fehler109
[libfirm] / ir / be / ia32 / ia32_optimize.c
index 16b478c..7ea0a65 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -38,6 +38,8 @@
 #include "irgwalk.h"
 #include "height.h"
 #include "irbitset.h"
+#include "irprintf.h"
+#include "error.h"
 
 #include "../be_t.h"
 #include "../beabi.h"
 #include "../bepeephole.h"
 
 #include "ia32_new_nodes.h"
+#include "ia32_optimize.h"
 #include "bearch_ia32_t.h"
 #include "gen_ia32_regalloc_if.h"
 #include "ia32_transform.h"
 #include "ia32_dbg_stat.h"
 #include "ia32_util.h"
+#include "ia32_architecture.h"
 
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
 static const arch_env_t *arch_env;
 static ia32_code_gen_t  *cg;
 
-typedef int is_op_func_t(const ir_node *n);
-typedef ir_node *load_func_t(dbg_info *db, ir_graph *irg, ir_node *block, ir_node *base, ir_node *index, ir_node *mem);
+static void peephole_IncSP_IncSP(ir_node *node);
 
-/**
- * checks if a node represents the NOREG value
- */
-static INLINE int be_is_NoReg(ia32_code_gen_t *cg, const ir_node *irn) {
-       return irn == cg->noreg_gp || irn == cg->noreg_xmm || irn == cg->noreg_vfp;
+#if 0
+static void peephole_ia32_Store_IncSP_to_push(ir_node *node)
+{
+       ir_node  *base  = get_irn_n(node, n_ia32_Store_base);
+       ir_node  *index = get_irn_n(node, n_ia32_Store_index);
+       ir_node  *mem   = get_irn_n(node, n_ia32_Store_mem);
+       ir_node  *incsp = base;
+       ir_node  *val;
+       ir_node  *noreg;
+       ir_graph *irg;
+       ir_node  *block;
+       dbg_info *dbgi;
+       ir_mode  *mode;
+       ir_node  *push;
+       ir_node  *proj;
+       int       offset;
+       int       node_offset;
+
+       /* nomem inidicates the store doesn't alias with anything else */
+       if(!is_NoMem(mem))
+               return;
+
+       /* find an IncSP in front of us, we might have to skip barriers for this */
+       while(is_Proj(incsp)) {
+               ir_node *proj_pred = get_Proj_pred(incsp);
+               if(!be_is_Barrier(proj_pred))
+                       return;
+               incsp = get_irn_n(proj_pred, get_Proj_proj(incsp));
+       }
+       if(!be_is_IncSP(incsp))
+               return;
+
+       peephole_IncSP_IncSP(incsp);
+
+       /* must be in the same block */
+       if(get_nodes_block(incsp) != get_nodes_block(node))
+               return;
+
+       if(!is_ia32_NoReg_GP(index) || get_ia32_am_sc(node) != NULL) {
+               panic("Invalid storeAM found (%+F)", node);
+       }
+
+       /* we should be the store to the end of the stackspace */
+       offset      = be_get_IncSP_offset(incsp);
+       mode        = get_ia32_ls_mode(node);
+       node_offset = get_ia32_am_offs_int(node);
+       if(node_offset != offset - get_mode_size_bytes(mode))
+               return;
+
+       /* we can use a push instead of the store */
+       irg   = current_ir_graph;
+       block = get_nodes_block(node);
+       dbgi  = get_irn_dbg_info(node);
+       noreg = ia32_new_NoReg_gp(cg);
+       base  = be_get_IncSP_pred(incsp);
+       val   = get_irn_n(node, n_ia32_Store_val);
+       push  = new_rd_ia32_Push(dbgi, irg, block, noreg, noreg, mem, base, val);
+
+       proj  = new_r_Proj(irg, block, push, mode_M, pn_ia32_Push_M);
+
+       be_set_IncSP_offset(incsp, offset - get_mode_size_bytes(mode));
+
+       sched_add_before(node, push);
+       sched_remove(node);
+
+       be_peephole_before_exchange(node, proj);
+       exchange(node, proj);
+       be_peephole_after_exchange(proj);
 }
 
