re PR rtl-optimization/20583 (ICE in output_operand: invalid expression as operand)

gcc/
	PR middle-end/20583
	* cse.c (cse_insn): Reject invalid forms of CONST earlier.

gcc/testsuite/
	PR middle-end/20583
	* gcc.c-torture/compile/pr20583.c: New.

From-SVN: r107278

gcc/ChangeLog

+2005-11-21  Kazu Hirata  <kazu@codesourcery.com>
+
+	PR middle-end/20583
+	* cse.c (cse_insn): Reject invalid forms of CONST earlier.
+
 2005-11-20  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* combine.c (try_combine): Do not run subst on i1src and i2src in

gcc/cse.c

@@ -5506,6 +5506,22 @@ cse_insn (rtx insn, rtx libcall_insn)
 	      break;
 	    }
 
+	  /* Reject certain invalid forms of CONST that we create.  */
+	  else if (CONSTANT_P (trial)
+		   && GET_CODE (trial) == CONST
+		   /* Reject cases that will cause decode_rtx_const to
+		      die.  On the alpha when simplifying a switch, we
+		      get (const (truncate (minus (label_ref)
+		      (label_ref)))).  */
+		   && (GET_CODE (XEXP (trial, 0)) == TRUNCATE
+		       /* Likewise on IA-64, except without the
+			  truncate.  */
+		       || (GET_CODE (XEXP (trial, 0)) == MINUS
+			   && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF
+			   && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF)))
+	    /* Do nothing for this case.  */
+	    ;
+
 	  /* Look for a substitution that makes a valid insn.  */
 	  else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0))
 	    {
@@ -5541,17 +5557,6 @@ cse_insn (rtx insn, rtx libcall_insn)
 
 	  else if (constant_pool_entries_cost
 		   && CONSTANT_P (trial)
-		   /* Reject cases that will cause decode_rtx_const to
-		      die.  On the alpha when simplifying a switch, we
-		      get (const (truncate (minus (label_ref)
-		      (label_ref)))).  */
-		   && ! (GET_CODE (trial) == CONST
-			 && GET_CODE (XEXP (trial, 0)) == TRUNCATE)
-		   /* Likewise on IA-64, except without the truncate.  */
-		   && ! (GET_CODE (trial) == CONST
-			 && GET_CODE (XEXP (trial, 0)) == MINUS
-			 && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF
-			 && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF)
 		   && (src_folded == 0
 		       || (!MEM_P (src_folded)
 			   && ! src_folded_force_flag))

gcc/testsuite/ChangeLog

+2005-11-21  Kazu Hirata  <kazu@codesourcery.com>
+
+	PR middle-end/20583
+	* gcc.c-torture/compile/pr20583.c: New.
+
 2005-11-20  Bernd Schmidt  <bernd.schmidt@analog.com>
 
 	* gcc.c-torture/execute/usmul.c: New test.

gcc/testsuite/gcc.c-torture/compile/pr20583.c

+/* PR target/20583
+   On m68k-none-elf, CSE used to generate
+
+     (set (reg:HI ...)
+          (const:HI (truncate:HI (minus:SI (label_ref ...)
+                                           (label_ref ...)))))
+
+   which output functions do not know how to handle.  Make sure that
+   such a constant will be rejected.  */
+
+void bar (unsigned int);
+
+void
+foo (void)
+{
+  char buf[1] = { 3 };
+  const char *p = buf;
+  const char **q = &p;
+  unsigned int ch;
+  switch (**q)
+    {
+    case 1:  ch = 5; break;
+    case 2:  ch = 4; break;
+    case 3:  ch = 3; break;
+    case 4:  ch = 2; break;
+    case 5:  ch = 1; break;
+    default: ch = 0; break;
+    }
+  bar (ch);
+}