** Authors: Martin Trapp, Christian Schaefer
**
** ircons.c: basic and more detailed irnode constructors
-** store, block and parameter administration ,
+** store, block and parameter administration.
** Adapted to extended FIRM nodes (exceptions...) and commented
** by Goetz Lindenmaier
*/
# include "ircons.h"
-# include "array.h"
+# include "common.h"
+# include "irvrfy.h"
+# include "irop.h"
# include "iropt.h"
+# include "irgmod.h"
+# include "array.h"
/* memset belongs to string.h */
# include "string.h"
+# include "irnode.h"
-/* irnode constructor */
-/* create a new irnode in irg, with an op, mode, arity and */
-/* some incoming irnodes */
-/* this constructor is used in every specified irnode constructor */
-inline ir_node *
-new_ir_node (ir_graph *irg, ir_node *block, ir_op *op, ir_mode *mode,
- int arity, ir_node **in)
-{
- ir_node *res;
- int node_size = offsetof (ir_node, attr) + op->attr_size;
-
- res = (ir_node *) obstack_alloc (irg->obst, node_size);
-
- res->kind = k_ir_node;
- res->op = op;
- res->mode = mode;
- res->visit = 0;
- res->link = NULL;
- if (arity < 0) {
- res->in = NEW_ARR_F (ir_node *, 1);
- } else {
- res->in = NEW_ARR_D (ir_node *, irg->obst, (arity+1));
- memcpy (&res->in[1], in, sizeof (ir_node *) * arity);
- }
- res->in[0] = block;
- return res;
-}
-
-
-
+#if USE_EXPICIT_PHI_IN_STACK
+/* A stack needed for the automatic Phi node construction in constructor
+ Phi_in. */
+struct Phi_in_stack {
+ ir_node **stack;
+ int pos;
+};
+#endif
/*********************************************** */
/** privat interfaces, for professional use only */
-/*CS*/
+/* Constructs a Block with a fixed number of predecessors.
+ Does not set current_block. */
+
inline ir_node *
new_r_Block (ir_graph *irg, int arity, ir_node **in)
{
ir_node *res;
- return res;
+ res = new_ir_node (irg, NULL, op_Block, mode_R, arity, in);
+ set_Block_matured(res, 1);
+ irn_vrfy (res);
+ return res;
}
ir_node *
res = new_ir_node (irg, block, op_Start, mode_T, 0, NULL);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
-
ir_node *
new_r_End (ir_graph *irg, ir_node *block)
{
res = new_ir_node (irg, block, op_End, mode_X, -1, NULL);
- ir_vrfy (res);
- return res;
-
-}
-
-
-/* Creates a Phi node with 0 predecessors */
-inline ir_node *
-new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
-{
- ir_node *res;
-
- res = new_ir_node (irg, block, op_Phi, mode, 0, NULL);
-
- /* GL I'm not sure whether we should optimize this guy. *
- res = optimize (res); ??? */
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Phi, mode, arity, in);
res = optimize (res);
- ir_vrfy (res);
- return res;
-}
-
-/* This is a stack used for allocating and deallocating nodes in
- new_r_Phi_in. The original implementation used the obstack
- to model this stack, now it is explicit. This reduces side effects.
-*/
-#if USE_EXPICIT_PHI_IN_STACK
-Phi_in_stack *
-new_Phi_in_stack() {
- Phi_in_stack *res;
-
- res = (Phi_in_stack *) malloc ( sizeof (Phi_in_stack));
-
- res->stack = NEW_ARR_F (ir_node *, 1);
- res->pos = 0;
-
- return res;
-}
-
-
-void free_to_Phi_in_stack(ir_node *phi) {
- assert(get_irn_opcode(phi) == iro_Phi);
-
- if (ARR_LEN(current_ir_graph->Phi_in_stack->stack) ==
- current_ir_graph->Phi_in_stack->pos)
- ARR_APP1 (ir_node *, current_ir_graph->Phi_in_stack->stack, phi);
- else
- current_ir_graph->Phi_in_stack->stack[current_ir_graph->Phi_in_stack->pos] = phi;
-
- (current_ir_graph->Phi_in_stack->pos)++;
-}
-
-ir_node *
-alloc_or_pop_from_Phi_in_stack(ir_graph *irg, ir_node *block, ir_mode *mode,
- int arity, ir_node **in) {
- ir_node *res;
- ir_node **stack = current_ir_graph->Phi_in_stack->stack;
- int pos = current_ir_graph->Phi_in_stack->pos;
-
-
- if (pos == 0) {
- /* We need to allocate a new node */
- res = new_ir_node (irg, block, op_Phi, mode, arity, in);
- } else {
- /* reuse the old node and initialize it again. */
- res = stack[pos-1];
-
- assert (res->kind == k_ir_node);
- assert (res->op == op_Phi);
- res->mode = mode;
- res->visit = 0;
- res->link = NULL;
- assert (arity >= 0);
- /* ???!!! How to free the old in array?? */
- res->in = NEW_ARR_D (ir_node *, irg->obst, (arity+1));
- res->in[0] = block;
- memcpy (&res->in[1], in, sizeof (ir_node *) * arity);
-
- (current_ir_graph->Phi_in_stack->pos)--;
- }
- return res;
-}
-#endif
-
-
-
-/* Creates a Phi node with a given, fixed array **in of predecessors.
