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authorspop <spop@138bc75d-0d04-0410-961f-82ee72b054a4>2010-02-06 17:40:58 +0000
committerspop <spop@138bc75d-0d04-0410-961f-82ee72b054a4>2010-02-06 17:40:58 +0000
commit4fe30658aab9f7e74524b27edf43944316ec00cc (patch)
treed46826408a5b7850a128e0a431b5408ac18ff717 /gcc/graphite-dependences.c
parentabc97125f23cb62c65ad140c43165fb3ea221149 (diff)
downloadgcc-4fe30658aab9f7e74524b27edf43944316ec00cc.tar.gz
Add missing function comments.
2010-01-20 Sebastian Pop <sebastian.pop@amd.com> * graphite-dependences.c (lexicographically_gt_p): Add comments. (build_lexicographically_gt_constraint): Same. (dependence_polyhedron_1): Same. (dependence_polyhedron): Same. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@156543 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/graphite-dependences.c')
-rw-r--r--gcc/graphite-dependences.c59
1 files changed, 45 insertions, 14 deletions
diff --git a/gcc/graphite-dependences.c b/gcc/graphite-dependences.c
index bc9d2708133..e096cba7e26 100644
--- a/gcc/graphite-dependences.c
+++ b/gcc/graphite-dependences.c
@@ -262,8 +262,13 @@ build_pairwise_scheduling (graphite_dim_t dim,
return res;
}
-/* Returns true when adding the lexicographical constraints at level I
- to the RES dependence polyhedron returns an empty polyhedron. */
+/* Returns true when adding to the RES dependence polyhedron the
+ lexicographical constraint: "DIM compared to DIM + OFFSET" returns
+ an empty polyhedron. The comparison depends on DIRECTION as: if
+ DIRECTION is equal to -1, the first dimension DIM to be compared
+ comes before the second dimension DIM + OFFSET, equal to 0 when DIM
+ and DIM + OFFSET are equal, and DIRECTION is set to 1 when DIM
+ comes after DIM + OFFSET. */
static bool
lexicographically_gt_p (ppl_Pointset_Powerset_C_Polyhedron_t res,
@@ -284,13 +289,21 @@ lexicographically_gt_p (ppl_Pointset_Powerset_C_Polyhedron_t res,
return !empty_p;
}
-/* Build the precedence constraints for the lexicographical comparison
- of time vectors RES following the lexicographical order. */
+/* Add to a non empty polyhedron RES the precedence constraints for
+ the lexicographical comparison of time vectors in RES following the
+ lexicographical order. DIM is the dimension of the polyhedron RES.
+ TDIM is the number of loops common to the two statements that are
+ compared lexicographically, i.e. the number of loops containing
+ both statements. OFFSET is the number of dimensions needed to
+ represent the first statement, i.e. dimT1 + dimI1 in the layout of
+ the RES polyhedron: T1|I1|T2|I2|S1|S2|G. DIRECTION is equal to 1
+ when statement 1 is after statement 2, equal to -1 when statement 1
+ is before statement 2. */
static void
build_lexicographically_gt_constraint (ppl_Pointset_Powerset_C_Polyhedron_t *res,
graphite_dim_t dim,
- graphite_dim_t tdim1,
+ graphite_dim_t tdim,
graphite_dim_t offset,
int direction)
{
@@ -299,19 +312,21 @@ build_lexicographically_gt_constraint (ppl_Pointset_Powerset_C_Polyhedron_t *res
if (lexicographically_gt_p (*res, dim, offset, direction, 0))
return;
- for (i = 0; i < tdim1 - 1; i++)
+ for (i = 0; i < tdim - 1; i++)
{
ppl_Pointset_Powerset_C_Polyhedron_t sceq;
+ /* All the dimensions up to I are equal, ... */
sceq = build_pairwise_scheduling (dim, i, offset, 0);
ppl_Pointset_Powerset_C_Polyhedron_intersection_assign (*res, sceq);
ppl_delete_Pointset_Powerset_C_Polyhedron (sceq);
+ /* ... and at depth I+1 they are not equal anymore. */
if (lexicographically_gt_p (*res, dim, offset, direction, i + 1))
return;
}
- if (i == tdim1 - 1)
+ if (i == tdim - 1)
{
ppl_delete_Pointset_Powerset_C_Polyhedron (*res);
ppl_new_Pointset_Powerset_C_Polyhedron_from_space_dimension (res, dim, 1);
@@ -327,14 +342,22 @@ build_lexicographically_gt_constraint (ppl_Pointset_Powerset_C_Polyhedron_t *res
| T1 and T2 the scattering dimensions for PDR1 and PDR2
| I1 and I2 the iteration domains
| S1 and S2 the subscripts
- | G the global parameters. */
+ | G the global parameters.
