2005-01-21  Jakub Jelinek  <jakub@redhat.com>

	* flow.c (propagate_one_insn): Formatting.

	PR middle-end/19551
	* flow.c (libcall_dead_p): Be more conservative if unsure.
	If there are any instructions between insn and call, see if they are
	all dead before saying the libcall is dead.

	* gcc.c-torture/execute/20050121-1.c: New test.
	* gcc.dg/20050121-2.c: New test.

--- gcc/flow.c.jj	2005-01-18 17:02:41.000000000 +0100
+++ gcc/flow.c	2005-01-21 19:46:30.000000000 +0100
@@ -1587,7 +1587,7 @@ propagate_one_insn (struct propagate_blo
       pbi->cc0_live = 0;
 
       if (libcall_is_dead)
-	prev = propagate_block_delete_libcall ( insn, note);
+	prev = propagate_block_delete_libcall (insn, note);
       else
 	{
 
@@ -2290,7 +2290,7 @@ libcall_dead_p (struct propagate_block_i
     {
       rtx r = SET_SRC (x);
 
-      if (REG_P (r))
+      if (REG_P (r) || GET_CODE (r) == SUBREG)
 	{
 	  rtx call = XEXP (note, 0);
 	  rtx call_pat;
@@ -2324,10 +2324,20 @@ libcall_dead_p (struct propagate_block_i
 	      call_pat = XVECEXP (call_pat, 0, i);
 	    }
 
-	  return insn_dead_p (pbi, call_pat, 1, REG_NOTES (call));
+	  if (! insn_dead_p (pbi, call_pat, 1, REG_NOTES (call)))
+	    return 0;
+
+	  while ((insn = PREV_INSN (insn)) != call)
+	    {
+	      if (! INSN_P (insn))
+		continue;
+	      if (! insn_dead_p (pbi, PATTERN (insn), 0, REG_NOTES (insn)))
+		return 0;
+	    }
+	  return 1;
 	}
     }
-  return 1;
+  return 0;
 }
 
 /* 1 if register REGNO was alive at a place where `setjmp' was called
--- gcc/testsuite/gcc.c-torture/execute/20050121-1.c.jj	2005-01-21 19:53:52.000000000 +0100
+++ gcc/testsuite/gcc.c-torture/execute/20050121-1.c	2005-01-21 19:49:45.000000000 +0100
@@ -0,0 +1,63 @@
+/* PR middle-end/19551 */
+
+extern void abort ();
+
+#define T(type, name) \
+__attribute__((pure)) _Complex type		\
+foo_##name (int x)				\
+{						\
+  _Complex type r;				\
+  __real r = x + 1;				\
+  __imag r = x - 1;				\
+  return r;					\
+}						\
+						\
+void						\
+bar_##name (type *x)				\
+{						\
+  *x = __real foo_##name (5);			\
+}						\
+						\
+void						\
+baz_##name (type *x)				\
+{						\
+  *x = __imag foo_##name (5);			\
+}
+
+typedef long double ldouble_t;
+typedef long long llong;
+
+T (float, float)
+T (double, double)
+T (long double, ldouble_t)
+T (char, char)
+T (short, short)
+T (int, int)
+T (long, long)
+T (long long, llong)
+#undef T
+
+int
+main (void)
+{
+#define T(type, name) \
+  {						\
+    type var = 0;				\
+    bar_##name (&var);				\
+    if (var != 6)				\
+      abort ();					\
+    var = 0;					\
+    baz_##name (&var);				\
+    if (var != 4)				\
+      abort ();					\
+  }
+  T (float, float)
+  T (double, double)
+  T (long double, ldouble_t)
+  T (char, char)
+  T (short, short)
+  T (int, int)
+  T (long, long)
+  T (long long, llong)
+  return 0;
+}
--- gcc/testsuite/gcc.dg/20050121-2.c.jj	2005-01-21 22:18:43.433594254 +0100
+++ gcc/testsuite/gcc.dg/20050121-2.c	2005-01-21 21:52:05.000000000 +0100
@@ -0,0 +1,67 @@
+/* PR middle-end/19551 */
+/* { dg-options "-O2" } */
+/* { dg-do link } */
+
+extern void abort ();
+
+#define T(type, name) \
+extern __attribute__((pure)) _Complex type	\
+foo_c##name (int x);				\
+						\
+void						\
+bar_c##name (type *x)				\
+{						\
+  type f = __real foo_c##name (5);		\
+  if (0) *x = f;				\
+}						\
+						\
+void						\
+baz_c##name (type *x)				\
+{						\
+  type f = __imag foo_c##name (5);		\
+  if (0) *x = f;				\
+}						\
+						\
+extern __attribute__((pure)) type		\
+foo_##name (int x);				\
+						\
+void						\
+bar_##name (type *x)				\
+{						\
+  type f = foo_##name (5);			\
+  if (0) *x = f;				\
+}
+
+typedef long double ldouble_t;
+typedef long long llong;
+
+T (float, float)
+T (double, double)
+T (long double, ldouble_t)
+T (char, char)
+T (short, short)
+T (int, int)
+T (long, long)
+T (long long, llong)
+#undef T
+
+int
+main (void)
+{
+#define T(type, name) \
+  {						\
+    type var = 0;				\
+    bar_c##name (&var);				\
+    baz_c##name (&var);				\
+    bar_##name (&var);				\
+  }
+  T (float, float)
+  T (double, double)
+  T (long double, ldouble_t)
+  T (char, char)
+  T (short, short)
+  T (int, int)
+  T (long, long)
+  T (long long, llong)
+  return 0;
+}