[Libclc-dev] [PATCH 1/9] RFC: Refactor clcmacro.h to vectorize without hi/lo

[Tom Stellard]

On Tue, Jul 22, 2014 at 08:46:42PM -0500, Aaron Watry wrote:
> There are odd things happening with 16x vectors in nextafter() and sign().
> 
> When I changed float16 load/store to use the assembly path in later
> patches instead of the macro-vectorized version, nextafter and sign
> stopped working (next 2 commits/patches).
> 
> As near as I can tell, we're getting correct results for
> elements 0-7, but then elements 8+ are wrong. The final result
> seems to be composed of the first 8 elements of the computed
> result, and then elements 16-23, which are likely uninitialized.
> 
> I'd like to say the issue is in clang, but I have nothing to back
> that up at the moment and give that this patch fixes the issue, I’m
> not sure how much time I want to spend investigating right now.
> 
> Explicitly splitting all of the vectorize macros the way that this patch
> does gets everything working again, but I have a feeling that we're
> papering over a bug somewhere, hence the RFC subject.
> 
> I’m not sure what’s going on here, and it’s only the nextafter/sign
> functions that regressed. This patch fixes the test results in piglit.
> 
> No significant change on number of instructions in bitcode
> for nextafter float16 (2-3 instructions savings over ~350 lines).
> 

Were you testing this on Evergreen?  The sign() test passes for me on
SI without this patch.