-/********************************************************************************************************
- *  _____                _           _         ____        _   _           _          _   _
- * |  __ \              | |         | |       / __ \      | | (_)         (_)        | | (_)
- * | |__) |__  ___ _ __ | |__   ___ | | ___  | |  | |_ __ | |_ _ _ __ ___  _ ______ _| |_ _  ___  _ __
- * |  ___/ _ \/ _ \ '_ \| '_ \ / _ \| |/ _ \ | |  | | '_ \| __| | '_ ` _ \| |_  / _` | __| |/ _ \| '_ \
- * | |  |  __/  __/ |_) | | | | (_) | |  __/ | |__| | |_) | |_| | | | | | | |/ / (_| | |_| | (_) | | | |
- * |_|   \___|\___| .__/|_| |_|\___/|_|\___|  \____/| .__/ \__|_|_| |_| |_|_/___\__,_|\__|_|\___/|_| |_|
- *                | |                               | |
- *                |_|                               |_|
- ********************************************************************************************************/
+static void peephole_ia32_Store(ir_node *node)
+{
+       peephole_ia32_Store_IncSP_to_push(node);
+}
+#endif
 
-/**
- * NOTE: THESE PEEPHOLE OPTIMIZATIONS MUST BE CALLED AFTER SCHEDULING AND REGISTER ALLOCATION.
- */
+static int produces_zero_flag(ir_node *node, int pn)
+{
+       ir_node                     *count;
+       const ia32_immediate_attr_t *imm_attr;
+
+       if(!is_ia32_irn(node))
+               return 0;
+
+       if(pn >= 0) {
+               if(pn != pn_ia32_res)
+                       return 0;
+       }
+
+       switch(get_ia32_irn_opcode(node)) {
+       case iro_ia32_Add:
+       case iro_ia32_Adc:
+       case iro_ia32_And:
+       case iro_ia32_Or:
+       case iro_ia32_Xor:
+       case iro_ia32_Sub:
+       case iro_ia32_Sbb:
+       case iro_ia32_Neg:
+       case iro_ia32_Inc:
+       case iro_ia32_Dec:
+               return 1;
+
+       case iro_ia32_ShlD:
+       case iro_ia32_ShrD:
+       case iro_ia32_Shl:
+       case iro_ia32_Shr:
+       case iro_ia32_Sar:
+               assert(n_ia32_ShlD_count == n_ia32_ShrD_count);
+               assert(n_ia32_Shl_count == n_ia32_Shr_count
+                               && n_ia32_Shl_count == n_ia32_Sar_count);
+               if(is_ia32_ShlD(node) || is_ia32_ShrD(node)) {
+                       count = get_irn_n(node, n_ia32_ShlD_count);
+               } else {
+                       count = get_irn_n(node, n_ia32_Shl_count);
+               }
+               /* when shift count is zero the flags are not affected, so we can only
+                * do this for constants != 0 */
+               if(!is_ia32_Immediate(count))
+                       return 0;
+
+               imm_attr = get_ia32_immediate_attr_const(count);
+               if(imm_attr->symconst != NULL)
+                       return 0;
+               if((imm_attr->offset & 0x1f) == 0)
+                       return 0;
+               return 1;
+
+       default:
+               break;
+       }
+       return 0;
+}
+
+static ir_node *turn_into_mode_t(ir_node *node)
+{
+       ir_node               *block;
+       ir_node               *res_proj;
+       ir_node               *new_node;
+       const arch_register_t *reg;
+
+       if(get_irn_mode(node) == mode_T)
+               return node;
+
+       assert(get_irn_mode(node) == mode_Iu);
+
+       new_node = exact_copy(node);
+       set_irn_mode(new_node, mode_T);
+
+       block    = get_nodes_block(new_node);
+       res_proj = new_r_Proj(current_ir_graph, block, new_node, mode_Iu,
+                             pn_ia32_res);
+
+       reg = arch_get_irn_register(arch_env, node);
+       arch_set_irn_register(arch_env, res_proj, reg);
+
+       be_peephole_before_exchange(node, res_proj);
+       sched_add_before(node, new_node);
+       sched_remove(node);
+       exchange(node, res_proj);
+       be_peephole_after_exchange(res_proj);
+
+       return new_node;
+}
+
+static void peephole_ia32_Test(ir_node *node)
+{
+       ir_node *left  = get_irn_n(node, n_ia32_Test_left);
+       ir_node *right = get_irn_n(node, n_ia32_Test_right);
+       ir_node *flags_proj;
+       ir_node *block;
+       ir_mode *flags_mode;
+       int      pn    = -1;
+       ir_node *schedpoint;
+       const ir_edge_t       *edge;
+
+       assert(n_ia32_Test_left == n_ia32_Test8Bit_left
+                       && n_ia32_Test_right == n_ia32_Test8Bit_right);
+
+       /* we need a test for 0 */
+       if(left != right)
+               return;
+
+       block = get_nodes_block(node);
+       if(get_nodes_block(left) != block)
+               return;
+
+       if(is_Proj(left)) {
+               pn   = get_Proj_proj(left);
+               left = get_Proj_pred(left);
+       }
+
+       /* walk schedule up and abort when we find left or some other node destroys
+          the flags */
+       schedpoint = sched_prev(node);
+       while(schedpoint != left) {
+               schedpoint = sched_prev(schedpoint);
+               if(arch_irn_is(arch_env, schedpoint, modify_flags))
+                       return;
+               if(schedpoint == block)
+                       panic("couldn't find left");
+       }
+
+       /* make sure only Lg/Eq tests are used */
+       foreach_out_edge(node, edge) {
+               ir_node *user = get_edge_src_irn(edge);
+               int      pnc  = get_ia32_condcode(user);
+
+               if(pnc != pn_Cmp_Eq && pnc != pn_Cmp_Lg) {
+                       return;
+               }
+       }
+
+       if(!produces_zero_flag(left, pn))
+               return;
+
+       left = turn_into_mode_t(left);
+
+       flags_mode = ia32_reg_classes[CLASS_ia32_flags].mode;
+       flags_proj = new_r_Proj(current_ir_graph, block, left, flags_mode,
+                               pn_ia32_flags);
+       arch_set_irn_register(arch_env, flags_proj, &ia32_flags_regs[REG_EFLAGS]);
+
+       assert(get_irn_mode(node) != mode_T);
+
+       be_peephole_before_exchange(node, flags_proj);
+       exchange(node, flags_proj);
+       sched_remove(node);
+       be_peephole_after_exchange(flags_proj);
+}
 
