[Libclc-dev] [PATCH 1/2] Add hadd builtin

[Tom Stellard]

On Wed, Aug 14, 2013 at 11:38:17AM -0500, Aaron Watry wrote:
> (x + y) >> 1 gets changed to:
> (x>>1) + (y>>1) + (x&y&1)
> 
> Saves us having to do any llvm assembly and overflow checking in the addition.

Reviewed-by: Tom Stellard <thomas.stellard at amd.com>

> ---
>  generic/include/clc/clc.h            | 1 +
>  generic/include/clc/integer/hadd.h   | 2 ++
>  generic/include/clc/integer/hadd.inc | 1 +
>  generic/lib/SOURCES                  | 1 +
>  generic/lib/integer/hadd.cl          | 4 ++++
>  generic/lib/integer/hadd.inc         | 6 ++++++
>  6 files changed, 15 insertions(+)
>  create mode 100644 generic/include/clc/integer/hadd.h
>  create mode 100644 generic/include/clc/integer/hadd.inc
>  create mode 100644 generic/lib/integer/hadd.cl
>  create mode 100644 generic/lib/integer/hadd.inc
> 
> diff --git a/generic/include/clc/clc.h b/generic/include/clc/clc.h
> index bc873c3..f9b2c38 100644
> --- a/generic/include/clc/clc.h
> +++ b/generic/include/clc/clc.h
> @@ -65,6 +65,7 @@
>  #include <clc/integer/abs_diff.h>
>  #include <clc/integer/add_sat.h>
>  #include <clc/integer/clz.h>
> +#include <clc/integer/hadd.h>
>  #include <clc/integer/mad24.h>
>  #include <clc/integer/mul24.h>
>  #include <clc/integer/mul_hi.h>
> diff --git a/generic/include/clc/integer/hadd.h b/generic/include/clc/integer/hadd.h
> new file mode 100644
> index 0000000..37304e2
> --- /dev/null
> +++ b/generic/include/clc/integer/hadd.h
> @@ -0,0 +1,2 @@
> +#define __CLC_BODY <clc/integer/hadd.inc>
> +#include <clc/integer/gentype.inc>
> diff --git a/generic/include/clc/integer/hadd.inc b/generic/include/clc/integer/hadd.inc
> new file mode 100644
> index 0000000..f698989
> --- /dev/null
> +++ b/generic/include/clc/integer/hadd.inc
> @@ -0,0 +1 @@
> +_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE hadd(__CLC_GENTYPE x, __CLC_GENTYPE y);
> diff --git a/generic/lib/SOURCES b/generic/lib/SOURCES
> index b8322f2..0e66d71 100644
> --- a/generic/lib/SOURCES
> +++ b/generic/lib/SOURCES
> @@ -11,6 +11,7 @@ integer/add_sat_impl.ll
>  integer/clz.cl
>  integer/clz_if.ll
>  integer/clz_impl.ll
> +integer/hadd.cl
>  integer/mad24.cl
>  integer/mul24.cl
>  integer/mul_hi.cl
> diff --git a/generic/lib/integer/hadd.cl b/generic/lib/integer/hadd.cl
> new file mode 100644
> index 0000000..749026e
> --- /dev/null
> +++ b/generic/lib/integer/hadd.cl
> @@ -0,0 +1,4 @@
> +#include <clc/clc.h>
> +
> +#define __CLC_BODY <hadd.inc>
> +#include <clc/integer/gentype.inc>
> diff --git a/generic/lib/integer/hadd.inc b/generic/lib/integer/hadd.inc
> new file mode 100644
> index 0000000..ea59d9b
> --- /dev/null
> +++ b/generic/lib/integer/hadd.inc
> @@ -0,0 +1,6 @@
> +//hadd = (x+y)>>1
> +//This can be simplified to x>>1 + y>>1 + (1 if both x and y have the 1s bit set)
> +//This saves us having to do any checks for overflow in the addition sum
> +_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE hadd(__CLC_GENTYPE x, __CLC_GENTYPE y) {
> +    return (x>>(__CLC_GENTYPE)1)+(y>>(__CLC_GENTYPE)1)+(x&y&(__CLC_GENTYPE)1);
> +}
> -- 
> 1.8.1.2
> 
> 
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