- Improved addressmode optimisation for conv nodes
[libfirm] / ir / be / ia32 / ia32_optimize.c
index 3307735..0d434a7 100644 (file)
@@ -21,6 +21,7 @@
 #include "irgmod.h"
 #include "irgwalk.h"
 #include "height.h"
+#include "irbitset.h"
 
 #include "../be_t.h"
 #include "../beabi.h"
@@ -32,6 +33,9 @@
 #include "gen_ia32_regalloc_if.h"     /* the generated interface (register type and class defenitions) */
 #include "ia32_transform.h"
 #include "ia32_dbg_stat.h"
+#include "ia32_util.h"
+
+#define AGGRESSIVE_AM
 
 typedef enum {
        IA32_AM_CAND_NONE  = 0,
@@ -104,12 +108,12 @@ static ir_node *gen_SymConst(ia32_transform_env_t *env) {
        if (mode_is_float(mode)) {
                FP_USED(env->cg);
                if (USE_SSE2(env->cg))
-                       cnst = new_rd_ia32_xConst(dbg, irg, block, get_irg_no_mem(irg), mode);
+                       cnst = new_rd_ia32_xConst(dbg, irg, block, mode);
                else
-                       cnst = new_rd_ia32_vfConst(dbg, irg, block, get_irg_no_mem(irg), mode);
+                       cnst = new_rd_ia32_vfConst(dbg, irg, block, mode);
        }
        else
-               cnst = new_rd_ia32_Const(dbg, irg, block, get_irg_no_mem(irg), mode);
+               cnst = new_rd_ia32_Const(dbg, irg, block, mode);
 
        set_ia32_Const_attr(cnst, env->irn);
 
@@ -209,95 +213,125 @@ static ir_node *gen_Const(ia32_transform_env_t *env) {
                env->irn  = cnst;
                env->mode = mode_P;
                cnst      = gen_SymConst(env);
+               add_irn_dep(cnst, be_abi_get_start_barrier(env->cg->birg->abi));
                set_Load_ptr(get_Proj_pred(load), cnst);
                cnst      = load;
        }
        else {
-               cnst = new_rd_ia32_Const(dbg, irg, block, get_irg_no_mem(irg), get_irn_mode(node));
+               cnst = new_rd_ia32_Const(dbg, irg, block, get_irn_mode(node));
+               add_irn_dep(cnst, be_abi_get_start_barrier(env->cg->birg->abi));
                set_ia32_Const_attr(cnst, node);
        }
+
        return cnst;
 }
 
-
-
 /**
  * Transforms (all) Const's into ia32_Const and places them in the
  * block where they are used (or in the cfg-pred Block in case of Phi's).
  * Additionally all reference nodes are changed into mode_Is nodes.
+ * NOTE: irn must be a firm constant!
  */
-void ia32_place_consts_set_modes(ir_node *irn, void *env) {
-       ia32_code_gen_t      *cg = env;
-       ia32_transform_env_t  tenv;
-       ir_mode              *mode;
-       ir_node              *pred, *cnst;
-       int                   i;
-       opcode                opc;
-
-       if (is_Block(irn))
-               return;
-
-       mode = get_irn_mode(irn);
+static void ia32_transform_const(ir_node *irn, void *env) {
+       ia32_code_gen_t      *cg   = env;
+       ir_node              *cnst = NULL;
+       ia32_transform_env_t tenv;
+
+       tenv.cg   = cg;
+       tenv.irg  = cg->irg;
+       tenv.mode = get_irn_mode(irn);
+       tenv.dbg  = get_irn_dbg_info(irn);
+       tenv.irn  = irn;
+       DEBUG_ONLY(tenv.mod = cg->mod;)
 
-       /* transform all reference nodes into mode_Is nodes */
-       if (mode_is_reference(mode)) {
-               mode = mode_Is;
-               set_irn_mode(irn, mode);
+#if 1
+       /* place const either in the smallest dominator of all its users or the original block */
+       if (cg->opt & IA32_OPT_PLACECNST)
+               tenv.block = node_users_smallest_common_dominator(irn, 1);
+       else
+               tenv.block = get_nodes_block(irn);
+#else
+       /* Actually, there is no real sense in placing     */
+       /* the Consts in the successor of the start block. */
+       {
+               ir_node *afterstart = NULL;
+               ir_node *startblock = get_irg_start_block(tenv.irg);
+               const ir_edge_t *edge;
+
+               foreach_block_succ(startblock, edge) {
+                       ir_node *block = get_edge_src_irn(edge);
+                       if (block != startblock) {
+                               afterstart = block;
+                               break;
+                       }
+               }
+               assert(afterstart != NULL);
+               tenv.block = afterstart;
        }
+#endif
 
-       /*
-               Annotate mode of stored value to link field of the Store
-               as floating point converts might be optimized and we would
-               loose the mode.
-       */
-       if (get_irn_opcode(irn) == iro_Store) {
-               set_irn_link(irn, get_irn_mode(get_Store_value(irn)));
+       switch (get_irn_opcode(irn)) {
+               case iro_Const:
+                       cnst = gen_Const(&tenv);
+                       break;
+               case iro_SymConst:
+                       cnst = gen_SymConst(&tenv);
+                       break;
+               default:
+                       assert(0 && "Wrong usage of ia32_transform_const!");
        }
 
