked an inline comment as done. ================ Comment at: lib/Sema/SemaExpr.cpp:8084 @@ +8083,3 @@ + *RHSExpr = ImpCastExprToType(RHSExpr->get(), LHSType, CK_BitCast); + return LHSType; + } ---------------- ahatanak wrote: > My understanding is that, when we have a compound assign like "LHS += RHS", > this function (CheckVectorOperands) is supposed to return the result type > (LHS + RHS). However, it is returning different types for "<1 x T> += T" and > "T += <1 x T>" (the former returns <1 x T> and the latter returns T). Would > CheckAssignmentOperands reject the compound statement if you returned the > vector type here? > > Also, are you planning to allow the same kind of conversions done above for > non-compound assignment statements (e.g., <4 x short> += <2 x int>) in the > future? 1) CheckAssignmentOperands doesn't reject the compound statement if we return the vector type instead, because it already supports vector to scalar cast idiom. It makes more sense to return a vector indeed, gonna change that.
2) It would be nice to catch up with GCC with the idioms supported for regular (non-ext) vectors (like splatting scalar operands to vectors in a arith binops), and those, AFAIK, don't include support for truncation as in the example you suggested. I guess this is supported with ext-vectors, but I don't see any reason to support it for "regular" vectors. https://reviews.llvm.org/D24472 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
