(attach_deaths): Don't add a REG_DEAD note if a REG_UNUSED note is

already present.

From-SVN: r9871

diff --git a/gcc/sched.c b/gcc/sched.c
index 97332280f40cd2b5b7005cc4b7313b49be819e52..ccd8b563a7a3ed11fcde2c21212c6e3fa3d8aa89 100644 (file)
--- a/gcc/sched.c
+++ b/gcc/sched.c
@@ -2864,7 +2864,12 @@ attach_deaths (x, insn, set_p)
 #endif
                && regno != STACK_POINTER_REGNUM)
              {
-               if (! all_needed && ! dead_or_set_p (insn, x))
+               /* ??? It is perhaps a dead_or_set_p bug that it does
+                  not check for REG_UNUSED notes itself.  This is necessary
+                  for the case where the SET_DEST is a subreg of regno, as
+                  dead_or_set_p handles subregs specially.  */
+               if (! all_needed && ! dead_or_set_p (insn, x)
+                   && ! find_regno_note (insn, REG_UNUSED, regno))
                  {
                    /* Check for the case where the register dying partially
                       overlaps the register set by this insn.  */