-       tenv.block    = get_nodes_block(irn);
-       tenv.cg       = cg;
-       tenv.irg      = cg->irg;
-       DEBUG_ONLY(tenv.mod = cg->mod;)
+       assert(cnst && "Could not create ia32 Const");
 
-       /* Loop over all predecessors and check for Sym/Const nodes */
-       for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
-               pred      = get_irn_n(irn, i);
-               cnst      = NULL;
-               opc       = get_irn_opcode(pred);
-               tenv.irn  = pred;
-               tenv.mode = get_irn_mode(pred);
-               tenv.dbg  = get_irn_dbg_info(pred);
-
-               /* If it's a Phi, then we need to create the */
-               /* new Const in it's predecessor block       */
-               if (is_Phi(irn)) {
-                       tenv.block = get_Block_cfgpred_block(get_nodes_block(irn), i);
-               }
+       /* set the new ia32 const */
+       exchange(irn, cnst);
+}
 
-               /* put the const into the block where the original const was */
-               if (! (cg->opt & IA32_OPT_PLACECNST)) {
-                       tenv.block = get_nodes_block(pred);
-               }
+/**
+ * Transform all firm consts and assure, we visit each const only once.
+ */
+static void ia32_place_consts_walker(ir_node *irn, void *env) {
+       ia32_code_gen_t *cg = env;
 
-               switch (opc) {
-                       case iro_Const:
-                               cnst = gen_Const(&tenv);
-                               break;
-                       case iro_SymConst:
-                               cnst = gen_SymConst(&tenv);
-                               break;
-                       default:
-                               break;
-               }
+       if (! is_Const(irn) && ! is_SymConst(irn))
+               return;
 
-               /* if we found a const, then set it */
-               if (cnst) {
-                       set_irn_n(irn, i, cnst);
-               }
+       ia32_transform_const(irn, cg);
+}
+
+/**
+ * Replace reference modes with mode_Iu and preserve store value modes.
+ */
+static void ia32_set_modes(ir_node *irn, void *env) {
+       if (is_Block(irn))
+               return;
+
+       /* transform all reference nodes into mode_Iu nodes */
+       if (mode_is_reference(get_irn_mode(irn))) {
+               set_irn_mode(irn, mode_Iu);
        }
 }
 
+/**
+ * Walks over the graph, transforms all firm consts into ia32 consts
+ * and places them into the "best" block.
+ * @param cg  The ia32 codegenerator object
+ */
+static void ia32_transform_all_firm_consts(ia32_code_gen_t *cg) {
+       irg_walk_graph(cg->irg, NULL, ia32_place_consts_walker, cg);
+}
 
+/* Place all consts and change pointer arithmetics into unsigned integer arithmetics. */
+void ia32_pre_transform_phase(ia32_code_gen_t *cg) {
+       /*
+               We need to transform the consts twice:
+               - the psi condition tree transformer needs existing constants to be ia32 constants
+               - the psi condition tree transformer inserts new firm constants which need to be transformed
+       */
+       ia32_transform_all_firm_consts(cg);
+       irg_walk_graph(cg->irg, ia32_set_modes, ia32_transform_psi_cond_tree, cg);
+       ia32_transform_all_firm_consts(cg);
+}
 
 /********************************************************************************************************
  *  _____                _           _         ____        _   _           _          _   _
@@ -438,146 +472,158 @@ static void ia32_optimize_CondJmp(ir_node *irn, ia32_code_gen_t *cg) {
        }
 }
 
+// only optimize up to 48 stores behind IncSPs
+#define MAXPUSH_OPTIMIZE       48
+
 /**
- * Creates a Push from Store(IncSP(gp_reg_size))
+ * Tries to create pushs from IncSP,Store combinations
  */
-static void ia32_create_Push(ir_node *irn, ia32_code_gen_t *cg) {
-       ir_node  *sp  = get_irn_n(irn, 0);
+static void ia32_create_Pushs(ir_node *irn, ia32_code_gen_t *cg) {
+       int i;
+       int offset;
+       ir_node *node;
+       ir_node *stores[MAXPUSH_OPTIMIZE];
+       ir_node *block = get_nodes_block(irn);
        ir_graph *irg = cg->irg;
-       ir_node *val, *next, *push, *bl, *proj_M, *proj_res, *old_proj_M, *mem;
-       const ir_edge_t *edge;
-       heights_t *h;
+       ir_node *curr_sp;
+       ir_mode *spmode = get_irn_mode(irn);
 
-       /* do not create push if store has already an offset assigned or base is not a IncSP */
-       if (get_ia32_am_offs(irn) || ! be_is_IncSP(sp))
-               return;
+       memset(stores, 0, sizeof(stores));
 
-       /* do not create push if index is not NOREG */
-       if (arch_get_irn_register(cg->arch_env, get_irn_n(irn, 1)) !=
-               &ia32_gp_regs[REG_GP_NOREG])
-               return;
+       assert(be_is_IncSP(irn));
 
-       /* do not create push for floating point */
-       val = get_irn_n(irn, 2);
-       if (mode_is_float(get_irn_mode(val)))
+       offset = be_get_IncSP_offset(irn);
+       if(offset < 4)
                return;
 
