RFA: Fix PR35044

[Joern Rennecke]

-------------- next part --------------
regression tested in revision r144445 on gcc11.

2008-01-19  J"orn Rennecke  <joern.rennecke@arc.com>

	* resource.c (find_dead_or_set_registers): Don't consider sets inside
	a COND_EXEC to kill the value in a register.

Index: gcc/gcc/resource.c
===================================================================
--- gcc/gcc/resource.c	(revision 144445)
+++ gcc/gcc/resource.c	(working copy)
@@ -530,26 +530,40 @@ find_dead_or_set_registers (rtx target, 
 		     filled by instructions from the target.  This is correct
 		     if the branch is not taken.  Since we are following both
 		     paths from the branch, we must also compute correct info
-		     if the branch is taken.  We do this by inverting all of
-		     the INSN_FROM_TARGET_P bits, calling mark_set_resources,
-		     and then inverting the INSN_FROM_TARGET_P bits again.  */
+		     if the branch is taken.  We do this by inlining the loop
+		     for processing the sequence, and inverting the sense of
+		     the INSN_FROM_TARGET_P test for the target.  */
 
 		  if (GET_CODE (PATTERN (insn)) == SEQUENCE
 		      && INSN_ANNULLED_BRANCH_P (this_jump_insn))
 		    {
-		      for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++)
-			INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i))
-			  = ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i));
+		      rtx x = PATTERN (insn);
+		      int i;
 
 		      target_set = set;
-		      mark_set_resources (insn, &target_set, 0,
-					  MARK_SRC_DEST_CALL);
-
-		      for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++)
-			INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i))
-			  = ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i));
+		      for (i = 0; i < XVECLEN (x, 0); i++)
+			if ((i == 0 || INSN_FROM_TARGET_P (XVECEXP (x, 0, i)))
+			    && (GET_CODE (PATTERN (XVECEXP (x, 0, i)))
+				!= COND_EXEC))
+			  mark_set_resources (XVECEXP (x, 0, i), &target_set,
+					      0, MARK_SRC_DEST_CALL);
+		      for (i = 0; i < XVECLEN (x, 0); i++)
+			if ((i == 0 || !INSN_FROM_TARGET_P (XVECEXP (x, 0, i)))
+			    && (GET_CODE (PATTERN (XVECEXP (x, 0, i)))
+				!= COND_EXEC))
+			  mark_set_resources (XVECEXP (x, 0, i), &set,
+					      0, MARK_SRC_DEST_CALL);
+		    }
+		  else if (GET_CODE (PATTERN (insn)) == SEQUENCE)
+		    {
+		      rtx x = PATTERN (insn);
+		      int i;
 
-		      mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
+		      for (i = 0; i < XVECLEN (x, 0); i++)
+			if (GET_CODE (PATTERN (XVECEXP (x, 0, i))) != COND_EXEC)
+			  mark_set_resources (XVECEXP (x, 0, i), &set,
+					      0, MARK_SRC_DEST_CALL);
+		      target_set = set;
 		    }
 		  else
 		    {
@@ -591,7 +605,8 @@ find_dead_or_set_registers (rtx target, 
 	}
 
       mark_referenced_resources (insn, &needed, 1);
-      mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
+      if (GET_CODE (PATTERN (insn)) != COND_EXEC)
+	mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
 
       COPY_HARD_REG_SET (scratch, set.regs);
       AND_COMPL_HARD_REG_SET (scratch, needed.regs);