-/* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors: Christian Schaefer, Goetz Lindenmaier
-**
-** iropt --- optimizations intertwined with IR construction.
-*/
-
-/* $Id$ */
+/*
+ * Project: libFIRM
+ * File name: ir/ir/iropt.c
+ * Purpose: iropt --- optimizations intertwined with IR construction.
+ * Author: Christian Schaefer
+ * Modified by: Goetz Lindenmaier
+ * Created:
+ * CVS-ID: $Id$
+ * Copyright: (c) 1998-2003 Universität Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
#ifdef HAVE_CONFIG_H
# include <config.h>
# include "irgmod.h"
# include "irvrfy.h"
# include "tv.h"
-# include "tune.h"
-# include "debinfo.h"
+# include "dbginfo_t.h"
+# include "iropt_dbg.h"
/* Make types visible to allow most efficient access */
# include "entity_t.h"
-/* Trivial inlineable routine for copy propagation.
- Does follow Ids, needed to optimize inlined code. */
-static inline ir_node *
+/* Trivial INLINEable routine for copy propagation.
+ Does follow Ids, needed to optimize INLINEd code. */
+static INLINE ir_node *
follow_Id (ir_node *n)
{
while (get_irn_op (n) == op_Id) n = get_Id_pred (n);
return n;
}
-static inline tarval *
+static INLINE tarval *
value_of (ir_node *n)
{
if ((n != NULL) && (get_irn_op(n) == op_Const))
- return get_Const_tarval(n);
+ return get_Const_tarval(n); /* might return tarval_bad */
else
- return NULL;
+ return tarval_bad;
}
-/* if n can be computed, return the value, else NULL. Performs
+/* if n can be computed, return the value, else tarval_bad. Performs
constant folding. GL: Only if n is arithmetic operator? */
tarval *
computed_value (ir_node *n)
tarval *res;
ir_node *a = NULL, *b = NULL; /* initialized to shut up gcc */
- tarval *ta = NULL, *tb = NULL; /* initialized to shut up gcc */
+ /* initialized to uniformly filter invalid constants */
+ tarval *ta = tarval_bad, *tb = tarval_bad;
- res = NULL;
+ res = tarval_bad;
/* get the operands we will work on for simple cases. */
if (is_binop(n)) {
switch (get_irn_opcode(n)) {
case iro_Const:
res = get_Const_tarval(n);
+ break;
+ case iro_SymConst:
+ if ((get_SymConst_kind(n) == size) &&
+ (get_type_state(get_SymConst_type(n))) == layout_fixed)
+ res = new_tarval_from_long (get_type_size(get_SymConst_type(n)), mode_Is);
+ break;
case iro_Add:
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))
- && (get_irn_mode(a) != mode_p)) {
+ if ((ta != tarval_bad) && (tb != tarval_bad)
+ && (get_irn_mode(a) == get_irn_mode(b))
+ && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
res = tarval_add (ta, tb);
}
break;
case iro_Sub:
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))
- && (get_irn_mode(a) != mode_p)) {
+ if ((ta != tarval_bad) && (tb != tarval_bad)
+ && (get_irn_mode(a) == get_irn_mode(b))
+ && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
res = tarval_sub (ta, tb);
- } else if (a == b) {
- res = tarval_mode_null [get_irn_modecode (n)];
}
break;
case iro_Minus:
- if (ta && mode_is_float(get_irn_mode(a)))
+ if ((ta != tarval_bad) && mode_is_signed(get_irn_mode(a)))
res = tarval_neg (ta);
break;
case iro_Mul:
- if (ta && tb) /* tarval_mul tests for equivalent modes itself */ {
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
res = tarval_mul (ta, tb);
} else {
/* a*0 = 0 or 0*b = 0:
calls computed_value recursive and returns the 0 with proper
mode. */
tarval *v;
- if ( (tarval_classify ((v = computed_value (a))) == 0)
- || (tarval_classify ((v = computed_value (b))) == 0)) {
+ if ( ( ((v = computed_value (a)) != tarval_bad)
+ && (v == get_mode_null(get_tarval_mode(v))) )
+ || ( ((v = computed_value (b)) != tarval_bad)
+ && (v == get_mode_null(get_tarval_mode(v))) )) {
res = v;
}
}
break;
case iro_Quot:
/* This was missing in original implementation. Why? */
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))) {
- if (tarval_classify(tb) == 0) {res = NULL; break;}
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ if (tb == get_mode_null(get_tarval_mode(tb))) break; /* div by zero: return tarval_bad */
res = tarval_quo(ta, tb);
}
break;
case iro_Div:
/* This was missing in original implementation. Why? */
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))) {
- if (tarval_classify(tb) == 0) {res = NULL; break;}
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ if (tb == get_mode_null(get_tarval_mode(tb))) break; /* div by zero: return tarval_bad */
res = tarval_div(ta, tb);
}
break;
case iro_Mod:
/* This was missing in original implementation. Why? */
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))) {
- if (tarval_classify(tb) == 0) {res = NULL; break;}
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ if (tb == get_mode_null(get_tarval_mode(tb))) break; /* div by zero: return tarval_bad */
res = tarval_mod(ta, tb);
}
break;
/* for iro_DivMod see iro_Proj */
case iro_Abs:
- if (ta)
+ if (ta != tarval_bad)
res = tarval_abs (ta);
break;
case iro_And:
- if (ta && tb) {
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
res = tarval_and (ta, tb);
} else {
tarval *v;
- if ( (tarval_classify ((v = computed_value (a))) == 0)
- || (tarval_classify ((v = computed_value (b))) == 0)) {
+ if ( (tarval_classify ((v = computed_value (a))) == TV_CLASSIFY_NULL)
+ || (tarval_classify ((v = computed_value (b))) == TV_CLASSIFY_NULL)) {
res = v;
}
}
break;
case iro_Or:
- if (ta && tb) {
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
res = tarval_or (ta, tb);
} else {
tarval *v;
- if ( (tarval_classify ((v = computed_value (a))) == -1)
- || (tarval_classify ((v = computed_value (b))) == -1)) {
+ if ( (tarval_classify ((v = computed_value (a))) == TV_CLASSIFY_ALL_ONE)
+ || (tarval_classify ((v = computed_value (b))) == TV_CLASSIFY_ALL_ONE)) {
res = v;
}
}
break;
- case iro_Eor: if (ta && tb) { res = tarval_eor (ta, tb); } break;
- case iro_Not: if (ta) { res = tarval_neg (ta); } break;
- case iro_Shl: if (ta && tb) { res = tarval_shl (ta, tb); } break;
- /* tarval_shr is faulty !! */
- case iro_Shr: if (ta && tb) { res = tarval_shr (ta, tb); } break;
- case iro_Shrs:if (ta && tb) { /*res = tarval_shrs (ta, tb)*/; } break;
- case iro_Rot: if (ta && tb) { /*res = tarval_rot (ta, tb)*/; } break;
- case iro_Conv:if (ta) { res = tarval_convert_to (ta, get_irn_mode (n)); }
+ case iro_Eor:
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ res = tarval_eor (ta, tb);
+ }
+ break;
+ case iro_Not:
+ if ((ta != tarval_bad)) {
+ res = tarval_not (ta);
+ }
+ break;
+ case iro_Shl:
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ res = tarval_shl (ta, tb);
+ }
+ break;
+ case iro_Shr:
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ res = tarval_shr (ta, tb);
+ }
+ break;
+ case iro_Shrs:
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ res = tarval_shrs (ta, tb);
+ }
+ break;
+ case iro_Rot:
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ /*res = tarval_rot (ta, tb)*/;
+ }
+ break;
+ case iro_Conv:
+ if (ta != tarval_bad) {
+ res = tarval_convert_to (ta, get_irn_mode (n));
+ }
break;
case iro_Proj: /* iro_Cmp */
{
only 1 is used.
