gimple_seq *pre_p, gimple_seq *post_p,
bool want_value)
{
- enum gimplify_status ret = GS_OK;
+ enum gimplify_status ret = GS_UNHANDLED;
+ bool changed;
- while (ret != GS_UNHANDLED)
- switch (TREE_CODE (*from_p))
- {
- case VAR_DECL:
- /* If we're assigning from a read-only variable initialized with
- a constructor, do the direct assignment from the constructor,
- but only if neither source nor target are volatile since this
- latter assignment might end up being done on a per-field basis. */
- if (DECL_INITIAL (*from_p)
- && TREE_READONLY (*from_p)
- && !TREE_THIS_VOLATILE (*from_p)
- && !TREE_THIS_VOLATILE (*to_p)
- && TREE_CODE (DECL_INITIAL (*from_p)) == CONSTRUCTOR)
+ do
+ {
+ changed = false;
+ switch (TREE_CODE (*from_p))
+ {
+ case VAR_DECL:
+ /* If we're assigning from a read-only variable initialized with
+ a constructor, do the direct assignment from the constructor,
+ but only if neither source nor target are volatile since this
+ latter assignment might end up being done on a per-field basis. */
+ if (DECL_INITIAL (*from_p)
+ && TREE_READONLY (*from_p)
+ && !TREE_THIS_VOLATILE (*from_p)
+ && !TREE_THIS_VOLATILE (*to_p)
+ && TREE_CODE (DECL_INITIAL (*from_p)) == CONSTRUCTOR)
+ {
+ tree old_from = *from_p;
+ enum gimplify_status subret;
+
+ /* Move the constructor into the RHS. */
+ *from_p = unshare_expr (DECL_INITIAL (*from_p));
+
+ /* Let's see if gimplify_init_constructor will need to put
+ it in memory. */
+ subret = gimplify_init_constructor (expr_p, NULL, NULL,
+ false, true);
+ if (subret == GS_ERROR)
+ {
+ /* If so, revert the change. */
+ *from_p = old_from;
+ }
+ else
+ {
+ ret = GS_OK;
+ changed = true;
+ }
+ }
+ break;
+ case INDIRECT_REF:
{
- tree old_from = *from_p;
+ /* If we have code like
- /* Move the constructor into the RHS. */
- *from_p = unshare_expr (DECL_INITIAL (*from_p));
+ *(const A*)(A*)&x
- /* Let's see if gimplify_init_constructor will need to put
- it in memory. If so, revert the change. */
- ret = gimplify_init_constructor (expr_p, NULL, NULL, false, true);
- if (ret == GS_ERROR)
+ where the type of "x" is a (possibly cv-qualified variant
+ of "A"), treat the entire expression as identical to "x".
+ This kind of code arises in C++ when an object is bound
+ to a const reference, and if "x" is a TARGET_EXPR we want
+ to take advantage of the optimization below. */
+ tree t = gimple_fold_indirect_ref_rhs (TREE_OPERAND (*from_p, 0));
+ if (t)
{
- *from_p = old_from;
- /* Fall through. */
+ *from_p = t;
+ ret = GS_OK;
+ changed = true;
}
- else
+ break;
+ }
+
+ case TARGET_EXPR:
+ {
+ /* If we are initializing something from a TARGET_EXPR, strip the
+ TARGET_EXPR and initialize it directly, if possible. This can't
+ be done if the initializer is void, since that implies that the
+ temporary is set in some non-trivial way.
+
+ ??? What about code that pulls out the temp and uses it
+ elsewhere? I think that such code never uses the TARGET_EXPR as
+ an initializer. If I'm wrong, we'll die because the temp won't
+ have any RTL. In that case, I guess we'll need to replace
+ references somehow. */
+ tree init = TARGET_EXPR_INITIAL (*from_p);
+
+ if (init
+ && !VOID_TYPE_P (TREE_TYPE (init)))
{
+ *from_p = init;
ret = GS_OK;
- break;
+ changed = true;
}
}
- ret = GS_UNHANDLED;
- break;
- case INDIRECT_REF:
- {
- /* If we have code like
+ break;
- *(const A*)(A*)&x
+ case COMPOUND_EXPR:
+ /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
+ caught. */
+ gimplify_compound_expr (from_p, pre_p, true);
+ ret = GS_OK;
+ changed = true;
+ break;
- where the type of "x" is a (possibly cv-qualified variant
- of "A"), treat the entire expression as identical to "x".
