Improve alias analysis for ia64

From-SVN: r38660

3 files changed, 78 insertions, 26 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 900ee74..669c9e1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -16,6 +16,12 @@ Wed Jan  3 08:53:50 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 	* cse.c (cse_rtx_varies_p): Accept additional FROM_ALIAS arg.  All
 	callers changed.
 
+	* alias.c (throughout): Use ORIGINAL_REGNO when accessing
+	reg_base_value and reg_known_value arrays.
+	(init_alias_analysis): Add more cases to detect known values.
+	* sched-deps.c (deps_may_trap_p): New function.
+	(sched_analyze_2): Use it.
+
 2001-01-03  Alexandre Oliva  <aoliva@redhat.com>
 
 	* combine.c (simplify_shift_const): Even if we're sign-extracting,
diff --git a/gcc/alias.c b/gcc/alias.c
index be29fc2..4f9eef3 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -148,7 +148,8 @@ static rtx *new_reg_base_value;
 static unsigned int reg_base_value_size; /* size of reg_base_value array */
 
 #define REG_BASE_VALUE(X) \
-  (REGNO (X) < reg_base_value_size ? reg_base_value[REGNO (X)] : 0)
+  (ORIGINAL_REGNO (X) < reg_base_value_size \
+   ? reg_base_value[ORIGINAL_REGNO (X)] : 0)
 
 /* Vector of known invariant relationships between registers.  Set in
    loop unrolling.  Indexed by register number, if nonzero the value
@@ -659,6 +660,7 @@ static rtx
 find_base_value (src)
      register rtx src;
 {
+  unsigned int regno;
   switch (GET_CODE (src))
     {
     case SYMBOL_REF:
@@ -666,12 +668,13 @@ find_base_value (src)
       return src;
 
     case REG:
+      regno = ORIGINAL_REGNO (src);
       /* At the start of a function, argument registers have known base
 	 values which may be lost later.  Returning an ADDRESS
 	 expression here allows optimization based on argument values
 	 even when the argument registers are used for other purposes.  */
-      if (REGNO (src) < FIRST_PSEUDO_REGISTER && copying_arguments)
-	return new_reg_base_value[REGNO (src)];
+      if (regno < FIRST_PSEUDO_REGISTER && copying_arguments)
+	return new_reg_base_value[regno];
 
       /* If a pseudo has a known base value, return it.  Do not do this
 	 for hard regs since it can result in a circular dependency
@@ -679,10 +682,10 @@ find_base_value (src)
 
 	 The test above is not sufficient because the scheduler may move
 	 a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN.  */
-      if (REGNO (src) >= FIRST_PSEUDO_REGISTER
-	  && (unsigned) REGNO (src) < reg_base_value_size
-	  && reg_base_value[REGNO (src)])
-	return reg_base_value[REGNO (src)];
+      if (regno >= FIRST_PSEUDO_REGISTER
+	  && regno < reg_base_value_size
+	  && reg_base_value[regno])
+	return reg_base_value[regno];
 
       return src;
 
@@ -789,7 +792,7 @@ record_set (dest, set, data)
   if (GET_CODE (dest) != REG)
     return;
 
-  regno = REGNO (dest);
+  regno = ORIGINAL_REGNO (dest);
 
   if (regno >= reg_base_value_size)
     abort ();
@@ -870,8 +873,8 @@ record_base_value (regno, val, invariant)
 
   if (GET_CODE (val) == REG)
     {
-      if (REGNO (val) < reg_base_value_size)
-	reg_base_value[regno] = reg_base_value[REGNO (val)];
+      if (ORIGINAL_REGNO (val) < reg_base_value_size)
+	reg_base_value[regno] = reg_base_value[ORIGINAL_REGNO (val)];
 
       return;
     }
@@ -889,10 +892,10 @@ canon_rtx (x)
      rtx x;
 {
   /* Recursively look for equivalences.  */
-  if (GET_CODE (x) == REG && REGNO (x) >= FIRST_PSEUDO_REGISTER
-      && REGNO (x) < reg_known_value_size)
-    return reg_known_value[REGNO (x)] == x
-      ? x : canon_rtx (reg_known_value[REGNO (x)]);
+  if (GET_CODE (x) == REG && ORIGINAL_REGNO (x) >= FIRST_PSEUDO_REGISTER
+      && ORIGINAL_REGNO (x) < reg_known_value_size)
+    return reg_known_value[ORIGINAL_REGNO (x)] == x
+      ? x : canon_rtx (reg_known_value[ORIGINAL_REGNO (x)]);
   else if (GET_CODE (x) == PLUS)
     {
       rtx x0 = canon_rtx (XEXP (x, 0));
@@ -2208,17 +2211,42 @@ init_alias_analysis ()
 