There are several case where we can evaluate a Cmp node:
1. The nodes compared are both the same. If we compare for
- equal, this will return true, else it will return false.
- This step relies on cse.
+ equal, greater equal, ... this will return true, else it
+ will return false. This step relies on cse.
2. The predecessors of Cmp are target values. We can evaluate
the Cmp.
3. The predecessors are Allocs or void* constants. Allocs never
if (aa == ab) { /* 1.: */
/* This is a tric with the bits used for encoding the Cmp
Proj numbers, the following statement is not the same:
- res = tarval_from_long (mode_b, (get_Proj_proj(n) == Eq)): */
- res = tarval_from_long (mode_b, (get_Proj_proj(n) & irpn_Eq));
+ res = new_tarval_from_long ((get_Proj_proj(n) == Eq), mode_b) */
+ res = new_tarval_from_long ((get_Proj_proj(n) & Eq), mode_b);
} else {
tarval *taa = computed_value (aa);
tarval *tab = computed_value (ab);
- if (taa && tab) { /* 2.: */
+ if ((taa != tarval_bad) && (tab != tarval_bad)) { /* 2.: */
/* strange checks... */
- ir_pncmp flags = tarval_comp (taa, tab);
- if (flags != irpn_False) {
- res = tarval_from_long (mode_b, get_Proj_proj(n) & flags);
+ pnc_number flags = tarval_cmp (taa, tab);
+ if (flags != False) {
+ res = new_tarval_from_long (get_Proj_proj(n) & flags, mode_b);
}
} else { /* check for 3.: */
ir_node *aaa = skip_nop(skip_Proj(aa));
ir_node *aba = skip_nop(skip_Proj(ab));
if ( ( (/* aa is ProjP and aaa is Alloc */
(get_irn_op(aa) == op_Proj)
- && (get_irn_mode(aa) == mode_p)
+ && (mode_is_reference(get_irn_mode(aa)))
&& (get_irn_op(aaa) == op_Alloc))
&& ( (/* ab is constant void */
(get_irn_op(ab) == op_Const)
- && (get_irn_mode(ab) == mode_p)
- && (get_Const_tarval(ab) == tarval_p_void))
+ && (mode_is_reference(get_irn_mode(ab)))
+ && (get_Const_tarval(ab) == get_mode_null(get_irn_mode(ab))))
|| (/* ab is other Alloc */
(get_irn_op(ab) == op_Proj)
- && (get_irn_mode(ab) == mode_p)
+ && (mode_is_reference(get_irn_mode(ab)))
&& (get_irn_op(aba) == op_Alloc)
&& (aaa != aba))))
|| (/* aa is void and aba is Alloc */
(get_irn_op(aa) == op_Const)
- && (get_irn_mode(aa) == mode_p)
- && (get_Const_tarval(aa) == tarval_p_void)
+ && (mode_is_reference(get_irn_mode(aa)))
+ && (get_Const_tarval(aa) == get_mode_null(get_irn_mode(aa)))
&& (get_irn_op(ab) == op_Proj)
- && (get_irn_mode(ab) == mode_p)
+ && (mode_is_reference(get_irn_mode(ab)))
&& (get_irn_op(aba) == op_Alloc)))
/* 3.: */
- res = tarval_from_long (mode_b, get_Proj_proj(n) & irpn_Ne);
+ res = new_tarval_from_long (get_Proj_proj(n) & Ne, mode_b);
}
}
} else if (get_irn_op(a) == op_DivMod) {
ta = value_of(get_DivMod_left(a));
tb = value_of(get_DivMod_right(a));
- if (ta && tb && (get_irn_mode(a) == get_irn_mode(b))) {
- if (tarval_classify(tb) == 0) {res = NULL; break;}
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ if (tb == get_mode_null(get_tarval_mode(tb))) break; /* div by zero: return tarval_bad */
if (get_Proj_proj(n)== 0) /* Div */
res = tarval_div(ta, tb);
else /* Mod */
res = tarval_mod(ta, tb);
}
- } else {
- /* printf(" # comp_val: Proj node, not optimized\n"); */
}
}
break;
} /* compute node */
-
+#if 0
/* returns 1 if the a and b are pointers to different locations. */
-bool
+static bool
different_identity (ir_node *a, ir_node *b)
{
- assert (get_irn_mode (a) == mode_p
- && get_irn_mode (b) == mode_p);
+ assert (mode_is_reference(get_irn_mode (a))
+ && mode_is_reference(get_irn_mode (b)));
if (get_irn_op (a) == op_Proj && get_irn_op(b) == op_Proj) {
ir_node *a1 = get_Proj_pred (a);
}
return 0;
}
-
+#endif
/* equivalent_node returns a node equivalent to N. It skips all nodes that
perform no actual computation, as, e.g., the Id nodes. It does not create
new nodes. It is therefore safe to free N if the node returned is not N.