-       /* do not create push if IncSp doesn't expand stack or expand size is different from register size */
-       if (be_get_IncSP_direction(sp) != be_stack_dir_expand ||
-               be_get_IncSP_offset(sp) != get_mode_size_bytes(ia32_reg_classes[CLASS_ia32_gp].mode))
-               return;
+       /*
+        * We first walk the schedule after the IncSP node as long as we find
+        * suitable stores that could be transformed to a push.
+        * We save them into the stores array which is sorted by the frame offset/4
+        * attached to the node
+        */
+       for(node = sched_next(irn); !sched_is_end(node); node = sched_next(node)) {
+               const char *am_offs;
+               ir_node *mem;
+               int offset = -1;
+               int n;
+               int storeslot;
+
+               // it has to be a store
+               if(!is_ia32_Store(node))
+                       break;
 
-       /* do not create push, if there is a path (inside the block) from the push value to IncSP */
-       h = heights_new(cg->irg);
-       if (get_nodes_block(val) == get_nodes_block(sp) &&
-               heights_reachable_in_block(h, val, sp))
-       {
-               heights_free(h);
-               return;
-       }
-       heights_free(h);
+               // it has to use our sp value
+               if(get_irn_n(node, 0) != irn)
+                       continue;
+               // store has to be attached to NoMem
+               mem = get_irn_n(node, 3);
+               if(!is_NoMem(mem)) {
+                       continue;
+               }
 
-       /* ok, translate into Push */
-       edge       = get_irn_out_edge_first(irn);
-       old_proj_M = get_edge_src_irn(edge);
-       bl         = get_nodes_block(irn);
+               if( (get_ia32_am_flavour(node) & ia32_am_IS) != 0)
+                       break;
 
-       next = sched_next(irn);
-       sched_remove(irn);
-       sched_remove(sp);
+               am_offs = get_ia32_am_offs(node);
+               if(am_offs == NULL) {
+                       offset = 0;
+               } else {
+                       // the am_offs has to be of the form "+NUMBER"
+                       if(sscanf(am_offs, "+%d%n", &offset, &n) != 1 || am_offs[n] != '\0') {
+                               // we shouldn't have any cases in the compiler at the moment
+                               // that produce something different from esp+XX
+                               assert(0);
+                               break;
+                       }
+               }
 
-       /*
-               build memory input:
-               if the IncSP points to NoMem -> just use the memory input from store
-               if IncSP points to somewhere else -> sync memory of IncSP and Store
-       */
-       mem = be_get_IncSP_mem(sp);
-       if (mem == get_irg_no_mem(irg))
-               mem = get_irn_n(irn, 3);
-       else {
-               ir_node *in[2];
+               storeslot = offset / 4;
+               if(storeslot >= MAXPUSH_OPTIMIZE)
+                       continue;
+
+               // storing into the same slot twice is bad (and shouldn't happen...)
+               if(stores[storeslot] != NULL)
+                       break;
+
+               // storing at half-slots is bad
+               if(offset % 4 != 0)
+                       break;
 
-               in[0] = mem;
-               in[1] = get_irn_n(irn, 3);
-               mem   = new_r_Sync(irg, bl, 2, in);
+               stores[storeslot] = node;
        }
 
-       push = new_rd_ia32_Push(NULL, irg, bl, be_get_IncSP_pred(sp), val, mem);
-       proj_res = new_r_Proj(irg, bl, push, get_irn_mode(sp), pn_ia32_Push_stack);
-       proj_M   = new_r_Proj(irg, bl, push, mode_M, pn_ia32_Push_M);
+       curr_sp = get_irn_n(irn, 0);
 
-       /* copy a possible constant from the store */
-       set_ia32_id_cnst(push, get_ia32_id_cnst(irn));
-       set_ia32_immop_type(push, get_ia32_immop_type(irn));
+       // walk the stores in inverse order and create pushs for them
+       i = (offset / 4) - 1;
+       if(i >= MAXPUSH_OPTIMIZE) {
+               i = MAXPUSH_OPTIMIZE - 1;
+       }
 
-       /* the push must have SP out register */
-       arch_set_irn_register(cg->arch_env, push, arch_get_irn_register(cg->arch_env, sp));
+       for( ; i >= 0; --i) {
+               const ir_edge_t *edge, *next;
+               const arch_register_t *spreg;
+               ir_node *push;
+               ir_node *val, *mem;
+               ir_node *store = stores[i];
+               ir_node *noreg = ia32_new_NoReg_gp(cg);
 
-       exchange(old_proj_M, proj_M);
-       exchange(sp, proj_res);
-       sched_add_before(next, push);
-       sched_add_after(push, proj_res);
-}
+               if(store == NULL || is_Bad(store))
+                       break;
 
-/**
- * Creates a Pop from IncSP(Load(sp))
- */
-static void ia32_create_Pop(ir_node *irn, ia32_code_gen_t *cg) {
-       ir_node *old_proj_M = be_get_IncSP_mem(irn);
-       ir_node *load = skip_Proj(old_proj_M);
-       ir_node *old_proj_res = NULL;
-       ir_node *bl, *pop, *next, *proj_res, *proj_sp, *proj_M;
-       const ir_edge_t *edge;
-       const arch_register_t *reg, *sp;
+               val = get_irn_n(store, 2);
+               mem = get_irn_n(store, 3);
+               spreg = arch_get_irn_register(cg->arch_env, curr_sp);
 
