777-arm.diff

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index fa4e083..8327265 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -73,6 +73,9 @@
 #include "builtins.h"
 #include "tm-constrs.h"
 #include "rtl-iter.h"
+#include "tree-pass.h"
+#include "context.h"
+#include <set>

 /* This file should be included last.  */
 #include "target-def.h"
@@ -3397,6 +3400,20 @@ arm_option_override (void)

   /* Init initial mode for testing.  */
   thumb_flipper = TARGET_THUMB;
+
+  /* Registering the pass must be done at start up.  It's
+     convenient to do it here.  */
+
+  rtl_opt_pass *make_pass_rtl_remove_temps (gcc::context *);
+  opt_pass *new_pass = make_pass_rtl_remove_temps (g);
+  struct register_pass_info insert_pass_rtl_remove_temps =
+    {
+      new_pass,            /* pass */
+      "combine",       /* reference_pass_name */
+      1,           /* ref_pass_instance_number */
+      PASS_POS_INSERT_BEFORE   /* po_op */
+    };
+  register_pass (&insert_pass_rtl_remove_temps);
 }

 static void
@@ -29781,4 +29798,181 @@ arm_sched_fusion_priority (rtx_insn *insn, int max_pri,
   *pri = tmp;
   return;
 }
+
+std::set<int> seen_regs;
+
+static rtx_insn *
+get_def_insn (rtx_insn *insn, rtx reg)
+{
+  df_ref use;
+  struct df_link *ref_chain, *ref_link;
+
+  use = df_find_use (insn, reg);
+  gcc_assert (use != NULL);
+  ref_chain = DF_REF_CHAIN (use);
+
+  // ??? Punt if a use has multiple defs
+  if (ref_chain->next)
+    return NULL;
+
+  if (ref_chain->ref == NULL || DF_REF_INSN_INFO (ref_chain->ref) == NULL)
+    return NULL;
+
+  return DF_REF_INSN (ref_chain->ref);
+}
+
+static bool
+def_candidate_p (rtx expr)
+{
+  if (GET_CODE (expr) != AND)
+    return false;
+
+  if (GET_MODE (expr) != SImode)
+    return false;
+
+  rtx op0 = XEXP (expr, 0);
+  rtx op1 = XEXP (expr, 1);
+
+  if (!REG_P (op0) || GET_MODE (op0) != SImode)
+    return false;
+
+  if (GET_CODE (op1) != CONST_INT)
+    return false;
+
+  return true;
+}
+
+static void
+do_remove_temp (rtx_insn *insn)
+{
+  rtx exp = PATTERN (insn);
+
+  if (GET_CODE (exp) != SET)
+    return;
+  exp = XEXP (exp, 1);
+  if (GET_CODE (exp) != COMPARE)
+    return;
+  if (GET_MODE (exp) != CCmode)
+    return;
+
+  rtx compare_expr = exp;
+  rtx op0 = XEXP (exp, 0);
+  if (!REG_P (op0))
+    return;
+
+  if (GET_MODE (op0) != SImode)
+    return;
+
+  rtx op1 = XEXP (exp, 1);
+  if (GET_CODE (op1) != CONST_INT || INTVAL (op1) != 0)
+    return;
+
+  rtx_insn *def_insn = get_def_insn (insn, op0);
+  if (def_insn == NULL)
+    return;
+
+  rtx pat = PATTERN (def_insn);
+  if (!def_candidate_p (XEXP (pat, 1)))
+    return;
+
+  rtx result_reg = XEXP (pat, 0);
+  if (!REG_P (result_reg) || GET_MODE (result_reg) != SImode)
+    return;
+
+  gcc_assert (REG_P (result_reg));
+  std::pair< std::set<int>::iterator, bool > ret = seen_regs.insert (REGNO (result_reg));
+  if (ret.second == true)
+    return;
+
+  rtx reg = gen_reg_rtx (SImode);
+  rtx_insn *x = emit_insn_before (copy_rtx (pat), insn);
+  recog_memoized (x);
+}
+
+static void
+rtl_remove_temps_init()
+{
+  df_set_flags (DF_RD_PRUNE_DEAD_DEFS);
+  df_chain_add_problem (DF_UD_CHAIN);
+  df_analyze ();
+  df_set_flags (DF_DEFER_INSN_RESCAN);
+}
+
+static unsigned int
+execute_rtl_remove_temps (void)
+{
+
+  rtx_insn *insn, *last, *first;
+
+  for (insn = first = get_insns (), last = get_last_insn (); insn != last; insn = NEXT_INSN (insn))
+    {
+      if (!INSN_P (insn))
+   continue;
+
+      rtx pat = PATTERN (insn);
+      /* ??? set and use of register cannot happen in PARALLEL */
+      if (GET_CODE (pat) == PARALLEL)
+   continue;
+      else if (GET_CODE (pat) == SEQUENCE)
+   {
+     push_topmost_sequence ();
+     execute_rtl_remove_temps ();
+     pop_topmost_sequence ();
+   }
+      else
+   do_remove_temp (insn);
+    }
+
+  return 0;
+}
+
+namespace {
+
+const pass_data pass_data_rtl_remove_temps =
+{
+  RTL_PASS, /* type */
+  "remove-temps", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  TV_NONE,
+  PROP_cfglayout, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  TODO_df_finish, /* todo_flags_finish */
+};
+
+class pass_rtl_remove_temps : public rtl_opt_pass
+{
+public:
+  pass_rtl_remove_temps (gcc::context *ctxt)
+    : rtl_opt_pass (pass_data_rtl_remove_temps, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  virtual bool gate (function *);
+  virtual unsigned int execute (function *);
+
+}; // class pass_rtl_remove_temps
+
+bool
+pass_rtl_remove_temps::gate (function *)
+{
+  return flag_rtl_remove_temps != 0 && optimize > 0;
+}
+
+} // anon namespace
+
+unsigned int
+pass_rtl_remove_temps::execute (function *)
+{
+  rtl_remove_temps_init ();
+  return execute_rtl_remove_temps ();
+}
+
+rtl_opt_pass *
+make_pass_rtl_remove_temps (gcc::context *ctxt)
+{
+  return new pass_rtl_remove_temps (ctxt);
+}
+
 #include "gt-arm.h"