- If the Phi node is unnecessary, as the same value reaches the block
- through all control flow paths, it is eliminated and the value
- returned directly. This constructor is only intended for use in
- the automatic Phi node generation triggered by get_value or mature.
- The implementation is quite tricky and depends on the fact, that
- the nodes are allocated on a stack:
- The in array contains predecessors and NULLs. The NULLs appear,
- if get_r_value_internal, that computed the predecessors, reached
- the same block on two paths. In this case the same value reaches
- this block on both paths, there is no definition in between. We need
- not allocate a Phi where these path's merge, but we have to communicate
- this fact to the caller. This happens by returning a pointer to the
- node the caller _will_ allocate. (Yes, we predict the address. We can
- do so because the nodes are allocated on the obstack.) The caller then
- finds a pointer to itself and, when this routine is called again,
- eliminates itself.
- */
-inline ir_node *
-new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
- ir_node **in, int ins)
-{
- int i;
- ir_node *res, *known;
-
- /* allocate a new node on the obstack.
- This can return a node to which some of the pointers in the in-array
- already point.
- Attention: the constructor copies the in array, i.e., the later changes
- to the array in this routine do not affect the constructed node! If
- the in array contains NULLs, there will be missing predecessors in the
- returned node.
- Is this a possible internal state of the Phi node generation? */
-#if USE_EXPICIT_PHI_IN_STACK
- res = known = alloc_or_pop_from_Phi_in_stack(irg, block, mode, ins, in);
-#else
- res = known = new_ir_node (irg, block, op_Phi, mode, ins, in);
-#endif
- /* The in-array can contain NULLs. These were returned by get_r_value_internal
- if it reached the same block/definition on a second path.
- The NULLs are replaced by the node itself to simplify the test in the
- next loop. */
- for (i=0; i < ins; ++i)
- if (in[i] == NULL) in[i] = res;
-
- /* This loop checks whether the Phi has more than one predecessor.
- If so, it is a real Phi node and we break the loop. Else the
- Phi node merges the same definition on several paths and therefore
- is not needed. */
- for (i=0; i < ins; ++i)
- {
- if (in[i]==res || in[i]==known) continue;
-
- if (known==res)
- known = in[i];
- else
- break;
- }
-
- /* i==ins: there is at most one predecessor, we don't need a phi node. */
- if (i==ins) {
-#if USE_EXPICIT_PHI_IN_STACK
- free_to_Phi_in_stack(res);
-#else
- obstack_free (current_ir_graph->obst, res);
-#endif
- res = known;
- } else {
- res = optimize (res);
- ir_vrfy (res);
- }
-
- /* return the pointer to the Phi node. This node might be deallocated! */
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Const, mode, 0, NULL);
res->attr.con = con;
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
#if 0
res = local_optimize_newby (res);
ir_node *res;
res = new_ir_node (irg, block, op_Id, mode, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *
-new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg, ir_mode *mode, long proj)
+new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg, ir_mode *mode,
+ long proj)
{
ir_node *in[1] = {arg};
ir_node *res;
res = new_ir_node (irg, block, op_Proj, mode, 1, in);
res->attr.proj = proj;
+
+ assert(res);
+ assert(get_Proj_pred(res));
+ assert(get_nodes_Block(get_Proj_pred(res)));
+
res = optimize (res);
- ir_vrfy (res);
+
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Conv, mode, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Tuple, mode_T, arity, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Add, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Sub, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Minus, mode, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Mul, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
{
ir_node *in[3] = {memop, op1, op2};
ir_node *res;
- res = new_ir_node (irg, block, op_Quot, mode_T, 2, in);
+ res = new_ir_node (irg, block, op_Quot, mode_T, 3, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
{
ir_node *in[3] = {memop, op1, op2};
ir_node *res;
- res = new_ir_node (irg, block, op_DivMod, mode_T, 2, in);
+ res = new_ir_node (irg, block, op_DivMod, mode_T, 3, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
{
ir_node *in[3] = {memop, op1, op2};
ir_node *res;
- res = new_ir_node (irg, block, op_Div, mode_T, 2, in);
+ res = new_ir_node (irg, block, op_Div, mode_T, 3, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
{
ir_node *in[3] = {memop, op1, op2};