-       if (! is_ia32_Load(load) || get_ia32_am_offs(load))
-               return;
+               // create a push
+               push = new_rd_ia32_Push(NULL, irg, block, noreg, noreg, val, curr_sp, mem);
+               if(get_ia32_immop_type(store) != ia32_ImmNone) {
+                       copy_ia32_Immop_attr(push, store);
+               }
+               sched_add_before(irn, push);
 
-       if (arch_get_irn_register(cg->arch_env, get_irn_n(load, 1)) !=
-               &ia32_gp_regs[REG_GP_NOREG])
-               return;
-       if (arch_get_irn_register(cg->arch_env, get_irn_n(load, 0)) != cg->isa->arch_isa.sp)
-               return;
+               // create stackpointer proj
+               curr_sp = new_r_Proj(irg, block, push, spmode, pn_ia32_Push_stack);
+               arch_set_irn_register(cg->arch_env, curr_sp, spreg);
+               sched_add_before(irn, curr_sp);
 
-       /* ok, translate into pop */
-       foreach_out_edge(load, edge) {
-               ir_node *succ = get_edge_src_irn(edge);
-               if (succ != old_proj_M) {
-                       old_proj_res = succ;
-                       break;
+               // rewire memprojs of the store
+               foreach_out_edge_safe(store, edge, next) {
+                       ir_node *succ = get_edge_src_irn(edge);
+
+                       assert(is_Proj(succ) && get_Proj_proj(succ) == pn_ia32_Store_M);
+                       set_irn_n(succ, 0, push);
                }
-       }
-       if (! old_proj_res) {
-               assert(0);
-               return; /* should not happen */
-       }
 
-       bl = get_nodes_block(load);
+               // we can remove the store now
+               set_irn_n(store, 0, new_Bad());
+               set_irn_n(store, 1, new_Bad());
+               set_irn_n(store, 2, new_Bad());
+               set_irn_n(store, 3, new_Bad());
+               sched_remove(store);
 
-       /* IncSP is typically scheduled after the load, so remove it first */
-       sched_remove(irn);
-       next = sched_next(old_proj_res);
-       sched_remove(old_proj_res);
-       sched_remove(load);
+               offset -= 4;
+       }
 
-       reg = arch_get_irn_register(cg->arch_env, load);
-       sp  = arch_get_irn_register(cg->arch_env, irn);
+       be_set_IncSP_offset(irn, offset);
 
-       pop      = new_rd_ia32_Pop(NULL, current_ir_graph, bl, get_irn_n(irn, 0), get_irn_n(load, 2));
-       proj_res = new_r_Proj(current_ir_graph, bl, pop, get_irn_mode(old_proj_res), pn_ia32_Pop_res);
-       proj_sp  = new_r_Proj(current_ir_graph, bl, pop, get_irn_mode(irn), pn_ia32_Pop_stack);
-       proj_M   = new_r_Proj(current_ir_graph, bl, pop, mode_M, pn_ia32_Pop_M);
+       // can we remove the IncSP now?
+       if(offset == 0) {
+               const ir_edge_t *edge, *next;
 
-       exchange(old_proj_M, proj_M);
-       exchange(old_proj_res, proj_res);
-       exchange(irn, proj_sp);
+               foreach_out_edge_safe(irn, edge, next) {
+                       ir_node *arg = get_edge_src_irn(edge);
+                       int pos = get_edge_src_pos(edge);
 
-       arch_set_irn_register(cg->arch_env, proj_res, reg);
-       arch_set_irn_register(cg->arch_env, proj_sp, sp);
+                       set_irn_n(arg, pos, curr_sp);
+               }
 
-       sched_add_before(next, proj_sp);
-       sched_add_before(proj_sp, proj_res);
-       sched_add_before(proj_res,pop);
+               set_irn_n(irn, 0, new_Bad());
+               sched_remove(irn);
+       } else {
+               set_irn_n(irn, 0, curr_sp);
+       }
 }
 
 /**
@@ -589,33 +635,23 @@ static void ia32_optimize_IncSP(ir_node *irn, ia32_code_gen_t *cg) {
 
        if (be_is_IncSP(prev) && real_uses == 1) {
                /* first IncSP has only one IncSP user, kill the first one */
-               unsigned       prev_offs = be_get_IncSP_offset(prev);
-               be_stack_dir_t prev_dir  = be_get_IncSP_direction(prev);
-               unsigned       curr_offs = be_get_IncSP_offset(irn);
-               be_stack_dir_t curr_dir  = be_get_IncSP_direction(irn);
+               int prev_offs = be_get_IncSP_offset(prev);
+               int curr_offs = be_get_IncSP_offset(irn);
 
-               int new_ofs = prev_offs * (prev_dir == be_stack_dir_expand ? -1 : +1) +
-                                   curr_offs * (curr_dir == be_stack_dir_expand ? -1 : +1);
-
-               if (new_ofs < 0) {
-                       new_ofs  = -new_ofs;
-                       curr_dir = be_stack_dir_expand;
-               }
-               else
-                       curr_dir = be_stack_dir_shrink;
-               be_set_IncSP_offset(prev, 0);
-               be_set_IncSP_offset(irn, (unsigned)new_ofs);
-               be_set_IncSP_direction(irn, curr_dir);
+               be_set_IncSP_offset(prev, prev_offs + curr_offs);
 
