diff options
Diffstat (limited to 'gcc/tree.c')
| -rw-r--r-- | gcc/tree.c | 191 |
1 files changed, 135 insertions, 56 deletions
@@ -621,7 +621,6 @@ make_node_stat (enum tree_code code MEM_STAT_DECL) case tcc_constant: TREE_CONSTANT (t) = 1; - TREE_INVARIANT (t) = 1; break; case tcc_expression: @@ -1192,7 +1191,6 @@ build_string (int len, const char *str) memset (s, 0, sizeof (struct tree_common)); TREE_SET_CODE (s, STRING_CST); TREE_CONSTANT (s) = 1; - TREE_INVARIANT (s) = 1; TREE_STRING_LENGTH (s) = len; memcpy (s->string.str, str, len); s->string.str[len] = '\0'; @@ -2056,7 +2054,111 @@ staticp (tree arg) return NULL; } } + + + +/* Return whether OP is a DECL whose address is function-invariant. */ + +bool +decl_address_invariant_p (const_tree op) +{ + /* The conditions below are slightly less strict than the one in + staticp. */ + + switch (TREE_CODE (op)) + { + case PARM_DECL: + case RESULT_DECL: + case LABEL_DECL: + case FUNCTION_DECL: + return true; + + case VAR_DECL: + if (((TREE_STATIC (op) || DECL_EXTERNAL (op)) + && !DECL_DLLIMPORT_P (op)) + || DECL_THREAD_LOCAL_P (op) + || DECL_CONTEXT (op) == current_function_decl + || decl_function_context (op) == current_function_decl) + return true; + break; + + case CONST_DECL: + if ((TREE_STATIC (op) || DECL_EXTERNAL (op)) + || decl_function_context (op) == current_function_decl) + return true; + break; + + default: + break; + } + + return false; +} + + +/* Return true if T is function-invariant (internal function, does + not handle arithmetic; that's handled in skip_simple_arithmetic and + tree_invariant_p). */ + +static bool tree_invariant_p (tree t); + +static bool +tree_invariant_p_1 (tree t) +{ + tree op; + + if (TREE_CONSTANT (t) + || (TREE_READONLY (t) && !TREE_SIDE_EFFECTS (t))) + return true; + + switch (TREE_CODE (t)) + { + case SAVE_EXPR: + return true; + + case ADDR_EXPR: + op = TREE_OPERAND (t, 0); + while (handled_component_p (op)) + { + switch (TREE_CODE (op)) + { + case ARRAY_REF: + case ARRAY_RANGE_REF: + if (!tree_invariant_p (TREE_OPERAND (op, 1)) + || TREE_OPERAND (op, 2) != NULL_TREE + || TREE_OPERAND (op, 3) != NULL_TREE) + return false; + break; + + case COMPONENT_REF: + if (TREE_OPERAND (op, 2) != NULL_TREE) + return false; + break; + + default:; + } + op = TREE_OPERAND (op, 0); + } + + return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op); + + default: + break; + } + + return false; +} + +/* Return true if T is function-invariant. */ + +static bool +tree_invariant_p (tree t) +{ + tree inner = skip_simple_arithmetic (t); + return tree_invariant_p_1 (inner); +} + /* Wrap a SAVE_EXPR around EXPR, if appropriate. Do this to any expression which may be used in more than one place, but must be evaluated only once. @@ -2091,11 +2193,10 @@ save_expr (tree expr) Since it is no problem to reevaluate literals, we just return the literal node. */ inner = skip_simple_arithmetic (t); + if (TREE_CODE (inner) == ERROR_MARK) + return inner; - if (TREE_INVARIANT (inner) - || (TREE_READONLY (inner) && ! TREE_SIDE_EFFECTS (inner)) - || TREE_CODE (inner) == SAVE_EXPR - || TREE_CODE (inner) == ERROR_MARK) + if (tree_invariant_p_1 (inner)) return t; /* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since @@ -2116,7 +2217,6 @@ save_expr (tree expr) value was computed on both sides of the jump. So make sure it isn't eliminated as dead. */ TREE_SIDE_EFFECTS (t) = 1; - TREE_INVARIANT (t) = 1; return t; } @@ -2144,9 +2244,9 @@ skip_simple_arithmetic (tree expr) inner = TREE_OPERAND (inner, 0); else if (BINARY_CLASS_P (inner)) { - if (TREE_INVARIANT (TREE_OPERAND (inner, 1))) + if (tree_invariant_p (TREE_OPERAND (inner, 1))) inner = TREE_OPERAND (inner, 0); - else if (TREE_INVARIANT (TREE_OPERAND (inner, 0))) + else if (tree_invariant_p (TREE_OPERAND (inner, 0))) inner = TREE_OPERAND (inner, 1); else break; @@ -2815,7 +2915,7 @@ stabilize_reference_1 (tree e) ignore things that are actual constant or that already have been handled by this function. */ - if (TREE_INVARIANT (e)) + if (tree_invariant_p (e)) return e; switch (TREE_CODE_CLASS (code)) @@ -2868,7 +2968,6 @@ stabilize_reference_1 (tree e) TREE_READONLY (result) = TREE_READONLY (e); TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e); TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e); - TREE_INVARIANT (result) = 1; return result; } @@ -2876,13 +2975,13 @@ stabilize_reference_1 (tree e) /* Low-level constructors for expressions. */ /* A helper function for build1 and constant folders. Set TREE_CONSTANT, - TREE_INVARIANT, and TREE_SIDE_EFFECTS for an ADDR_EXPR. */ + and TREE_SIDE_EFFECTS for an ADDR_EXPR. */ void recompute_tree_invariant_for_addr_expr (tree t) { tree node; - bool tc = true, ti = true, se = false; + bool tc = true, se = false; /* We started out assuming this address is both invariant and constant, but does not have side effects. Now go down any handled components and see if @@ -2892,9 +2991,8 @@ recompute_tree_invariant_for_addr_expr (tree t) ??? Note that this code makes no attempt to deal with the case where taking the address of something causes a copy due to misalignment. */ -#define UPDATE_TITCSE(NODE) \ +#define UPDATE_FLAGS(NODE) \ do { tree _node = (NODE); \ - if (_node && !TREE_INVARIANT (_node)) ti = false; \ if (_node && !TREE_CONSTANT (_node)) tc = false; \ if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0) @@ -2908,11 +3006,11 @@ do { tree _node = (NODE); \ || TREE_CODE (node) == ARRAY_RANGE_REF) && TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE) { - UPDATE_TITCSE (TREE_OPERAND (node, 1)); + UPDATE_FLAGS (TREE_OPERAND (node, 1)); if (TREE_OPERAND (node, 2)) - UPDATE_TITCSE (TREE_OPERAND (node, 2)); + UPDATE_FLAGS (TREE_OPERAND (node, 2)); if (TREE_OPERAND (node, 3)) - UPDATE_TITCSE (TREE_OPERAND (node, 3)); + UPDATE_FLAGS (TREE_OPERAND (node, 3)); } /* Likewise, just because this is a COMPONENT_REF doesn't mean we have a FIELD_DECL, apparently. The G++ front end can put something else @@ -2921,46 +3019,35 @@ do { tree _node = (NODE); \ && TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL) { if (TREE_OPERAND (node, 2)) - UPDATE_TITCSE (TREE_OPERAND (node, 2)); + UPDATE_FLAGS (TREE_OPERAND (node, 2)); } else if (TREE_CODE (node) == BIT_FIELD_REF) - UPDATE_TITCSE (TREE_OPERAND (node, 2)); + UPDATE_FLAGS (TREE_OPERAND (node, 2)); } - node = lang_hooks.expr_to_decl (node, &tc, &ti, &se); + node = lang_hooks.expr_to_decl (node, &tc, &se); /* Now see what's inside. If it's an INDIRECT_REF, copy our properties from - the address, since &(*a)->b is a form of addition. If it's a decl, it's - invariant and constant if the decl is static. It's also invariant if it's - a decl in the current function. Taking the address of a volatile variable - is not volatile. If it's a constant, the address is both invariant and - constant. Otherwise it's neither. */ + the address, since &(*a)->b is a form of addition. If it's a constant, the + address is constant too. If it's a decl, its address is constant if the + decl is static. Everything else is not constant and, furthermore, + taking the address of a volatile variable is not volatile. */ if (TREE_CODE (node) == INDIRECT_REF) - UPDATE_TITCSE (TREE_OPERAND (node, 0)); - else