ir_node *res;
- res = new_ir_node (irg, block, op_Mod, mode_T, 2, in);
+ res = new_ir_node (irg, block, op_Mod, mode_T, 3, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_And, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Or, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Eor, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Not, mode, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Shl, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Shr, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Shrs, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Rot, mode, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Abs, mode, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Cmp, mode_T, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Jmp, mode_X, 0, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
ir_node *res;
res = new_ir_node (irg, block, op_Cond, mode_T, 1, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
set_Call_type(res, type);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
int r_arity;
r_arity = arity+1;
-
NEW_ARR_A (ir_node *, r_in, r_arity);
-
r_in[0] = store;
-
memcpy (&r_in[1], in, sizeof (ir_node *) * arity);
-
res = new_ir_node (irg, block, op_Return, mode_X, r_arity, r_in);
-
res = optimize (res);
-
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Raise, mode_X, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Load, mode_T, 2, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Store, mode_T, 3, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res->attr.a.type = alloc_type;
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res->attr.f = free_type;
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res->attr.s.ent = ent;
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
{
ir_node *in[0] = {};
ir_node *res;
- res = new_ir_node (irg, block, op_SymConst, mode_I, 0, in);
+ ir_mode *mode;
+ if (symkind == linkage_ptr_info)
+ mode = mode_p;
+ else
+ mode = mode_I;
+ res = new_ir_node (irg, block, op_SymConst, mode, 0, in);
res->attr.i.num = symkind;
if (symkind == linkage_ptr_info) {
res->attr.i.tori.typ = (type *)value;
}
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
res = new_ir_node (irg, block, op_Sync, mode_M, arity, in);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
-
ir_node *
-new_r_Bad (ir_node *block)
+new_r_Bad ()
{
return current_ir_graph->bad;
}
op_Start, mode_T, 0, NULL);
res = optimize (res);
- ir_vrfy (res);
+ irn_vrfy (res);
return res;
}
-
ir_node *
new_End (void)
{
op_End, mode_X, -1, NULL);
res = optimize (res);
- ir_vrfy (res);
- return res;
+ irn_vrfy (res);
+ return res;
}
ir_node *
res = new_ir_node (current_ir_graph, NULL, op_Block, mode_R, -1, NULL);
current_ir_graph->current_block = res;
res->attr.block.matured = 0;
- set_Block_block_visit(res, 0);
+ set_Block_block_visited(res, 0);
/* forget this optimization. use this only if mature !!!!
res = optimize (res); */
- ir_vrfy (res);
+ irn_vrfy (res);
/** create a new dynamic array, which stores all parameters in irnodes */
/** using the same obstack as the whole irgraph */
return res;
}
+/*************************************************************************/
+/* Methods necessary for automatic Phi node creation */
+/*
+ ir_node *phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
+ ir_node *get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
+ ir_node *new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
+ ir_node *new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode, ir_node **in, int ins)
+
+ Call Graph: ( A ---> B == A "calls" B)
+
+ get_value mature_block
+ | |
+ | |
+ | |
+ | ---> phi_merge
+ | / / \
+ | / / \
+ \|/ / |/_ \
+ get_r_value_internal |
+ | |
+ | |
+ \|/ \|/
+ new_r_Phi0 new_r_Phi_in
+
+*****************************************************************************/
+
+/* Creates a Phi node with 0 predecessors */
+inline ir_node *
+new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
+{
+ ir_node *res;
+ res = new_ir_node (irg, block, op_Phi, mode, 0, NULL);
+ irn_vrfy (res);
+ return res;
+}
+
+/* There are two implementations of the Phi node construction. The first
+ is faster, but does not work for blocks with more than 2 predecessors.
+ The second works always but is slower and causes more unnecessary Phi
+ nodes.
+ Select the implementations by the following preprocessor flag set in
+ common/common.h: */
+#if USE_FAST_PHI_CONSTRUCTION
+
+/* This is a stack used for allocating and deallocating nodes in
+ new_r_Phi_in. The original implementation used the obstack
+ to model this stack, now it is explicit. This reduces side effects.