 // only optimize up to 48 stores behind IncSPs
 #define MAXPUSH_OPTIMIZE       48
@@ -88,7 +299,7 @@ static INLINE int be_is_NoReg(ia32_code_gen_t *cg, const ir_node *irn) {
 /**
  * Tries to create pushs from IncSP,Store combinations
  */
-static void ia32_create_Pushs(ir_node *irn)
+static void peephole_IncSP_Store_to_push(ir_node *irn)
 {
        int i;
        int offset;
@@ -175,9 +386,7 @@ static void ia32_create_Pushs(ir_node *irn)
                mem = get_irn_n(store, n_ia32_mem);
                spreg = arch_get_irn_register(cg->arch_env, curr_sp);
 
-               push = new_rd_ia32_Push(get_irn_dbg_info(store), irg, block, noreg, noreg, mem, val, curr_sp);
-
-               set_ia32_am_support(push, ia32_am_Source, ia32_am_unary);
+               push = new_rd_ia32_Push(get_irn_dbg_info(store), irg, block, noreg, noreg, mem, curr_sp, val);
 
                sched_add_before(irn, push);
 
@@ -198,29 +407,13 @@ static void ia32_create_Pushs(ir_node *irn)
        }
 
        be_set_IncSP_offset(irn, offset);
-
-       // can we remove the IncSP now?
-       if(offset == 0) {
-               const ir_edge_t *edge, *next;
-
-               foreach_out_edge_safe(irn, edge, next) {
-                       ir_node *arg = get_edge_src_irn(edge);
-                       int pos = get_edge_src_pos(edge);
-
-                       set_irn_n(arg, pos, curr_sp);
-               }
-
-               set_irn_n(irn, 0, new_Bad());
-               sched_remove(irn);
-       } else {
-               set_irn_n(irn, 0, curr_sp);
-       }
+       be_set_IncSP_pred(irn, curr_sp);
 }
 
 /**
  * Tries to optimize two following IncSP.
  */
-static void ia32_optimize_IncSP(ir_node *node)
+static void peephole_IncSP_IncSP(ir_node *node)
 {
        int      pred_offs;
        int      curr_offs;
@@ -254,33 +447,103 @@ static void ia32_optimize_IncSP(ir_node *node)
                offs = curr_offs + pred_offs;
        }
 
+       /* add pred offset to ours and remove pred IncSP */
        be_set_IncSP_offset(node, offs);
 
-       /* rewire dependency edges */
        predpred = be_get_IncSP_pred(pred);
-       edges_reroute_kind(pred, predpred, EDGE_KIND_DEP, current_ir_graph);
+       be_peephole_before_exchange(pred, predpred);
 
-       /* Omit the IncSP */
+       /* rewire dependency edges */
+       edges_reroute_kind(pred, predpred, EDGE_KIND_DEP, current_ir_graph);
        be_set_IncSP_pred(node, predpred);
        sched_remove(pred);
        be_kill_node(pred);
+
+       be_peephole_after_exchange(predpred);
 }
 
-/**
- * Performs Peephole Optimizations.
- */
-static void ia32_peephole_optimize_node(ir_node *node, void *env)
+static const arch_register_t *get_free_gp_reg(void)
 {
-       (void) env;
-       if (be_is_IncSP(node)) {
-               ia32_optimize_IncSP(node);
+       int i;
+
+       for(i = 0; i < N_ia32_gp_REGS; ++i) {
