diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 31 |
1 files changed, 26 insertions, 5 deletions
@@ -408,6 +408,9 @@ static int hash_arg_in_memory; each recording one expression's information. That expression is in the `exp' field. + The canon_exp field contains a canonical (from the point of view of + alias analysis) version of the `exp' field. + Those elements with the same hash code are chained in both directions through the `next_same_hash' and `prev_same_hash' fields. @@ -447,6 +450,7 @@ static int hash_arg_in_memory; struct table_elt { rtx exp; + rtx canon_exp; struct table_elt *next_same_hash; struct table_elt *prev_same_hash; struct table_elt *next_same_value; @@ -1498,6 +1502,7 @@ insert (x, classp, hash, mode) } elt->exp = x; + elt->canon_exp = NULL_RTX; elt->cost = COST (x); elt->next_same_value = 0; elt->prev_same_value = 0; @@ -1823,6 +1828,10 @@ invalidate (x, full_mode) return; case MEM: + /* Calculate the canonical version of X here so that + true_dependence doesn't generate new RTL for X on each call. */ + x = canon_rtx (x); + /* Remove all hash table elements that refer to overlapping pieces of memory. */ if (full_mode == VOIDmode) @@ -1835,11 +1844,23 @@ invalidate (x, full_mode) for (p = table[i]; p; p = next) { next = p->next_same_hash; - if (p->in_memory - && (GET_CODE (p->exp) != MEM - || true_dependence (x, full_mode, p->exp, - cse_rtx_varies_p))) - remove_from_table (p, i); + if (p->in_memory) + { + if (GET_CODE (p->exp) != MEM) + remove_from_table (p, i); + else + { + /* Just canonicalize the expression once; + otherwise each time we call invalidate + true_dependence will canonicalize the + expression again. */ + if (!p->canon_exp) + p->canon_exp = canon_rtx (p->exp); + if (true_dependence (x, full_mode, p->canon_exp, + cse_rtx_varies_p)) + remove_from_table (p, i); + } + } } } return; |