diff options
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 1521 |
1 files changed, 1441 insertions, 80 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 33fca2ab32e..b0375c377aa 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -68,11 +68,10 @@ const char *const built_in_names[(int) END_BUILTINS] = tree built_in_decls[(int) END_BUILTINS]; /* Declarations used when constructing the builtin implicitly in the compiler. It may be NULL_TREE when this is invalid (for instance runtime is not - required to implement the function call in all cases. */ + required to implement the function call in all cases). */ tree implicit_built_in_decls[(int) END_BUILTINS]; static int get_pointer_alignment (tree, unsigned int); -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 *); @@ -96,7 +95,6 @@ static void expand_errno_check (tree, rtx); static rtx expand_builtin_mathfn (tree, rtx, rtx); static rtx expand_builtin_mathfn_2 (tree, rtx, rtx); static rtx expand_builtin_mathfn_3 (tree, rtx, rtx); -static rtx expand_builtin_constant_p (tree, enum machine_mode); static rtx expand_builtin_args_info (tree); static rtx expand_builtin_next_arg (tree); static rtx expand_builtin_va_start (tree); @@ -163,6 +161,22 @@ static tree fold_builtin_strcmp (tree); static tree fold_builtin_strncmp (tree); static tree fold_builtin_signbit (tree); +static tree simplify_builtin_memcmp (tree); +static tree simplify_builtin_strcmp (tree); +static tree simplify_builtin_strncmp (tree); +static tree simplify_builtin_strpbrk (tree); +static tree simplify_builtin_strstr (tree); +static tree simplify_builtin_strchr (tree); +static tree simplify_builtin_strrchr (tree); +static tree simplify_builtin_strcat (tree); +static tree simplify_builtin_strncat (tree); +static tree simplify_builtin_strspn (tree); +static tree simplify_builtin_strcspn (tree); +static void simplify_builtin_next_arg (tree); +static void simplify_builtin_va_start (tree); +static tree simplify_builtin_sprintf (tree, int); + + /* Return the alignment in bits of EXP, a pointer valued expression. But don't return more than MAX_ALIGN no matter what. The alignment returned is, by default, the alignment of the thing that @@ -247,7 +261,7 @@ get_pointer_alignment (tree exp, unsigned int max_align) Unfortunately, string_constant can't access the values of const char arrays with initializers, so neither can we do so here. */ -static tree +tree c_strlen (tree src, int only_value) { tree offset_node; @@ -407,6 +421,21 @@ target_char_cast (tree cst, char *p) return 0; } +/* Similar to save_expr, but assumes that arbitrary code is not executed + in between the multiple evaluations. In particular, we assume that a + non-addressable local variable will not be modified. */ + +static tree +builtin_save_expr (tree exp) +{ + if (TREE_ADDRESSABLE (exp) == 0 + && (TREE_CODE (exp) == PARM_DECL + || (TREE_CODE (exp) == VAR_DECL && !TREE_STATIC (exp)))) + return exp; + + return save_expr (exp); +} + /* Given TEM, a pointer to a stack frame, follow the dynamic chain COUNT times to get the address of either a higher stack frame, or a return address located within it (depending on FNDECL_CODE). */ @@ -739,6 +768,79 @@ expand_builtin_longjmp (rtx buf_addr, rtx value) } } +/* Expand a call to __builtin_nonlocal_goto. We're passed the target label + and the address of the save area. */ + +static rtx +expand_builtin_nonlocal_goto (tree arglist) +{ + tree t_label, t_save_area; + rtx r_label, r_save_area, r_fp, r_sp, insn; + + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + t_label = TREE_VALUE (arglist); + arglist = TREE_CHAIN (arglist); + t_save_area = TREE_VALUE (arglist); + + r_label = expand_expr (t_label, NULL_RTX, VOIDmode, 0); + r_save_area = expand_expr (t_save_area, NULL_RTX, VOIDmode, 0); + r_fp = gen_rtx_MEM (Pmode, r_save_area); + r_sp = gen_rtx_MEM (STACK_SAVEAREA_MODE (SAVE_NONLOCAL), + plus_constant (r_save_area, GET_MODE_SIZE (Pmode))); + + current_function_has_nonlocal_goto = 1; + +#if HAVE_nonlocal_goto + /* ??? We no longer need to pass the static chain value, afaik. */ + if (HAVE_nonlocal_goto) + emit_insn (gen_nonlocal_goto (const0_rtx, r_label, r_sp, r_fp)); + else +#endif + { + r_label = copy_to_reg (r_label); + + emit_insn (gen_rtx_CLOBBER (VOIDmode, + gen_rtx_MEM (BLKmode, + gen_rtx_SCRATCH (VOIDmode)))); + + emit_insn (gen_rtx_CLOBBER (VOIDmode, + gen_rtx_MEM (BLKmode, + hard_frame_pointer_rtx))); + + /* Restore frame pointer for containing function. + This sets the actual hard register used for the frame pointer + to the location of the function's incoming static chain info. + The non-local goto handler will then adjust it to contain the + proper value and reload the argument pointer, if needed. */ + emit_move_insn (hard_frame_pointer_rtx, r_fp); + emit_stack_restore (SAVE_NONLOCAL, r_sp, NULL_RTX); + + /* USE of hard_frame_pointer_rtx added for consistency; + not clear if really needed. */ + emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); + emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx)); + emit_indirect_jump (r_label); + } + + /* Search backwards to the jump insn and mark it as a + non-local goto. */ + for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) + { + if (GET_CODE (insn) == JUMP_INSN) + { + REG_NOTES (insn) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO, + const0_rtx, REG_NOTES (insn)); + break; + } + else