+               const arch_register_t *reg = &ia32_gp_regs[i];
+               if(arch_register_type_is(reg, ignore))
+                       continue;
 
-               if (cg->opt & IA32_OPT_PUSHARGS)
-                       ia32_create_Pushs(node);
+               if(be_peephole_get_value(CLASS_ia32_gp, i) == NULL)
+                       return &ia32_gp_regs[i];
        }
+
+       return NULL;
 }
 
-static ir_node *optimize_ia32_Const(ir_node *node)
+static void peephole_be_IncSP(ir_node *node)
+{
+       const arch_register_t *esp = &ia32_gp_regs[REG_ESP];
+       const arch_register_t *reg;
+       ir_graph              *irg;
+       dbg_info              *dbgi;
+       ir_node               *block;
+       ir_node               *keep;
+       ir_node               *val;
+       ir_node               *pop;
+       ir_node               *noreg;
+       ir_node               *stack;
+       int                    offset;
+
+       /* first optimize incsp->incsp combinations */
+       peephole_IncSP_IncSP(node);
+
+       /* transform IncSP->Store combinations to Push where possible */
+       peephole_IncSP_Store_to_push(node);
+
+       /* replace IncSP -4 by Pop freereg when possible */
+       offset = be_get_IncSP_offset(node);
+       if(offset != -4)
+               return;
+
+       if(arch_get_irn_register(arch_env, node) != esp)
+               return;
+
+       reg = get_free_gp_reg();
+       if(reg == NULL)
+               return;
+
+       irg   = current_ir_graph;
+       dbgi  = get_irn_dbg_info(node);
+       block = get_nodes_block(node);
+       noreg = ia32_new_NoReg_gp(cg);
+       stack = be_get_IncSP_pred(node);
+       pop   = new_rd_ia32_Pop(dbgi, irg, block, noreg, noreg, new_NoMem(), stack);
+
+       stack = new_r_Proj(irg, block, pop, mode_Iu, pn_ia32_Pop_stack);
+       arch_set_irn_register(arch_env, stack, esp);
+       val   = new_r_Proj(irg, block, pop, mode_Iu, pn_ia32_Pop_res);
+       arch_set_irn_register(arch_env, val, reg);
+
+       sched_add_before(node, pop);
+
+       keep  = sched_next(node);
+       if(!be_is_Keep(keep)) {
+               ir_node *in[1];
+               in[0] = val;
+               keep = be_new_Keep(&ia32_reg_classes[CLASS_ia32_gp], irg, block, 1, in);
+               sched_add_before(node, keep);
+       } else {
+               be_Keep_add_node(keep, &ia32_reg_classes[CLASS_ia32_gp], val);
+       }
+
+       be_peephole_before_exchange(node, stack);
+       sched_remove(node);
+       exchange(node, stack);
+       be_peephole_after_exchange(stack);
+}
+
+/**
+ * Peephole optimisation for ia32_Const's
+ */
+static void peephole_ia32_Const(ir_node *node)
 {
        const ia32_immediate_attr_t *attr = get_ia32_immediate_attr_const(node);
        const arch_register_t       *reg;
@@ -293,10 +556,10 @@ static ir_node *optimize_ia32_Const(ir_node *node)
 
