Re: [066/nnn] poly_int: omp_max_vf

[Jeff Law]

On 10/23/2017 11:27 AM, Richard Sandiford wrote:
> This patch makes omp_max_vf return a polynomial vectorization factor.
> We then need to be able to stash a polynomial value in
> OMP_CLAUSE_SAFELEN_EXPR too:
> 
>/* If max_vf is non-zero, then we can use only a vectorization factor
>   up to the max_vf we chose.  So stick it into the safelen clause.  */
> 
> For now the cfgloop safelen is still constant though.
> 
> 
> 2017-10-23  Richard Sandiford  
>   Alan Hayward  
>   David Sherwood  
> 
> gcc/
>   * omp-general.h (omp_max_vf): Return a poly_uint64 instead of an int.
>   * omp-general.c (omp_max_vf): Likewise.
>   * omp-expand.c (omp_adjust_chunk_size): Update call to omp_max_vf.
>   (expand_omp_simd): Handle polynomial safelen.
>   * omp-low.c (omplow_simd_context): Add a default constructor.
>   (omplow_simd_context::max_vf): Change from int to poly_uint64.
>   (lower_rec_simd_input_clauses): Update accordingly.
>   (lower_rec_input_clauses): Likewise.
OK.
jeff

[066/nnn] poly_int: omp_max_vf

[Richard Sandiford]

This patch makes omp_max_vf return a polynomial vectorization factor.
We then need to be able to stash a polynomial value in
OMP_CLAUSE_SAFELEN_EXPR too:

   /* If max_vf is non-zero, then we can use only a vectorization factor
  up to the max_vf we chose.  So stick it into the safelen clause.  */

For now the cfgloop safelen is still constant though.


2017-10-23  Richard Sandiford  
Alan Hayward  
David Sherwood  

gcc/
* omp-general.h (omp_max_vf): Return a poly_uint64 instead of an int.
* omp-general.c (omp_max_vf): Likewise.
* omp-expand.c (omp_adjust_chunk_size): Update call to omp_max_vf.
(expand_omp_simd): Handle polynomial safelen.
* omp-low.c (omplow_simd_context): Add a default constructor.
(omplow_simd_context::max_vf): Change from int to poly_uint64.
(lower_rec_simd_input_clauses): Update accordingly.
(lower_rec_input_clauses): Likewise.

Index: gcc/omp-general.h
===
--- gcc/omp-general.h   2017-05-18 07:51:12.357753671 +0100
+++ gcc/omp-general.h   2017-10-23 17:22:29.881163047 +0100
@@ -78,7 +78,7 @@ extern tree omp_get_for_step_from_incr (
 extern void omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd,
  struct omp_for_data_loop *loops);
 extern gimple *omp_build_barrier (tree lhs);
-extern int omp_max_vf (void);
+extern poly_uint64 omp_max_vf (void);
 extern int omp_max_simt_vf (void);
 extern tree oacc_launch_pack (unsigned code, tree device, unsigned op);
 extern void oacc_replace_fn_attrib (tree fn, tree dims);
Index: gcc/omp-general.c
===
--- gcc/omp-general.c   2017-08-10 14:36:08.449457108 +0100
+++ gcc/omp-general.c   2017-10-23 17:22:29.881163047 +0100
@@ -423,7 +423,7 @@ omp_build_barrier (tree lhs)
 
 /* Return maximum possible vectorization factor for the target.  */
 
-int
+poly_uint64
 omp_max_vf (void)
 {
   if (!optimize
Index: gcc/omp-expand.c
===
--- gcc/omp-expand.c2017-10-02 09:10:57.525659817 +0100
+++ gcc/omp-expand.c2017-10-23 17:22:29.881163047 +0100
@@ -206,8 +206,8 @@ omp_adjust_chunk_size (tree chunk_size,
   if (!simd_schedule)
 return chunk_size;
 
-  int vf = omp_max_vf ();
-  if (vf == 1)
+  poly_uint64 vf = omp_max_vf ();
+  if (must_eq (vf, 1U))
 return chunk_size;
 
   tree type = TREE_TYPE (chunk_size);
@@ -4609,11 +4609,12 @@ expand_omp_simd (struct omp_region *regi
 
   if (safelen)
 {
+  poly_uint64 val;
   safelen = OMP_CLAUSE_SAFELEN_EXPR (safelen);
-  if (TREE_CODE (safelen) != INTEGER_CST)
+  if (!poly_int_tree_p (safelen, ))
safelen_int = 0;
-  else if (tree_fits_uhwi_p (safelen) && tree_to_uhwi (safelen) < INT_MAX)
-   safelen_int = tree_to_uhwi (safelen);
+  else
+   safelen_int = MIN (constant_lower_bound (val), INT_MAX);
   if (safelen_int == 1)
safelen_int = 0;
 }
Index: gcc/omp-low.c
===
--- gcc/omp-low.c   2017-10-23 17:17:01.432034493 +0100
+++ gcc/omp-low.c   2017-10-23 17:22:29.882163248 +0100
@@ -3487,11 +3487,12 @@ omp_clause_aligned_alignment (tree claus
and lower_rec_input_clauses.  */
 
 struct omplow_simd_context {
+  omplow_simd_context () { memset (this, 0, sizeof (*this)); }
   tree idx;
   tree lane;
   vec simt_eargs;
   gimple_seq simt_dlist;
-  int max_vf;
+  poly_uint64_pod max_vf;
   bool is_simt;
 };
 
@@ -3502,28 +3503,30 @@ struct omplow_simd_context {
 lower_rec_simd_input_clauses (tree new_var, omp_context *ctx,
  omplow_simd_context *sctx, tree , tree )
 {
-  if (sctx->max_vf == 0)
+  if (known_zero (sctx->max_vf))
 {
   sctx->max_vf = sctx->is_simt ? omp_max_simt_vf () : omp_max_vf ();
-  if (sctx->max_vf > 1)
+  if (may_gt (sctx->max_vf, 1U))
{
  tree c = omp_find_clause (gimple_omp_for_clauses (ctx->stmt),
OMP_CLAUSE_SAFELEN);
- if (c
- && (TREE_CODE (OMP_CLAUSE_SAFELEN_EXPR (c)) != INTEGER_CST
- || tree_int_cst_sgn (OMP_CLAUSE_SAFELEN_EXPR (c)) != 1))
-   sctx->max_vf = 1;
- else if (c && compare_tree_int (OMP_CLAUSE_SAFELEN_EXPR (c),
- sctx->max_vf) == -1)
-   sctx->max_vf = tree_to_shwi (OMP_CLAUSE_SAFELEN_EXPR (c));
+ if (c)
+   {
+ poly_uint64 safe_len;
+ if (!poly_int_tree_p (OMP_CLAUSE_SAFELEN_EXPR (c), _len)
+ || may_lt (safe_len, 1U))
+   sctx->max_vf = 1;
+ else
+   sctx->max_vf = lower_bound (sctx->max_vf, safe_len);
+   }
}
-  if