Makefile.in (stupid.o): Update dependencies.

	* Makefile.in (stupid.o): Update dependencies.
	(global.o): Likewise.
	* global.c: Include reload.h
	(reg_becomes_live): New function.
	(reg_dies): New function.
	(build_insn_chain): New function.
	(global_alloc): Call build_insn_chain before calling reload.
	* reload.h (struct needs): New structure definition.
	(struct insn_chain): Likewise.
	(reload_insn_chain): Declare variable.
	(new_insn_chain): Declare function.
	* reload1.c (reload_startobj): New variable.
	(reload_insn_chain): New variable.
	(unused_insn_chains): New variable.
	(new_insn_chain): New function.
	(init_reload): Initialize reload_startobj, not reload_firstobj.
	(reload): Initialize reload_firstobj.
	Before returning, free everything on the reload_obstack.
	* stupid.c: Include insn-config.h, reload.h and basic-block.h.
	(reg_where_dead_chain, reg_where_born_exact, reg_where_born_clobber,
	current_chain): New variables.
	(reg_where_born): Delete variable.
	(REG_WHERE_BORN): New macro.
	(find_clobbered_regs): New function.
	(stupid_life_analysis): Don't allocate/free reg_where_born.
	Allocate and free reg_where_born_exact, reg_where_born_clobber,
	reg_where_dead_chain.
	Use REG_WHERE_BORN instead of reg_where_born.
	While processing the insns, build the reload_insn_chain with
	information about register lifetimes.
	(stupid_reg_compare): Use REG_WHERE_BORN instead of reg_where_born.
	(stupid_mark_refs): Replace arg INSN with arg CHAIN.  All callers
	changed.
	Compute and information about birth and death of pseudo registers in
	reg_where_dead_chain, reg_where_born_exact and reg_where_born_clobber.
	Delete code to set elements of reg_where_born.

From-SVN: r22862

1 files changed, 137 insertions, 1 deletions

diff --git a/gcc/global.c b/gcc/global.c
index e7edb6d36ac..04a836c0003 100644
--- a/gcc/global.c
+++ b/gcc/global.c
@@ -29,6 +29,7 @@ Boston, MA 02111-1307, USA.  */
 #include "basic-block.h"
 #include "regs.h"
 #include "insn-config.h"
+#include "reload.h"
 #include "output.h"
 #include "toplev.h"
 
@@ -268,6 +269,9 @@ static void mark_reg_death	PROTO((rtx));
 static void mark_reg_live_nc	PROTO((int, enum machine_mode));
 static void set_preference	PROTO((rtx, rtx));
 static void dump_conflicts	PROTO((FILE *));
+static void reg_becomes_live	PROTO((rtx, rtx));
+static void reg_dies		PROTO((int, enum machine_mode));
+static void build_insn_chain	PROTO((rtx));
 
 /* Perform allocation of pseudo-registers not allocated by local_alloc.
    FILE is a file to output debugging information on,
@@ -573,7 +577,10 @@ global_alloc (file)
 	 for the sake of debugging information.  */
   if (n_basic_blocks > 0)
 #endif
-    retval = reload (get_insns (), 1, file);
+    {
+      build_insn_chain (get_insns ());
+      retval = reload (get_insns (), 1, file);
+    }
 
   free (conflicts);
   return retval;
@@ -1648,6 +1655,135 @@ mark_elimination (from, to)
       }
 }
 