        /* try to transform a mov 0, reg to xor reg reg */
        if(attr->offset != 0 || attr->symconst != NULL)
-               return NULL;
-       /* xor destroys the flags, so noone must be using them */
+               return;
+       /* xor destroys the flags, so no-one must be using them */
        if(be_peephole_get_value(CLASS_ia32_flags, REG_EFLAGS) != NULL)
-               return NULL;
+               return;
 
        reg = arch_get_irn_register(arch_env, node);
        assert(be_peephole_get_reg_value(reg) == NULL);
@@ -314,29 +577,246 @@ static ir_node *optimize_ia32_Const(ir_node *node)
 
        sched_add_before(node, produceval);
        sched_add_before(node, xor);
+
+       be_peephole_before_exchange(node, xor);
        exchange(node, xor);
        sched_remove(node);
+       be_peephole_after_exchange(xor);
+}
 
-       return xor;
+static INLINE int is_noreg(ia32_code_gen_t *cg, const ir_node *node)
+{
+       return node == cg->noreg_gp;
 }
 
-static void register_peephole_optimisation(ir_op *op, peephole_opt_func func)
+static ir_node *create_immediate_from_int(ia32_code_gen_t *cg, int val)
 {
+       ir_graph *irg         = current_ir_graph;
+       ir_node  *start_block = get_irg_start_block(irg);
+       ir_node  *immediate   = new_rd_ia32_Immediate(NULL, irg, start_block, NULL,
+                                                     0, val);
+       arch_set_irn_register(cg->arch_env, immediate, &ia32_gp_regs[REG_GP_NOREG]);
+
+       return immediate;
+}
+
+static ir_node *create_immediate_from_am(ia32_code_gen_t *cg,
+                                         const ir_node *node)
+{
+       ir_graph  *irg     = get_irn_irg(node);
+       ir_node   *block   = get_nodes_block(node);
+       int        offset  = get_ia32_am_offs_int(node);
+       int        sc_sign = is_ia32_am_sc_sign(node);
+       ir_entity *entity  = get_ia32_am_sc(node);
+       ir_node   *res;
+
+       res = new_rd_ia32_Immediate(NULL, irg, block, entity, sc_sign, offset);
+       arch_set_irn_register(cg->arch_env, res, &ia32_gp_regs[REG_GP_NOREG]);
+       return res;
+}
+
+static int is_am_one(const ir_node *node)
+{
+       int        offset  = get_ia32_am_offs_int(node);
+       ir_entity *entity  = get_ia32_am_sc(node);
+
+       return offset == 1 && entity == NULL;
+}
+
+static int is_am_minus_one(const ir_node *node)
+{
+       int        offset  = get_ia32_am_offs_int(node);
+       ir_entity *entity  = get_ia32_am_sc(node);
+
+       return offset == -1 && entity == NULL;
+}
+
+/**
+ * Transforms a LEA into an Add or SHL if possible.
+ */
+static void peephole_ia32_Lea(ir_node *node)
+{
+       const arch_env_t      *arch_env = cg->arch_env;
+       ir_graph              *irg      = current_ir_graph;
+       ir_node               *base;
+       ir_node               *index;
+       const arch_register_t *base_reg;
+       const arch_register_t *index_reg;
+       const arch_register_t *out_reg;
+       int                    scale;
+       int                    has_immediates;
+       ir_node               *op1;
+       ir_node               *op2;
+       dbg_info              *dbgi;
+       ir_node               *block;
+       ir_node               *res;
+       ir_node               *noreg;
+       ir_node               *nomem;
+
+       assert(is_ia32_Lea(node));
+
+       /* we can only do this if are allowed to globber the flags */
+       if(be_peephole_get_value(CLASS_ia32_flags, REG_EFLAGS) != NULL)
+               return;
+
+       base  = get_irn_n(node, n_ia32_Lea_base);
+       index = get_irn_n(node, n_ia32_Lea_index);
+
+       if(is_noreg(cg, base)) {
+               base     = NULL;
+               base_reg = NULL;
+       } else {
+               base_reg = arch_get_irn_register(arch_env, base);
+       }
+       if(is_noreg(cg, index)) {
+               index     = NULL;
+               index_reg = NULL;
+       } else {
+               index_reg = arch_get_irn_register(arch_env, index);
+       }
+
+       if(base == NULL && index == NULL) {
+               /* we shouldn't construct these in the first place... */
+#ifdef DEBUG_libfirm
+               ir_fprintf(stderr, "Optimisation warning: found immediate only lea\n");
+#endif
+               return;
+       }
+
+       out_reg = arch_get_irn_register(arch_env, node);
+       scale   = get_ia32_am_scale(node);