+*/
+#if USE_EXPICIT_PHI_IN_STACK
+Phi_in_stack *
+new_Phi_in_stack() {
+ Phi_in_stack *res;
+
+ res = (Phi_in_stack *) malloc ( sizeof (Phi_in_stack));
+
+ res->stack = NEW_ARR_F (ir_node *, 1);
+ res->pos = 0;
+
+ return res;
+}
+
+void free_to_Phi_in_stack(ir_node *phi) {
+ assert(get_irn_opcode(phi) == iro_Phi);
+
+ if (ARR_LEN(current_ir_graph->Phi_in_stack->stack) ==
+ current_ir_graph->Phi_in_stack->pos)
+ ARR_APP1 (ir_node *, current_ir_graph->Phi_in_stack->stack, phi);
+ else
+ current_ir_graph->Phi_in_stack->stack[current_ir_graph->Phi_in_stack->pos] = phi;
+
+ (current_ir_graph->Phi_in_stack->pos)++;
+}
+
+ir_node *
+alloc_or_pop_from_Phi_in_stack(ir_graph *irg, ir_node *block, ir_mode *mode,
+ int arity, ir_node **in) {
+ ir_node *res;
+ ir_node **stack = current_ir_graph->Phi_in_stack->stack;
+ int pos = current_ir_graph->Phi_in_stack->pos;
+
+
+ if (pos == 0) {
+ /* We need to allocate a new node */
+ res = new_ir_node (irg, block, op_Phi, mode, arity, in);
+ } else {
+ /* reuse the old node and initialize it again. */
+ res = stack[pos-1];
+
+ assert (res->kind == k_ir_node);
+ assert (res->op == op_Phi);
+ res->mode = mode;
+ res->visited = 0;
+ res->link = NULL;
+ assert (arity >= 0);
+ /* ???!!! How to free the old in array?? */
+ res->in = NEW_ARR_D (ir_node *, irg->obst, (arity+1));
+ res->in[0] = block;
+ memcpy (&res->in[1], in, sizeof (ir_node *) * arity);
+
+ (current_ir_graph->Phi_in_stack->pos)--;
+ }
+ return res;
+}
+#endif /* USE_EXPICIT_PHI_IN_STACK */
+
+/* Creates a Phi node with a given, fixed array **in of predecessors.
+ If the Phi node is unnecessary, as the same value reaches the block
+ through all control flow paths, it is eliminated and the value
+ returned directly. This constructor is only intended for use in
+ the automatic Phi node generation triggered by get_value or mature.
+ The implementation is quite tricky and depends on the fact, that
+ the nodes are allocated on a stack:
+ The in array contains predecessors and NULLs. The NULLs appear,
+ if get_r_value_internal, that computed the predecessors, reached
+ the same block on two paths. In this case the same value reaches
+ this block on both paths, there is no definition in between. We need
+ not allocate a Phi where these path's merge, but we have to communicate
+ this fact to the caller. This happens by returning a pointer to the
+ node the caller _will_ allocate. (Yes, we predict the address. We can
+ do so because the nodes are allocated on the obstack.) The caller then
+ finds a pointer to itself and, when this routine is called again,
+ eliminates itself.
+ */
+inline ir_node *
+new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
+ ir_node **in, int ins)
+{
+ int i;
+ ir_node *res, *known;
+
+ /* allocate a new node on the obstack.
+ This can return a node to which some of the pointers in the in-array
+ already point.
+ Attention: the constructor copies the in array, i.e., the later changes
+ to the array in this routine do not affect the constructed node! If
+ the in array contains NULLs, there will be missing predecessors in the
+ returned node.
+ Is this a possible internal state of the Phi node generation? */
+#if USE_EXPICIT_PHI_IN_STACK
+ res = known = alloc_or_pop_from_Phi_in_stack(irg, block, mode, ins, in);
+#else
+ res = known = new_ir_node (irg, block, op_Phi, mode, ins, in);
+#endif
+ /* The in-array can contain NULLs. These were returned by
+ get_r_value_internal if it reached the same block/definition on a
+ second path.
+ The NULLs are replaced by the node itself to simplify the test in the
+ next loop. */
+ for (i=0; i < ins; ++i)
+ if (in[i] == NULL) in[i] = res;
+
+ /* This loop checks whether the Phi has more than one predecessor.
