diff options
Diffstat (limited to 'gcc/fortran/trans-expr.c')
| -rw-r--r-- | gcc/fortran/trans-expr.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c index 98a54d9..454755b 100644 --- a/gcc/fortran/trans-expr.c +++ b/gcc/fortran/trans-expr.c @@ -2689,6 +2689,32 @@ gfc_optimize_len_trim (tree len, tree str, int kind) return -1; } +/* Helper to build a call to memcmp. */ + +static tree +build_memcmp_call (tree s1, tree s2, tree n) +{ + tree tmp; + + if (!POINTER_TYPE_P (TREE_TYPE (s1))) + s1 = gfc_build_addr_expr (pvoid_type_node, s1); + else + s1 = fold_convert (pvoid_type_node, s1); + + if (!POINTER_TYPE_P (TREE_TYPE (s2))) + s2 = gfc_build_addr_expr (pvoid_type_node, s2); + else + s2 = fold_convert (pvoid_type_node, s2); + + n = fold_convert (size_type_node, n); + + tmp = build_call_expr_loc (input_location, + builtin_decl_explicit (BUILT_IN_MEMCMP), + 3, s1, s2, n); + + return fold_convert (integer_type_node, tmp); +} + /* Compare two strings. If they are all single characters, the result is the subtraction of them. Otherwise, we build a library call. */ @@ -2730,6 +2756,26 @@ gfc_build_compare_string (tree len1, tree str1, tree len2, tree str2, int kind, return integer_one_node; } + /* We can compare via memcpy if the strings are known to be equal + in length and they are + - kind=1 + - kind=4 and the comparision is for (in)equality. */ + + if (INTEGER_CST_P (len1) && INTEGER_CST_P (len2) + && tree_int_cst_equal (len1, len2) + && (kind == 1 || code == EQ_EXPR || code == NE_EXPR)) + { + tree tmp; + tree chartype; + + chartype = gfc_get_char_type (kind); + tmp = fold_build2_loc (input_location, MULT_EXPR, TREE_TYPE(len1), + fold_convert (TREE_TYPE(len1), + TYPE_SIZE_UNIT(chartype)), + len1); + return build_memcmp_call (str1, str2, tmp); + } + /* Build a call for the comparison. */ if (kind == 1) fndecl = gfor_fndecl_compare_string; |