+       assert(!is_ia32_need_stackent(node) || get_ia32_frame_ent(node) != NULL);
+       /* check if we have immediates values (frame entities should already be
+        * expressed in the offsets) */
+       if(get_ia32_am_offs_int(node) != 0 || get_ia32_am_sc(node) != NULL) {
+               has_immediates = 1;
+       } else {
+               has_immediates = 0;
+       }
+
+       /* we can transform leas where the out register is the same as either the
+        * base or index register back to an Add or Shl */
+       if(out_reg == base_reg) {
+               if(index == NULL) {
+#ifdef DEBUG_libfirm
+                       if(!has_immediates) {
+                               ir_fprintf(stderr, "Optimisation warning: found lea which is "
+                                          "just a copy\n");
+                       }
+#endif
+                       op1 = base;
+                       goto make_add_immediate;
+               }
+               if(scale == 0 && !has_immediates) {
+                       op1 = base;
+                       op2 = index;
+                       goto make_add;
+               }
+               /* can't create an add */
+               return;
+       } else if(out_reg == index_reg) {
+               if(base == NULL) {
+                       if(has_immediates && scale == 0) {
+                               op1 = index;
+                               goto make_add_immediate;
+                       } else if(!has_immediates && scale > 0) {
+                               op1 = index;
+                               op2 = create_immediate_from_int(cg, scale);
+                               goto make_shl;
+                       } else if(!has_immediates) {
+#ifdef DEBUG_libfirm
+                               ir_fprintf(stderr, "Optimisation warning: found lea which is "
+                                          "just a copy\n");
+#endif
+                       }
+               } else if(scale == 0 && !has_immediates) {
+                       op1 = index;
+                       op2 = base;
+                       goto make_add;
+               }
+               /* can't create an add */
+               return;
+       } else {
+               /* can't create an add */
+               return;
+       }
+
+make_add_immediate:
+       if(ia32_cg_config.use_incdec) {
+               if(is_am_one(node)) {
+                       dbgi  = get_irn_dbg_info(node);
+                       block = get_nodes_block(node);
+                       res   = new_rd_ia32_Inc(dbgi, irg, block, op1);
+                       arch_set_irn_register(arch_env, res, out_reg);
+                       goto exchange;
+               }
+               if(is_am_minus_one(node)) {
+                       dbgi  = get_irn_dbg_info(node);
+                       block = get_nodes_block(node);
+                       res   = new_rd_ia32_Dec(dbgi, irg, block, op1);
+                       arch_set_irn_register(arch_env, res, out_reg);
+                       goto exchange;
+               }
+       }
+       op2 = create_immediate_from_am(cg, node);
+
+make_add:
+       dbgi  = get_irn_dbg_info(node);
+       block = get_nodes_block(node);
+       noreg = ia32_new_NoReg_gp(cg);
+       nomem = new_NoMem();
+       res   = new_rd_ia32_Add(dbgi, irg, block, noreg, noreg, nomem, op1, op2);
+       arch_set_irn_register(arch_env, res, out_reg);
+       set_ia32_commutative(res);
+       goto exchange;
+
+make_shl:
+       dbgi  = get_irn_dbg_info(node);
+       block = get_nodes_block(node);
+       noreg = ia32_new_NoReg_gp(cg);
+       nomem = new_NoMem();
+       res   = new_rd_ia32_Shl(dbgi, irg, block, op1, op2);
+       arch_set_irn_register(arch_env, res, out_reg);
+       goto exchange;
+
+exchange:
+       SET_IA32_ORIG_NODE(res, ia32_get_old_node_name(cg, node));
+
+       /* add new ADD/SHL to schedule */
+       DBG_OPT_LEA2ADD(node, res);
+
+       /* exchange the Add and the LEA */
+       be_peephole_before_exchange(node, res);
+       sched_add_before(node, res);
+       sched_remove(node);
+       exchange(node, res);
+       be_peephole_after_exchange(res);
+}
+
+/**
+ * Register a peephole optimisation function.
+ */
+static void register_peephole_optimisation(ir_op *op, peephole_opt_func func) {
        assert(op->ops.generic == NULL);
        op->ops.generic = (void*) func;
 }
 