+ If so, it is a real Phi node and we break the loop. Else the
+ Phi node merges the same definition on several paths and therefore
+ is not needed. */
+ for (i=0; i < ins; ++i)
+ {
+ if (in[i]==res || in[i]==known) continue;
+
+ if (known==res)
+ known = in[i];
+ else
+ break;
+ }
+
+ /* i==ins: there is at most one predecessor, we don't need a phi node. */
+ if (i==ins) {
+#if USE_EXPICIT_PHI_IN_STACK
+ free_to_Phi_in_stack(res);
+#else
+ obstack_free (current_ir_graph->obst, res);
+#endif
+ res = known;
+ } else {
+ res = optimize (res);
+ irn_vrfy (res);
+ }
+
+ /* return the pointer to the Phi node. This node might be deallocated! */
+ return res;
+}
+
+inline ir_node *
+get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
+
+/** This function computes the predecessors for a real Phi node, and then
+ allocates and returns this node. The routine called to allocate the
+ node might optimize it away and return a real value, or even a pointer
+ to a deallocated Phi node on top of the obstack!
+ This function is called with an in-array of proper size. **/
+static inline ir_node *
+phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
+{
+ ir_node *prevBlock, *res;
+ int i;
+
+ /* This loop goes to all predecessor blocks of the block the Phi node is in
+ and there finds the operands of the Phi node by calling
+ get_r_value_internal. */
+ for (i = 1; i <= ins; ++i) {
+ assert (block->in[i]);
+ prevBlock = block->in[i]->in[0]; /* go past control flow op to prev block */
+ assert (prevBlock);
+ nin[i-1] = get_r_value_internal (prevBlock, pos, mode);
+ }
+
+ /* After collecting all predecessors into the array nin a new Phi node
+ with these predecessors is created. This constructor contains an
+ optimization: If all predecessors of the Phi node are identical it
+ returns the only operand instead of a new Phi node. If the value
+ passes two different control flow edges without being defined, and
+ this is the second path treated, a pointer to the node that will be
+ allocated for the first path (recursion) is returned. We already
+ know the address of this node, as it is the next node to be allocated
+ and will be placed on top of the obstack. (The obstack is a _stack_!) */
+ res = new_r_Phi_in (current_ir_graph, block, mode, nin, ins);
+
+ /* Now we now the value for "pos" and can enter it in the array with
+ all known local variables. Attention: this might be a pointer to
+ a node, that later will be allocated!!! See new_r_Phi_in.
+ If this is called in mature, after some set_value in the same block,
+ the proper value must not be overwritten:
+ The call order
+ get_value (makes Phi0, put's it into graph_arr)
+ set_value (overwrites Phi0 in graph_arr)
+ mature_block (upgrades Phi0, puts it again into graph_arr, overwriting
+ the proper value.)
+ fails. */
+ if (!block->attr.block.graph_arr[pos]) {
+ block->attr.block.graph_arr[pos] = res;
+ } else {
+ /* printf(" value already computed by %s\n",
+ id_to_str(block->attr.block.graph_arr[pos]->op->name)); */
+ }
+
+ return res;
+}
+
+/* This function returns the last definition of a variable. In case
+ this variable was last defined in a previous block, Phi nodes are
+ inserted. If the part of the firm graph containing the definition
+ is not yet constructed, a dummy Phi node is returned. */
+inline ir_node *
+get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
+{
+ ir_node *res;
+ /* There are 4 cases to treat.
+
+ 1. The block is not mature and we visit it the first time. We can not
+ create a proper Phi node, therefore a Phi0, i.e., a Phi without
+ predecessors is returned. This node is added to the linked list (field
+ "link") of the containing block to be completed when this block is
+ matured. (Comlpletion will add a new Phi and turn the Phi0 into an Id
+ node.)
+
+ 2. The value is already known in this block, graph_arr[pos] is set and we
+ visit the block the first time. We can return the value without
+ creating any new nodes.
+
+ 3. The block is mature and we visit it the first time. A Phi node needs
+ to be created (phi_merge). If the Phi is not needed, as all it's
+ operands are the same value reaching the block through different
+ paths, it's optimized away and the value itself is returned.
+
+ 4. The block is mature, and we visit it the second time. Now two
+ subcases are possible:
+ * The value was computed completely the last time we were here. This
+ is the case if there is no loop. We can return the proper value.
+ * The recursion that visited this node and set the flag did not
+ return yet. We are computing a value in a loop and need to
+ break the recursion without knowing the result yet.
+ @@@ strange case. Straight forward we would create a Phi before
+ starting the computation of it's predecessors. In this case we will find
+ a Phi here in any case. The problem is that this implementation only
+ creates a Phi after computing the predecessors, so that it is hard to
+ compute self references of this Phi. @@@
+ There is no simple check for the second subcase. Therefore we check
+ for a second visit and treat all such cases as the second subcase.
+ Anyways, the basic situation is the same: we reached a block
+ on two paths without finding a definition of the value: No Phi
+ nodes are needed on both paths.
+ We return this information "Two paths, no Phi needed" by a very tricky
+ implementation that relies on the fact that an obstack is a stack and
+ will return a node with the same address on different allocations.