 	      if (set != 0
 		  && GET_CODE (SET_DEST (set)) == REG
-		  && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER
-		  && REG_NOTES (insn) != 0
-		  && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
-		       && REG_N_SETS (REGNO (SET_DEST (set))) == 1)
-		      || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
-		  && GET_CODE (XEXP (note, 0)) != EXPR_LIST
-		  && ! reg_overlap_mentioned_p (SET_DEST (set), XEXP (note, 0)))
+		  && ORIGINAL_REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER)
 		{
-		  int regno = REGNO (SET_DEST (set));
-		  reg_known_value[regno] = XEXP (note, 0);
-		  reg_known_equiv_p[regno] = REG_NOTE_KIND (note) == REG_EQUIV;
+		  unsigned int regno = ORIGINAL_REGNO (SET_DEST (set));
+		  rtx src = SET_SRC (set);
+
+		  if (REG_NOTES (insn) != 0
+		      && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
+			   && REG_N_SETS (regno) == 1)
+			  || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
+		      && GET_CODE (XEXP (note, 0)) != EXPR_LIST
+		      && ! reg_overlap_mentioned_p (SET_DEST (set), XEXP (note, 0)))
+		    {
+		      reg_known_value[regno] = XEXP (note, 0);
+		      reg_known_equiv_p[regno] = REG_NOTE_KIND (note) == REG_EQUIV;
+		    }
+		  else if (REG_N_SETS (regno) == 1
+			   && GET_CODE (src) == PLUS
+			   && GET_CODE (XEXP (src, 0)) == REG
+			   && ORIGINAL_REGNO (XEXP (src, 0)) >= FIRST_PSEUDO_REGISTER
+			   && (reg_known_value[ORIGINAL_REGNO (XEXP (src, 0))])
+			   && GET_CODE (XEXP (src, 1)) == CONST_INT)
+		    {
+		      rtx op0 = XEXP (src, 0);
+		      if (reg_known_value[ORIGINAL_REGNO (op0)])
+			op0 = reg_known_value[ORIGINAL_REGNO (op0)];
+		      reg_known_value[regno]
+			= plus_constant_for_output (op0,
+						    INTVAL (XEXP (src, 1)));
+		      reg_known_equiv_p[regno] = 0;
+		    }
+		  else if (REG_N_SETS (regno) == 1
+			   && ! rtx_varies_p (src, 1))
+		    {
+		      reg_known_value[regno] = src;
+		      reg_known_equiv_p[regno] = 0;
+		    }
 		}
 	    }
 	  else if (GET_CODE (insn) == NOTE
@@ -2265,7 +2293,7 @@ init_alias_analysis ()
 	  rtx base = reg_base_value[ui];
 	  if (base && GET_CODE (base) == REG)
 	    {
-	      unsigned int base_regno = REGNO (base);
+	      unsigned int base_regno = ORIGINAL_REGNO (base);
 	      if (base_regno == ui)		/* register set from itself */
 		reg_base_value[ui] = 0;
 	      else
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index 8d1e2f7..750285e 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -74,6 +74,7 @@ static sbitmap *output_dependency_cache;
 static sbitmap *forward_dependency_cache;
 #endif
 
+static int deps_may_trap_p PARAMS ((rtx));
 static void remove_dependence PARAMS ((rtx, rtx));
 static void set_sched_group_p PARAMS ((rtx));
 
@@ -86,6 +87,21 @@ static rtx group_leader PARAMS ((rtx));
 static rtx get_condition PARAMS ((rtx));
 static int conditions_mutex_p PARAMS ((rtx, rtx));
 
+/* Return nonzero if a load of the memory reference MEM can cause a trap.  */
+
+static int
+deps_may_trap_p (mem)
+     rtx mem;
+{
+  rtx addr = XEXP (mem, 0);
+
+  if (REG_P (addr)
+      && ORIGINAL_REGNO (addr) >= FIRST_PSEUDO_REGISTER
+      && reg_known_value[ORIGINAL_REGNO (addr)])
+    addr = reg_known_value[ORIGINAL_REGNO (addr)];
+  return rtx_addr_can_trap_p (addr);
+}
+
 /* Return the INSN_LIST containing INSN in LIST, or NULL
    if LIST does not contain INSN.  */
 
@@ -817,7 +833,9 @@ sched_analyze_2 (deps, x, insn)
 	  }
 
 	for (u = deps->last_pending_memory_flush; u; u = XEXP (u, 1))
-	  add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
+	  if (GET_CODE (XEXP (u, 0)) != JUMP_INSN
+	      || deps_may_trap_p (x))
+	    add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
 
 	/* Always add these dependencies to pending_reads, since
 	   this insn may be followed by a write.  */