RE: [PATCH] middle-end: Add MULT_EXPR recognition for cond scalar reduction

["Kong, Lingling" <lingling.kong@intel.com>]

Hi  Richard,  could you help to have a look for the patch ?

Ok for master ?

> Hi,
> 
> The conditional mult reduction cannot be recognized with current GCC. The
> following loop cannot be vectorized.
> Now add MULT_EXPR recognition for conditional scalar reduction.
> 
> float summa(int n, float *arg1, float *arg2)
> {
>     int i;
>     float res1 = 1.0;
>     for(i = 0; i < n; i++) {
>       if(arg2[i])
>         res1 *= arg1[i];
>     }
>     return res1;
> }
> 
> gcc/ChangeLog:
> 
> 	* tree-if-conv.cc (is_cond_scalar_reduction): Add MULT_EXPR
> 	recognition.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.dg/tree-ssa/gen-vect-34.c: New test.
> 	* gcc.dg/vect/vect-ifcvt-18.c: New test.
> ---
>  gcc/testsuite/gcc.dg/tree-ssa/gen-vect-34.c | 16 +++++++++
>  gcc/testsuite/gcc.dg/vect/vect-ifcvt-18.c   | 38 +++++++++++++++++++++
>  gcc/tree-if-conv.cc                         |  1 +
>  3 files changed, 55 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/gen-vect-34.c
>  create mode 100644 gcc/testsuite/gcc.dg/vect/vect-ifcvt-18.c
> 
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-34.c
> b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-34.c
> new file mode 100644
> index 00000000000..8d2d36401fe
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-34.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Ofast -fdump-tree-vect-details" } */
> +/* { dg-additional-options "-mavx2" { target { x86_64-*-* i?86-*-* } }
> +} */
> +
> +float summul(int n, float *arg1, float *arg2)
> +{
> +    int i;
> +    float res1 = 1.0;
> +    for(i = 0; i < n; i++) {
> +      if(arg2[i])
> +        res1 *= arg1[i];
> +    }
> +    return res1;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" {
> +target { ! { avr-*-* pru-*-* } } } } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-ifcvt-18.c
> b/gcc/testsuite/gcc.dg/vect/vect-ifcvt-18.c
> new file mode 100644
> index 00000000000..c1d3c27d819
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-ifcvt-18.c
> @@ -0,0 +1,38 @@
> +/* { dg-require-effective-target vect_condition } */
> +/* { dg-require-effective-target vect_float } */
> +/* { dg-additional-options "-Ofast -mavx" { target avx_runtime } } */
> +
> +
> +int A0[4] = {36,39,42,45};
> +int B0[4] = {42,42,0,42};
> +float A1[8] = {36,39,42,45,43,32,21,12}; float B1[8] =
> +{42,42,0,42,42,42,0,42}; double A2[16] =
> +{36,39,42,45,43,32,21,12,23,34,45,56,42,78,89,11};
> +double B2[16] = {42,42,0,42,42,42,42,42,42,42,42,42,0,42,42,42};
> +
> +int main ()
> +{
> +  int i, j;
> +  int res0 = 1;
> +  float res1 = 1.0;
> +  double res2 = 1.0;
> +
> +  for (i = 0; i < 4; i++)
> +    if (B0[i])
> +      res0 *= A0[i];
> +
> +  for (i = 0; i < 8; i++)
> +    if (B1[i])
> +      res1 *= A1[i];
> +
> +  for (i = 0; i < 16; i++)
> +    if (B2[i])
> +      res2 *= A2[i];
> +  /* check results:  */
> +  if (res0 != 63180 || res1 != 1043228160.000000
> +      ||res2 != 3296728515318523101184.000000)
> +      __builtin_abort ();
> +  return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump "vectorized 3 loops" "vect" { target
> +i?86-*-* x86_64-*-* } } } */
> diff --git a/gcc/tree-if-conv.cc b/gcc/tree-if-conv.cc index
> 1c8e1a45234..bac29fb5574 100644
> --- a/gcc/tree-if-conv.cc
> +++ b/gcc/tree-if-conv.cc
> @@ -1739,6 +1739,7 @@ is_cond_scalar_reduction (gimple *phi, gimple
> **reduc, tree arg_0, tree arg_1,
> 
>    if (reduction_op != PLUS_EXPR
>        && reduction_op != MINUS_EXPR
> +      && reduction_op != MULT_EXPR
>        && reduction_op != BIT_IOR_EXPR
>        && reduction_op != BIT_XOR_EXPR
>        && reduction_op != BIT_AND_EXPR)
> --
> 2.18.2