+ Look also at phi_merge and new_r_phi_in to understand this.
+ @@@ Unfortunately this does not work, see testprogram three_cfpred_example.
+
+ */
+
+ /* case 4 -- already visited. */
+ if (get_irn_visited(block) == get_irg_visited(current_ir_graph)) return NULL;
+
+ /* visited the first time */
+ set_irn_visited(block, get_irg_visited(current_ir_graph));
+
+ /* Get the local valid value */
+ res = block->attr.block.graph_arr[pos];
+
+ /* case 2 -- If the value is actually computed, return it. */
+ if (res) { return res;};
+
+ if (block->attr.block.matured) { /* case 3 */
+
+ /* The Phi has the same amount of ins as the corresponding block. */
+ int ins = get_irn_arity(block);
+ ir_node **nin;
+ NEW_ARR_A (ir_node *, nin, ins);
+
+ /* Phi merge collects the predecessors and then creates a node. */
+ res = phi_merge (block, pos, mode, nin, ins);
+
+ } else { /* case 1 */
+ /* The block is not mature, we don't know how many in's are needed. A Phi
+ with zero predecessors is created. Such a Phi node is called Phi0
+ node. (There is also an obsolete Phi0 opcode.) The Phi0 is then added
+ to the list of Phi0 nodes in this block to be matured by mature_block
+ later.
+ The Phi0 has to remember the pos of it's internal value. If the real
+ Phi is computed, pos is used to update the array with the local
+ values. */
+
+ res = new_r_Phi0 (current_ir_graph, block, mode);
+ res->attr.phi0_pos = pos;
+ res->link = block->link;
+ block->link = res;
+ }
+
+ /* If we get here, the frontend missed a use-before-definition error */
+ if (!res) {
+ /* Error Message */
+ printf("Error: no value set. Use of undefined variable. Initializing
+ to zero.\n");
+ assert (mode->code >= irm_f && mode->code <= irm_p);
+ res = new_r_Const (current_ir_graph, block, mode,
+ tarval_mode_null[mode->code]);
+ }
+
+ /* The local valid value is available now. */
+ block->attr.block.graph_arr[pos] = res;
+
+ return res;
+}
+
+#else /* if 0 */
+
+/** This is the simple algorithm. If first generates a Phi0, then
+ it starts the recursion. This causes an Id at the entry of
+ every block that has no definition of the value! **/
+
+#if USE_EXPICIT_PHI_IN_STACK
+/* Just a dummy */
+Phi_in_stack * new_Phi_in_stack() { return NULL; }
+#endif
+
+inline ir_node *
+new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
+ ir_node **in, int ins)
+{
+ int i;
+ ir_node *res, *known;
+
+ /* Allocate a new node on the obstack. The allocation copies the in
+ array. */
+ res = new_ir_node (irg, block, op_Phi, mode, ins, in);
+
+ /* This loop checks whether the Phi has more than one predecessor.
+ If so, it is a real Phi node and we break the loop. Else the
+ Phi node merges the same definition on several paths and therefore
+ is not needed. Don't consider Bad nodes! */
+ known = res;
+ for (i=0; i < ins; ++i)
+ {
+ if (in[i]==res || in[i]==known || is_Bad(in[i])) continue;
+
+ if (known==res)
+ known = in[i];
+ else
+ break;
+ }
+
+ /* i==ins: there is at most one predecessor, we don't need a phi node. */
+ if (i==ins) {
+ if (res != known) {
+ obstack_free (current_ir_graph->obst, res);
+ res = known;
+ } else {
+ /* A undefined value, e.g., in unreachable code. */
+ res = new_Bad();
+ }
+ } else {
+ res = optimize (res);
+ irn_vrfy (res);
+ }
+
+ return res;
+}
+
+inline ir_node *
+get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
+
+/** This function allocates a dummy Phi node to break recursions,
+ computes the predecessors for the real phi node, and then
+ allocates and returns this node. The routine called to allocate the
+ node might optimize it away and return a real value.
