From 71dea1dd60888030f3130f16933becdf597538ab Mon Sep 17 00:00:00 2001 From: Wilco Dijkstra Date: Wed, 5 Oct 2016 12:31:05 +0000 Subject: [PATCH] Move all existing strchr and strrchr folding from builtins.c to gimple-fold.c. gcc/ * builtins.c (fold_builtin_strchr): Remove function. (fold_builtin_strrchr): Likewise. (fold_builtin2): Remove strchr, index, strrchr, rindex cases. * gimple-fold.c (target_char_cst_p): New function. (gimple_fold_builtin_strchr) Add more foldings. (gimple_fold_builtin): Add index, strrchr, rindex cases. From-SVN: r240782 --- gcc/ChangeLog | 9 ++++ gcc/builtins.c | 128 ---------------------------------------------- gcc/gimple-fold.c | 69 ++++++++++++++++++++++--- 3 files changed, 70 insertions(+), 136 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4fcd8f5b69e..81e4235d2e4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2016-10-05 Wilco Dijkstra + + * builtins.c (fold_builtin_strchr): Remove function. + (fold_builtin_strrchr): Likewise. + (fold_builtin2): Remove strchr, index, strrchr, rindex cases. + * gimple-fold.c (target_char_cst_p): New function. + (gimple_fold_builtin_strchr) Add more foldings. + (gimple_fold_builtin): Add index, strrchr, rindex cases. + 2016-10-05 Richard Biener PR middle-end/77863 diff --git a/gcc/builtins.c b/gcc/builtins.c index 35cb109bc4b..facecd3cfef 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -148,7 +148,6 @@ static tree rewrite_call_expr (location_t, tree, int, tree, int, ...); static bool validate_arg (const_tree, enum tree_code code); static rtx expand_builtin_fabs (tree, rtx, rtx); static rtx expand_builtin_signbit (tree, rtx); -static tree fold_builtin_strchr (location_t, tree, tree, tree); static tree fold_builtin_memchr (location_t, tree, tree, tree, tree); static tree fold_builtin_memcmp (location_t, tree, tree, tree); static tree fold_builtin_strcmp (location_t, tree, tree); @@ -168,7 +167,6 @@ static tree fold_builtin_varargs (location_t, tree, tree*, int); static tree fold_builtin_strpbrk (location_t, tree, tree, tree); static tree fold_builtin_strstr (location_t, tree, tree, tree); -static tree fold_builtin_strrchr (location_t, tree, tree, tree); static tree fold_builtin_strspn (location_t, tree, tree); static tree fold_builtin_strcspn (location_t, tree, tree); @@ -8395,14 +8393,6 @@ fold_builtin_2 (location_t loc, tree fndecl, tree arg0, tree arg1) case BUILT_IN_STRCSPN: return fold_builtin_strcspn (loc, arg0, arg1); - case BUILT_IN_STRCHR: - case BUILT_IN_INDEX: - return fold_builtin_strchr (loc, arg0, arg1, type); - - case BUILT_IN_STRRCHR: - case BUILT_IN_RINDEX: - return fold_builtin_strrchr (loc, arg0, arg1, type); - case BUILT_IN_STRCMP: return fold_builtin_strcmp (loc, arg0, arg1); @@ -8895,124 +8885,6 @@ fold_builtin_strstr (location_t loc, tree s1, tree s2, tree type) } } -/* Simplify a call to the strchr builtin. S1 and S2 are the arguments to - the call, and TYPE is its return type. - - Return NULL_TREE if no simplification was possible, otherwise return the - simplified form of the call as a tree. - - The simplified form may be a constant or other expression which - computes the same value, but in a more efficient manner (including - calls to other builtin functions). - - The call may contain arguments which need to be evaluated, but - which are not useful to determine the result of the call. In - this case we return a chain of COMPOUND_EXPRs. The LHS of each - COMPOUND_EXPR will be an argument which must be evaluated. - COMPOUND_EXPRs are chained through their RHS. The RHS of the last - COMPOUND_EXPR in the chain will contain the tree for the simplified - form of the builtin function call. */ - -static tree -fold_builtin_strchr (location_t loc, tree s1, tree s2, tree type) -{ - if (!validate_arg (s1, POINTER_TYPE) - || !validate_arg (s2, INTEGER_TYPE)) - return NULL_TREE; - else - { - const char *p1; - - if (TREE_CODE (s2) != INTEGER_CST) - return NULL_TREE; - - p1 = c_getstr (s1); - if (p1 != NULL) - { - char c; - const char *r; - tree tem; - - if (target_char_cast (s2, &c)) - return NULL_TREE; - - r = strchr (p1, c); - - if (r == NULL) - return build_int_cst (TREE_TYPE (s1), 0); - - /* Return an offset into the constant string argument. */ - tem = fold_build_pointer_plus_hwi_loc (loc, s1, r - p1); - return fold_convert_loc (loc, type, tem); - } - return NULL_TREE; - } -} - -/* Simplify a call to the strrchr builtin. S1 and S2 are the arguments to - the call, and TYPE is its return type. - - Return NULL_TREE if no simplification was possible, otherwise return the - simplified form of the call as a tree. - - The simplified form may be a constant or other expression which - computes the same value, but in a more efficient manner (including - calls to other builtin