-void ia32_peephole_optimization(ir_graph *irg, ia32_code_gen_t *new_cg)
+/* Perform peephole-optimizations. */
+void ia32_peephole_optimization(ia32_code_gen_t *new_cg)
 {
        cg       = new_cg;
        arch_env = cg->arch_env;
 
        /* register peephole optimisations */
        clear_irp_opcodes_generic_func();
-       register_peephole_optimisation(op_ia32_Const, optimize_ia32_Const);
+       register_peephole_optimisation(op_ia32_Const, peephole_ia32_Const);
+       //register_peephole_optimisation(op_ia32_Store, peephole_ia32_Store);
+       register_peephole_optimisation(op_be_IncSP, peephole_be_IncSP);
+       register_peephole_optimisation(op_ia32_Lea, peephole_ia32_Lea);
+       register_peephole_optimisation(op_ia32_Test, peephole_ia32_Test);
+       register_peephole_optimisation(op_ia32_Test8Bit, peephole_ia32_Test);
 
        be_peephole_opt(cg->birg);
-       irg_walk_graph(irg, ia32_peephole_optimize_node, NULL, NULL);
 }
 
 /**
@@ -367,15 +847,24 @@ static INLINE void try_kill(ir_node *node)
 static void optimize_conv_store(ir_node *node)
 {
        ir_node *pred;
+       ir_node *pred_proj;
        ir_mode *conv_mode;
        ir_mode *store_mode;
 
        if(!is_ia32_Store(node) && !is_ia32_Store8Bit(node))
                return;
 
-       pred = get_irn_n(node, 2);
+       assert(n_ia32_Store_val == n_ia32_Store8Bit_val);
+       pred_proj = get_irn_n(node, n_ia32_Store_val);
+       if(is_Proj(pred_proj)) {
+               pred = get_Proj_pred(pred_proj);
+       } else {
+               pred = pred_proj;
+       }
        if(!is_ia32_Conv_I2I(pred) && !is_ia32_Conv_I2I8Bit(pred))
                return;
+       if(get_ia32_op_type(pred) != ia32_Normal)
+               return;
 