If a node returns a Tuple we can not just skip it. If the size of the
in array fits, we transform n into a tuple (e.g., Div). */
-static ir_node *
+ir_node *
equivalent_node (ir_node *n)
{
int ins;
ir_node *a = NULL; /* to shutup gcc */
ir_node *b = NULL; /* to shutup gcc */
ir_node *c = NULL; /* to shutup gcc */
+ ir_node *oldn = n;
ins = get_irn_arity (n);
case iro_Block:
{
/* The Block constructor does not call optimize, but mature_block
- calls the optimization. */
+ calls the optimization. */
assert(get_Block_matured(n));
- /* A single entry Block following a single exit Block can be merged,
- if it is not the Start block. */
+ /* Straightening: a single entry Block following a single exit Block
+ can be merged, if it is not the Start block. */
/* !!! Beware, all Phi-nodes of n must have been optimized away.
- This should be true, as the block is matured before optimize is called.
+ This should be true, as the block is matured before optimize is called.
But what about Phi-cycles with the Phi0/Id that could not be resolved?
- Remaining Phi nodes are just Ids. */
- if (get_Block_n_cfgpreds(n) == 1
- && get_irn_op(get_Block_cfgpred(n, 0)) == op_Jmp) {
- n = get_nodes_Block(get_Block_cfgpred(n, 0));
-
- } else if ((n != current_ir_graph->start_block) &&
- (n != current_ir_graph->end_block) ) {
- int i;
- /* If all inputs are dead, this block is dead too, except if it is
+ Remaining Phi nodes are just Ids. */
+ if ((get_Block_n_cfgpreds(n) == 1) &&
+ (get_irn_op(get_Block_cfgpred(n, 0)) == op_Jmp) &&
+ (get_opt_control_flow_straightening())) {
+ n = get_nodes_Block(get_Block_cfgpred(n, 0)); DBG_OPT_STG;
+
+ } else if ((get_Block_n_cfgpreds(n) == 2) &&
+ (get_opt_control_flow_weak_simplification())) {
+ /* Test whether Cond jumps twice to this block
+ @@@ we could do this also with two loops finding two preds from several ones. */
+ a = get_Block_cfgpred(n, 0);
+ b = get_Block_cfgpred(n, 1);
+ if ((get_irn_op(a) == op_Proj) &&
+ (get_irn_op(b) == op_Proj) &&
+ (get_Proj_pred(a) == get_Proj_pred(b)) &&
+ (get_irn_op(get_Proj_pred(a)) == op_Cond) &&
+ (get_irn_mode(get_Cond_selector(get_Proj_pred(a))) == mode_b)) {
+ /* Also a single entry Block following a single exit Block. Phis have
+ twice the same operand and will be optimized away. */
+ n = get_nodes_Block(a); DBG_OPT_IFSIM;
+ }
+ } else if (get_opt_unreachable_code() &&
+ (n != current_ir_graph->start_block) &&
+ (n != current_ir_graph->end_block) ) {
+ int i;
+ /* If all inputs are dead, this block is dead too, except if it is
the start or end block. This is a step of unreachable code
- elimination */
- for (i = 0; i < get_Block_n_cfgpreds(n); i++) {
- if (!is_Bad(get_Block_cfgpred(n, i))) break;
- }
- if (i == get_Block_n_cfgpreds(n))
- n = new_Bad();
+ elimination */
+ for (i = 0; i < get_Block_n_cfgpreds(n); i++) {
+ if (!is_Bad(get_Block_cfgpred(n, i))) break;
+ }
+ if (i == get_Block_n_cfgpreds(n))
+ n = new_Bad();
}
}
break;
/** remove stuff as x+0, x*1 x&true ... constant expression evaluation **/
case iro_Or: if (a == b) {n = a; break;}
case iro_Add:
- case iro_Eor:
- { tarval *tv;
- ir_node *on;
- /* After running compute_node there is only one constant predecessor.
- Find this predecessors value and remember the other node: */
- if ((tv = computed_value (a))) {
- on = b;
- } else if ((tv = computed_value (b))) {
- on = a;
- } else break;
-
- /* If this predecessors constant value is zero, the operation is
- unnecessary. Remove it: */
- if (tarval_classify (tv) == 0) {
- n = on;
- }
+ case iro_Eor: {
+ tarval *tv;
+ ir_node *on;
+ /* After running compute_node there is only one constant predecessor.
+ Find this predecessors value and remember the other node: */
+ if ((tv = computed_value (a)) != tarval_bad) {
+ on = b;
+ } else if ((tv = computed_value (b)) != tarval_bad) {
+ on = a;
+ } else break;
+
+ /* If this predecessors constant value is zero, the operation is
+ unnecessary. Remove it: */
+ if (tarval_classify (tv) == TV_CLASSIFY_NULL) {
+ n = on; DBG_OPT_ALGSIM1;
}
- break;
+ } break;
case iro_Sub:
case iro_Shl:
case iro_Shr:
case iro_Shrs:
case iro_Rot:
/* these operations are not commutative. Test only one predecessor. */
- if (tarval_classify (computed_value (b)) == 0) {
- n = a;
+ if (tarval_classify (computed_value (b)) == TV_CLASSIFY_NULL) {
+ n = a; DBG_OPT_ALGSIM1;
/* Test if b > #bits of a ==> return 0 / divide b by #bits
--> transform node? */
}
case iro_Not: /* NotNot x == x */
case iro_Minus: /* --x == x */ /* ??? Is this possible or can --x raise an
out of bounds exception if min =! max? */
- if (get_irn_op(get_unop_op(n)) == get_irn_op(n))
- n = get_unop_op(get_unop_op(n));
+ if (get_irn_op(get_unop_op(n)) == get_irn_op(n)) {
+ n = get_unop_op(get_unop_op(n)); DBG_OPT_ALGSIM2;
+ }
break;
case iro_Mul:
/* Mul is commutative and has again an other neutral element. */
- if (tarval_classify (computed_value (a)) == 1) {
- n = b;
- } else if (tarval_classify (computed_value (b)) == 1) {
- n = a;
+ if (tarval_classify (computed_value (a)) == TV_CLASSIFY_ONE) {
+ n = b; DBG_OPT_ALGSIM1;
+ } else if (tarval_classify (computed_value (b)) == TV_CLASSIFY_ONE) {
+ n = a; DBG_OPT_ALGSIM1;
}
break;
case iro_Div:
/* Div is not commutative. */
- if (tarval_classify (computed_value (b)) == 1) { /* div(x, 1) == x */
+ if (tarval_classify (computed_value (b)) == TV_CLASSIFY_ONE) { /* div(x, 1) == x */
/* Turn Div into a tuple (mem, bad, a) */
ir_node *mem = get_Div_mem(n);
turn_into_tuple(n, 3);
set_Tuple_pred(n, 2, a);
}
break;
- /* GL: Why are they skipped? DivMod allocates new nodes --> it's
- teated in transform node.
