This fixes an assertion in Sema::CreateBuiltinBinOp that fails when one
of the vector operand's element type is a typedef of __fp16.
rdar://problem/55983556
This commit fixes a bug in the handling of storage-only __fp16 vectors
where clang didn't promote __fp16 vector operands to float vectors.
Conceptually, it performs the following transformation on the AST in
CreateBuiltinBinOp and CreateBuiltinUnaryOp:
(Before)
typedef __fp16 half4 __attribute__ ((vector_size (8)));
typedef float float4 __attribute__ ((vector_size (16)));
half4 hv0, hv1, hv2, hv3;
hv0 = hv1 + hv2 + hv3;
(After)
float4 t0 = (float4)hv1 + (float4)hv2;
float4 t1 = t0 + (float4)hv3;
hv0 = (half4)t1;
Note that this commit fixes the bug for targets that set
HalfArgsAndReturns to true (ARM and ARM64). Targets using intrinsics
such as llvm.convert.to.fp16 to handle __fp16 are still broken.
rdar://problem/20625184
Differential Revision: https://reviews.llvm.org/D32520
llvm-svn: 314056
Akira Hatanaka