if (GET_CODE (insn) == CALL_INSN) + break; + } + + return const0_rtx; +} + /* __builtin_update_setjmp_buf is passed a pointer to an array of five words (not all will be used on all machines) that was passed to __builtin_setjmp. It updates the stack pointer in that block to correspond to the current @@ -1230,7 +1332,7 @@ expand_builtin_apply (rtx function, rtx arguments, rtx argsize) } /* All arguments and registers used for the call are set up by now! */ - function = prepare_call_address (function, NULL_TREE, &call_fusage, 0, 0); + function = prepare_call_address (function, NULL, &call_fusage, 0, 0); /* Ensure address is valid. SYMBOL_REF is already valid, so no need, and we don't want to load it into a register as an optimization, @@ -1384,32 +1486,6 @@ expand_builtin_classify_type (tree arglist) return GEN_INT (no_type_class); } -/* Expand expression EXP, which is a call to __builtin_constant_p. */ - -static rtx -expand_builtin_constant_p (tree arglist, enum machine_mode target_mode) -{ - rtx tmp; - - if (arglist == 0) - return const0_rtx; - arglist = TREE_VALUE (arglist); - - /* We have taken care of the easy cases during constant folding. This - case is not obvious, so emit (constant_p_rtx (ARGLIST)) and let CSE - get a chance to see if it can deduce whether ARGLIST is constant. - If CSE isn't going to run, of course, don't bother waiting. */ - - if (cse_not_expected) - return const0_rtx; - - current_function_calls_constant_p = 1; - - tmp = expand_expr (arglist, NULL_RTX, VOIDmode, 0); - tmp = gen_rtx_CONSTANT_P_RTX (target_mode, tmp); - return tmp; -} - /* This helper macro, meant to be used in mathfn_built_in below, determines which among a set of three builtin math functions is appropriate for a given type mode. The `F' and `L' cases are @@ -1682,7 +1758,7 @@ expand_builtin_mathfn (tree exp, rtx target, rtx subtarget) /* Wrap the computation of the argument in a SAVE_EXPR, as we may need to expand the argument again. This way, we will not perform side-effects more the once. */ - narg = save_expr (arg); + narg = builtin_save_expr (arg); if (narg != arg) { arglist = build_tree_list (NULL_TREE, arg); @@ -1821,8 +1897,8 @@ expand_builtin_mathfn_2 (tree exp, rtx target, rtx subtarget) if (! flag_errno_math || ! HONOR_NANS (mode)) errno_set = false; - /* Alway stabilize the argument list. */ - narg = save_expr (arg1); + /* Always stabilize the argument list. */ + narg = builtin_save_expr (arg1); if (narg != arg1) { temp = build_tree_list (NULL_TREE, narg); @@ -1831,7 +1907,7 @@ expand_builtin_mathfn_2 (tree exp, rtx target, rtx subtarget) else temp = TREE_CHAIN (arglist); - narg = save_expr (arg0); + narg = builtin_save_expr (arg0); if (narg != arg0) { arglist = tree_cons (NULL_TREE, narg, temp); @@ -3488,8 +3564,8 @@ expand_builtin_strcmp (tree exp, rtx target, enum machine_mode mode) result = gen_reg_rtx (insn_mode); /* Stabilize the arguments in case gen_cmpstrsi fails. */ - arg1 = save_expr (arg1); - arg2 = save_expr (arg2); + arg1 = builtin_save_expr (arg1); + arg2 = builtin_save_expr (arg2); arg1_rtx = get_memory_rtx (arg1); arg2_rtx = get_memory_rtx (arg2); @@ -3659,9 +3735,9 @@ expand_builtin_strncmp (tree exp, rtx target, enum machine_mode mode) result = gen_reg_rtx (insn_mode); /* Stabilize the arguments in case gen_cmpstrsi fails. */ - arg1 = save_expr (arg1); - arg2 = save_expr (arg2); - len = save_expr (len); + arg1 = builtin_save_expr (arg1); + arg2 = builtin_save_expr (arg2); + len = builtin_save_expr (len); arg1_rtx = get_memory_rtx (arg1); arg2_rtx = get_memory_rtx (arg2); @@ -3731,7 +3807,7 @@ expand_builtin_strcat (tree arglist, rtx target, enum machine_mode mode) arglist = tree_cons (NULL_TREE, src, arglist); /* We're going to use dst more than once. */ - dst = save_expr (dst); + dst = builtin_save_expr (dst); /* Create strlen (dst). */ newdst = @@ -4401,6 +4477,12 @@ expand_builtin_alloca (tree arglist, rtx target) rtx op0; rtx result; + /* In -fmudflap-instrumented code, alloca() and __builtin_alloca() + should always expand to function calls. These can be intercepted + in libmudflap. */ + if (flag_mudflap) + return 0; + if (!validate_arglist (arglist, INTEGER_TYPE, VOID_TYPE)) return 0; @@ -4748,6 +4830,7 @@ build_string_literal (int len, const char *str) type = build_array_type (elem, index); TREE_TYPE (t) = type; TREE_CONSTANT (t) = 1; + TREE_INVARIANT (t) = 1; TREE_READONLY (t) = 1; TREE_STATIC (t) = 1; @@ -5041,6 +5124,111 @@ expand_builtin_sprintf (tree arglist, rtx target, enum machine_mode mode) return 0; } +/* Expand a call to either the entry or exit function profiler. */ + +static rtx +expand_builtin_profile_func (bool exitp) +{ + rtx this, which; + + this = DECL_RTL (current_function_decl); + if (GET_CODE (this) == MEM) + this = XEXP (this, 0); + else + abort (); + + if (exitp) + which = profile_function_exit_libfunc; + else + which = profile_function_entry_libfunc; + + emit_library_call (which, LCT_NORMAL, VOIDmode, 2, this, Pmode, + expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS, + 0, hard_frame_pointer_rtx), + Pmode); + + return const0_rtx; +} + +/* Given a trampoline address, make sure it satisfies TRAMPOLINE_ALIGNMENT. */ + +static rtx +round_trampoline_addr (rtx tramp) +{ + rtx temp, addend, mask; + + /* If we don't need too much alignment, we'll have been guaranteed + proper alignment by get_trampoline_type. */ + if (TRAMPOLINE_ALIGNMENT <= STACK_BOUNDARY) + return tramp; + + /* Round address up to desired boundary. */ + temp = gen_reg_rtx (Pmode); + addend = GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1); + mask = GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT); + + temp = expand_simple_binop (Pmode, PLUS, tramp, addend, + temp, 0, OPTAB_LIB_WIDEN); + tramp = expand_simple_binop (Pmode, AND, temp, mask, + temp, 0, OPTAB_LIB_WIDEN); + + return tramp; +} + +static rtx +expand_builtin_init_trampoline (tree arglist) +{ + tree t_tramp, t_func, t_chain; + rtx r_tramp, r_func, r_chain; +#ifdef TRAMPOLINE_TEMPLATE + rtx blktramp; +#endif + + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, + POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + t_tramp = TREE_VALUE (arglist); + arglist = TREE_CHAIN (arglist); + t_func = TREE_VALUE (arglist); + arglist = TREE_CHAIN (arglist); + t_chain = TREE_VALUE (arglist); + + r_tramp = expand_expr (t_tramp, NULL_RTX, VOIDmode, 0); + r_func = expand_expr (t_func, NULL_RTX, VOIDmode, 0); + r_chain = expand_expr (t_chain, NULL_RTX, VOIDmode, 0); + + /* Generate insns to initialize the trampoline. */ + r_tramp = round_trampoline_addr (r_tramp); +#ifdef TRAMPOLINE_TEMPLATE + blktramp = gen_rtx_MEM (BLKmode, r_tramp); + set_mem_align (blktramp, TRAMPOLINE_ALIGNMENT); + emit_block_move (blktramp, assemble_trampoline_template (), + GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL); +#endif + trampolines_created = 1; + INITIALIZE_TRAMPOLINE (r_tramp, r_func, r_chain); + + return const0_rtx; +} + +static rtx +expand_builtin_adjust_trampoline (tree arglist) +{ + rtx tramp; + + if (!validate_arglist (arglist, POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + tramp = expand_expr (TREE_VALUE (arglist), NULL_RTX, VOIDmode, 0); + tramp = round_trampoline_addr (tramp); +#ifdef TRAMPOLINE_ADJUST_ADDRESS + TRAMPOLINE_ADJUST_ADDRESS (tramp); +#endif + + return tramp; +} + /* Expand a call to the built-in signbit, signbitf or signbitl function. Return NULL_RTX if a normal call should be emitted rather than expanding the function in-line. EXP is the expression that is a call to the builtin @@ -5453,13 +5641,14 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode, /* Return the address of the first anonymous stack arg. */ case BUILT_IN_NEXT_ARG: + simplify_builtin_next_arg (arglist); return expand_builtin_next_arg (arglist); case BUILT_IN_CLASSIFY_TYPE: return expand_builtin_classify_type (arglist); case BUILT_IN_CONSTANT_P: - return expand_builtin_constant_p (arglist, target_mode); + return const0_rtx; case BUILT_IN_FRAME_ADDRESS: case BUILT_IN_RETURN_ADDRESS: @@ -5481,6 +5670,18 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode, return target; break; + case BUILT_IN_STACK_ALLOC: + expand_stack_alloc (TREE_VALUE (arglist), + TREE_VALUE (TREE_CHAIN (arglist))); + return const0_rtx; + + case BUILT_IN_STACK_SAVE: + return expand_stack_save (); + + case BUILT_IN_STACK_RESTORE: + expand_stack_restore (TREE_VALUE (arglist)); + return const0_rtx; + case BUILT_IN_FFS: case BUILT_IN_FFSL: case BUILT_IN_FFSLL: @@ -5684,6 +5885,12 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode, return const0_rtx; } + case BUILT_IN_NONLOCAL_GOTO: + target = expand_builtin_nonlocal_goto (arglist); + if (target) + return target; + break; + /* This updates the setjmp buffer that is its argument with the value of the current stack pointer. */ case BUILT_IN_UPDATE_SETJMP_BUF: @@ -5718,7 +5925,6 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode, if (target) return target; break; - case BUILT_IN_FPUTS_UNLOCKED: target = expand_builtin_fputs (arglist, target, true); if (target) @@ -5792,6 +5998,16 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode, expand_builtin_prefetch (arglist); return const0_rtx; + case BUILT_IN_PROFILE_FUNC_ENTER: + return expand_builtin_profile_func (false); + case BUILT_IN_PROFILE_FUNC_EXIT: + return expand_builtin_profile_func (true); + + case BUILT_IN_INIT_TRAMPOLINE: + return expand_builtin_init_trampoline (arglist); + case BUILT_IN_ADJUST_TRAMPOLINE: + return expand_builtin_adjust_trampoline (arglist); + case BUILT_IN_FORK: case BUILT_IN_EXECL: case BUILT_IN_EXECV: @@ -5927,6 +6143,44 @@ fold_builtin_constant_p (tree arglist) return 0; } +/* Fold a call to __builtin_expect, if we expect that a comparison against + the argument will fold to a constant. In practice, this means a true + constant or the address of a non-weak symbol. ARGLIST is the argument + list of the call. */ + +static tree +fold_builtin_expect (tree arglist) +{ + tree arg, inner; + + if (arglist == 0) + return 0; + + arg = TREE_VALUE (arglist); + + /* If the argument isn't invariant, then there's nothing we can do. */ + if (!TREE_INVARIANT (arg)) + return 0; + + /* If we're looking at an address of a weak decl, then do not fold. */ + inner = arg; + STRIP_NOPS (inner); + if (TREE_CODE (inner) == ADDR_EXPR) + { + do + { + inner = TREE_OPERAND (inner, 0); + } + while (TREE_CODE (inner) == COMPONENT_REF + || TREE_CODE (inner) == ARRAY_REF); + if (DECL_P (inner) && DECL_WEAK (inner)) + return 0; + } + + /* Otherwise, ARG already has the proper type for the return value. */ + return arg; +} + /* Fold a call to __builtin_classify_type. */ static tree @@ -6196,13 +6450,13 @@ fold_builtin_cabs (tree arglist, tree type) { tree rpart, ipart, result, arglist; - arg = save_expr (arg); + arg = builtin_save_expr (arg); rpart = fold (build1 (REALPART_EXPR, type, arg)); ipart = fold (build1 (IMAGPART_EXPR, type, arg)); - rpart = save_expr (rpart); - ipart = save_expr (ipart); + rpart = builtin_save_expr (rpart); + ipart = builtin_save_expr (ipart); result = fold (build (PLUS_EXPR, type, fold (build (MULT_EXPR, type, @@ -6995,11 +7249,16 @@ fold_builtin_isascii (tree arglist) /* Transform isascii(c) -> ((c & ~0x7f) == 0). */ tree arg = TREE_VALUE (arglist); - return fold (build (EQ_EXPR, integer_type_node, - build (BIT_AND_EXPR, integer_type_node, arg, - build_int_2 (~ (unsigned HOST_WIDE_INT) 0x7f, - ~ (HOST_WIDE_INT) 0)), - integer_zero_node)); + arg = fold (build (EQ_EXPR, integer_type_node, + build (BIT_AND_EXPR, integer_type_node, arg, + build_int_2 (~ (unsigned HOST_WIDE_INT) 0x7f, + ~ (HOST_WIDE_INT) 0)), + integer_zero_node)); + + if (in_gimple_form && !TREE_CONSTANT (arg)) + return NULL_TREE; + else + return arg; } } @@ -7038,15 +7297,19 @@ fold_builtin_isdigit (tree arglist) build_int_2 (TARGET_DIGIT0, 0))); arg = build (LE_EXPR, integer_type_node, arg, fold_convert (unsigned_type_node, build_int_2 (9, 0))); - return fold (arg); + arg = fold (arg); + if (in_gimple_form && !TREE_CONSTANT (arg)) + return NULL_TREE; + else + return arg; } } /* Used by constant folding to eliminate some builtin calls early. EXP is the CALL_EXPR of a call to a builtin function. */ -tree -fold_builtin (tree exp) +static tree +fold_builtin_1 (tree exp) { tree fndecl = get_callee_fndecl (exp); tree arglist = TREE_OPERAND (exp, 1); @@ -7060,6 +7323,9 @@ fold_builtin (tree exp) case BUILT_IN_CONSTANT_P: return fold_builtin_constant_p (arglist); + case BUILT_IN_EXPECT: + return fold_builtin_expect (arglist); + case BUILT_IN_CLASSIFY_TYPE: return fold_builtin_classify_type (arglist); @@ -7557,6 +7823,24 @@ fold_builtin (tree exp) return 0; } +/* A wrapper function for builtin folding that prevents warnings for + "statement without effect" and the like, caused by removing the + call node earlier than the warning is generated. */ + +tree +fold_builtin (tree exp) +{ + exp = fold_builtin_1 (exp); + if (exp) + { + /* ??? Don't clobber shared nodes such as integer_zero_node. */ + if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c') + exp = build1 (NOP_EXPR, TREE_TYPE (exp), exp); + TREE_NO_WARNING (exp) = 1; + } + return exp; +} + /* Conveniently construct a function call expression. */ tree @@ -7566,7 +7850,7 @@ build_function_call_expr (tree fn, tree arglist) call_expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (fn)), fn); call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)), - call_expr, arglist); + call_expr, arglist, NULL_TREE); return fold (call_expr); } @@ -7631,31 +7915,6 @@ default_expand_builtin (tree exp ATTRIBUTE_UNUSED, return NULL_RTX; } -/* Instantiate all remaining CONSTANT_P_RTX nodes. */ - -void -purge_builtin_constant_p (void) -{ - rtx insn, set, arg, new, note; - - for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - if (INSN_P (insn) - && (set = single_set (insn)) != NULL_RTX - && (GET_CODE (arg = SET_SRC (set)) == CONSTANT_P_RTX - || (GET_CODE (arg) == SUBREG - && (GET_CODE (arg = SUBREG_REG (arg)) - == CONSTANT_P_RTX)))) - { - arg = XEXP (arg, 0); - new = CONSTANT_P (arg) ? const1_rtx : const0_rtx; - validate_change (insn, &SET_SRC (set), new, 0); - - /* Remove the REG_EQUAL note from the insn. */ - if ((note = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0) - remove_note (insn, note); - } -} - /* Returns true is EXP represents data that would potentially reside in a readonly section. */ @@ -7669,3 +7928,1105 @@ readonly_data_expr (tree exp) else return false; } + +/* Front-end to the simplify_builtin_XXX routines. + + EXP is a call to a builtin function. If possible try to simplify + that into a constant, expression or call to a more efficient + builtin function. + + If IGNORE is nonzero, then the result of this builtin function + call is ignored. + + If simplification is possible, return the simplified tree, otherwise + return NULL_TREE. */ + +tree +simplify_builtin (tree exp, int ignore) +{ + tree fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0); + tree arglist = TREE_OPERAND (exp, 1); + enum built_in_function fcode = DECL_FUNCTION_CODE (fndecl); + tree val; + + switch (fcode) + { + case BUILT_IN_FPUTS: + val = simplify_builtin_fputs (arglist, ignore, 0, NULL_TREE); + break; + case BUILT_IN_FPUTS_UNLOCKED: + val = simplify_builtin_fputs (arglist, ignore, 1, NULL_TREE); + break; + case BUILT_IN_STRSTR: + val = simplify_builtin_strstr (arglist); + break; + case BUILT_IN_STRCAT: + val = simplify_builtin_strcat (arglist); + break; + case BUILT_IN_STRNCAT: + val = simplify_builtin_strncat (arglist); + break; + case BUILT_IN_STRSPN: + val = simplify_builtin_strspn (arglist); + break; + case BUILT_IN_STRCSPN: + val = simplify_builtin_strcspn (arglist); + break; + case BUILT_IN_STRCHR: + case BUILT_IN_INDEX: + val = simplify_builtin_strchr (arglist); + break; + case BUILT_IN_STRRCHR: + case BUILT_IN_RINDEX: + val = simplify_builtin_strrchr (arglist); + break; + case BUILT_IN_STRCPY: + val = simplify_builtin_strcpy (arglist, NULL_TREE); + break; + case BUILT_IN_STRNCPY: + val = simplify_builtin_strncpy (arglist, NULL_TREE); + break; + case BUILT_IN_STRCMP: + val = simplify_builtin_strcmp (arglist); + break; + case BUILT_IN_STRNCMP: + val = simplify_builtin_strncmp (arglist); + break; + case BUILT_IN_STRPBRK: + val = simplify_builtin_strpbrk (arglist); + break; + case BUILT_IN_BCMP: + case BUILT_IN_MEMCMP: + val = simplify_builtin_memcmp (arglist); + break; + case BUILT_IN_VA_START: + simplify_builtin_va_start (arglist); + val = NULL_TREE; + break; + case BUILT_IN_SPRINTF: + val = simplify_builtin_sprintf (arglist, ignore); + break; + case BUILT_IN_CONSTANT_P: + val = fold_builtin_constant_p (arglist); + /* Gimplification will pull the CALL_EXPR for the builtin out of + an if condition. When not optimizing, we'll not CSE it back. + To avoid link error types of regressions, return false now. */ + if (!val && !optimize) + val = integer_zero_node; + break; + default: + val = NULL_TREE; + break; + } + + if (val) + val = convert (TREE_TYPE (exp), val); + return val; +} + +/* Simplify a call to the strstr builtin. + + Return 0 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 +simplify_builtin_strstr (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + tree fn; + const char *p1, *p2; + + p2 = c_getstr (s2); + if (p2 == NULL) + return 0; + + p1 = c_getstr (s1); + if (p1 != NULL) + { + const char *r = strstr (p1, p2); + + /* Return an offset into the constant string argument. */ + if (r == NULL) + return integer_zero_node; + else + return fold (build (PLUS_EXPR, TREE_TYPE (s1), + s1, convert (TREE_TYPE (s1), + ssize_int (r - p1)))); + } + + if (p2[0] == '\0') + return s1; + + if (p2[1] != '\0') + return 0; + + fn = implicit_built_in_decls[BUILT_IN_STRCHR]; + if (!fn) + return 0; + + /* New argument list transforming strstr(s1, s2) to + strchr(s1, s2[0]). */ + arglist = build_tree_list (NULL_TREE, build_int_2 (p2[0], 0)); + arglist = tree_cons (NULL_TREE, s1, arglist); + return build_function_call_expr (fn, arglist); + } +} + +/* Simplify a call to the strstr builtin. + + Return 0 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 +simplify_builtin_strchr (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + const char *p1; + + if (TREE_CODE (s2) != INTEGER_CST) + return 0; + + p1 = c_getstr (s1); + if (p1 != NULL) + { + char c; + const char *r; + + if (target_char_cast (s2, &c)) + return 0; + + r = strchr (p1, c); + + if (r == NULL) + return integer_zero_node; + + /* Return an offset into the constant string argument. */ + return fold (build (PLUS_EXPR, TREE_TYPE (s1), + s1, convert (TREE_TYPE (s1), + ssize_int (r - p1)))); + } + + /* FIXME: Should use here strchrM optab so that ports can optimize + this. */ + return 0; + } +} + +/* Simplify a call to the strrchr builtin. + + Return 0 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 +simplify_builtin_strrchr (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + tree fn; + const char *p1; + + if (TREE_CODE (s2) != INTEGER_CST) + return 0; + + p1 = c_getstr (s1); + if (p1 != NULL) + { + char c; + const char *r; + + if (target_char_cast (s2, &c)) + return 0; + + r = strrchr (p1, c); + + if (r == NULL) + return integer_zero_node; + + /* Return an offset into the constant string argument. */ + return fold (build (PLUS_EXPR, TREE_TYPE (s1), + s1, convert (TREE_TYPE (s1), + ssize_int (r - p1)))); + } + + if (! integer_zerop (s2)) + return 0; + + fn = implicit_built_in_decls[BUILT_IN_STRCHR]; + if (!fn) + return 0; + + /* Transform strrchr(s1, '\0') to strchr(s1, '\0'). */ + return build_function_call_expr (fn, arglist); + } +} + +/* Simplify a call to the strpbrk builtin. + + Return 0 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 +simplify_builtin_strpbrk (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + tree fn; + const char *p1, *p2; + + p2 = c_getstr (s2); + if (p2 == NULL) + return 0; + + p1 = c_getstr (s1); + if (p1 != NULL) + { + const char *r = strpbrk (p1, p2); + + if (r == NULL) + return integer_zero_node; + + /* Return an offset into the constant string argument. */ + return fold (build (PLUS_EXPR, TREE_TYPE (s1), + s1, convert (TREE_TYPE (s1), + ssize_int (r - p1)))); + } + + if (p2[0] == '\0') + { + /* strpbrk(x, "") == NULL. + Evaluate and ignore the arguments in case they had + side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, s1, + integer_zero_node); + } + + if (p2[1] != '\0') + return 0; /* Really call strpbrk. */ + + fn = implicit_built_in_decls[BUILT_IN_STRCHR]; + if (!fn) + return 0; + + /* New argument list transforming strpbrk(s1, s2) to + strchr(s1, s2[0]). */ + arglist = + build_tree_list (NULL_TREE, build_int_2 (p2[0], 0)); + arglist = tree_cons (NULL_TREE, s1, arglist); + return build_function_call_expr (fn, arglist); + } +} + +/* Simplify a call to the strcpy builtin. + + Return 0 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. */ + +tree +simplify_builtin_strcpy (tree arglist, tree len) +{ + tree fn; + + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + + fn = implicit_built_in_decls[BUILT_IN_MEMCPY]; + if (!fn) + return 0; + + if (!len) + { + len = c_strlen (TREE_VALUE (TREE_CHAIN (arglist)), 1); + if (!len) + return 0; + if (TREE_SIDE_EFFECTS (len)) + return 0; + } + + len = size_binop (PLUS_EXPR, len, ssize_int (1)); + chainon (arglist, build_tree_list (NULL_TREE, len)); + return build_function_call_expr (fn, arglist); +} + +/* Simplify a call to the strncpy builtin. + + Return 0 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. */ + +tree +simplify_builtin_strncpy (tree arglist, tree slen) +{ + if (!validate_arglist (arglist, + POINTER_TYPE, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + else + { + tree len = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); + tree fn; + + /* We must be passed a constant len parameter. */ + if (TREE_CODE (len) != INTEGER_CST) + return 0; + + /* If the len parameter is zero, return the dst parameter. */ + if (integer_zerop (len)) + { + /* Evaluate and ignore the src argument in case it has + side-effects and return the dst parameter. */ + return build (COMPOUND_EXPR, TREE_TYPE (TREE_VALUE (arglist)), + TREE_VALUE (TREE_CHAIN (arglist)), + TREE_VALUE (arglist)); + } + + if (!slen) + slen = c_strlen (TREE_VALUE (TREE_CHAIN (arglist)), 0); + + /* Now, we must be passed a constant src ptr parameter. */ + if (slen == 0 || TREE_CODE (slen) != INTEGER_CST) + return 0; + + slen = size_binop (PLUS_EXPR, slen, ssize_int (1)); + + /* We do not support simplification of this case, though we do + support it when expanding trees into RTL. */ + /* FIXME: generate a call to __builtin_memset. */ + if (tree_int_cst_lt (slen, len)) + return 0; + + /* OK transform into builtin memcpy. */ + fn = implicit_built_in_decls[BUILT_IN_MEMCPY]; + if (!fn) + return 0; + return build_function_call_expr (fn, arglist); + } +} + +/* Simplify a call to the memcmp builtin. + + Return 0 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 +simplify_builtin_memcmp (tree arglist) +{ + tree arg1, arg2, len; + const char *p1, *p2; + + if (!validate_arglist (arglist, + POINTER_TYPE, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + + arg1 = TREE_VALUE (arglist); + arg2 = TREE_VALUE (TREE_CHAIN (arglist)); + len = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); + + /* If the len parameter is zero, return zero. */ + if (host_integerp (len, 1) && tree_low_cst (len, 1) == 0) + { + /* Evaluate and ignore arg1 and arg2 in case they have + side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, arg1, + build (COMPOUND_EXPR, integer_type_node, + arg2, integer_zero_node)); + } + + p1 = c_getstr (arg1); + p2 = c_getstr (arg2); + + /* If all arguments are constant, and the value of len is not greater + than the lengths of arg1 and arg2, evaluate at compile-time. */ + if (host_integerp (len, 1) && p1 && p2 + && compare_tree_int (len, strlen (p1) + 1) <= 0 + && compare_tree_int (len, strlen (p2) + 1) <= 0) + { + const int r = memcmp (p1, p2, tree_low_cst (len, 1)); + + return (r < 0 + ? integer_minus_one_node + : (r > 0 ? integer_one_node : integer_zero_node)); + } + + /* If len parameter is one, return an expression corresponding to + (*(const unsigned char*)arg1 - (const unsigned char*)arg2). */ + if (host_integerp (len, 1) && tree_low_cst (len, 1) == 1) + { + tree cst_uchar_node = build_type_variant (unsigned_char_type_node, 1, 0); + tree cst_uchar_ptr_node = build_pointer_type (cst_uchar_node); + tree ind1 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg1)))); + tree ind2 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg2)))); + return fold (build (MINUS_EXPR, integer_type_node, ind1, ind2)); + } + + return 0; +} + +/* Simplify a call to the strcmp builtin. + + Return 0 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 +simplify_builtin_strcmp (tree arglist) +{ + tree arg1, arg2; + const char *p1, *p2; + + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + + arg1 = TREE_VALUE (arglist); + arg2 = TREE_VALUE (TREE_CHAIN (arglist)); + + /* If both arguments are equal (and not volatile), return zero. */ + if (operand_equal_p (arg1, arg2, 0)) + return integer_zero_node; + + p1 = c_getstr (arg1); + p2 = c_getstr (arg2); + + if (p1 && p2) + { + const int i = strcmp (p1, p2); + return (i < 0 + ? integer_minus_one_node + : (i > 0 ? integer_one_node : integer_zero_node)); + } + + /* If either arg is "", return an expression corresponding to + (*(const unsigned char*)arg1 - (const unsigned char*)arg2). */ + if ((p1 && *p1 == '\0') || (p2 && *p2 == '\0')) + { + tree cst_uchar_node = build_type_variant (unsigned_char_type_node, 1, 0); + tree cst_uchar_ptr_node = build_pointer_type (cst_uchar_node); + tree ind1 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg1)))); + tree ind2 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg2)))); + return fold (build (MINUS_EXPR, integer_type_node, ind1, ind2)); + } + + return 0; +} + +/* Simplify a call to the strncmp builtin. + + Return 0 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 +simplify_builtin_strncmp (tree arglist) +{ + tree arg1, arg2, arg3; + const char *p1, *p2; + + if (!validate_arglist (arglist, + POINTER_TYPE, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + + arg1 = TREE_VALUE (arglist); + arg2 = TREE_VALUE (TREE_CHAIN (arglist)); + arg3 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); + + /* If the len parameter is zero, return zero. */ + if (integer_zerop (arg3)) + { + /* Evaluate and ignore arg1 and arg2 in case they have + side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, arg1, + build (COMPOUND_EXPR, integer_type_node, + arg2, integer_zero_node)); + } + + /* If arg1 and arg2 are equal (and not volatile), return zero. */ + if (operand_equal_p (arg1, arg2, 0)) + { + /* Evaluate and ignore arg3 in case it has side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, arg3, integer_zero_node); + } + + p1 = c_getstr (arg1); + p2 = c_getstr (arg2); + + /* If all