- case iro_Mod, Quot, DivMod
- */
+ /*
+ case iro_Mod, Quot, DivMod
+ DivMod allocates new nodes --> it's treated in transform node.
+ What about Quot, DivMod?
+ */
case iro_And:
- if (a == b) n = a;
- /* And has it's own neutral element */
- else if (tarval_classify (computed_value (a)) == -1) {
+ if (a == b) {
+ n = a; /* And has it's own neutral element */
+ } else if (tarval_classify (computed_value (a)) == TV_CLASSIFY_ALL_ONE) {
n = b;
- } else if (tarval_classify (computed_value (b)) == -1) {
+ } else if (tarval_classify (computed_value (b)) == TV_CLASSIFY_ALL_ONE) {
n = a;
}
+ if (n != oldn) DBG_OPT_ALGSIM1;
break;
case iro_Conv:
- if (get_irn_mode(n) == get_irn_mode(a)) { /* No Conv necessary */
- n = a;
- } else if (get_irn_mode(n) == mode_b) {
- if (get_irn_op(a) == op_Conv &&
- get_irn_mode (get_Conv_op(a)) == mode_b) {
- n = get_Conv_op(a); /* Convb(Conv*(xxxb(...))) == xxxb(...) */
+ {
+ ir_mode *n_mode = get_irn_mode(n);
+ ir_mode *a_mode = get_irn_mode(a);
+
+ if (n_mode == a_mode) { /* No Conv necessary */
+ n = a; DBG_OPT_ALGSIM3;
+ } else if (get_irn_op(a) == op_Conv) { /* Conv(Conv(b)) */
+ ir_mode *b_mode;
+
+ b = get_Conv_op(a);
+ n_mode = get_irn_mode(n);
+ b_mode = get_irn_mode(b);
+
+ if (n_mode == b_mode) {
+ if (n_mode == mode_b) {
+ n = b; /* Convb(Conv*(xxxb(...))) == xxxb(...) */ DBG_OPT_ALGSIM1;
+ }
+ else if (mode_is_int(n_mode) || mode_is_character(n_mode)) {
+ if (smaller_mode(b_mode, a_mode)){
+ n = b; /* ConvS(ConvL(xxxS(...))) == xxxS(...) */ DBG_OPT_ALGSIM1;
+ }
+ }
}
}
break;
-
+ }
case iro_Phi:
{
/* Several optimizations:
ir_node *first_val = NULL; /* to shutup gcc */
ir_node *scnd_val = NULL; /* to shutup gcc */
+ if (!get_opt_normalize()) return n;
+
n_preds = get_Phi_n_preds(n);
block = get_nodes_Block(n);
- if (is_Bad(block)) return new_Bad();
- assert(get_irn_op (block) == op_Block);
-
- /* there should be no Phi nodes in the Start region. */
- if (block == current_ir_graph->start_block) {
- n = new_Bad();
- break;
- }
+ /* @@@ fliegt 'raus, sollte aber doch immer wahr sein!!!
+ assert(get_irn_arity(block) == n_preds && "phi in wrong block!"); */
+ if ((is_Bad(block)) || /* Control dead */
+ (block == current_ir_graph->start_block)) /* There should be no Phi nodes */
+ return new_Bad(); /* in the Start Block. */
- if (n_preds == 0) { /* Phi of dead Region without predecessors. */
- /* GL: why not return new_Bad? */
- break;
- }
+ if (n_preds == 0) break; /* Phi of dead Region without predecessors. */
#if 0
/* first we test for a special case: */
value that is known at a certain point. This is useful for
dataflow analysis. */
if (n_preds == 2) {
- ir_node *a = follow_Id (get_Phi_pred(n, 0));
- ir_node *b = follow_Id (get_Phi_pred(n, 1));
- if ( (get_irn_op(a) == op_Confirm)
- && (get_irn_op(b) == op_Confirm)
- && (follow_Id (get_irn_n(a, 0)) == follow_Id(get_irn_n(b, 0)))
- && (get_irn_n(a, 1) == get_irn_n (b, 1))
- && (a->data.num == (~b->data.num & irpn_True) )) {
- n = follow_Id (get_irn_n(a, 0));
- break;
- }
+ ir_node *a = follow_Id (get_Phi_pred(n, 0));
+ ir_node *b = follow_Id (get_Phi_pred(n, 1));
+ if ( (get_irn_op(a) == op_Confirm)
+ && (get_irn_op(b) == op_Confirm)
+ && (follow_Id (get_irn_n(a, 0)) == follow_Id(get_irn_n(b, 0)))
+ && (get_irn_n(a, 1) == get_irn_n (b, 1))
+ && (a->data.num == (~b->data.num & irpn_True) )) {
+ n = follow_Id (get_irn_n(a, 0));
+ break;
+ }
}
#endif
first_val = follow_Id(get_Phi_pred(n, i));
/* skip Id's */
set_Phi_pred(n, i, first_val);
- if ( (first_val != n) /* not self pointer */
- && (get_irn_op(first_val) != op_Bad) /* value not dead */
- && !(is_Bad (get_Block_cfgpred(block, i))) ) { /* not dead control flow */
- break; /* then found first value. */
- }
+ if ( (first_val != n) /* not self pointer */
+ && (get_irn_op(first_val) != op_Bad) /* value not dead */
+ && !(is_Bad (get_Block_cfgpred(block, i))) ) { /* not dead control flow */
+ break; /* then found first value. */
+ }
}
/* A totally Bad or self-referencing Phi (we didn't break the above loop) */
scnd_val = NULL;
/* follow_Id () for rest of inputs, determine if any of these
- are non-self-referencing */
+ are non-self-referencing */
while (++i < n_preds) {
scnd_val = follow_Id(get_Phi_pred(n, i));
/* skip Id's */
set_Phi_pred(n, i, scnd_val);
if ( (scnd_val != n)
- && (scnd_val != first_val)
- && (get_irn_op(scnd_val) != op_Bad)
- && !(is_Bad (get_Block_cfgpred(block, i))) ) {
+ && (scnd_val != first_val)
+ && (get_irn_op(scnd_val) != op_Bad)
+ && !(is_Bad (get_Block_cfgpred(block, i))) ) {
break;
- }
+ }
}
/* Fold, if no multiple distinct non-self-referencing inputs */
if (i >= n_preds) {
- n = first_val;
+ n = first_val; DBG_OPT_PHI;
} else {
- /* skip the remaining Ids. */
- while (++i < n_preds) {
- set_Phi_pred(n, i, follow_Id(get_Phi_pred(n, i)));
- }
+ /* skip the remaining Ids. */
+ while (++i < n_preds) {
+ set_Phi_pred(n, i, follow_Id(get_Phi_pred(n, i)));
+ }
}
}
break;
case iro_Load:
{
#if 0 /* Is an illegal transformation: different nodes can
- represent the same pointer value!! */
+ represent the same pointer value!! */
