[4.4 PATCH] Fix another signed 1 bit comparison issue (PR middle-end/48973)

[Jakub Jelinek]

Hi!

The 4.4 expr.c is significantly different from 4.5 that the PR48973
backport wasn't trivial, and apparently I've missed another place
- on the 4.4 branch the new pr48973-{1,2}.c tests fail on s390{,x}-linux.

The following patch fixes it, ok for 4.4 branch?

2011-07-21  Jakub Jelinek  <ja...@redhat.com>

        PR middle-end/48973
        * expr.c (expand_expr_real_1) <case TRUTH_ANDIF_EXPR:>: If
        the comparison has a single bit signed type, use
        constm1_rtx instead of const1_rtx for true value.

--- gcc/expr.c  (revision 176517)
+++ gcc/expr.c  (working copy)
@@ -9171,7 +9171,9 @@ expand_expr_real_1 (tree exp, rtx target
       jumpifnot (exp, op1, -1);
 
       if (target)
-       emit_move_insn (target, const1_rtx);
+       emit_move_insn (target,
+                       TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type)
+                       ? constm1_rtx : const1_rtx);
 
       emit_label (op1);
       return ignore ? const0_rtx : target;

        Jakub