Re: [PATCH] Vect: Remove restrictions on dotprod signedness

[Richard Biener <rguenther@suse.de>]

On Wed, 5 May 2021, Tamar Christina wrote:

> Hi All,
> 
> There's no reason that the sign of the operands of dot-product have to all be
> the same.  The only restriction really is that the sign of the multiplicands
> are the same, however the sign between the multiplier and the accumulator need
> not be the same.
> 
> The type of the overall operations should be determined by the sign of the
> multiplicand which is already being done by optabs-tree.c.
> 
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
> 
> Ok for master?

OK if the rest of the series is.

Richard.

> Thanks,
> Tamar
> 
> gcc/ChangeLog:
> 
> 	* tree-vect-patterns.c (vect_recog_dot_prod_pattern): Remove sign check.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.dg/vect/vect-reduc-dot-2.c: Expect to pass.
> 	* gcc.dg/vect/vect-reduc-dot-3.c: Likewise.
> 	* gcc.dg/vect/vect-reduc-dot-6.c: Likewise.
> 	* gcc.dg/vect/vect-reduc-dot-7.c: Likewise.
> 
> --- inline copy of patch -- 
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-2.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-2.c
> index 25757d2b6713b53a325979b96f89396dbf4675b8..2ebe98887a6072b9e674846af1df38cdc94258dd 100644
> --- a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-2.c
> +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-2.c
> @@ -6,5 +6,5 @@
>  
>  #include "vect-reduc-dot-1.c"
>  
> -/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
> +/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
>  
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-3.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-3.c
> index b1deb64e186da99ef42cb687d107445c0b800bd8..6a6679d522350ab4c19836f5537119122f0e654e 100644
> --- a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-3.c
> +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-3.c
> @@ -6,5 +6,5 @@
>  
>  #include "vect-reduc-dot-1.c"
>  
> -/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
> +/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
>  
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-6.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-6.c
> index b690c9f2eb18b34f4b147d779bb3da582e285399..0cd4b823643bd4fadd529b2fe4e1d664aa1159ad 100644
> --- a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-6.c
> +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-6.c
> @@ -6,5 +6,5 @@
>  
>  #include "vect-reduc-dot-1.c"
>  
> -/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
> +/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
>  
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-7.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-7.c
> index 29e442e8bbf7176cf861518dc171a83d82967764..eefee2e2ca27d749cd3af2238723aeae4e60a429 100644
> --- a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-7.c
> +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-7.c
> @@ -6,5 +6,5 @@
>  
>  #include "vect-reduc-dot-1.c"
>  
> -/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
> +/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
>  
> diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
> index 803de3fc287371fa202610a55b17e2c8934672f3..441d6cd28c4eaded7abd756164890dbcffd2f3b8 100644
> --- a/gcc/tree-vect-patterns.c
> +++ b/gcc/tree-vect-patterns.c
> @@ -946,7 +946,8 @@ vect_recog_dot_prod_pattern (vec_info *vinfo,
>       In which
>       - DX is double the size of X
>       - DY is double the size of Y
> -     - DX, DY, DPROD all have the same type
> +     - DX, DY, DPROD all have the same type but the sign
> +       between DX, DY and DPROD can differ.
>       - sum is the same size of DPROD or bigger
>       - sum has been recognized as a reduction variable.
>  
> @@ -988,12 +989,6 @@ vect_recog_dot_prod_pattern (vec_info *vinfo,
>  			     false, 2, unprom0, &half_type))
>      return NULL;
>  
> -  /* If there are two widening operations, make sure they agree on
> -     the sign of the extension.  */
> -  if (TYPE_PRECISION (unprom_mult.type) != TYPE_PRECISION (type)
> -      && TYPE_SIGN (unprom_mult.type) != TYPE_SIGN (half_type))
> -    return NULL;
> -
>    vect_pattern_detected ("vect_recog_dot_prod_pattern", last_stmt);
>  
>    tree half_vectype;
> 
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)