                /* Omit the optimized IncSP */
                be_set_IncSP_pred(irn, be_get_IncSP_pred(prev));
+
+               set_irn_n(prev, 0, new_Bad());
+               sched_remove(prev);
        }
 }
 
 /**
  * Performs Peephole Optimizations.
  */
-void ia32_peephole_optimization(ir_node *irn, void *env) {
+static void ia32_peephole_optimize_node(ir_node *irn, void *env) {
        ia32_code_gen_t *cg = env;
 
        /* AMD CPUs want explicit compare before conditional jump  */
@@ -625,14 +661,18 @@ void ia32_peephole_optimization(ir_node *irn, void *env) {
                else if (is_ia32_CondJmp(irn))
                        ia32_optimize_CondJmp(irn, cg);
        }
-       /* seems to be buggy when using Pushes */
-//     else if (be_is_IncSP(irn))
-//             ia32_optimize_IncSP(irn, cg);
-       else if (is_ia32_Store(irn))
-               ia32_create_Push(irn, cg);
-}
 
+       if (be_is_IncSP(irn)) {
+               // optimize_IncSP doesn't respect dependency edges yet...
+               //ia32_optimize_IncSP(irn, cg);
+               (void) ia32_optimize_IncSP;
+               ia32_create_Pushs(irn, cg);
+       }
+}
 
+void ia32_peephole_optimization(ir_graph *irg, ia32_code_gen_t *cg) {
+       irg_walk_graph(irg, ia32_peephole_optimize_node, NULL, cg);
+}
 
 /******************************************************************
  *              _     _                   __  __           _
@@ -664,48 +704,6 @@ static int ia32_get_irn_n_edges(const ir_node *irn) {
        return cnt;
 }
 
-/**
- * Returns the first mode_M Proj connected to irn.
- */
-static ir_node *get_mem_proj(const ir_node *irn) {
-       const ir_edge_t *edge;
-       ir_node         *src;
-
-       assert(get_irn_mode(irn) == mode_T && "expected mode_T node");
-
-       foreach_out_edge(irn, edge) {
-               src = get_edge_src_irn(edge);
-
-               assert(is_Proj(src) && "Proj expected");
-
-               if (get_irn_mode(src) == mode_M)
-                       return src;
-       }
-
-       return NULL;
-}
-
-/**
- * Returns the first Proj with mode != mode_M connected to irn.
- */
-static ir_node *get_res_proj(const ir_node *irn) {
-       const ir_edge_t *edge;
-       ir_node         *src;
-
-       assert(get_irn_mode(irn) == mode_T && "expected mode_T node");
-
-       foreach_out_edge(irn, edge) {
-               src = get_edge_src_irn(edge);
-
-               assert(is_Proj(src) && "Proj expected");
-
-               if (get_irn_mode(src) != mode_M)
-                       return src;
-       }
-
-       return NULL;
-}
-
 /**
  * Determines if pred is a Proj and if is_op_func returns true for it's predecessor.
  *
@@ -763,6 +761,7 @@ static int is_addr_candidate(const ir_node *block, const ir_node *irn) {
 
        in = left;
 
+#ifndef AGGRESSIVE_AM
        if (pred_is_specific_nodeblock(block, in, is_ia32_Ld)) {
                n         = ia32_get_irn_n_edges(in);
                is_cand   = (n == 1) ? 0 : is_cand;  /* load with only one user: don't create LEA */
@@ -774,6 +773,9 @@ static int is_addr_candidate(const ir_node *block, const ir_node *irn) {
                n         = ia32_get_irn_n_edges(in);
                is_cand   = (n == 1) ? 0 : is_cand;  /* load with only one user: don't create LEA */
        }
+#else
+       (void) n;
+#endif
 
        is_cand = get_ia32_frame_ent(irn) ? 1 : is_cand;
 
@@ -796,9 +798,10 @@ static int is_addr_candidate(const ir_node *block, const ir_node *irn) {
  */
 static ia32_am_cand_t is_am_candidate(ia32_code_gen_t *cg, heights_t *h, const ir_node *block, ir_node *irn) {
        ir_node *in, *load, *other, *left, *right;
-       int      n, is_cand = 0, cand;
+       int      is_cand = 0, cand;
 
-       if (is_ia32_Ld(irn) || is_ia32_St(irn) || is_ia32_Store8Bit(irn) || is_ia32_vfild(irn) || is_ia32_vfist(irn))
+       if (is_ia32_Ld(irn) || is_ia32_St(irn) || is_ia32_Store8Bit(irn) || is_ia32_vfild(irn) || is_ia32_vfist(irn) ||
+               is_ia32_GetST0(irn) || is_ia32_SetST0(irn) || is_ia32_xStoreSimple(irn))
                return 0;
 
        left  = get_irn_n(irn, 2);
@@ -807,16 +810,30 @@ static ia32_am_cand_t is_am_candidate(ia32_code_gen_t *cg, heights_t *h, const i
        in = left;
 
        if (pred_is_specific_nodeblock(block, in, is_ia32_Ld)) {
+#ifndef AGGRESSIVE_AM
+               int n;
                n         = ia32_get_irn_n_edges(in);
                is_cand   = (n == 1) ? 1 : is_cand;  /* load with more than one user: no AM */
+#else
+               is_cand   = 1;
+#endif
 
                load  = get_Proj_pred(in);
                other = right;
 
