/* Heuristics and transform for loop blocking and strip mining on
polyhedral representation.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2009, 2010 Free Software Foundation, Inc.
Contributed by Sebastian Pop <sebastian.pop@amd.com> and
Pranav Garg <pranav.garg2107@gmail.com>.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
-#include "ggc.h"
-#include "tree.h"
-#include "rtl.h"
-#include "output.h"
-#include "basic-block.h"
-#include "diagnostic.h"
#include "tree-flow.h"
-#include "toplev.h"
#include "tree-dump.h"
-#include "timevar.h"
#include "cfgloop.h"
#include "tree-chrec.h"
#include "tree-data-ref.h"
-#include "tree-scalar-evolution.h"
-#include "tree-pass.h"
-#include "domwalk.h"
-#include "value-prof.h"
-#include "pointer-set.h"
-#include "gimple.h"
-#include "params.h"
+#include "sese.h"
#ifdef HAVE_cloog
-#include "cloog/cloog.h"
#include "ppl_c.h"
-#include "sese.h"
#include "graphite-ppl.h"
-#include "graphite.h"
#include "graphite-poly.h"
# }
*/
-static bool
+static void
pbb_strip_mine_time_depth (poly_bb_p pbb, int time_depth, int stride)
{
ppl_dimension_type iter, dim, strip;
ppl_Polyhedron_add_constraint (res, new_cstr);
ppl_delete_Constraint (new_cstr);
}
-
- return true;
}
-/* Returns true when strip mining with STRIDE of the loop around PBB
- at DEPTH is profitable. */
+/* Returns true when strip mining with STRIDE of the loop LST is
+ profitable. */
static bool
-pbb_strip_mine_profitable_p (poly_bb_p pbb,
- graphite_dim_t depth,
- int stride)
+lst_strip_mine_profitable_p (lst_p lst, int stride)
{
- Value niter, strip_stride;
+ mpz_t niter, strip_stride;
bool res;
- value_init (strip_stride);
- value_init (niter);
- value_set_si (strip_stride, stride);
- pbb_number_of_iterations_at_time (pbb, psct_dynamic_dim (pbb, depth), niter);
- res = value_gt (niter, strip_stride);
- value_clear (strip_stride);
- value_clear (niter);
+ gcc_assert (LST_LOOP_P (lst));
+ mpz_init (strip_stride);
+ mpz_init (niter);
+
+ mpz_set_si (strip_stride, stride);
+ lst_niter_for_loop (lst, niter);
+ res = (mpz_cmp (niter, strip_stride) > 0);
+ mpz_clear (strip_stride);
+ mpz_clear (niter);
return res;
}
-/* Strip-mines all the loops of LST that are considered profitable to
- strip-mine. Return true if it did strip-mined some loops. */
+/* Strip-mines all the loops of LST with STRIDE. Return the number of
+ loops strip-mined. */
-static bool
-lst_do_strip_mine_loop (lst_p lst, int depth)
+static int
+lst_do_strip_mine_loop (lst_p lst, int depth, int stride)
{
int i;
lst_p l;
- int stride = PARAM_VALUE (PARAM_LOOP_BLOCK_TILE_SIZE);
poly_bb_p pbb;
if (!lst)
- return false;
+ return 0;
if (LST_LOOP_P (lst))
{
- bool res = false;
+ int res = 0;
- for (i = 0; VEC_iterate (lst_p, LST_SEQ (lst), i, l); i++)
- res |= lst_do_strip_mine_loop (l, depth);
+ FOR_EACH_VEC_ELT (lst_p, LST_SEQ (lst), i, l)
+ res += lst_do_strip_mine_loop (l, depth, stride);
return res;
}
pbb = LST_PBB (lst);
- return pbb_strip_mine_time_depth (pbb, psct_dynamic_dim (pbb, depth),
- stride);
+ pbb_strip_mine_time_depth (pbb, psct_dynamic_dim (pbb, depth), stride);
+ return 1;
}
-/* Strip-mines all the loops of LST that are considered profitable to
- strip-mine. Return true if it did strip-mined some loops. */
+/* Strip-mines all the loops of LST with STRIDE. When STRIDE is zero,
+ read the stride from the PARAM_LOOP_BLOCK_TILE_SIZE. Return the
+ number of strip-mined loops.
-static bool
-lst_do_strip_mine (lst_p lst)
+ Strip mining transforms a loop
+
+ | for (i = 0; i < N; i++)
+ | S (i);
+
+ into the following loop nest:
+
+ | for (k = 0; k < N; k += STRIDE)
+ | for (j = 0; j < STRIDE; j++)
+ | S (i = k + j);
+*/
+
+static int
+lst_do_strip_mine (lst_p lst, int stride)
{
int i;
lst_p l;
- bool res = false;
- int stride = PARAM_VALUE (PARAM_LOOP_BLOCK_TILE_SIZE);
+ int res = 0;
int depth;
+ if (!stride)
+ stride = PARAM_VALUE (PARAM_LOOP_BLOCK_TILE_SIZE);
+
if (!lst
|| !LST_LOOP_P (lst))
return false;
- for (i = 0; VEC_iterate (lst_p, LST_SEQ (lst), i, l); i++)
- res |= lst_do_strip_mine (l);
+ FOR_EACH_VEC_ELT (lst_p, LST_SEQ (lst), i, l)
+ res += lst_do_strip_mine (l, stride);
depth = lst_depth (lst);
if (depth >= 0
- && pbb_strip_mine_profitable_p (LST_PBB (lst_find_first_pbb (lst)),
- depth, stride))
+ && lst_strip_mine_profitable_p (lst, stride))
{
- res |= lst_do_strip_mine_loop (lst, lst_depth (lst));
+ res += lst_do_strip_mine_loop (lst, lst_depth (lst), stride);
lst_add_loop_under_loop (lst);
}
return res;
}
-/* Strip mines all the loops in SCOP. Nothing profitable in all this:
- this is just a driver function. */
+/* Strip mines all the loops in SCOP. Returns the number of
+ strip-mined loops. */
-bool
-scop_do_strip_mine (scop_p scop)
+int
+scop_do_strip_mine (scop_p scop, int stride)
{
- bool transform_done = false;
-
- store_scattering (scop);
-
- transform_done = lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop));
-
- if (!transform_done)
- return false;
-
- if (!graphite_legal_transform (scop))
- {
- restore_scattering (scop);
- return false;
- }
-
- return transform_done;
+ return lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop), stride);
}
/* Loop blocks all the loops in SCOP. Returns true when we manage to
bool
scop_do_block (scop_p scop)
{
- bool strip_mined = false;
- bool interchanged = false;
-
store_scattering (scop);
- strip_mined = lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop));
- interchanged = scop_do_interchange (scop);
-
- /* If we don't interchange loops, then the strip mine is not
- profitable, and the transform is not a loop blocking. */
- if (!interchanged
- || !graphite_legal_transform (scop))
+ /* If we don't strip mine at least two loops, or not interchange
+ loops, the strip mine alone will not be profitable, and the
+ transform is not a loop blocking: so revert the transform. */
+ if (lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop), 0) < 2
+ || scop_do_interchange (scop) == 0)
{
restore_scattering (scop);
return false;
}
- else if (strip_mined && interchanged
- && dump_file && (dump_flags & TDF_DETAILS))
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "SCoP will be loop blocked.\n");
- return strip_mined || interchanged;
+ return true;
}
#endif
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