a = skip_Proj(get_Load_mem(n));
b = get_Load_ptr(n);
&& get_Store_ptr(a) == b
&& skip_Proj(get_Store_value(a)) == c) {
/* We have twice exactly the same store -- a write after write. */
- n = a;
+ n = a; DBG_OPT_WAW;
} else if (get_irn_op(c) == op_Load
- && (a == c || skip_Proj(get_Load_mem(c)) == a)
- && get_Load_ptr(c) == b )
- /* !!!??? and a cryptic test */ {
+ && (a == c || skip_Proj(get_Load_mem(c)) == a)
+ && get_Load_ptr(c) == b ) {
/* We just loaded the value from the same memory, i.e., the store
doesn't change the memory -- a write after read. */
- a = get_Store_mem(n);
+ a = get_Store_mem(n);
turn_into_tuple(n, 2);
set_Tuple_pred(n, 0, a);
- set_Tuple_pred(n, 1, new_Bad());
- }
+ set_Tuple_pred(n, 1, new_Bad()); DBG_OPT_WAR;
+ }
}
break;
if ( get_irn_op(a) == op_Tuple) {
/* Remove the Tuple/Proj combination. */
- if ( get_Proj_proj(n) <= get_Tuple_n_preds(a) ) {
- n = get_Tuple_pred(a, get_Proj_proj(n));
- } else {
+ if ( get_Proj_proj(n) <= get_Tuple_n_preds(a) ) {
+ n = get_Tuple_pred(a, get_Proj_proj(n)); DBG_OPT_TUPLE;
+ } else {
assert(0); /* This should not happen! */
- n = new_Bad();
- }
+ n = new_Bad();
+ }
} else if (get_irn_mode(n) == mode_X &&
- is_Bad(get_nodes_Block(n))) {
- /* Remove dead control flow. */
- n = new_Bad();
+ is_Bad(get_nodes_Block(n))) {
+ /* Remove dead control flow -- early gigo. */
+ n = new_Bad();
}
}
break;
case iro_Id:
- n = follow_Id (n);
+ n = follow_Id (n); DBG_OPT_ID;
break;
default: break;
return n;
} /* end equivalent_node() */
+/* do node specific optimizations of nodes predecessors. */
+static void
+optimize_preds(ir_node *n) {
+ ir_node *a = NULL, *b = NULL;
+
+ /* get the operands we will work on for simple cases. */
+ if (is_binop(n)) {
+ a = get_binop_left(n);
+ b = get_binop_right(n);
+ } else if (is_unop(n)) {
+ a = get_unop_op(n);
+ }
+
+ switch (get_irn_opcode(n)) {
+
+ case iro_Cmp:
+ /* We don't want Cast as input to Cmp. */
+ if (get_irn_op(a) == op_Cast) {
+ a = get_Cast_op(a);
+ set_Cmp_left(n, a);
+ }
+ if (get_irn_op(b) == op_Cast) {
+ b = get_Cast_op(b);
+ set_Cmp_right(n, b);
+ }
+ break;
+
+ default: break;
+ } /* end switch */
+}
-/* tries several [inplace] [optimizing] transformations and returns a
+
+/* tries several [inplace] [optimizing] transformations and returns an
equivalent node. The difference to equivalent_node is that these
transformations _do_ generate new nodes, and thus the old node must
not be freed even if the equivalent node isn't the old one. */
static ir_node *
-transform_node (ir_node *n)
-{
-
+transform_node (ir_node *n) {
ir_node *a = NULL, *b;
tarval *ta, *tb;
switch (get_irn_opcode(n)) {
+ case iro_Div: {
+ ta = computed_value(n);
+ if (ta != tarval_bad) {
+ /* Turn Div into a tuple (mem, bad, value) */
+ ir_node *mem = get_Div_mem(n);
+ turn_into_tuple(n, 3);
+ set_Tuple_pred(n, 0, mem);
+ set_Tuple_pred(n, 1, new_Bad());
+ set_Tuple_pred(n, 2, new_Const(get_tarval_mode(ta), ta));
+ }
+ } break;
+ case iro_Mod: {
+ ta = computed_value(n);
+ if (ta != tarval_bad) {
+ /* Turn Mod into a tuple (mem, bad, value) */
+ ir_node *mem = get_Mod_mem(n);
+ turn_into_tuple(n, 3);
+ set_Tuple_pred(n, 0, mem);
+ set_Tuple_pred(n, 1, new_Bad());
+ set_Tuple_pred(n, 2, new_Const(get_tarval_mode(ta), ta));
+ }
+ } break;
case iro_DivMod: {
int evaluated = 0;
b = get_DivMod_right(n);
mode = get_irn_mode(a);
- if (!( mode_is_int(get_irn_mode(a))
- && mode_is_int(get_irn_mode(b))))
+ if (!(mode_is_int(get_irn_mode(a)) &&
+ mode_is_int(get_irn_mode(b))))
break;
if (a == b) {
- a = new_Const (mode, tarval_from_long (mode, 1));
- b = new_Const (mode, tarval_from_long (mode, 0));
+ a = new_Const (mode, get_mode_one(mode));
+ b = new_Const (mode, get_mode_null(mode));
evaluated = 1;
} else {
ta = value_of(a);
tb = value_of(b);
- if (tb) {
- if (tarval_classify(tb) == 1) {
- b = new_Const (mode, tarval_from_long (mode, 0));
- evaluated = 1;
- } else if (ta) {
- tarval *resa, *resb;
+ if (tb != tarval_bad) {
+ if (tb == get_mode_one(get_tarval_mode(tb))) {
+ b = new_Const (mode, get_mode_null(mode));
+ evaluated = 1;
+ } else if (ta != tarval_bad) {
+ tarval *resa, *resb;
resa = tarval_div (ta, tb);
- if (!resa) break; /* Causes exception!!! Model by replacing through
- Jmp for X result!? */
+ if (resa == tarval_bad) break; /* Causes exception!!! Model by replacing through
+ Jmp for X result!? */
resb = tarval_mod (ta, tb);
- if (!resb) break; /* Causes exception! */
- a = new_Const (mode, resa);
- b = new_Const (mode, resb);
- evaluated = 1;
- }
- } else if (tarval_classify (ta) == 0) {
+ if (resb == tarval_bad) break; /* Causes exception! */
+ a = new_Const (mode, resa);
+ b = new_Const (mode, resb);
+ evaluated = 1;
+ }
+ } else if (ta == get_mode_null(get_tarval_mode(ta))) {
b = a;
- evaluated = 1;
+ evaluated = 1;
}
}
if (evaluated) { /* replace by tuple */
a = get_Cond_selector(n);
ta = value_of(a);
- if (ta && (get_irn_mode(a) == mode_b)) {
+ if ((ta != tarval_bad) &&
+ (get_irn_mode(a) == mode_b) &&
+ (get_opt_unreachable_code())) {
/* It's a boolean Cond, branching on a boolean constant.