-Tom

> Signed-off-by: Aaron Watry <awatry at gmail.com>
> ---
>  generic/lib/clcmacro.h | 84 +++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 73 insertions(+), 11 deletions(-)
> 
> diff --git a/generic/lib/clcmacro.h b/generic/lib/clcmacro.h
> index 730073a..64b1770 100644
> --- a/generic/lib/clcmacro.h
> +++ b/generic/lib/clcmacro.h
> @@ -1,44 +1,106 @@
>  #define _CLC_UNARY_VECTORIZE(DECLSPEC, RET_TYPE, FUNCTION, ARG1_TYPE) \
>    DECLSPEC RET_TYPE##2 FUNCTION(ARG1_TYPE##2 x) { \
> -    return (RET_TYPE##2)(FUNCTION(x.x), FUNCTION(x.y)); \
> +    return (RET_TYPE##2){FUNCTION(x.s0), FUNCTION(x.s1)}; \
>    } \
>  \
>    DECLSPEC RET_TYPE##3 FUNCTION(ARG1_TYPE##3 x) { \
> -    return (RET_TYPE##3)(FUNCTION(x.x), FUNCTION(x.y), FUNCTION(x.z)); \
> +    return (RET_TYPE##3){FUNCTION(x.s0), FUNCTION(x.s1), FUNCTION(x.s2)}; \
>    } \
>  \
>    DECLSPEC RET_TYPE##4 FUNCTION(ARG1_TYPE##4 x) { \
> -    return (RET_TYPE##4)(FUNCTION(x.lo), FUNCTION(x.hi)); \
> +    return (RET_TYPE##4){ \
> +      FUNCTION(x.s0), \
> +      FUNCTION(x.s1), \
> +      FUNCTION(x.s2), \
> +      FUNCTION(x.s3), \
> +    }; \
>    } \
>  \
>    DECLSPEC RET_TYPE##8 FUNCTION(ARG1_TYPE##8 x) { \
> -    return (RET_TYPE##8)(FUNCTION(x.lo), FUNCTION(x.hi)); \
> +    return (RET_TYPE##8){ \
> +      FUNCTION(x.s0), \
> +      FUNCTION(x.s1), \
> +      FUNCTION(x.s2), \
> +      FUNCTION(x.s3), \
> +      FUNCTION(x.s4), \
> +      FUNCTION(x.s5), \
> +      FUNCTION(x.s6), \
> +      FUNCTION(x.s7), \
> +    }; \
>    } \
>  \
>    DECLSPEC RET_TYPE##16 FUNCTION(ARG1_TYPE##16 x) { \
> -    return (RET_TYPE##16)(FUNCTION(x.lo), FUNCTION(x.hi)); \
> +    return (RET_TYPE##16){ \
> +      FUNCTION(x.s0), \
> +      FUNCTION(x.s1), \
> +      FUNCTION(x.s2), \
> +      FUNCTION(x.s3), \
> +      FUNCTION(x.s4), \
> +      FUNCTION(x.s5), \
> +      FUNCTION(x.s6), \
> +      FUNCTION(x.s7), \
> +      FUNCTION(x.s8), \
> +      FUNCTION(x.s9), \
> +      FUNCTION(x.sa), \
> +      FUNCTION(x.sb), \
> +      FUNCTION(x.sc), \
> +      FUNCTION(x.sd), \
> +      FUNCTION(x.se), \
> +      FUNCTION(x.sf) \
> +    }; \
>    }
>  
>  #define _CLC_BINARY_VECTORIZE(DECLSPEC, RET_TYPE, FUNCTION, ARG1_TYPE, ARG2_TYPE) \
>    DECLSPEC RET_TYPE##2 FUNCTION(ARG1_TYPE##2 x, ARG2_TYPE##2 y) { \
> -    return (RET_TYPE##2)(FUNCTION(x.x, y.x), FUNCTION(x.y, y.y)); \
> +    return (RET_TYPE##2){FUNCTION(x.s0, y.s0), FUNCTION(x.s1, y.s1)}; \
>    } \
>  \
>    DECLSPEC RET_TYPE##3 FUNCTION(ARG1_TYPE##3 x, ARG2_TYPE##3 y) { \
> -    return (RET_TYPE##3)(FUNCTION(x.x, y.x), FUNCTION(x.y, y.y), \
> -                         FUNCTION(x.z, y.z)); \
> +    return (RET_TYPE##3){FUNCTION(x.s0, y.s0), FUNCTION(x.s1, y.s1), \
> +                         FUNCTION(x.s2, y.s2)}; \
>    } \
>  \
>    DECLSPEC RET_TYPE##4 FUNCTION(ARG1_TYPE##4 x, ARG2_TYPE##4 y) { \
> -    return (RET_TYPE##4)(FUNCTION(x.lo, y.lo), FUNCTION(x.hi, y.hi)); \
> +    return (RET_TYPE##4){ \
> +      FUNCTION(x.s0, y.s0), \
> +      FUNCTION(x.s1, y.s1), \
> +      FUNCTION(x.s2, y.s2), \
> +      FUNCTION(x.s3, y.s3), \
> +    }; \
>    } \
>  \
>    DECLSPEC RET_TYPE##8 FUNCTION(ARG1_TYPE##8 x, ARG2_TYPE##8 y) { \
> -    return (RET_TYPE##8)(FUNCTION(x.lo, y.lo), FUNCTION(x.hi, y.hi)); \
> +    return (RET_TYPE##8){ \
> +      FUNCTION(x.s0, y.s0), \
> +      FUNCTION(x.s1, y.s1), \
> +      FUNCTION(x.s2, y.s2), \
> +      FUNCTION(x.s3, y.s3), \
> +      FUNCTION(x.s4, y.s4), \
> +      FUNCTION(x.s5, y.s5), \
> +      FUNCTION(x.s6, y.s6), \
> +      FUNCTION(x.s7, y.s7), \
> +    }; \
>    } \
>  \
>    DECLSPEC RET_TYPE##16 FUNCTION(ARG1_TYPE##16 x, ARG2_TYPE##16 y) { \
> -    return (RET_TYPE##16)(FUNCTION(x.lo, y.lo), FUNCTION(x.hi, y.hi)); \
> +    return (RET_TYPE##16){ \
> +      FUNCTION(x.s0, y.s0), \
> +      FUNCTION(x.s1, y.s1), \
> +      FUNCTION(x.s2, y.s2), \
> +      FUNCTION(x.s3, y.s3), \
> +      FUNCTION(x.s4, y.s4), \
> +      FUNCTION(x.s5, y.s5), \
> +      FUNCTION(x.s6, y.s6), \
> +      FUNCTION(x.s7, y.s7), \
> +      FUNCTION(x.s8, y.s8), \
> +      FUNCTION(x.s9, y.s9), \
> +      FUNCTION(x.sa, y.sa), \
> +      FUNCTION(x.sb, y.sb), \
> +      FUNCTION(x.sc, y.sc), \
> +      FUNCTION(x.sd, y.sd), \
> +      FUNCTION(x.se, y.se), \
> +      FUNCTION(x.sf, y.sf) \
> +    }; \
>    }
>  
>  #define _CLC_DEFINE_BINARY_BUILTIN(RET_TYPE, FUNCTION, BUILTIN, ARG1_TYPE, ARG2_TYPE) \
> -- 
> 1.9.1
> 
> 
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