bruno added inline comments. ================ Comment at: lib/Sema/SemaExpr.cpp:8090 @@ +8089,3 @@ + *RHSExpr = ImpCastExprToType(RHSExpr->get(), LHSType, CK_BitCast); + return VecType; + } ---------------- ahatanak wrote: > Sorry I wasn't clear, but I was asking whether you were planning to allow > the following conversions for compound statements. > > ``` > typedef short s4 __attribute__ ((vector_size(8))); > typedef int i2 __attribute__ ((vector_size(8))); > s4 a; > i2 b; > a = a + b; // clang accepts this. > a += b; // currently clang rejects this. > ``` > > Also, I feel clang is inconsistent in warning about incompatible types. In > the following example, it issues a warning for the first line, but is silent > about the second line: > > ``` > a = b + a; // incompatible vector types warning > a = a + b; // no warning > ``` > > I don't think we have to fix everything in this patch, but just wanted to > know what your thoughts were. You're right, the diagnostics are bad here, this patch adds some FIXMEs so we can later work on it. A PR would be nice though (we have an internal track for that as well, see rdar://problem/28067874).
Given your example: a = a + b; // clang accepts this. a += b; // currently clang rejects this. IMO, clang should reject `a = a + b` too if not in OpenCL mode, which means whenever (a) `a` and `b` have same size but different num elt and (b) `a` and `b` are generic vectors (non ext-vectors). However, It looks like we have tests that rely on this behavior, we should probably find out why first and clean it up. I also think we should support splatting when one of the operands is a scalar and the other a non ext-vector (as of now we currently only do it for OpenCL). This is basically what GCC supports https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html. https://reviews.llvm.org/D24472 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