+               /* 8bit Loads are not supported (for binary ops),
+                * they cannot be used with every register */
+               if (get_irn_arity(irn) != 4 && get_mode_size_bits(get_ia32_ls_mode(load)) < 16) {
+                       assert(get_irn_arity(irn) == 5);
+                       is_cand = 0;
+               }
+
                /* If there is a data dependency of other irn from load: cannot use AM */
-               if (get_nodes_block(other) == block) {
+               if (is_cand && get_nodes_block(other) == block) {
                        other   = skip_Proj(other);
                        is_cand = heights_reachable_in_block(h, other, load) ? 0 : is_cand;
+                       /* this could happen in loops */
+                       is_cand = heights_reachable_in_block(h, load, irn) ? 0 : is_cand;
                }
        }
 
@@ -825,16 +842,25 @@ static ia32_am_cand_t is_am_candidate(ia32_code_gen_t *cg, heights_t *h, const i
        is_cand = 0;
 
        if (pred_is_specific_nodeblock(block, in, is_ia32_Ld)) {
+#ifndef AGGRESSIVE_AM
+               int n;
                n         = ia32_get_irn_n_edges(in);
                is_cand   = (n == 1) ? 1 : is_cand;  /* load with more than one user: no AM */
+#endif
 
                load  = get_Proj_pred(in);
                other = left;
 
+               /* 8bit Loads are not supported, they cannot be used with every register */
+               if (get_mode_size_bits(get_ia32_ls_mode(load)) < 16)
+                       is_cand = 0;
+
                /* If there is a data dependency of other irn from load: cannot use load */
-               if (get_nodes_block(other) == block) {
+               if (is_cand && get_nodes_block(other) == block) {
                        other   = skip_Proj(other);
                        is_cand = heights_reachable_in_block(h, other, load) ? 0 : is_cand;
+                       /* this could happen in loops */
+                       is_cand = heights_reachable_in_block(h, load, irn) ? 0 : is_cand;
                }
        }
 
@@ -905,8 +931,6 @@ typedef enum _ia32_take_lea_attr {
 static int do_new_lea(ir_node *irn, ir_node *base, ir_node *index, ir_node *lea,
                int have_am_sc, ia32_code_gen_t *cg)
 {
-       ir_node *lea_base = get_irn_n(lea, 0);
-       ir_node *lea_idx  = get_irn_n(lea, 1);
        entity  *irn_ent  = get_ia32_frame_ent(irn);
        entity  *lea_ent  = get_ia32_frame_ent(lea);
        int      ret_val  = 0;
@@ -996,6 +1020,43 @@ static int do_new_lea(ir_node *irn, ir_node *base, ir_node *index, ir_node *lea,
        return ret_val;
 }
 
+/**
+ * Adds res before irn into schedule if irn was scheduled.
+ * @param irn  The schedule point
+ * @param res  The node to be scheduled
+ */
+static INLINE void try_add_to_sched(ir_node *irn, ir_node *res) {
+       if (sched_is_scheduled(irn))
+               sched_add_before(irn, res);
+}
+
+/**
+ * Removes irn from schedule if it was scheduled. If irn is a mode_T node
+ * all it's Projs are removed as well.
+ * @param irn  The irn to be removed from schedule
+ */
+static INLINE void try_remove_from_sched(ir_node *irn) {
+       int i, arity;
+
+       if (sched_is_scheduled(irn)) {
+               if (get_irn_mode(irn) == mode_T) {
+                       const ir_edge_t *edge;
+                       foreach_out_edge(irn, edge) {
+                               ir_node *proj = get_edge_src_irn(edge);
+                               if (sched_is_scheduled(proj)) {
+                                       set_irn_n(proj, 0, new_Bad());
+                                       sched_remove(proj);
+                               }
+                       }
+               }
+
+               arity = get_irn_arity(irn);
+               for(i = 0; i < arity; ++i) {
+                       set_irn_n(irn, i, new_Bad());
+               }
+               sched_remove(irn);
+       }
+}
 
 /**
  * Folds Add or Sub to LEA if possible
@@ -1020,6 +1081,7 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
        entity     *lea_ent    = NULL;
        ir_node    *left, *right, *temp;
        ir_node    *base, *index;
+       int consumed_left_shift;
        ia32_am_flavour_t am_flav;
        DEBUG_ONLY(firm_dbg_module_t *mod = cg->mod;)
 
@@ -1105,8 +1167,9 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
 
        if (isadd) {
                /* default for add -> make right operand to index */
-               index = right;
-               dolea = 1;
+               index               = right;
+               dolea               = 1;
+               consumed_left_shift = -1;
 
                DBG((mod, LEVEL_1, "\tgot LEA candidate with index %+F\n", index));
 
@@ -1114,6 +1177,7 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
                temp = left;
                if (is_ia32_Lea(left)) {
                        temp = right;
+                       consumed_left_shift = 0;
                }
 
                /* check for SHL 1,2,3 */
@@ -1125,7 +1189,8 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
                                scale = get_tarval_long(get_ia32_Immop_tarval(temp));
 
                                if (scale <= 3) {
-                                       index = get_irn_n(temp, 2);
+                                       index               = get_irn_n(temp, 2);
+                                       consumed_left_shift = consumed_left_shift < 0 ? 1 : 0;
 