+
+ SCAT1 and SCAT2 are the scattering polyhedra for PDR1 and PDR2.
+ When ORIGINAL_SCATTERING_P is true, then the scattering polyhedra
+ SCAT1 and SCAT2 correspond to the original scattering of the
+ program, otherwise they correspond to the transformed scattering.
+
+ DIRECTION is equal to 1 when statement 1 is after statement 2,
+ equal to -1 when statement 1 is before statement 2. */
static poly_ddr_p
dependence_polyhedron_1 (poly_bb_p pbb1, poly_bb_p pbb2,
ppl_Pointset_Powerset_C_Polyhedron_t d1,
ppl_Pointset_Powerset_C_Polyhedron_t d2,
poly_dr_p pdr1, poly_dr_p pdr2,
- ppl_Polyhedron_t s1, ppl_Polyhedron_t s2,
+ ppl_Polyhedron_t scat1, ppl_Polyhedron_t scat2,
int direction,
bool original_scattering_p)
{
@@ -361,8 +384,8 @@ dependence_polyhedron_1 (poly_bb_p pbb1, poly_bb_p pbb2,
(&context, SCOP_CONTEXT (scop));
ppl_insert_dimensions_pointset (context, 0, dim - gdim);
- ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron (&sc1, s1);
- ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron (&sc2, s2);
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron (&sc1, scat1);
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron (&sc2, scat2);
id1 = map_into_dep_poly (dim, gdim, d1, ddim1, tdim1);
id2 = map_into_dep_poly (dim, gdim, d2, ddim2, tdim1 + ddim1 + tdim2);
@@ -405,14 +428,22 @@ dependence_polyhedron_1 (poly_bb_p pbb1, poly_bb_p pbb2,
}
/* Build the dependence polyhedron for data references PDR1 and PDR2.
- If possible use already cached information. */
+ If possible use already cached information.
+
+ SCAT1 and SCAT2 are the scattering polyhedra for PDR1 and PDR2.
+ When ORIGINAL_SCATTERING_P is true, then the scattering polyhedra
+ SCAT1 and SCAT2 correspond to the original scattering of the
+ program, otherwise they correspond to the transformed scattering.
+
+ DIRECTION is equal to 1 when statement 1 is after statement 2,
+ equal to -1 when statement 1 is before statement 2. */
static poly_ddr_p
dependence_polyhedron (poly_bb_p pbb1, poly_bb_p pbb2,
ppl_Pointset_Powerset_C_Polyhedron_t d1,
ppl_Pointset_Powerset_C_Polyhedron_t d2,
poly_dr_p pdr1, poly_dr_p pdr2,
- ppl_Polyhedron_t s1, ppl_Polyhedron_t s2,
+ ppl_Polyhedron_t scat1, ppl_Polyhedron_t scat2,
int direction,
bool original_scattering_p)
{
@@ -433,7 +464,7 @@ dependence_polyhedron (poly_bb_p pbb1, poly_bb_p pbb2,
}
res = dependence_polyhedron_1 (pbb1, pbb2, d1, d2, pdr1, pdr2,
- s1, s2, direction, original_scattering_p);
+ scat1, scat2, direction, original_scattering_p);
if (original_scattering_p)
*x = res;