- This kind of code arises in C++ when an object is bound
- to a const reference, and if "x" is a TARGET_EXPR we want
- to take advantage of the optimization below. */
- tree t = gimple_fold_indirect_ref_rhs (TREE_OPERAND (*from_p, 0));
- if (t)
+ case CONSTRUCTOR:
+ /* If we're initializing from a CONSTRUCTOR, break this into
+ individual MODIFY_EXPRs. */
+ return gimplify_init_constructor (expr_p, pre_p, post_p, want_value,
+ false);
+
+ case COND_EXPR:
+ /* If we're assigning to a non-register type, push the assignment
+ down into the branches. This is mandatory for ADDRESSABLE types,
+ since we cannot generate temporaries for such, but it saves a
+ copy in other cases as well. */
+ if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
{
- *from_p = t;
- ret = GS_OK;
+ /* This code should mirror the code in gimplify_cond_expr. */
+ enum tree_code code = TREE_CODE (*expr_p);
+ tree cond = *from_p;
+ tree result = *to_p;
+
+ ret = gimplify_expr (&result, pre_p, post_p,
+ is_gimple_lvalue, fb_lvalue);
+ if (ret != GS_ERROR)
+ ret = GS_OK;
+
+ if (TREE_TYPE (TREE_OPERAND (cond, 1)) != void_type_node)
+ TREE_OPERAND (cond, 1)
+ = build2 (code, void_type_node, result,
+ TREE_OPERAND (cond, 1));
+ if (TREE_TYPE (TREE_OPERAND (cond, 2)) != void_type_node)
+ TREE_OPERAND (cond, 2)
+ = build2 (code, void_type_node, unshare_expr (result),
+ TREE_OPERAND (cond, 2));
+
+ TREE_TYPE (cond) = void_type_node;
+ recalculate_side_effects (cond);
+
+ if (want_value)
+ {
+ gimplify_and_add (cond, pre_p);
+ *expr_p = unshare_expr (result);
+ }
+ else
+ *expr_p = cond;
+ return ret;
}
- else
- ret = GS_UNHANDLED;
break;
- }
- case TARGET_EXPR:
- {
- /* If we are initializing something from a TARGET_EXPR, strip the
- TARGET_EXPR and initialize it directly, if possible. This can't
- be done if the initializer is void, since that implies that the
- temporary is set in some non-trivial way.
-
- ??? What about code that pulls out the temp and uses it
- elsewhere? I think that such code never uses the TARGET_EXPR as
- an initializer. If I'm wrong, we'll die because the temp won't
- have any RTL. In that case, I guess we'll need to replace
- references somehow. */
- tree init = TARGET_EXPR_INITIAL (*from_p);
-
- if (init
- && !VOID_TYPE_P (TREE_TYPE (init)))
+ case CALL_EXPR:
+ /* For calls that return in memory, give *to_p as the CALL_EXPR's
+ return slot so that we don't generate a temporary. */
+ if (!CALL_EXPR_RETURN_SLOT_OPT (*from_p)
+ && aggregate_value_p (*from_p, *from_p))
{
- *from_p = init;
- ret = GS_OK;
+ bool use_target;
+
+ if (!(rhs_predicate_for (*to_p))(*from_p))
+ /* If we need a temporary, *to_p isn't accurate. */
+ use_target = false;
+ else if (TREE_CODE (*to_p) == RESULT_DECL
+ && DECL_NAME (*to_p) == NULL_TREE
+ && needs_to_live_in_memory (*to_p))
+ /* It's OK to use the return slot directly unless it's an NRV. */
+ use_target = true;
+ else if (is_gimple_reg_type (TREE_TYPE (*to_p))
+ || (DECL_P (*to_p) && DECL_REGISTER (*to_p)))
+ /* Don't force regs into memory. */
+ use_target = false;
+ else if (TREE_CODE (*expr_p) == INIT_EXPR)
+ /* It's OK to use the target directly if it's being
+ initialized. */
+ use_target = true;
+ else if (!is_gimple_non_addressable (*to_p))
+ /* Don't use the original target if it's already addressable;
+ if its address escapes, and the called function uses the
+ NRV optimization, a conforming program could see *to_p
+ change before the called function returns; see c++/19317.
