[cfe-dev] Question about type checking of vector type operand on Sema

[jingu]

2013-06-08 오전 8:10, John McCall 쓴 글:
> On Jun 7, 2013, at 3:54 PM, jingu <jingu at codeplay.com> wrote:
>> 2013-06-08 오전 7:50, John McCall 쓴 글:
>>> On Jun 7, 2013, at 8:16 AM, JinGu Kang <jingu at codeplay.com> wrote:
>>>> I have a question about type checking of vector type operand on Sema.
>>>>
>>>> I tested a code and clang generated error as following:
>>>>
>>>> source code:
>>>> typedef float float2  __attribute__((ext_vector_type(2)));
>>>>
>>>> void test(float2 a, float2 b) {
>>>>   float2 t0 = (a + b) / 2;
>>>> }
>>>>
>>>> error: can't convert between vector values of different size
>>>>       ('float __attribute__((ext_vector_type(2)))' and 'float')
>>>>   float2 t0 = (a + b) / 2;
>>>>                  ~~~~~~~ ^ ~
>>>>
>>>> The problem is that "Sema::CheckVectorOperands()" function does not consider about the case of float vector and integer scalar. Does someone let me know why clang prevents this case? I couldn't find some information. I think clang need to support this case. Given this case, I send a simple patch to process this case.
>>> This looks good overall, but please add test cases for the new behavior.
>> Thanks for your response. Could let me know how to add test cases? I did not have experience to do that.
> Look for an existing file in test/ that seems to be testing similar features and add some code to it that exercises the cases that you now expect to work.
>
> In particular, I would suggest adding something to test/CodeGen/ext-vector.c  that verifies that IR-generation will produce reasonable LLVM IR for your test cases.
>
> John.
Thanks John, I will try to do that.

JinGu Kang