                                        DBG((mod, LEVEL_1, "\tgot scaled index %+F\n", index));
                                }
@@ -1142,10 +1207,8 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
                        if (left == right) {
                                base = noreg;
                        }
-                       else if (! is_ia32_Lea(left) && (index != right)) {
-                               /* index != right -> we found a good Shl           */
-                               /* left  != LEA   -> this Shl was the left operand */
-                               /* -> base is right operand                        */
+                       else if (consumed_left_shift == 1) {
+                               /* -> base is right operand  */
                                base = (right == lea_o) ? noreg : right;
                        }
                }
@@ -1261,25 +1324,46 @@ static ir_node *fold_addr(ia32_code_gen_t *cg, ir_node *irn, ir_node *noreg) {
                DBG((mod, LEVEL_1, "\tLEA [%+F + %+F * %d + %s]\n", base, index, scale, get_ia32_am_offs(res)));
 
                /* we will exchange it, report here before the Proj is created */
-               if (shift && lea && lea_o)
+               if (shift && lea && lea_o) {
+                       try_remove_from_sched(shift);
+                       try_remove_from_sched(lea);
+                       try_remove_from_sched(lea_o);
                        DBG_OPT_LEA4(irn, lea_o, lea, shift, res);
-               else if (shift && lea)
+               }
+               else if (shift && lea) {
+                       try_remove_from_sched(shift);
+                       try_remove_from_sched(lea);
                        DBG_OPT_LEA3(irn, lea, shift, res);
-               else if (shift && lea_o)
+               }
+               else if (shift && lea_o) {
+                       try_remove_from_sched(shift);
+                       try_remove_from_sched(lea_o);
                        DBG_OPT_LEA3(irn, lea_o, shift, res);
-               else if (lea && lea_o)
+               }
+               else if (lea && lea_o) {
+                       try_remove_from_sched(lea);
+                       try_remove_from_sched(lea_o);
                        DBG_OPT_LEA3(irn, lea_o, lea, res);
-               else if (shift)
+               }
+               else if (shift) {
+                       try_remove_from_sched(shift);
                        DBG_OPT_LEA2(irn, shift, res);
-               else if (lea)
+               }
+               else if (lea) {
+                       try_remove_from_sched(lea);
                        DBG_OPT_LEA2(irn, lea, res);
-               else if (lea_o)
+               }
+               else if (lea_o) {
+                       try_remove_from_sched(lea_o);
                        DBG_OPT_LEA2(irn, lea_o, res);
+               }
                else
                        DBG_OPT_LEA1(irn, res);
 
                /* get the result Proj of the Add/Sub */
-               irn = get_res_proj(irn);
+               try_add_to_sched(irn, res);
+               try_remove_from_sched(irn);
+               irn = ia32_get_res_proj(irn);
 
                assert(irn && "Couldn't find result proj");
 
@@ -1323,6 +1407,8 @@ static void merge_loadstore_lea(ir_node *irn, ir_node *lea) {
        set_irn_n(irn, 0, get_irn_n(lea, 0));
        set_irn_n(irn, 1, get_irn_n(lea, 1));
 
+       try_remove_from_sched(lea);
+
        /* clear remat flag */
        set_ia32_flags(irn, get_ia32_flags(irn) & ~arch_irn_flags_rematerializable);
 
@@ -1415,7 +1501,6 @@ static void optimize_lea(ir_node *irn, void *env) {
        }
 }
 
-
 /**
  * Checks for address mode patterns and performs the
  * necessary transformations.
@@ -1425,8 +1510,7 @@ static void optimize_am(ir_node *irn, void *env) {
        ia32_am_opt_env_t *am_opt_env = env;
        ia32_code_gen_t   *cg         = am_opt_env->cg;
        heights_t         *h          = am_opt_env->h;
-       ir_node           *block, *noreg_gp, *noreg_fp;
-       ir_node           *left, *right;
+       ir_node           *block, *left, *right;
        ir_node           *store, *load, *mem_proj;
        ir_node           *succ, *addr_b, *addr_i;
        int               check_am_src          = 0;
@@ -1436,9 +1520,7 @@ static void optimize_am(ir_node *irn, void *env) {
        if (! is_ia32_irn(irn) || is_ia32_Ld(irn) || is_ia32_St(irn) || is_ia32_Store8Bit(irn))
                return;
 
-       block    = get_nodes_block(irn);
-       noreg_gp = ia32_new_NoReg_gp(cg);
-       noreg_fp = ia32_new_NoReg_fp(cg);
+       block = get_nodes_block(irn);
 
        DBG((mod, LEVEL_1, "checking for AM\n"));
 
@@ -1471,6 +1553,7 @@ static void optimize_am(ir_node *irn, void *env) {
                if (get_irn_arity(irn) == 4) {
                        /* it's an "unary" operation */
                        right = left;
+                       cand = IA32_AM_CAND_BOTH;
                }
                else {
                        right = get_irn_n(irn, 3);
@@ -1501,7 +1584,7 @@ static void optimize_am(ir_node *irn, void *env) {
                        /* check further, otherwise we check for Store and remember the address, */
                        /* the Store points to. */
 
-                       succ = get_res_proj(irn);
+                       succ = ia32_get_res_proj(irn);
                        assert(succ && "Couldn't find result proj");
 
