This patch fixes a bug that causes the prologue to use more temporary
registers than necessary. Backported to 4.7 and 4.8.
* config/tilegx/tilegx.c (tilegx_expand_prologue): Avoid
double-decrement of next_scratch_regno.
--- gcc/config/tilegx/tilegx.c (revision 197134)
+++ gcc/config/tilegx/tilegx.c (working copy)
@@ -3999,11 +3999,10 @@ tilegx_expand_prologue (void)
if (r == NULL_RTX)
{
- rtx p = compute_frame_addr (offset, &next_scratch_regno);
- r = gen_rtx_REG (Pmode, next_scratch_regno--);
- reg_save_addr[which_scratch] = r;
-
- emit_insn (gen_rtx_SET (VOIDmode, r, p));
+ int prev_scratch_regno = next_scratch_regno;
+ r = compute_frame_addr (offset, &next_scratch_regno);
+ if (prev_scratch_regno != next_scratch_regno)
+ reg_save_addr[which_scratch] = r;
}
else
{