Replace it by a tuple (Bad, Jmp) or (Jmp, Bad) */
jmp = new_r_Jmp(current_ir_graph, get_nodes_Block(n));
turn_into_tuple(n, 2);
- if (tv_val_b(ta) == 1) /* GL: I hope this returns 1 if true */ {
- set_Tuple_pred(n, 0, new_Bad());
- set_Tuple_pred(n, 1, jmp);
+ if (ta == tarval_b_true) {
+ set_Tuple_pred(n, 0, new_Bad());
+ set_Tuple_pred(n, 1, jmp);
} else {
- set_Tuple_pred(n, 0, jmp);
- set_Tuple_pred(n, 1, new_Bad());
+ set_Tuple_pred(n, 0, jmp);
+ set_Tuple_pred(n, 1, new_Bad());
}
/* We might generate an endless loop, so keep it alive. */
add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_Block(n));
- } else if (ta && (get_irn_mode(a) == mode_I) && (get_Cond_kind(n) == dense)) {
+ } else if ((ta != tarval_bad) &&
+ (get_irn_mode(a) == mode_Iu) &&
+ (get_Cond_kind(n) == dense) &&
+ (get_opt_unreachable_code())) {
/* I don't want to allow Tuples smaller than the biggest Proj.
Also this tuple might get really big...
I generate the Jmp here, and remember it in link. Link is used
set_irn_link(n, new_r_Jmp(current_ir_graph, get_nodes_Block(n)));
/* We might generate an endless loop, so keep it alive. */
add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_Block(n));
- } else if ( (get_irn_op(get_Cond_selector(n)) == op_Eor)
- && (get_irn_mode(get_Cond_selector(n)) == mode_b)
- && (tarval_classify(computed_value(get_Eor_right(a))) == 1)) {
+ } else if ((get_irn_op(a) == op_Eor)
+ && (get_irn_mode(a) == mode_b)
+ && (tarval_classify(computed_value(get_Eor_right(a))) == TV_CLASSIFY_ONE)) {
/* The Eor is a negate. Generate a new Cond without the negate,
simulate the negate by exchanging the results. */
set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_Block(n),
- get_Eor_left(a)));
- } else if ( (get_irn_op(get_Cond_selector(n)) == op_Not)
- && (get_irn_mode(get_Cond_selector(n)) == mode_b)) {
+ get_Eor_left(a)));
+ } else if ((get_irn_op(a) == op_Not)
+ && (get_irn_mode(a) == mode_b)) {
/* A Not before the Cond. Generate a new Cond without the Not,
simulate the Not by exchanging the results. */
set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_Block(n),
- get_Not_op(a)));
+ get_Not_op(a)));
}
}
break;
case iro_Proj: {
a = get_Proj_pred(n);
- if ( (get_irn_op(a) == op_Cond)
- && get_irn_link(a)
- && get_irn_op(get_irn_link(a)) == op_Cond) {
- /* Use the better Cond if the Proj projs from a Cond which get's
- its result from an Eor/Not. */
- assert ( ( (get_irn_op(get_Cond_selector(a)) == op_Eor)
- || (get_irn_op(get_Cond_selector(a)) == op_Not))
- && (get_irn_mode(get_Cond_selector(a)) == mode_b)
- && (get_irn_op(get_irn_link(a)) == op_Cond)
- && (get_Cond_selector(get_irn_link(a)) ==
- get_Eor_left(get_Cond_selector(a))));
+ if ((get_irn_op(a) == op_Cond)
+ && get_irn_link(a)
+ && get_irn_op(get_irn_link(a)) == op_Cond) {
+ /* Use the better Cond if the Proj projs from a Cond which get's
+ its result from an Eor/Not. */
+ assert (((get_irn_op(get_Cond_selector(a)) == op_Eor)
+ || (get_irn_op(get_Cond_selector(a)) == op_Not))
+ && (get_irn_mode(get_Cond_selector(a)) == mode_b)
+ && (get_irn_op(get_irn_link(a)) == op_Cond)
+ && (get_Cond_selector(get_irn_link(a)) == get_Eor_left(get_Cond_selector(a))));
set_Proj_pred(n, get_irn_link(a));
if (get_Proj_proj(n) == 0)
set_Proj_proj(n, 1);
else
set_Proj_proj(n, 0);
- } else if ( (get_irn_op(a) == op_Cond)
- && (get_irn_mode(get_Cond_selector(a)) == mode_I)
- && value_of(a)
- && (get_Cond_kind(a) == dense)) {
+ } else if ((get_irn_op(a) == op_Cond)
+ && (get_irn_mode(get_Cond_selector(a)) == mode_Iu)
+ && value_of(a)
+ && (get_Cond_kind(a) == dense)
+ && (get_opt_unreachable_code())) {
/* The Cond is a Switch on a Constant */
- if (get_Proj_proj(n) == tv_val_CHIL(value_of(a))) {
+ if (get_Proj_proj(n) == tarval_to_long(value_of(a))) {
/* The always taken branch, reuse the existing Jmp. */
if (!get_irn_link(a)) /* well, if it exists ;-> */