arguments are constant, evaluate at compile-time. */ + if (host_integerp (arg3, 1) && p1 && p2) + { + const int r = strncmp (p1, p2, tree_low_cst (arg3, 1)); + return (r < 0 + ? integer_minus_one_node + : (r > 0 ? integer_one_node : integer_zero_node)); + } + + /* If len == 1 or (either string parameter is "" and (len >= 1)), + return (*(const u_char*)arg1 - *(const u_char*)arg2). */ + if (host_integerp (arg3, 1) + && (tree_low_cst (arg3, 1) == 1 + || (tree_low_cst (arg3, 1) > 1 + && ((p1 && *p1 == '\0') || (p2 && *p2 == '\0'))))) + { + tree cst_uchar_node = build_type_variant (unsigned_char_type_node, 1, 0); + tree cst_uchar_ptr_node = build_pointer_type (cst_uchar_node); + tree ind1 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg1)))); + tree ind2 = + fold (build1 (CONVERT_EXPR, integer_type_node, + build1 (INDIRECT_REF, cst_uchar_node, + build1 (NOP_EXPR, cst_uchar_ptr_node, arg2)))); + return fold (build (MINUS_EXPR, integer_type_node, ind1, ind2)); + } + + return 0; +} + +/* Simplify a call to the strcat builtin. + + Return 0 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 +simplify_builtin_strcat (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + else + { + tree dst = TREE_VALUE (arglist), + src = TREE_VALUE (TREE_CHAIN (arglist)); + const char *p = c_getstr (src); + + /* If the string length is zero, return the dst parameter. */ + if (p && *p == '\0') + return dst; + + return 0; + } +} + +/* Simplify a call to the strncat builtin. + + Return 0 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 +simplify_builtin_strncat (tree arglist) +{ + if (!validate_arglist (arglist, + POINTER_TYPE, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) + return 0; + else + { + tree dst = TREE_VALUE (arglist); + tree src = TREE_VALUE (TREE_CHAIN (arglist)); + tree len = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); + const char *p = c_getstr (src); + + /* If the requested length is zero, or the src parameter string + length is zero, return the dst parameter. */ + if (integer_zerop (len) || (p && *p == '\0')) + return build (COMPOUND_EXPR, TREE_TYPE (dst), src, + build (COMPOUND_EXPR, integer_type_node, len, dst)); + + /* If the requested len is greater than or equal to the string + length, call strcat. */ + if (TREE_CODE (len) == INTEGER_CST && p + && compare_tree_int (len, strlen (p)) >= 0) + { + tree newarglist + = tree_cons (NULL_TREE, dst, build_tree_list (NULL_TREE, src)); + tree fn = implicit_built_in_decls[BUILT_IN_STRCAT]; + + /* If the replacement _DECL isn't initialized, don't do the + transformation. */ + if (!fn) + return 0; + + return build_function_call_expr (fn, newarglist); + } + return 0; + } +} + +/* Simplify a call to the strspn builtin. + + Return 0 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 +simplify_builtin_strspn (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + const char *p1 = c_getstr (s1), *p2 = c_getstr (s2); + + /* If both arguments are constants, evaluate at compile-time. */ + if (p1 && p2) + { + const size_t r = strspn (p1, p2); + return size_int (r); + } + + /* If either argument is "", return 0. */ + if ((p1 && *p1 == '\0') || (p2 && *p2 == '\0')) + { + /* Evaluate and ignore both arguments in case either one has + side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, s1, + build (COMPOUND_EXPR, integer_type_node, + s2, integer_zero_node)); + } + return 0; + } +} + +/* Simplify a call to the strcspn builtin. + + Return 0 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 +simplify_builtin_strcspn (tree arglist) +{ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + else + { + tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist)); + const char *p1 = c_getstr (s1), *p2 = c_getstr (s2); + + /* If both arguments are constants, evaluate at compile-time. */ + if (p1 && p2) + { + const size_t r = strcspn (p1, p2); + return size_int (r); + } + + /* If the first argument is "", return 0. */ + if (p1 && *p1 == '\0') + { + /* Evaluate and ignore argument s2 in case it has + side-effects. */ + return build (COMPOUND_EXPR, integer_type_node, + s2, integer_zero_node); + } + + /* If the second argument is "", return __builtin_strlen(s1). */ + if (p2 && *p2 == '\0') + { + tree newarglist = build_tree_list (NULL_TREE, s1), + fn = implicit_built_in_decls[BUILT_IN_STRLEN]; + + /* If the replacement _DECL isn't initialized, don't do the + transformation. */ + if (!fn) + return 0; + + return build_function_call_expr (fn, newarglist); + } + return 0; + } +} + +/* Simplify a call to the fputs builtin. + + Return 0 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. + + If KNOWN_LEN is non-NULL, it represents the known length of the string. + This is determined by SSA-CCP in cases where the string itself is not + known to be constant but its length is always the same constant. */ + +tree +simplify_builtin_fputs (tree arglist, int ignore, int unlocked, tree known_len) +{ + tree len, fn; + tree fn_fputc = unlocked ? implicit_built_in_decls[BUILT_IN_FPUTC_UNLOCKED] + : implicit_built_in_decls[BUILT_IN_FPUTC]; + tree fn_fwrite = unlocked ? implicit_built_in_decls[BUILT_IN_FWRITE_UNLOCKED] + : implicit_built_in_decls[BUILT_IN_FWRITE]; + + /* If the return value is used, or the replacement _DECL isn't + initialized, don't do the transformation. */ + if (!ignore || !fn_fputc || !fn_fwrite) + return 0; + + /* Verify the arguments