        /* the store only stores the lower bits, so we only need the conv
         * it it shrinks the mode */
@@ -384,9 +873,11 @@ static void optimize_conv_store(ir_node *node)
        if(get_mode_size_bits(conv_mode) < get_mode_size_bits(store_mode))
                return;
 
-       set_irn_n(node, 2, get_irn_n(pred, 2));
-       if(get_irn_n_edges(pred) == 0) {
-               be_kill_node(pred);
+       set_irn_n(node, n_ia32_Store_val, get_irn_n(pred, n_ia32_Conv_I2I_val));
+       if(get_irn_n_edges(pred_proj) == 0) {
+               be_kill_node(pred_proj);
+               if(pred != pred_proj)
+                       be_kill_node(pred);
        }
 }
 
@@ -399,7 +890,8 @@ static void optimize_load_conv(ir_node *node)
        if (!is_ia32_Conv_I2I(node) && !is_ia32_Conv_I2I8Bit(node))
                return;
 
-       pred = get_irn_n(node, 2);
+       assert(n_ia32_Conv_I2I_val == n_ia32_Conv_I2I8Bit_val);
+       pred = get_irn_n(node, n_ia32_Conv_I2I_val);
        if(!is_Proj(pred))
                return;
 
@@ -439,6 +931,8 @@ static void optimize_conv_conv(ir_node *node)
 {
        ir_node *pred_proj, *pred, *result_conv;
        ir_mode *pred_mode, *conv_mode;
+       int      conv_mode_bits;
+       int      pred_mode_bits;
 
        if (!is_ia32_Conv_I2I(node) && !is_ia32_Conv_I2I8Bit(node))
                return;
@@ -455,11 +949,17 @@ static void optimize_conv_conv(ir_node *node)
 
        /* we know that after a conv, the upper bits are sign extended
         * so we only need the 2nd conv if it shrinks the mode */
-       conv_mode = get_ia32_ls_mode(node);
-       pred_mode = get_ia32_ls_mode(pred);
-       /* if 2nd conv is smaller then first conv, then we can always take the 2nd
-        * conv */
-       if(get_mode_size_bits(conv_mode) <= get_mode_size_bits(pred_mode)) {
+       conv_mode      = get_ia32_ls_mode(node);
+       conv_mode_bits = get_mode_size_bits(conv_mode);
+       pred_mode      = get_ia32_ls_mode(pred);
+       pred_mode_bits = get_mode_size_bits(pred_mode);
+
+       if(conv_mode_bits == pred_mode_bits
+                       && get_mode_sign(conv_mode) == get_mode_sign(pred_mode)) {
+               result_conv = pred_proj;
+       } else if(conv_mode_bits <= pred_mode_bits) {
+               /* if 2nd conv is smaller then first conv, then we can always take the
+                * 2nd conv */
                if(get_irn_n_edges(pred_proj) == 1) {
                        result_conv = pred_proj;
                        set_ia32_ls_mode(pred, conv_mode);
@@ -470,8 +970,7 @@ static void optimize_conv_conv(ir_node *node)
                                set_ia32_in_req_all(pred, get_ia32_in_req_all(node));
                        }
                } else {
-                       /* TODO: construct syncs/stuff here but we'll probably end up with
-                        * 2 statements anyway */
+                       /* we don't want to end up with 2 loads, so we better do nothing */
                        if(get_irn_mode(pred) == mode_T) {
                                return;
                        }
@@ -502,8 +1001,10 @@ static void optimize_conv_conv(ir_node *node)
        /* kill the conv */
        exchange(node, result_conv);
 
-       if(get_irn_n_edges(pred) == 0) {
-               be_kill_node(pred);
+       if(get_irn_n_edges(pred_proj) == 0) {
+               be_kill_node(pred_proj);
+               if(pred != pred_proj)
+                       be_kill_node(pred);
        }
        optimize_conv_conv(result_conv);
 }