set_irn_link(a, new_r_Jmp(current_ir_graph, get_nodes_Block(n)));
assert(get_irn_op(get_irn_link(a)) == op_Jmp);
n = get_irn_link(a);
} else {/* Not taken control flow, but be careful with the default! */
- if (get_Proj_proj(n) < a->attr.c.default_proj){
- /* a never taken branch */
- n = new_Bad();
- } else {
- a->attr.c.default_proj = get_Proj_proj(n);
- }
+ if (get_Proj_proj(n) < a->attr.c.default_proj){
+ /* a never taken branch */
+ n = new_Bad();
+ } else {
+ a->attr.c.default_proj = get_Proj_proj(n);
+ }
}
}
} break;
a = get_Eor_left(n);
b = get_Eor_right(n);
- if ( (get_irn_mode(n) == mode_b)
- && (get_irn_op(a) == op_Proj)
- && (get_irn_mode(a) == mode_b)
- && (tarval_classify (computed_value (b)) == 1)
- && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
+ if ((get_irn_mode(n) == mode_b)
+ && (get_irn_op(a) == op_Proj)
+ && (get_irn_mode(a) == mode_b)
+ && (tarval_classify (computed_value (b)) == TV_CLASSIFY_ONE)
+ && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
/* The Eor negates a Cmp. The Cmp has the negated result anyways! */
n = new_r_Proj(current_ir_graph, get_nodes_Block(n), get_Proj_pred(a),
mode_b, get_negated_pnc(get_Proj_proj(a)));
- else if ( (get_irn_mode(n) == mode_b)
- && (tarval_classify (computed_value (b)) == 1))
+ else if ((get_irn_mode(n) == mode_b)
+ && (tarval_classify (computed_value (b)) == TV_CLASSIFY_ONE))
/* The Eor is a Not. Replace it by a Not. */
/* ????!!!Extend to bitfield 1111111. */
n = new_r_Not(current_ir_graph, get_nodes_Block(n), a, mode_b);
a = get_Not_op(n);
if ( (get_irn_mode(n) == mode_b)
- && (get_irn_op(a) == op_Proj)
- && (get_irn_mode(a) == mode_b)
- && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
+ && (get_irn_op(a) == op_Proj)
+ && (get_irn_mode(a) == mode_b)
+ && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
/* We negate a Cmp. The Cmp has the negated result anyways! */
n = new_r_Proj(current_ir_graph, get_nodes_Block(n), get_Proj_pred(a),
mode_b, get_negated_pnc(get_Proj_proj(a)));
/* **************** Common Subexpression Elimination **************** */
+/** The size of the hash table used, should estimate the number of nodes
+ in a graph. */
+#define N_IR_NODES 512
+
/* Compare function for two nodes in the hash table. Gets two */
/* nodes as parameters. Returns 0 if the nodes are a cse. */
static int
(get_irn_mode(a) != get_irn_mode(b))) return 1;
/* compare if a's in and b's in are equal */
- /* GL: we optimize only nodes with in arrays of fixed sizes.
- if (get_irn_arity (a) != -2) {
- ins = get_irn_arity (a);
- if (ins != get_irn_arity (b)) return 1;
- ain = get_irn_in (a);
- bin = get_irn_in (b);
- }
- */
if (get_irn_arity (a) != get_irn_arity(b))
return 1;
switch (get_irn_opcode(a)) {
case iro_Const:
- return get_irn_const_attr (a) != get_irn_const_attr (b);
+ return (get_Const_tarval(a) != get_Const_tarval(b))
+ || (get_Const_type(a) != get_Const_type(b));
case iro_Proj:
return get_irn_proj_attr (a) != get_irn_proj_attr (b);
+ case iro_Filter:
+ return get_Filter_proj(a) != get_Filter_proj(b);
case iro_Alloc:
return (get_irn_alloc_attr(a).where != get_irn_alloc_attr(b).where)
|| (get_irn_alloc_attr(a).type != get_irn_alloc_attr(b).type);
|| (get_irn_sel_attr(a).ent->name != get_irn_sel_attr(b).ent->name)
|| (get_irn_sel_attr(a).ent->owner != get_irn_sel_attr(b).ent->owner)
|| (get_irn_sel_attr(a).ent->ld_name != get_irn_sel_attr(b).ent->ld_name)
- || (get_irn_sel_attr(a).ent->type != get_irn_sel_attr(b).ent->type)
- || (get_irn_sel_attr(a).ltyp != get_irn_sel_attr(b).ltyp);
+ || (get_irn_sel_attr(a).ent->type != get_irn_sel_attr(b).ent->type);
case iro_Phi:
return get_irn_phi_attr (a) != get_irn_phi_attr (b);
+ case iro_Cast:
+ return get_Cast_type(a) != get_Cast_type(b);
default: ;
}
pset *
new_identities (void)
{
- return new_pset (vt_cmp, TUNE_NIR_NODES);
+ return new_pset (vt_cmp, N_IR_NODES);
}
void
/* Return the canonical node computing the same value as n.