in the original call. */ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE)) + return 0; + + len = (known_len) ? known_len : c_strlen (TREE_VALUE (arglist), 0); + + /* Get the length of the string passed to fputs. If the length + can't be determined, punt. */ + if (!len + || TREE_CODE (len) != INTEGER_CST) + return 0; + + switch (compare_tree_int (len, 1)) + { + case -1: /* length is 0, delete the call entirely . */ + { + return build (COMPOUND_EXPR, integer_type_node, + TREE_VALUE (TREE_CHAIN (arglist)), integer_zero_node); + } + case 0: /* length is 1, call fputc. */ + { + const char *p = c_getstr (TREE_VALUE (arglist)); + + if (p != NULL) + { + /* New argument list transforming fputs(string, stream) to + fputc(string[0], stream). */ + arglist = + build_tree_list (NULL_TREE, TREE_VALUE (TREE_CHAIN (arglist))); + arglist = + tree_cons (NULL_TREE, build_int_2 (p[0], 0), arglist); + fn = fn_fputc; + break; + } + } + /* FALLTHROUGH */ + case 1: /* length is greater than 1, call fwrite. */ + { + tree string_arg; + + /* If optimizing for size keep fputs. */ + if (optimize_size) + return 0; + string_arg = TREE_VALUE (arglist); + /* New argument list transforming fputs(string, stream) to + fwrite(string, 1, len, stream). */ + arglist = build_tree_list (NULL_TREE, TREE_VALUE (TREE_CHAIN (arglist))); + arglist = tree_cons (NULL_TREE, len, arglist); + arglist = tree_cons (NULL_TREE, size_one_node, arglist); + arglist = tree_cons (NULL_TREE, string_arg, arglist); + fn = fn_fwrite; + break; + } + default: + abort (); + } + + return build_function_call_expr (fn, arglist); +} + +static void +simplify_builtin_va_start (tree arglist) +{ + tree chain = TREE_CHAIN (arglist); + + if (TREE_CHAIN (chain)) + error ("too many arguments to function `va_start'"); + + simplify_builtin_next_arg (chain); +} + +static void +simplify_builtin_next_arg (tree arglist) +{ + tree fntype = TREE_TYPE (current_function_decl); + + if (TYPE_ARG_TYPES (fntype) == 0 + || (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype))) + == void_type_node)) + error ("`va_start' used in function with fixed args"); + else if (arglist) + { + tree last_parm = tree_last (DECL_ARGUMENTS (current_function_decl)); + tree arg = TREE_VALUE (arglist); + + /* Strip off all nops for the sake of the comparison. This + is not quite the same as STRIP_NOPS. It does more. + We must also strip off INDIRECT_EXPR for C++ reference + parameters. */ + while (TREE_CODE (arg) == NOP_EXPR + || TREE_CODE (arg) == CONVERT_EXPR + || TREE_CODE (arg) == NON_LVALUE_EXPR + || TREE_CODE (arg) == INDIRECT_REF) + arg = TREE_OPERAND (arg, 0); + if (arg != last_parm) + warning ("second parameter of `va_start' not last named argument"); + TREE_VALUE (arglist) = arg; + } + else + /* Evidently an out of date version of <stdarg.h>; can't validate + va_start's second argument, but can still work as intended. */ + warning ("`__builtin_next_arg' called without an argument"); +} + + +/* Simplify a call to the sprintf builtin. + + Return 0 if no simplification was possible, otherwise return the + simplified form of the call as a tree. If IGNORED is true, it means that + the caller does not use the returned value of the function. */ + +static tree +simplify_builtin_sprintf (tree arglist, int ignored) +{ + tree call, retval, dest, fmt; + const char *fmt_str = NULL; + + /* Verify the required arguments in the original call. We deal with two + types of sprintf() calls: 'sprintf (str, fmt)' and + 'sprintf (dest, "%s", orig)'. */ + if (!validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, VOID_TYPE) + && !validate_arglist (arglist, POINTER_TYPE, POINTER_TYPE, POINTER_TYPE, + VOID_TYPE)) + return NULL_TREE; + + /* Get the destination string and the format specifier. */ + dest = TREE_VALUE (arglist); + fmt = TREE_VALUE (TREE_CHAIN (arglist)); + + /* Check whether the format is a literal string constant. */ + fmt_str = c_getstr (fmt); + if (fmt_str == NULL) + return NULL_TREE; + + call = NULL_TREE; + retval = NULL_TREE; + + /* If the format doesn't contain % args or %%, use strcpy. */ + if (strchr (fmt_str, '%') == NULL) + { + tree fn = implicit_built_in_decls[BUILT_IN_STRCPY]; + + if (!fn) + return NULL_TREE; + + /* Convert sprintf (str, fmt) into strcpy (str, fmt) when + 'format' is known to contain no % formats. */ + arglist = build_tree_list (NULL_TREE, fmt); + arglist = tree_cons (NULL_TREE, dest, arglist); + call = build_function_call_expr (fn, arglist); + if (!ignored) + retval = build_int_2 (strlen (fmt_str), 0); + } + + /* If the format is "%s", use strcpy if the result isn't used. */ + else if (fmt_str && strcmp (fmt_str, "%s") == 0) + { + tree fn, orig; + fn = implicit_built_in_decls[BUILT_IN_STRCPY]; + + if (!fn) + return NULL_TREE; + + /* Convert sprintf (str1, "%s", str2) into strcpy (str1, str2). */ + orig = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist))); + arglist = build_tree_list (NULL_TREE, orig); + arglist = tree_cons (NULL_TREE, dest, arglist); + if (!ignored) + { + retval = c_strlen (orig, 1); + if (!retval || TREE_CODE (retval) != INTEGER_CST) + return NULL_TREE; + } + call = build_function_call_expr (fn, arglist); + } + + if (call && retval) + { + retval = convert + (TREE_TYPE (TREE_TYPE (implicit_built_in_decls[BUILT_IN_SPRINTF])), + retval); + return build (COMPOUND_EXPR, TREE_TYPE (retval), call, retval); + } + else + return call; +} |