PR rtl-optimization/23898

	* output.h (get_attr_min_length): Declare.
	* final.c (get_attr_length_1): New function, broken out of:
	(get_attr_length).
	(get_attr_min_length): New function.
	* bb-reorder.c (copy_bb_p, get_uncond_jump_length): Use it.
	(duplicate_computed_gotos): Likewise.
	* genattr.c (insn_min_length): Generate declaration.
	* genattrtab.c (min_fn, min_attr_value): New functions.
	(make_length_attrs): Generate insn_min_length.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@104468 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 55 insertions, 2 deletions

diff --git a/gcc/genattrtab.c b/gcc/genattrtab.c
index 78a61e86981..359ddddae10 100644
--- a/gcc/genattrtab.c
+++ b/gcc/genattrtab.c
@@ -285,6 +285,7 @@ static rtx identity_fn		(rtx);
 static rtx zero_fn		(rtx);
 static rtx one_fn		(rtx);
 static rtx max_fn		(rtx);
+static rtx min_fn		(rtx);
 static void write_length_unit_log (void);
 static rtx simplify_cond	(rtx, int, int);
 static void clear_struct_flag (rtx);
@@ -307,6 +308,7 @@ static void gen_insn		(rtx, int);
 static void gen_delay		(rtx, int);
 static void write_test_expr	(rtx, int);
 static int max_attr_value	(rtx, int*);
+static int min_attr_value	(rtx, int*);
 static int or_attr_value	(rtx, int*);
 static void walk_attr_value	(rtx);
 static void write_attr_get	(struct attr_desc *);
@@ -1583,11 +1585,14 @@ make_length_attrs (void)
   static const char *new_names[] =
     {
       "*insn_default_length",
+      "*insn_min_length",
       "*insn_variable_length_p",
       "*insn_current_length"
     };
-  static rtx (*const no_address_fn[]) (rtx) = {identity_fn, zero_fn, zero_fn};
-  static rtx (*const address_fn[]) (rtx) = {max_fn, one_fn, identity_fn};
+  static rtx (*const no_address_fn[]) (rtx)
+    = {identity_fn,identity_fn, zero_fn, zero_fn};
+  static rtx (*const address_fn[]) (rtx)
+    = {max_fn, min_fn, one_fn, identity_fn};
   size_t i;
   struct attr_desc *length_attr, *new_attr;
   struct attr_value *av, *new_av;
@@ -1654,6 +1659,13 @@ max_fn (rtx exp)
   return make_numeric_value (max_attr_value (exp, &unknown));
 }
 
+static rtx
+min_fn (rtx exp)
+{
+  int unknown;
+  return make_numeric_value (min_attr_value (exp, &unknown));
+}
+
 static void
 write_length_unit_log (void)
 {
@@ -3531,6 +3543,47 @@ max_attr_value (rtx exp, int *unknownp)
   return current_max;
 }
 
+/* Given an attribute value, return the minimum CONST_STRING argument
+   encountered.  Set *UNKNOWNP and return 0 if the value is unknown.  */
+
+static int
+min_attr_value (rtx exp, int *unknownp)
+{
+  int current_min;
+  int i, n;
+
+  switch (GET_CODE (exp))
+    {
+    case CONST_STRING:
+      current_min = atoi (XSTR (exp, 0));
+      break;
+
+    case COND:
+      current_min = min_attr_value (XEXP (exp, 1), unknownp);
+      for (i = 0; i < XVECLEN (exp, 0); i += 2)
+	{
+	  n = min_attr_value (XVECEXP (exp, 0, i + 1), unknownp);
+	  if (n < current_min)
+	    current_min = n;
+	}
+      break;
+
+    case IF_THEN_ELSE:
+      current_min = min_attr_value (XEXP (exp, 1), unknownp);
+      n = min_attr_value (XEXP (exp, 2), unknownp);
+      if (n < current_min)
+	current_min = n;
+      break;
+
+    default:
+      *unknownp = 1;
+      current_min = INT_MAX;
+      break;
+    }
+
+  return current_min;
+}
+
 /* Given an attribute value, return the result of ORing together all
    CONST_STRING arguments encountered.  Set *UNKNOWNP and return -1
    if the numeric value is not known.  */