[Mesa-dev] [PATCH] gallivm: Fix uses of 2^24

[Roland Scheidegger]

Am 21.07.2014 17:53, schrieb Richard Sandiford:
> Fallback cases in lp_bld_arit.c used 2^24 to mean "2 to the power 24",
> but in C it's "2 xor 24", i.e. 26.  Fixed by using 1<< instead.
> 
> Signed-off-by: Richard Sandiford <rsandifo at linux.vnet.ibm.com>
> ---
>  src/gallium/auxiliary/gallivm/lp_bld_arit.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
> index 82ddb5a..a7a88ed 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
> @@ -1872,7 +1872,7 @@ lp_build_trunc(struct lp_build_context *bld,
>        const struct lp_type type = bld->type;
>        struct lp_type inttype;
>        struct lp_build_context intbld;
> -      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 2^24);
> +      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
>        LLVMValueRef trunc, res, anosign, mask;
>        LLVMTypeRef int_vec_type = bld->int_vec_type;
>        LLVMTypeRef vec_type = bld->vec_type;
> @@ -1927,7 +1927,7 @@ lp_build_round(struct lp_build_context *bld,
>        const struct lp_type type = bld->type;
>        struct lp_type inttype;
>        struct lp_build_context intbld;
> -      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 2^24);
> +      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
>        LLVMValueRef res, anosign, mask;
>        LLVMTypeRef int_vec_type = bld->int_vec_type;
>        LLVMTypeRef vec_type = bld->vec_type;
> @@ -1980,7 +1980,7 @@ lp_build_floor(struct lp_build_context *bld,
>        const struct lp_type type = bld->type;
>        struct lp_type inttype;
>        struct lp_build_context intbld;
> -      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 2^24);
> +      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
>        LLVMValueRef trunc, res, anosign, mask;
>        LLVMTypeRef int_vec_type = bld->int_vec_type;
>        LLVMTypeRef vec_type = bld->vec_type;
> @@ -2049,7 +2049,7 @@ lp_build_ceil(struct lp_build_context *bld,
>        const struct lp_type type = bld->type;
>        struct lp_type inttype;
>        struct lp_build_context intbld;
> -      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 2^24);
> +      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
>        LLVMValueRef trunc, res, anosign, mask, tmp;
>        LLVMTypeRef int_vec_type = bld->int_vec_type;
>        LLVMTypeRef vec_type = bld->vec_type;
> 

Oops not sure what I was thinking when I wrote that. I guess when
testing it passed lp_test_arit because there are actually no values
between 26 and 2^24 which get tested, but in practice the results are
probably pretty terrible...
I think this should be candidate for stable.

Reviewed-by: Roland Scheidegger <sroland at vmware.com>