functions). - - The call may contain arguments which need to be evaluated, but - which are not useful to determine the result of the call. In - this case we return a chain of COMPOUND_EXPRs. The LHS of each - COMPOUND_EXPR will be an argument which must be evaluated. - COMPOUND_EXPRs are chained through their RHS. The RHS of the last - COMPOUND_EXPR in the chain will contain the tree for the simplified - form of the builtin function call. */ - -static tree -fold_builtin_strrchr (location_t loc, tree s1, tree s2, tree type) -{ - if (!validate_arg (s1, POINTER_TYPE) - || !validate_arg (s2, INTEGER_TYPE)) - return NULL_TREE; - else - { - tree fn; - const char *p1; - - if (TREE_CODE (s2) != INTEGER_CST) - return NULL_TREE; - - p1 = c_getstr (s1); - if (p1 != NULL) - { - char c; - const char *r; - tree tem; - - if (target_char_cast (s2, &c)) - return NULL_TREE; - - r = strrchr (p1, c); - - if (r == NULL) - return build_int_cst (TREE_TYPE (s1), 0); - - /* Return an offset into the constant string argument. */ - tem = fold_build_pointer_plus_hwi_loc (loc, s1, r - p1); - return fold_convert_loc (loc, type, tem); - } - - if (! integer_zerop (s2)) - return NULL_TREE; - - fn = builtin_decl_implicit (BUILT_IN_STRCHR); - if (!fn) - return NULL_TREE; - - /* Transform strrchr(s1, '\0') to strchr(s1, '\0'). */ - return build_call_expr_loc (loc, fn, 2, s1, s2); - } -} - /* Simplify a call to the strpbrk builtin. S1 and S2 are the arguments to the call, and TYPE is its return type. diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 1aae8456bc8..59c4cb80a36 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -57,6 +57,20 @@ along with GCC; see the file COPYING3. If not see #include "tree-cfg.h" +/* Return true if T is a constant and the value cast to a target char + can be represented by a host char. + Store the casted char constant in *P if so. */ + +static bool +target_char_cst_p (tree t, char *p) +{ + if (!tree_fits_uhwi_p (t) || CHAR_TYPE_SIZE != HOST_BITS_PER_CHAR) + return false; + + *p = (char)tree_to_uhwi (t); + return true; +} + /* Return true when DECL can be referenced from current unit. FROM_DECL (if non-null) specify constructor of variable DECL was taken from. We can get declarations that are not possible to reference for various @@ -1457,23 +1471,61 @@ gimple_fold_builtin_strncpy (gimple_stmt_iterator *gsi, return true; } -/* Simplify strchr (str, 0) into str + strlen (str). +/* Fold function call to builtin strchr or strrchr. + If both arguments are constant, evaluate and fold the result, + otherwise simplify str(r)chr (str, 0) into str + strlen (str). In general strlen is significantly faster than strchr due to being a simpler operation. */ static bool -gimple_fold_builtin_strchr (gimple_stmt_iterator *gsi) +gimple_fold_builtin_strchr (gimple_stmt_iterator *gsi, bool is_strrchr) { gimple *stmt = gsi_stmt (*gsi); tree str = gimple_call_arg (stmt, 0); tree c = gimple_call_arg (stmt, 1); location_t loc = gimple_location (stmt); + const char *p; + char ch; - if (optimize_function_for_size_p (cfun)) + if (!gimple_call_lhs (stmt)) return false; - if (!integer_zerop (c) || !gimple_call_lhs (stmt)) + if ((p = c_getstr (str)) && target_char_cst_p (c, &ch)) + { + const char *p1 = is_strrchr ? strrchr (p, ch) : strchr (p, ch); + + if (p1 == NULL) + { + replace_call_with_value (gsi, integer_zero_node); + return true; + } + + tree len = build_int_cst (size_type_node, p1 - p); + gimple_seq stmts = NULL; + gimple *new_stmt = gimple_build_assign (gimple_call_lhs (stmt), + POINTER_PLUS_EXPR, str, len); + gimple_seq_add_stmt_without_update (&stmts, new_stmt); + gsi_replace_with_seq_vops (gsi, stmts); + return true; + } + + if (!integer_zerop (c)) return false; + /* Transform strrchr (s, 0) to strchr (s, 0) when optimizing for size. */ + if (optimize_function_for_size_p (cfun)) + { + tree strchr_fn = builtin_decl_implicit (BUILT_IN_STRCHR); + + if (is_strrchr && strchr_fn) + { + gimple *repl = gimple_build_call (strchr_fn, 2, str, c); + replace_call_with_call_and_fold (gsi, repl); + return true; + } + + return false; + } + tree len; tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN); @@ -2947,11 +2999,12 @@ gimple_fold_builtin (gimple_stmt_iterator *gsi) gimple_call_arg (stmt, 1)); case BUILT_IN_STRNCAT: return gimple_fold_builtin_strncat (gsi); + case BUILT_IN_INDEX: case BUILT_IN_STRCHR: - if (gimple_fold_builtin_strchr (gsi)) - return true; - /* Perform additional folding in builtin.c. */ - break; + return gimple_fold_builtin_strchr (gsi, false); + case BUILT_IN_RINDEX: + case BUILT_IN_STRRCHR: + return gimple_fold_builtin_strchr (gsi, true); case BUILT_IN_FPUTS: return gimple_fold_builtin_fputs (gsi, gimple_call_arg (stmt, 0), gimple_call_arg (stmt, 1), false); -- 2.30.2