Looks up the node in a hash table. */
-static inline ir_node *
+static INLINE ir_node *
identify (pset *value_table, ir_node *n)
{
ir_node *o = NULL;
/* During construction we set the pinned flag in the graph right when the
optimizatin is performed. The flag turning on procedure global cse could
be changed between two allocations. This way we are safe. */
-static inline ir_node *
+static INLINE ir_node *
identify_cons (pset *value_table, ir_node *n) {
ir_node *old = n;
n = identify(value_table, n);
/* garbage in, garbage out. If a node has a dead input, i.e., the
Bad node is input to the node, return the Bad node. */
-static inline ir_node *
+static INLINE ir_node *
gigo (ir_node *node)
{
int i;
ir_op* op = get_irn_op(node);
+#if 1
+ /* remove garbage blocks by looking at control flow that leaves the block
+ and replacing the control flow by Bad. */
+ if (get_irn_mode(node) == mode_X) {
+ ir_node *block = get_nodes_block(node);
+ if (get_irn_op(block) == op_Block && get_Block_matured(block)) {
+ for (i = 0; i < get_irn_arity(block); i++) {
+ if (!is_Bad(get_irn_n(block, i))) break;
+ }
+ if (i == get_irn_arity(block)) return new_Bad();
+ }
+ }
+#endif
+
/* Blocks, Phis and Tuples may have dead inputs, e.g., if one of the
blocks predecessors is dead. */
if ( op != op_Block && op != op_Phi && op != op_Tuple) {
}
}
#if 0
+ /* With this code we violate the agreement that local_optimize
+ only leaves Bads in Block, Phi and Tuple nodes. */
/* If Block has only Bads as predecessors it's garbage. */
/* If Phi has only Bads as predecessors it's garbage. */
- if (op == op_Block || op == op_Phi) {
+ if ((op == op_Block && get_Block_matured(node)) || op == op_Phi) {
for (i = 0; i < get_irn_arity(node); i++) {
if (!is_Bad(get_irn_n(node, i))) break;
}
- if (i = get_irn_arity(node)) node = new_Bad();
+ if (i == get_irn_arity(node)) node = new_Bad();
}
#endif
return node;
It can only be called if it is guaranteed that no other nodes
reference this one, i.e., right after construction of a node. */
ir_node *
-optimize (ir_node *n)
+optimize_node (ir_node *n)
{
tarval *tv;
ir_node *old_n = n;
if (get_irn_op(n) != op_Const) {
/* try to evaluate */
tv = computed_value (n);
- if (tv != NULL) {
+ if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
/* evaluation was succesful -- replace the node. */
obstack_free (current_ir_graph->obst, n);
- return new_Const (get_tv_mode (tv), tv);
+ return new_Const (get_tarval_mode (tv), tv);
}
}
}
/* remove unnecessary nodes */
- if (get_opt_constant_folding() || get_irn_op(n) == op_Phi)
+ if (get_opt_constant_folding() ||
+ (get_irn_op(n) == op_Phi) || /* always optimize these nodes. */
+ (get_irn_op(n) == op_Id) ||
+ (get_irn_op(n) == op_Proj) ||
+ (get_irn_op(n) == op_Block) ) /* Flags tested local. */
n = equivalent_node (n);
+ optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
+
/** common subexpression elimination **/
/* Checks whether n is already available. */
/* The block input is used to distinguish different subexpressions. Right
subexpressions within a block. */
if (get_opt_cse())
n = identify_cons (current_ir_graph->value_table, n);
- /* identify found a cse, so deallocate the old node. */
+
if (n != old_n) {
+ /* We found an existing, better node, so we can deallocate the old node. */
obstack_free (current_ir_graph->obst, old_n);
- /* The AmRoq fiasco returns n here. Martin's version doesn't. */
}
/* Some more constant expression evaluation that does not allow to
free the node. */
- if (get_opt_constant_folding())
+ if (get_opt_constant_folding() ||
+ (get_irn_op(n) == op_Cond) ||
+ (get_irn_op(n) == op_Proj)) /* Flags tested local. */
n = transform_node (n);
- /* Remove nodes with dead (Bad) input. */
- if (get_opt_unreachable_code())
- n = gigo (n);
+ /* Remove nodes with dead (Bad) input.
+ Run always for transformation induced Bads. */
+ n = gigo (n);
+
/* Now we can verify the node, as it has no dead inputs any more. */
irn_vrfy(n);
/* Now we have a legal, useful node. Enter it in hash table for cse */
- if (get_opt_cse()) {
+ if (get_opt_cse() && (get_irn_opcode(n) != iro_Block)) {
n = identify_remember (current_ir_graph->value_table, n);
}
-#if 0 /* GL: what's the use of this?? */
- if ((current_ir_graph->state & irgs_building) && IR_KEEP_ALIVE (n)) {
- assert (~current_ir_graph->state & irgs_keep_alives_in_arr);
- pdeq_putr (current_ir_graph->keep.living, n);
- }
-#endif
return n;
}
tarval *tv;
ir_node *old_n = n;
- if (!get_optimize()) return n;
+ if (!get_optimize() && (get_irn_op(n) != op_Phi)) return n;
/* if not optimize return n */
if (n == NULL) {
+ assert(0);
/* Here this is possible. Why? */
return n;
}
+
/* constant expression evaluation / constant folding */
if (get_opt_constant_folding()) {
/* constants can not be evaluated */
if (get_irn_op(n) != op_Const) {
/* try to evaluate */
tv = computed_value (n);
- if (tv != NULL) {
+ if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
/* evaluation was succesful -- replace the node. */
- n = new_Const (get_tv_mode (tv), tv);
- deb_info_copy(n, old_n, id_from_str("const_eval", 10));
+ n = new_Const (get_tarval_mode (tv), tv);
+ __dbg_info_merge_pair(n, old_n, dbg_const_eval);
return n;
- /* xprintf("* optimize: computed node %I\n", n->op->name);*/
}
}
}
/* remove unnecessary nodes */
/*if (get_opt_constant_folding()) */
- if (get_opt_constant_folding() || get_irn_op(n) == op_Phi)
+ if (get_opt_constant_folding() ||
+ (get_irn_op(n) == op_Phi) || /* always optimize these nodes. */
+ (get_irn_op(n) == op_Id) || /* ... */
+ (get_irn_op(n) == op_Proj) || /* ... */
+ (get_irn_op(n) == op_Block) ) /* Flags tested local. */
n = equivalent_node (n);
+ optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
+
/** common subexpression elimination **/
/* Checks whether n is already available. */
/* The block input is used to distinguish different subexpressions. Right
n = identify (current_ir_graph->value_table, n);
}
- /* identify found a cse, so deallocate the old node. */
- if (n != old_n) {
- /* The AmRoq fiasco returns n here. Martin's version doesn't. */
- }
-
/* Some more constant expression evaluation. */
- if (get_opt_constant_folding())
+ if (get_opt_constant_folding() ||
+ (get_irn_op(n) == op_Cond) ||
+ (get_irn_op(n) == op_Proj)) /* Flags tested local. */
n = transform_node (n);
- /* Remove nodes with dead (Bad) input. */
- if (get_opt_unreachable_code())
- n = gigo (n);
+ /* Remove nodes with dead (Bad) input.
+ Run always for transformation induced Bads. */
+ n = gigo (n);
+
/* Now we can verify the node, as it has no dead inputs any more. */
irn_vrfy(n);
set_irg_pinned(current_ir_graph, floats);
if (get_irg_outs_state(current_ir_graph) == outs_consistent)
set_irg_outs_inconsistent(current_ir_graph);
+ /* Maybe we could also test whether optimizing the node can
+ change the control graph. */
+ if (get_irg_dom_state(current_ir_graph) == dom_consistent)
+ set_irg_dom_inconsistent(current_ir_graph);
return optimize_in_place_2 (n);
}
projects / libfirm / blobdiff