+ When optimizing, the return_slot pass marks more functions
+ as safe after we have escape info. */
+ use_target = false;
+ else
+ use_target = true;
+
+ if (use_target)
+ {
+ CALL_EXPR_RETURN_SLOT_OPT (*from_p) = 1;
+ mark_addressable (*to_p);
+ }
}
- else
- ret = GS_UNHANDLED;
- }
- break;
+ break;
- case COMPOUND_EXPR:
- /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
- caught. */
- gimplify_compound_expr (from_p, pre_p, true);
- ret = GS_OK;
- break;
+ case WITH_SIZE_EXPR:
+ /* Likewise for calls that return an aggregate of non-constant size,
+ since we would not be able to generate a temporary at all. */
+ if (TREE_CODE (TREE_OPERAND (*from_p, 0)) == CALL_EXPR)
+ {
+ *from_p = TREE_OPERAND (*from_p, 0);
+ ret = GS_OK;
+ changed = true;
+ }
+ break;
- case CONSTRUCTOR:
- /* If we're initializing from a CONSTRUCTOR, break this into
- individual MODIFY_EXPRs. */
- return gimplify_init_constructor (expr_p, pre_p, post_p, want_value,
- false);
-
- case COND_EXPR:
- /* If we're assigning to a non-register type, push the assignment
- down into the branches. This is mandatory for ADDRESSABLE types,
- since we cannot generate temporaries for such, but it saves a
- copy in other cases as well. */
- if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
+ /* If we're initializing from a container, push the initialization
+ inside it. */
+ case CLEANUP_POINT_EXPR:
+ case BIND_EXPR:
+ case STATEMENT_LIST:
{
- /* This code should mirror the code in gimplify_cond_expr. */
- enum tree_code code = TREE_CODE (*expr_p);
- tree cond = *from_p;
- tree result = *to_p;
+ tree wrap = *from_p;
+ tree t;
- ret = gimplify_expr (&result, pre_p, post_p,
- is_gimple_lvalue, fb_lvalue);
+ ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_min_lval,
+ fb_lvalue);
if (ret != GS_ERROR)
ret = GS_OK;
- if (TREE_TYPE (TREE_OPERAND (cond, 1)) != void_type_node)
- TREE_OPERAND (cond, 1)
- = build2 (code, void_type_node, result,
- TREE_OPERAND (cond, 1));
- if (TREE_TYPE (TREE_OPERAND (cond, 2)) != void_type_node)
- TREE_OPERAND (cond, 2)
- = build2 (code, void_type_node, unshare_expr (result),
- TREE_OPERAND (cond, 2));
-
- TREE_TYPE (cond) = void_type_node;
- recalculate_side_effects (cond);
+ t = voidify_wrapper_expr (wrap, *expr_p);
+ gcc_assert (t == *expr_p);
if (want_value)
{
- gimplify_and_add (cond, pre_p);
- *expr_p = unshare_expr (result);
+ gimplify_and_add (wrap, pre_p);
+ *expr_p = unshare_expr (*to_p);
}
else
- *expr_p = cond;
- return ret;
+ *expr_p = wrap;
+ return GS_OK;
}
- else
- ret = GS_UNHANDLED;
- break;
- case CALL_EXPR:
- /* For calls that return in memory, give *to_p as the CALL_EXPR's
- return slot so that we don't generate a temporary. */
- if (!CALL_EXPR_RETURN_SLOT_OPT (*from_p)
- && aggregate_value_p (*from_p, *from_p))
+ case COMPOUND_LITERAL_EXPR:
{
- bool use_target;
-
- if (!(rhs_predicate_for (*to_p))(*from_p))
- /* If we need a temporary, *to_p isn't accurate. */
- use_target = false;
- else if (TREE_CODE (*to_p) == RESULT_DECL
- && DECL_NAME (*to_p) == NULL_TREE
- && needs_to_live_in_memory (*to_p))
- /* It's OK to use the return slot directly unless it's an NRV. */
- use_target = true;
- else if (is_gimple_reg_type (TREE_TYPE (*to_p))
- || (DECL_P (*to_p) && DECL_REGISTER (*to_p)))
- /* Don't force regs into memory. */
- use_target = false;
- else if (TREE_CODE (*expr_p) == INIT_EXPR)
- /* It's OK to use the target directly if it's being
- initialized. */
- use_target = true;
- else if (!is_gimple_non_addressable (*to_p))
- /* Don't use the original target if it's already addressable;
- if its address escapes, and the called function uses the
- NRV optimization, a conforming program could see *to_p
- change before the called function returns; see c++/19317.