+/* Used for communication between the following functions.  Holds the
+   current life information.  */
+static regset live_relevant_regs;
+
+/* Record in live_relevant_regs that register REG became live.  This
+   is called via note_stores.  */
+static void
+reg_becomes_live (reg, setter)
+     rtx reg;
+     rtx setter ATTRIBUTE_UNUSED;
+{
+  int regno;
+
+  if (GET_CODE (reg) == SUBREG)
+    reg = SUBREG_REG (reg);
+
+  if (GET_CODE (reg) != REG)
+    return;
+  
+  regno = REGNO (reg);
+  if (regno < FIRST_PSEUDO_REGISTER)
+    {
+      int nregs = HARD_REGNO_NREGS (regno, GET_MODE (reg));
+      while (nregs-- > 0)
+	SET_REGNO_REG_SET (live_relevant_regs, regno++);
+    }
+  else if (reg_renumber[regno] >= 0)
+    SET_REGNO_REG_SET (live_relevant_regs, regno);
+}
+
+/* Record in live_relevant_regs that register REGNO died.  */
+static void
+reg_dies (regno, mode)
+     int regno;
+     enum machine_mode mode;
+{
+  if (regno < FIRST_PSEUDO_REGISTER)
+    {
+      int nregs = HARD_REGNO_NREGS (regno, mode);
+      while (nregs-- > 0)
+	CLEAR_REGNO_REG_SET (live_relevant_regs, regno++);
+    }
+  else
+    CLEAR_REGNO_REG_SET (live_relevant_regs, regno);
+}
+
+/* Walk the insns of the current function and build reload_insn_chain,
+   and record register life information.  */
+static void
+build_insn_chain (first)
+     rtx first;
+{
+  struct insn_chain **p = &reload_insn_chain;
+  struct insn_chain *prev = 0;
+  int b = 0;
+
+  live_relevant_regs = ALLOCA_REG_SET ();
+
+  for (; first; first = NEXT_INSN (first))
+    {
+      struct insn_chain *c;
+
+      if (first == basic_block_head[b])
+	{
+	  int i;
+	  CLEAR_REG_SET (live_relevant_regs);
+	  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+	    if (REGNO_REG_SET_P (basic_block_live_at_start[b], i)
+		&& ! TEST_HARD_REG_BIT (eliminable_regset, i))
+	      SET_REGNO_REG_SET (live_relevant_regs, i);
+
+	  for (; i < max_regno; i++)
+	    if (reg_renumber[i] >= 0
+		&& REGNO_REG_SET_P (basic_block_live_at_start[b], i))
+	      SET_REGNO_REG_SET (live_relevant_regs, i);
+	}
+
+      if (GET_CODE (first) != NOTE && GET_CODE (first) != BARRIER)
+	{
+	  c = new_insn_chain ();
+	  c->prev = prev;
+	  prev = c;
+	  *p = c;
+	  p = &c->next;
+	  c->insn = first;
+	  c->block = b;
+
+	  COPY_REG_SET (c->live_before, live_relevant_regs);
+
+	  if (GET_RTX_CLASS (GET_CODE (first)) == 'i')
+	    {
+	      rtx link;
+
+	      /* Mark the death of everything that dies in this instruction.  */
+
+	      for (link = REG_NOTES (first); link; link = XEXP (link, 1))
+		if (REG_NOTE_KIND (link) == REG_DEAD
+		    && GET_CODE (XEXP (link, 0)) == REG)
+		  reg_dies (REGNO (XEXP (link, 0)), GET_MODE (XEXP (link, 0)));
+
+	      /* Mark everything born in this instruction as live.  */
+
+	      note_stores (PATTERN (first), reg_becomes_live);
+	    }
+
+	  /* Remember which registers are live at the end of the insn, before
+	     killing those with REG_UNUSED notes.  */
+	  COPY_REG_SET (c->live_after, live_relevant_regs);
+
+	  if (GET_RTX_CLASS (GET_CODE (first)) == 'i')
+	    {
+	      rtx link;
+
+	      /* Mark anything that is set in this insn and then unused as dying.  */
+
+	      for (link = REG_NOTES (first); link; link = XEXP (link, 1))
+		if (REG_NOTE_KIND (link) == REG_UNUSED
+		    && GET_CODE (XEXP (link, 0)) == REG)
+		  reg_dies (REGNO (XEXP (link, 0)), GET_MODE (XEXP (link, 0)));
+	    }
+	}
+
+      if (first == basic_block_end[b])
+	b++;
+    }
+  FREE_REG_SET (live_relevant_regs);
+  *p = 0;
+}
+
 /* Print debugging trace information if -greg switch is given,
    showing the information on which the allocation decisions are based.  */