if (DECL_P (node)) - { - if (staticp (node)) - ; - else if (decl_function_context (node) == current_function_decl - /* Addresses of thread-local variables are invariant. */ - || (TREE_CODE (node) == VAR_DECL - && DECL_THREAD_LOCAL_P (node))) - tc = false; - else - ti = tc = false; - } + UPDATE_FLAGS (TREE_OPERAND (node, 0)); else if (CONSTANT_CLASS_P (node)) ; + else if (DECL_P (node)) + tc &= (staticp (node) != NULL_TREE); else { - ti = tc = false; + tc = false; se |= TREE_SIDE_EFFECTS (node); } + TREE_CONSTANT (t) = tc; - TREE_INVARIANT (t) = ti; TREE_SIDE_EFFECTS (t) = se; -#undef UPDATE_TITCSE +#undef UPDATE_FLAGS } /* Build an expression of code CODE, data type TYPE, and operands as @@ -3057,9 +3144,6 @@ build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL) && node && !TYPE_P (node) && TREE_CONSTANT (node)) TREE_CONSTANT (t) = 1; - if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR) - && node && TREE_INVARIANT (node)) - TREE_INVARIANT (t) = 1; if (TREE_CODE_CLASS (code) == tcc_reference && node && TREE_THIS_VOLATILE (node)) TREE_THIS_VOLATILE (t) = 1; @@ -3080,15 +3164,13 @@ build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL) read_only = 0; \ if (!TREE_CONSTANT (arg##N)) \ constant = 0; \ - if (!TREE_INVARIANT (arg##N)) \ - invariant = 0; \ } \ } while (0) tree build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL) { - bool constant, read_only, side_effects, invariant; + bool constant, read_only, side_effects; tree t; gcc_assert (TREE_CODE_LENGTH (code) == 2); @@ -3125,14 +3207,12 @@ build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL) || TREE_CODE_CLASS (code) == tcc_binary); read_only = 1; side_effects = TREE_SIDE_EFFECTS (t); - invariant = constant; PROCESS_ARG(0); PROCESS_ARG(1); TREE_READONLY (t) = read_only; TREE_CONSTANT (t) = constant; - TREE_INVARIANT (t) = invariant; TREE_SIDE_EFFECTS (t) = side_effects; TREE_THIS_VOLATILE (t) = (TREE_CODE_CLASS (code) == tcc_reference @@ -3161,7 +3241,7 @@ tree build3_stat (enum tree_code code, tree tt, tree arg0, tree arg1, tree arg2 MEM_STAT_DECL) { - bool constant, read_only, side_effects, invariant; + bool constant, read_only, side_effects; tree t; gcc_assert (TREE_CODE_LENGTH (code) == 3); @@ -3197,7 +3277,7 @@ tree build4_stat (enum tree_code code, tree tt, tree arg0, tree arg1, tree arg2, tree arg3 MEM_STAT_DECL) { - bool constant, read_only, side_effects, invariant; + bool constant, read_only, side_effects; tree t; gcc_assert (TREE_CODE_LENGTH (code) == 4); @@ -3224,7 +3304,7 @@ tree build5_stat (enum tree_code code, tree tt, tree arg0, tree arg1, tree arg2, tree arg3, tree arg4 MEM_STAT_DECL) { - bool constant, read_only, side_effects, invariant; + bool constant, read_only, side_effects; tree t; gcc_assert (TREE_CODE_LENGTH (code) == 5); @@ -3253,7 +3333,7 @@ build7_stat (enum tree_code code, tree tt, tree arg0, tree arg1, tree arg2, tree arg3, tree arg4, tree arg5, tree arg6 MEM_STAT_DECL) { - bool constant, read_only, side_effects, invariant; + bool constant, read_only, side_effects; tree t; gcc_assert (code == TARGET_MEM_REF); @@ -3883,8 +3963,7 @@ merge_dllimport_decl_attributes (tree old, tree new) "after being referenced with dll linkage", new); /* If we have used a variable's address with dllimport linkage, keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the - decl may already have had TREE_INVARIANT and TREE_CONSTANT - computed. + decl may already have had TREE_CONSTANT computed. We still remove the attribute so that assembler code refers to '&foo rather than '_imp__foo'. */ if (TREE_CODE (old) == VAR_DECL && TREE_ADDRESSABLE (old)) |