- When optimizing, the return_slot pass marks more functions
- as safe after we have escape info. */
- use_target = false;
- else
- use_target = true;
-
- if (use_target)
+ tree complit = TREE_OPERAND (*expr_p, 1);
+ tree decl_s = COMPOUND_LITERAL_EXPR_DECL_EXPR (complit);
+ tree decl = DECL_EXPR_DECL (decl_s);
+ tree init = DECL_INITIAL (decl);
+
+ /* struct T x = (struct T) { 0, 1, 2 } can be optimized
+ into struct T x = { 0, 1, 2 } if the address of the
+ compound literal has never been taken. */
+ if (!TREE_ADDRESSABLE (complit)
+ && !TREE_ADDRESSABLE (decl)
+ && init)
{
- CALL_EXPR_RETURN_SLOT_OPT (*from_p) = 1;
- mark_addressable (*to_p);
+ *expr_p = copy_node (*expr_p);
+ TREE_OPERAND (*expr_p, 1) = init;
+ return GS_OK;
}
}
- ret = GS_UNHANDLED;
- break;
-
- case WITH_SIZE_EXPR:
- /* Likewise for calls that return an aggregate of non-constant size,
- since we would not be able to generate a temporary at all. */
- if (TREE_CODE (TREE_OPERAND (*from_p, 0)) == CALL_EXPR)
- {
- *from_p = TREE_OPERAND (*from_p, 0);
- ret = GS_OK;
- }
- else
- ret = GS_UNHANDLED;
- break;
-
- /* If we're initializing from a container, push the initialization
- inside it. */
- case CLEANUP_POINT_EXPR:
- case BIND_EXPR:
- case STATEMENT_LIST:
- {
- tree wrap = *from_p;
- tree t;
-
- ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_min_lval,
- fb_lvalue);
- if (ret != GS_ERROR)
- ret = GS_OK;
-
- t = voidify_wrapper_expr (wrap, *expr_p);
- gcc_assert (t == *expr_p);
-
- if (want_value)
- {
- gimplify_and_add (wrap, pre_p);
- *expr_p = unshare_expr (*to_p);
- }
- else
- *expr_p = wrap;
- return GS_OK;
- }
-
- case COMPOUND_LITERAL_EXPR:
- {
- tree complit = TREE_OPERAND (*expr_p, 1);
- tree decl_s = COMPOUND_LITERAL_EXPR_DECL_EXPR (complit);
- tree decl = DECL_EXPR_DECL (decl_s);
- tree init = DECL_INITIAL (decl);
-
- /* struct T x = (struct T) { 0, 1, 2 } can be optimized
- into struct T x = { 0, 1, 2 } if the address of the
- compound literal has never been taken. */
- if (!TREE_ADDRESSABLE (complit)
- && !TREE_ADDRESSABLE (decl)
- && init)
- {
- *expr_p = copy_node (*expr_p);
- TREE_OPERAND (*expr_p, 1) = init;
- return GS_OK;
- }
+ default:
+ break;
}
-
- default:
- ret = GS_UNHANDLED;
- break;
- }
+ }
+ while (changed);
return ret;
}
case MODIFY_EXPR:
case INIT_EXPR:
- ret = gimplify_modify_expr (expr_p, pre_p, post_p,
- fallback != fb_none);
+ {
+ tree from = TREE_OPERAND (*expr_p, 1);
+ ret = gimplify_modify_expr (expr_p, pre_p, post_p,
+ fallback != fb_none);
+ /* Don't let the end of loop logic change GS_OK into GS_ALL_DONE
+ if the RHS has changed. */
+ if (ret == GS_OK && *expr_p == save_expr
+ && TREE_OPERAND (*expr_p, 1) != from)
+ continue;
+ }
break;
case TRUTH_ANDIF_EXPR:
git://gcc.gnu.org / gcc.git / commitdiff