re PR rtl-optimization/17581 (Long long arithmetic fails inside a switch/case…

re PR rtl-optimization/17581 (Long long arithmetic fails inside a switch/case statement when compiled with -O2)


	PR rtl-optimization/17581
	* cselib.c (cselib_process_insn): The last instruction of a libcall
	block, with the REG_RETVAL note, should be considered in the libcall.
	* gcse.c (do_local_cprop): Allow constants to be propagated outside
	of libcall blocks.
	(adjust_libcall_notes): Use simplify_replace_rtx instead of
	replace_rtx to avoid creating invalid RTL in REG_RETVAL notes.

	* gcc.dg/pr17581-1.c: New test case.

From-SVN: r89873

gcc/ChangeLog

+2004-10-29  Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/17581
+	* cselib.c (cselib_process_insn): The last instruction of a libcall
+	block, with the REG_RETVAL note, should be considered in the libcall.
+	* gcse.c (do_local_cprop): Allow constants to be propagated outside
+	of libcall blocks.
+	(adjust_libcall_notes): Use simplify_replace_rtx instead of
+	replace_rtx to avoid creating invalid RTL in REG_RETVAL notes.
+
 2004-10-30  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* tree-phinodes.c (create_phi_node): Don't zero PHI_REWRITTEN.

gcc/cselib.c

@@ -1346,8 +1346,6 @@ cselib_process_insn (rtx insn)
 
   if (find_reg_note (insn, REG_LIBCALL, NULL))
     cselib_current_insn_in_libcall = true;
-  if (find_reg_note (insn, REG_RETVAL, NULL))
-    cselib_current_insn_in_libcall = false;
   cselib_current_insn = insn;
 
   /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp.  */
@@ -1358,12 +1356,16 @@ cselib_process_insn (rtx insn)
 	  && GET_CODE (PATTERN (insn)) == ASM_OPERANDS
 	  && MEM_VOLATILE_P (PATTERN (insn))))
     {
+      if (find_reg_note (insn, REG_RETVAL, NULL))
+        cselib_current_insn_in_libcall = false;
       clear_table ();
       return;
     }
 
   if (! INSN_P (insn))
     {
+      if (find_reg_note (insn, REG_RETVAL, NULL))
+        cselib_current_insn_in_libcall = false;
       cselib_current_insn = 0;
       return;
     }
@@ -1399,6 +1401,8 @@ cselib_process_insn (rtx insn)
       if (GET_CODE (XEXP (x, 0)) == CLOBBER)
 	cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
 
+  if (find_reg_note (insn, REG_RETVAL, NULL))
+    cselib_current_insn_in_libcall = false;
   cselib_current_insn = 0;
 
   if (n_useless_values > MAX_USELESS_VALUES)

gcc/gcse.c

@@ -3134,7 +3134,8 @@ do_local_cprop (rtx x, rtx insn, int alter_jumps, rtx *libcall_sp)
 	  rtx this_rtx = l->loc;
 	  rtx note;
 
-	  if (l->in_libcall)
+	  /* Don't CSE non-constant values out of libcall blocks.  */
+	  if (l->in_libcall && ! CONSTANT_P (this_rtx))
 	    continue;
 
 	  if (gcse_constant_p (this_rtx))
@@ -3222,7 +3223,7 @@ adjust_libcall_notes (rtx oldreg, rtx newval, rtx insn, rtx *libcall_sp)
 	      return true;
 	    }
 	}
-      XEXP (note, 0) = replace_rtx (XEXP (note, 0), oldreg, newval);
+      XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), oldreg, newval);
       insn = end;
     }
   return true;

gcc/testsuite/ChangeLog

+2004-10-29  Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/17581
+	* gcc.dg/pr17581-1.c: New test case.
+
 2004-10-28  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.dg/conversion/dr195.C: Adjust expected errors for DR195 not

gcc/testsuite/gcc.dg/pr17581-1.c

+/* PR rtl-optimization/17581 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int foo(int x)
+{
+  unsigned long long tmp = 0;
+
+  switch(x) {
+    case 21:
+      tmp |= 1;
+      tmp |= 2;
+      tmp |= 8;
+      break;
+    default:
+      break;
+  }
+  
+  return (int)tmp;
+}
+
+int main()
+{
+  if (foo(21) != 11)
+    abort ();
+  return 0;
+}
+