+ This function is called with an in-array of proper size. **/
+static inline ir_node *
+phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
+{
+ ir_node *prevBlock, *res, *phi0;
+ int i;
+
+
+ /* If this block has no value at pos create a Phi0 and remember it
+ in graph_arr to break recursions. */
+ phi0 = NULL;
+ if (!block->attr.block.graph_arr[pos]) {
+ /* Even if all variables are defined before use, it can happen that
+ we get to the start block, if a cond has been replaced by a tuple
+ (bad, jmp). As the start has a self referencing control flow edge,
+ we get a self referencing Id, which is hard to optimize away. We avoid
+ this by defining the value as a Bad node. *
+ if (block == get_irg_start_block(current_ir_graph)) {
+ block->attr.block.graph_arr[pos] = new_Bad();
+ return new_Bad();
+ } else */ {
+ phi0 = new_r_Phi0(current_ir_graph, block, mode);
+ block->attr.block.graph_arr[pos] = phi0;
+ }
+ }
+
+ /* This loop goes to all predecessor blocks of the block the Phi node
+ is in and there finds the operands of the Phi node by calling
+ get_r_value_internal. */
+ for (i = 1; i <= ins; ++i) {
+ assert (block->in[i]);
+ if (is_Bad(block->in[i])) {
+ /* In case a Cond has been optimized we would get right to the start block
+ with an invalid definition. */
+ nin[i-1] = new_Bad();
+ continue;
+ }
+ prevBlock = block->in[i]->in[0]; /* go past control flow op to prev block */
+ assert (prevBlock);
+ if (!is_Bad(prevBlock)) {
+ nin[i-1] = get_r_value_internal (prevBlock, pos, mode);
+ } else {
+ nin[i-1] = new_Bad();
+ }
+ }
+
+ /* After collecting all predecessors into the array nin a new Phi node
+ with these predecessors is created. This constructor contains an
+ optimization: If all predecessors of the Phi node are identical it
+ returns the only operand instead of a new Phi node. */
+ res = new_r_Phi_in (current_ir_graph, block, mode, nin, ins);
+
+ /* In case we allocated a Phi0 node at the beginning of this procedure,
+ we need to exchange this Phi0 with the real Phi. */
+ if (phi0) {
+ exchange(phi0, res);
+ block->attr.block.graph_arr[pos] = res;
+ }
+
+ return res;
+}
+
+/* This function returns the last definition of a variable. In case
+ this variable was last defined in a previous block, Phi nodes are
+ inserted. If the part of the firm graph containing the definition
+ is not yet constructed, a dummy Phi node is returned. */
+inline ir_node *
+get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
+{
+ ir_node *res;
+ /* There are 4 cases to treat.
+
+ 1. The block is not mature and we visit it the first time. We can not
+ create a proper Phi node, therefore a Phi0, i.e., a Phi without
+ predecessors is returned. This node is added to the linked list (field
+ "link") of the containing block to be completed when this block is
+ matured. (Comlpletion will add a new Phi and turn the Phi0 into an Id
+ node.)
+
+ 2. The value is already known in this block, graph_arr[pos] is set and we
+ visit the block the first time. We can return the value without
+ creating any new nodes.
+
+ 3. The block is mature and we visit it the first time. A Phi node needs
+ to be created (phi_merge). If the Phi is not needed, as all it's
+ operands are the same value reaching the block through different
+ paths, it's optimized away and the value itself is returned.
+
+ 4. The block is mature, and we visit it the second time. Now two
+ subcases are possible:
+ * The value was computed completely the last time we were here. This
+ is the case if there is no loop. We can return the proper value.
+ * The recursion that visited this node and set the flag did not
+ return yet. We are computing a value in a loop and need to
+ break the recursion. This case only happens if we visited
+ the same block with phi_merge before, which inserted a Phi0.
+ So we return the Phi0.
+ */
+
+ /* case 4 -- already visited. */
+ if (get_irn_visited(block) == get_irg_visited(current_ir_graph)) {
+ /* As phi_merge allocates a Phi0 this value is always defined. Here
+ is the critical difference of the two algorithms. */
+ assert(block->attr.block.graph_arr[pos]);
+ return block->attr.block.graph_arr[pos];
+ }
+
+ /* visited the first time */
+ set_irn_visited(block, get_irg_visited(current_ir_graph));
+
+ /* Get the local valid value */
+ res = block->attr.block.graph_arr[pos];
+
+ /* case 2 -- If the value is actually computed, return it. */
+ if (res) { return res; };
+
+ if (block->attr.block.matured) { /* case 3 */
+
+ /* The Phi has the same amount of ins as the corresponding block. */
+ int ins = get_irn_arity(block);
+ ir_node **nin;
+ NEW_ARR_A (ir_node *, nin, ins);
+
+ /* Phi merge collects the predecessors and then creates a node. */
+ res = phi_merge (block, pos, mode, nin, ins);
+
+ } else { /* case 1 */
+ /* The block is not mature, we don't know how many in's are needed. A Phi
+ with zero predecessors is created. Such a Phi node is called Phi0
+ node. The Phi0 is then added to the list of Phi0 nodes in this block
+ to be matured by mature_block later.
