PR bootstrap/52172

[pf3gnuchains/gcc-fork.git] / gcc / cselib.c

diff --git a/gcc/cselib.c b/gcc/cselib.c
index 456c875..d7cb355 100644 (file)
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -1372,8 +1372,18 @@ expand_loc (struct elt_loc_list *p, struct expand_value_data *evd,
   unsigned int regno = UINT_MAX;
   struct elt_loc_list *p_in = p;
 
-  for (; p; p = p -> next)
+  for (; p; p = p->next)
     {
+      /* Return these right away to avoid returning stack pointer based
+        expressions for frame pointer and vice versa, which is something
+        that would confuse DSE.  See the comment in cselib_expand_value_rtx_1
+        for more details.  */
+      if (REG_P (p->loc)
+         && (REGNO (p->loc) == STACK_POINTER_REGNUM
+             || REGNO (p->loc) == FRAME_POINTER_REGNUM
+             || REGNO (p->loc) == HARD_FRAME_POINTER_REGNUM
+             || REGNO (p->loc) == cfa_base_preserved_regno))
+       return p->loc;
       /* Avoid infinite recursion trying to expand a reg into a
         the same reg.  */
       if ((REG_P (p->loc))
@@ -1895,6 +1905,19 @@ cselib_subst_to_values (rtx x, enum machine_mode memmode)
   return copy;
 }
 
+/* Wrapper for cselib_subst_to_values, that indicates X is in INSN.  */
+
+rtx
+cselib_subst_to_values_from_insn (rtx x, enum machine_mode memmode, rtx insn)
+{
+  rtx ret;
+  gcc_assert (!cselib_current_insn);
+  cselib_current_insn = insn;
+  ret = cselib_subst_to_values (x, memmode);
+  cselib_current_insn = NULL;
+  return ret;
+}
+
 /* Look up the rtl expression X in our tables and return the value it
    has.  If CREATE is zero, we return NULL if we don't know the value.
    Otherwise, we create a new one if possible, using mode MODE if X