                        addr_b = NULL;
@@ -1565,22 +1648,24 @@ static void optimize_am(ir_node *irn, void *env) {
                                        if (get_irn_arity(irn) == 5) {
                                                /* binary AMop */
                                                set_irn_n(irn, 4, get_irn_n(load, 2));
-                                               set_irn_n(irn, 2, noreg_gp);
+                                               set_irn_n(irn, 2, ia32_get_admissible_noreg(cg, irn, 2));
                                        }
                                        else {
                                                /* unary AMop */
                                                set_irn_n(irn, 3, get_irn_n(load, 2));
-                                               set_irn_n(irn, 2, noreg_gp);
+                                               set_irn_n(irn, 2, ia32_get_admissible_noreg(cg, irn, 2));
                                        }
 
                                        /* connect the memory Proj of the Store to the op */
-                                       mem_proj = get_mem_proj(store);
+                                       mem_proj = ia32_get_proj_for_mode(store, mode_M);
                                        set_Proj_pred(mem_proj, irn);
                                        set_Proj_proj(mem_proj, 1);
 
                                        /* clear remat flag */
                                        set_ia32_flags(irn, get_ia32_flags(irn) & ~arch_irn_flags_rematerializable);
 
+                                       try_remove_from_sched(load);
+                                       try_remove_from_sched(store);
                                        DBG_OPT_AM_D(load, store, irn);
 
                                        DB((mod, LEVEL_1, "merged with %+F and %+F into dest AM\n", load, store));
@@ -1625,54 +1710,61 @@ static void optimize_am(ir_node *irn, void *env) {
                /* and right operand is a Load which only used by this irn */
                if (check_am_src                &&
                        (cand & IA32_AM_CAND_RIGHT) &&
-                       (get_irn_arity(irn) == 5)   &&
                        (ia32_get_irn_n_edges(right) == 1))
                {
-                       right = get_Proj_pred(right);
+                       ir_node *load = get_Proj_pred(right);
 
-                       addr_b = get_irn_n(right, 0);
-                       addr_i = get_irn_n(right, 1);
+                       addr_b = get_irn_n(load, 0);
+                       addr_i = get_irn_n(load, 1);
 
                        /* set new base, index and attributes */
                        set_irn_n(irn, 0, addr_b);
                        set_irn_n(irn, 1, addr_i);
-                       add_ia32_am_offs(irn, get_ia32_am_offs(right));
-                       set_ia32_am_scale(irn, get_ia32_am_scale(right));
-                       set_ia32_am_flavour(irn, get_ia32_am_flavour(right));
+                       add_ia32_am_offs(irn, get_ia32_am_offs(load));
+                       set_ia32_am_scale(irn, get_ia32_am_scale(load));
+                       set_ia32_am_flavour(irn, get_ia32_am_flavour(load));
                        set_ia32_op_type(irn, ia32_AddrModeS);
-                       set_ia32_frame_ent(irn, get_ia32_frame_ent(right));
-                       set_ia32_ls_mode(irn, get_ia32_ls_mode(right));
+                       set_ia32_frame_ent(irn, get_ia32_frame_ent(load));
+                       set_ia32_ls_mode(irn, get_ia32_ls_mode(load));
 
-                       set_ia32_am_sc(irn, get_ia32_am_sc(right));
-                       if (is_ia32_am_sc_sign(right))
+                       set_ia32_am_sc(irn, get_ia32_am_sc(load));
+                       if (is_ia32_am_sc_sign(load))
                                set_ia32_am_sc_sign(irn);
 
                        /* clear remat flag */
                        set_ia32_flags(irn, get_ia32_flags(irn) & ~arch_irn_flags_rematerializable);
 
-                       if (is_ia32_use_frame(right))
+                       if (is_ia32_use_frame(load))
                                set_ia32_use_frame(irn);
 
-                       /* connect to Load memory */
-                       set_irn_n(irn, 4, get_irn_n(right, 2));
+                       /* connect to Load memory and disconnect Load */
+                       if (get_irn_arity(irn) == 5) {
+                               /* binary AMop */
+                               set_irn_n(irn, 4, get_irn_n(load, 2));
+                               set_irn_n(irn, 3, ia32_get_admissible_noreg(cg, irn, 3));
+                       } else {
+                               assert(get_irn_arity(irn) == 4);
+                               /* unary AMop */
+                               set_irn_n(irn, 3, get_irn_n(load, 2));
+                               set_irn_n(irn, 2, ia32_get_admissible_noreg(cg, irn, 2));
+                       }
 
                        /* this is only needed for Compares, but currently ALL nodes
                         * have this attribute :-) */
                        set_ia32_pncode(irn, get_inversed_pnc(get_ia32_pncode(irn)));
 
-                       /* disconnect from Load */
-                       set_irn_n(irn, 3, noreg_gp);
-
-                       DBG_OPT_AM_S(right, irn);
+                       DBG_OPT_AM_S(load, irn);
 
                        /* If Load has a memory Proj, connect it to the op */
-                       mem_proj = get_mem_proj(right);
+                       mem_proj = ia32_get_proj_for_mode(load, mode_M);
                        if (mem_proj) {
                                set_Proj_pred(mem_proj, irn);
                                set_Proj_proj(mem_proj, 1);
                        }
 
-                       DB((mod, LEVEL_1, "merged with %+F into source AM\n", right));
+                       try_remove_from_sched(load);
+
+                       DB((mod, LEVEL_1, "merged with %+F into source AM\n", load));
                }
                else {
                        /* was exchanged but optimize failed: exchange back */