+ The Phi0 has to remember the pos of it's internal value. If the real
+ Phi is computed, pos is used to update the array with the local
+ values. */
+ res = new_r_Phi0 (current_ir_graph, block, mode);
+ res->attr.phi0_pos = pos;
+ res->link = block->link;
+ block->link = res;
+ }
+
+ /* If we get here, the frontend missed a use-before-definition error */
+ if (!res) {
+ /* Error Message */
+ printf("Error: no value set. Use of undefined variable. Initializing
+ to zero.\n");
+ assert (mode->code >= irm_f && mode->code <= irm_p);
+ res = new_r_Const (current_ir_graph, block, mode,
+ tarval_mode_null[mode->code]);
+ }
+
+ /* The local valid value is available now. */
+ block->attr.block.graph_arr[pos] = res;
+
+ return res;
+}
+
+#endif /* USE_FAST_PHI_CONSTRUCTION */
+
+/****************************************************************************/
+
+/** Finalize a Block node, when all control flows are known. */
+/** Acceptable parameters are only Block nodes. */
+void
+mature_block (ir_node *block)
+{
+
+ int ins;
+ ir_node *n, **nin;
+ ir_node *next;
+
+ assert (get_irn_opcode(block) == iro_Block);
+
+ if (!get_Block_matured(block)) {
+
+ /* turn the dynamic in-array into a static one. */
+ ins = ARR_LEN (block->in)-1;
+ NEW_ARR_A (ir_node *, nin, ins);
+
+ /* Traverse a chain of Phi nodes attached to this block and mature
+ these, too. **/
+ for (n = block->link; n; n=next) {
+ inc_irg_visited(current_ir_graph);
+ next = n->link;
+ exchange (n, phi_merge (block, n->attr.phi0_pos, n->mode, nin, ins));
+ }
+
+ block->attr.block.matured = 1;
+
+ /* Now, as the block is a finished firm node, we can optimize it.
+ Since other nodes have been allocated since the block was created
+ we can not free the node on the obstack. Therefore we have to call
+ optimize_in_place.
+ Unfortunately the optimization does not change a lot, as all allocated
+ nodes refer to the unoptimized node. */
+ block = optimize_in_place(block);
+ irn_vrfy(block);
+ }
+}
ir_node *
new_Phi (int arity, ir_node **in, ir_mode *mode)
store, callee, arity, in, type);
}
-/* make M parameter in call explicit:
-new_Return (ir_node* store, int arity, ir_node **in) */
ir_node *
new_Return (ir_node* store, int arity, ir_node **in)
{
return current_ir_graph->bad;
}
-#if 0
-/************************/
-/* ir block constructor */
+/*************************************************************************/
+/* Comfortable interface with automatic Phi node construction. */
+/* (Uses also constructors of ?? interface, except new_Block. */
+/* add an adge to a jmp node */
+void
+add_in_edge (ir_node *block, ir_node *jmp)
+{
+ if (block->attr.block.matured) {
+ printf("Error: Block already matured!\n");
+ }
+ else {
+ assert (jmp != NULL);
+ ARR_APP1 (ir_node *, block->in, jmp);
+ }
+}
-/* GL: what's this good for? */
+/* changing the current block */
+void
+switch_block (ir_node *target)
+{
+ current_ir_graph->current_block = target;
+}
-typedef struct ir_block {
- char closed;
- char matured;
- /* -1 = error, 0 = OK */
-} ir_block;
+/****************************/
+/* parameter administration */
-ir_block *
-new_ir_Block(void)
+/* get a value from the parameter array from the current block by its index */
+ir_node *
+get_value (int pos, ir_mode *mode)
{
- ir_block *res;
+ inc_irg_visited(current_ir_graph);
+ return get_r_value_internal (current_ir_graph->current_block, pos + 1, mode);
+}
- res->closed = -1;
- res->matured = -1;
+/* set a value at position pos in the parameter array from the current block */
+inline void
+set_value (int pos, ir_node *value)
+{
+ current_ir_graph->current_block->attr.block.graph_arr[pos + 1] = value;
+}
- return res;
+/* get the current store */
+inline ir_node *
+get_store (void)
+{
+ /* GL: one could call get_value instead */
+ inc_irg_visited(current_ir_graph);
+ return get_r_value_internal (current_ir_graph->current_block, 0, mode_M);
+}
+
+/* set the current store */
+inline void
+set_store (ir_node *store)
+{
+ /* GL: one could call set_value instead */
+ current_ir_graph->current_block->attr.block.graph_arr[0] = store;
}
-#endif
+/*************************************************************************/
/* initialize */
/* call once for each run of the library */