diff options
Diffstat (limited to 'gcc/tree-scalar-evolution.c')
| -rw-r--r-- | gcc/tree-scalar-evolution.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index ca808934efa..c923409d6ed 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -2547,10 +2547,13 @@ scev_reset (void) } /* Checks whether OP behaves as a simple affine iv of LOOP in STMT and returns - its BASE and STEP if possible. */ + its BASE and STEP if possible. If ALLOW_NONCONSTANT_STEP is true, we + want STEP to be invariant in LOOP. Otherwise we require it to be an + integer constant. */ bool -simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step) +simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step, + bool allow_nonconstant_step) { basic_block bb = bb_for_stmt (stmt); tree type, ev; @@ -2579,8 +2582,15 @@ simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step) return false; *step = CHREC_RIGHT (ev); - if (TREE_CODE (*step) != INTEGER_CST) + if (allow_nonconstant_step) + { + if (tree_contains_chrecs (*step, NULL) + || chrec_contains_symbols_defined_in_loop (*step, loop->num)) + return false; + } + else if (TREE_CODE (*step) != INTEGER_CST) return false; + *base = CHREC_LEFT (ev); if (tree_contains_chrecs (*base, NULL) || chrec_contains_symbols_defined_in_loop (*base, loop->num)) |