diff options
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 8d642de..a085ab2 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -1348,6 +1348,10 @@ get_range_strlen_tree (tree arg, bitmap *visited, strlen_range_kind rkind, } } + /* Set if VAL represents the maximum length based on array size (set + when exact length cannot be determined). */ + bool maxbound = false; + if (!val && rkind == SRK_LENRANGE) { if (TREE_CODE (arg) == ADDR_EXPR) @@ -1443,6 +1447,7 @@ get_range_strlen_tree (tree arg, bitmap *visited, strlen_range_kind rkind, pdata->minlen = ssize_int (0); } } + maxbound = true; } if (!val) @@ -1456,25 +1461,23 @@ get_range_strlen_tree (tree arg, bitmap *visited, strlen_range_kind rkind, && tree_int_cst_lt (val, pdata->minlen))) pdata->minlen = val; - if (pdata->maxbound) + if (pdata->maxbound && TREE_CODE (pdata->maxbound) == INTEGER_CST) { /* Adjust the tighter (more optimistic) string length bound if necessary and proceed to adjust the more conservative bound. */ if (TREE_CODE (val) == INTEGER_CST) { - if (TREE_CODE (pdata->maxbound) == INTEGER_CST) - { - if (tree_int_cst_lt (pdata->maxbound, val)) - pdata->maxbound = val; - } - else - pdata->maxbound = build_all_ones_cst (size_type_node); + if (tree_int_cst_lt (pdata->maxbound, val)) + pdata->maxbound = val; } else pdata->maxbound = val; } - else + else if (pdata->maxbound || maxbound) + /* Set PDATA->MAXBOUND only if it either isn't INTEGER_CST or + if VAL corresponds to the maximum length determined based + on the type of the object. */ pdata->maxbound = val; if (tight_bound) @@ -1655,8 +1658,11 @@ get_range_strlen (tree arg, bitmap *visited, /* Try to obtain the range of the lengths of the string(s) referenced by ARG, or the size of the largest array ARG refers to if the range - of lengths cannot be determined, and store all in *PDATA. ELTSIZE - is the expected size of the string element in bytes: 1 for char and + of lengths cannot be determined, and store all in *PDATA which must + be zero-initialized on input except PDATA->MAXBOUND may be set to + a non-null tree node other than INTEGER_CST to request to have it + set to the length of the longest string in a PHI. ELTSIZE is + the expected size of the string element in bytes: 1 for char and some power of 2 for wide characters. Return true if the range [PDATA->MINLEN, PDATA->MAXLEN] is suitable for optimization. Returning false means that a nonzero PDATA->MINLEN @@ -1668,6 +1674,7 @@ bool get_range_strlen (tree arg, c_strlen_data *pdata, unsigned eltsize) { bitmap visited = NULL; + tree maxbound = pdata->maxbound; if (!get_range_strlen (arg, &visited, SRK_LENRANGE, pdata, eltsize)) { @@ -1680,9 +1687,10 @@ get_range_strlen (tree arg, c_strlen_data *pdata, unsigned eltsize) else if (!pdata->minlen) pdata->minlen = ssize_int (0); - /* Unless its null, leave the more conservative MAXBOUND unchanged. */ - if (!pdata->maxbound) - pdata->maxbound = pdata->maxlen; + /* If it's unchanged from it initial non-null value, set the conservative + MAXBOUND to SIZE_MAX. Otherwise leave it null (if it is null). */ + if (maxbound && pdata->maxbound == maxbound) + pdata->maxbound = build_all_ones_cst (size_type_node); if (visited) BITMAP_FREE (visited); |