Merge pull request #651 from JoostK/patch-1

[mono.git] / mono / mini / ssa.c

diff --git a/mono/mini/ssa.c b/mono/mini/ssa.c
index df6d69ff167bdbec702ad6404a5444b8a40c3f8a..d58d814e11fb0685d48c275cc497a968b8ab034a 100644 (file)
--- a/mono/mini/ssa.c
+++ b/mono/mini/ssa.c
@@ -5,6 +5,7 @@
  *    Dietmar Maurer (dietmar@ximian.com)
  *
  * (C) 2003 Ximian, Inc.
+ * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
  */
 #include <config.h>
 #include <string.h>
@@ -268,7 +269,7 @@ mono_ssa_rename_vars (MonoCompile *cfg, int max_vars, MonoBasicBlock *bb, gboole
                        }
                        else if (G_UNLIKELY (!var && lvreg_defined [ins->dreg] && (ins->dreg >= MONO_MAX_IREGS))) {
                                /* Perform renaming for local vregs */
-                               lvreg_stack [ins->dreg] = mono_alloc_preg (cfg);
+                               lvreg_stack [ins->dreg] = vreg_is_ref (cfg, ins->dreg) ? mono_alloc_ireg_ref (cfg) : mono_alloc_preg (cfg);
                                ins->dreg = lvreg_stack [ins->dreg];
                        }
                        else
@@ -340,8 +341,6 @@ mono_ssa_compute (MonoCompile *cfg)
 
        g_assert (!(cfg->comp_done & MONO_COMP_SSA));
 
-       /* we dont support methods containing exception clauses */
-       g_assert (mono_method_get_header (cfg->method)->num_clauses == 0);
        g_assert (!cfg->disable_ssa);
 
        if (cfg->verbose_level >= 4)
@@ -485,7 +484,7 @@ void
 mono_ssa_remove (MonoCompile *cfg)
 {
        MonoInst *ins, *var, *move;
-       int i, j, first;
+       int bbindex, i, j, first;
 
        g_assert (cfg->comp_done & MONO_COMP_SSA);
 
@@ -553,12 +552,12 @@ mono_ssa_remove (MonoCompile *cfg)
         * can coalesce them into the original variable.
         */
 
-       for (i = 0; i < cfg->num_bblocks; ++i) {
-               MonoBasicBlock *bb = cfg->bblocks [i];
+       for (bbindex = 0; bbindex < cfg->num_bblocks; ++bbindex) {
+               MonoBasicBlock *bb = cfg->bblocks [bbindex];
 
                for (ins = bb->code; ins; ins = ins->next) {
                        const char *spec = INS_INFO (ins->opcode);
-                       int num_sregs, j;
+                       int num_sregs;
                        int sregs [MONO_MAX_SRC_REGS];
 
                        if (ins->opcode == OP_NOP)
@@ -582,7 +581,7 @@ mono_ssa_remove (MonoCompile *cfg)
                        }
 
                        num_sregs = mono_inst_get_src_registers (ins, sregs);
-                       for (j = 0; j < num_sregs; ++j) {
+                       for (i = 0; i < num_sregs; ++i) {
                                MonoInst *var = get_vreg_to_inst (cfg, sregs [i]);
 
                                if (var) {
@@ -685,7 +684,6 @@ mono_ssa_copyprop (MonoCompile *cfg)
                                /* Rewrite all uses of var to be uses of var2 */
                                int dreg = var->dreg;
                                int sreg1 = var2->dreg;
-                               const char *spec;
 
                                l = info->uses;
                                while (l) {
@@ -695,8 +693,6 @@ mono_ssa_copyprop (MonoCompile *cfg)
                                        int num_sregs;
                                        int sregs [MONO_MAX_SRC_REGS];
 
-                                       spec = INS_INFO (ins->opcode);
-
                                        num_sregs = mono_inst_get_src_registers (ins, sregs);
                                        for (i = 0; i < num_sregs; ++i) {
                                                if (sregs [i] == dreg)
@@ -1109,7 +1105,7 @@ fold_ins (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *ins, MonoInst **carray
 
                                /* Unlink target bblocks */
                                for (i = 0; i < table->table_size; ++i) {
-                                       if (i != idx) {
+                                       if (table->table [i] != table->table [idx]) {
                                                remove_bb_from_phis (cfg, bb, table->table [i]);
                                                mono_unlink_bblock (cfg, bb, table->table [i]);
                                        }
@@ -1168,6 +1164,15 @@ mono_ssa_cprop (MonoCompile *cfg)
                        info->cpstate = 2;
        }
 
+       for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
+               /*
+                * FIXME: This should be bb->flags & BB_FLAG_EXCEPTION_HANDLER, but
+                * that would still allow unreachable try's to be removed.
+                */
+               if (bb->region)
+                       add_cprop_bb (cfg, bb, &bblock_list);
+       }
+
        cvars = NULL;
 
        while (bblock_list) {
@@ -1179,11 +1184,13 @@ mono_ssa_cprop (MonoCompile *cfg)
 
                g_assert (bb->flags &  BB_REACHABLE);
 
-               if (bb->out_count == 1) {
-                       if (!(bb->out_bb [0]->flags &  BB_REACHABLE)) {
-                               bb->out_bb [0]->flags |= BB_REACHABLE;
-                               bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
-                       }
+               /* 
+                * Some bblocks are linked to 2 others even through they fall through to the
+                * next bblock.
+                */
+               if (!(bb->last_ins && MONO_IS_BRANCH_OP (bb->last_ins))) {
+                       for (i = 0; i < bb->out_count; ++i)
+                               add_cprop_bb (cfg, bb->out_bb [i], &bblock_list);
                }
 
                if (cfg->verbose_level > 1)