diff options
Diffstat (limited to 'gcc/tree-data-ref.c')
| -rw-r--r-- | gcc/tree-data-ref.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index 54494c2..d7a4253 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -3030,8 +3030,8 @@ subscript_dependence_tester (struct data_dependence_relation *ddr) NB_LOOPS is the total number of loops we are considering. FIRST_LOOP_DEPTH is the loop->depth of the first loop in the analyzed loop nest. - Return FALSE if the dependence relation is outside of the loop nest - starting at FIRST_LOOP_DEPTH. + Return FALSE when fail to represent the data dependence as a distance + vector. Return TRUE otherwise. */ static bool @@ -3196,6 +3196,23 @@ build_classic_dist_vector (struct data_dependence_relation *ddr, DDR_DIST_VECT (ddr) = dist_v; DDR_SIZE_VECT (ddr) = nb_loops; + + /* Verify a basic constraint: classic distance vectors should always + be lexicographically positive. */ + if (!lambda_vector_lexico_pos (DDR_DIST_VECT (ddr), + DDR_SIZE_VECT (ddr))) + { + if (DDR_SIZE_VECT (ddr) == 1) + /* This one is simple to fix, and can be fixed. + Multidimensional arrays cannot be fixed that simply. */ + lambda_vector_negate (DDR_DIST_VECT (ddr), DDR_DIST_VECT (ddr), + DDR_SIZE_VECT (ddr)); + else + /* This is not valid: we need the delta test for properly + fixing all this. */ + return false; + } + return true; } |