diff options
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 61 |
1 files changed, 48 insertions, 13 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 20ccda3..7297f67 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -85,7 +85,7 @@ static REAL_VALUE_TYPE dconstpi; static REAL_VALUE_TYPE dconste; static int get_pointer_alignment (tree, unsigned int); -static tree c_strlen (tree); +static tree c_strlen (tree, int); static const char *c_getstr (tree); static rtx c_readstr (const char *, enum machine_mode); static int target_char_cast (tree, char *); @@ -242,19 +242,42 @@ get_pointer_alignment (tree exp, unsigned int max_align) way, because it could contain a zero byte in the middle. TREE_STRING_LENGTH is the size of the character array, not the string. + ONLY_VALUE should be non-zero if the result is not going to be emitted + into the instruction stream and zero if it si going to be expanded. + E.g. with i++ ? "foo" : "bar", if ONLY_VALUE is non-zero, constant 3 + is returned, otherwise NULL, since + len = c_strlen (src, 1); if (len) expand_expr (len, ...); would not + evaluate the side-effects. + The value returned is of type `ssizetype'. Unfortunately, string_constant can't access the values of const char arrays with initializers, so neither can we do so here. */ static tree -c_strlen (tree src) +c_strlen (tree src, int only_value) { tree offset_node; HOST_WIDE_INT offset; int max; const char *ptr; + STRIP_NOPS (src); + if (TREE_CODE (src) == COND_EXPR + && (only_value || !TREE_SIDE_EFFECTS (TREE_OPERAND (src, 0)))) + { + tree len1, len2; + + len1 = c_strlen (TREE_OPERAND (src, 1), only_value); + len2 = c_strlen (TREE_OPERAND (src, 2), only_value); + if (tree_int_cst_equal (len1, len2)) + return len1; + } + + if (TREE_CODE (src) == COMPOUND_EXPR + && (only_value || !TREE_SIDE_EFFECTS (TREE_OPERAND (src, 0)))) + return c_strlen (TREE_OPERAND (src, 1), only_value); + src = string_constant (src, &offset_node); if (src == 0) return 0; @@ -2176,10 +2199,22 @@ expand_builtin_strlen (tree arglist, rtx target, int align; /* If the length can be computed at compile-time, return it. */ - len = c_strlen (src); + len = c_strlen (src, 0); if (len) return expand_expr (len, target, target_mode, EXPAND_NORMAL); + /* If the length can be computed at compile-time and is constant + integer, but there are side-effects in src, evaluate + src for side-effects, then return len. + E.g. x = strlen (i++ ? "xfoo" + 1 : "bar"); + can be optimized into: i++; x = 3; */ + len = c_strlen (src, 1); + if (len && TREE_CODE (len) == INTEGER_CST) + { + expand_expr (src, const0_rtx, VOIDmode, EXPAND_NORMAL); + return expand_expr (len, target, target_mode, EXPAND_NORMAL); + } + align = get_pointer_alignment (src, BIGGEST_ALIGNMENT) / BITS_PER_UNIT; /* If SRC is not a pointer type, don't do this operation inline. */ @@ -2759,7 +2794,7 @@ expand_builtin_strcpy (tree arglist, rtx target, enum machine_mode mode) return 0; src = TREE_VALUE (TREE_CHAIN (arglist)); - len = c_strlen (src); + len = c_strlen (src, 1); if (len == 0 || TREE_SIDE_EFFECTS (len)) return 0; @@ -2802,7 +2837,7 @@ expand_builtin_stpcpy (tree arglist, rtx target, enum machine_mode mode) because the latter will potentially produce pessimized code when used to produce the return value. */ src = TREE_VALUE (TREE_CHAIN (arglist)); - if (! c_getstr (src) || ! (len = c_strlen (src))) + if (! c_getstr (src) || ! (len = c_strlen (src, 0))) return 0; dst = TREE_VALUE (arglist); @@ -2841,7 +2876,7 @@ expand_builtin_strncpy (tree arglist, rtx target, enum machine_mode mode) return 0; else { - tree slen = c_strlen (TREE_VALUE (TREE_CHAIN (arglist))); + tree slen = c_strlen (TREE_VALUE (TREE_CHAIN (arglist)), 1); tree len = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); tree fn; @@ -3267,8 +3302,8 @@ expand_builtin_strcmp (tree exp, rtx target, enum machine_mode mode) enum machine_mode insn_mode = insn_data[(int) CODE_FOR_cmpstrsi].operand[0].mode; - len1 = c_strlen (arg1); - len2 = c_strlen (arg2); + len1 = c_strlen (arg1, 1); + len2 = c_strlen (arg2, 1); if (len1) len1 = size_binop (PLUS_EXPR, ssize_int (1), len1); @@ -3414,8 +3449,8 @@ expand_builtin_strncmp (tree exp, rtx target, enum machine_mode mode) enum machine_mode insn_mode = insn_data[(int) CODE_FOR_cmpstrsi].operand[0].mode; - len1 = c_strlen (arg1); - len2 = c_strlen (arg2); + len1 = c_strlen (arg1, 1); + len2 = c_strlen (arg2, 1); if (len1) len1 = size_binop (PLUS_EXPR, ssize_int (1), len1); @@ -4210,7 +4245,7 @@ expand_builtin_fputs (tree arglist, int ignore, int unlocked) /* Get the length of the string passed to fputs. If the length can't be determined, punt. */ - if (!(len = c_strlen (TREE_VALUE (arglist))) + if (!(len = c_strlen (TREE_VALUE (arglist), 1)) || TREE_CODE (len) != INTEGER_CST) return 0; @@ -4549,7 +4584,7 @@ expand_builtin_sprintf (tree arglist, rtx target, enum machine_mode mode) if (target != const0_rtx) { - len = c_strlen (arg); + len = c_strlen (arg, 1); if (! len || TREE_CODE (len) != INTEGER_CST) return 0; } @@ -5441,7 +5476,7 @@ fold_builtin (tree exp) case BUILT_IN_STRLEN: if (validate_arglist (arglist, POINTER_TYPE, VOID_TYPE)) { - tree len = c_strlen (TREE_VALUE (arglist)); + tree len = c_strlen (TREE_VALUE (arglist), 0); if (len) { /* Convert from the internal "sizetype" type to "size_t". */ |