* reload.c (reg_overlap_mentioned_for_reload_p):

	When looking at a PLUS in X, avoid spuriously returning nonzero
	when IN is a REG or another simple PLUS, or a MEM containing one.

	* loop.c (loop_invariant_p): Amend comment about where new registers
	might come from.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@74638 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d35a599..be45849 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2003-12-15  J"orn Rennecke <joern.rennecke@superh.com>
+
+       * reload.c (reg_overlap_mentioned_for_reload_p):
+       When looking at a PLUS in X, avoid spuriously returning nonzero
+       when IN is a REG or another simple PLUS, or a MEM containing one.
+
+       * loop.c (loop_invariant_p): Amend comment about where new registers
+       might come from.
+
 2003-12-15  Andreas Jaeger  <aj@suse.de>
 
        * config/rs6000/rs6000.c (rs6000_output_function_epilogue): Remove

diff --git a/gcc/loop.c b/gcc/loop.c
index 8deb398..93bb328 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -3298,8 +3298,14 @@ loop_invariant_p (const struct loop *loop, rtx x)
        return 0;
 
       /* Out-of-range regs can occur when we are called from unrolling.
-        These have always been created by the unroller and are set in
-        the loop, hence are never invariant.  */
+        These registers created by the unroller are set in the loop,
+        hence are never invariant.
+        Other out-of-range regs can be generated by load_mems; those that
+        are written to in the loop are not invariant, while those that are
+        not written to are invariant.  It would be easy for load_mems
+        to set n_times_set correctly for these registers, however, there
+        is no easy way to distinguish them from registers created by the
+        unroller.  */
 
       if (REGNO (x) >= (unsigned) regs->num)
        return 0;

diff --git a/gcc/reload.c b/gcc/reload.c
index fe0f047..13f6900 100644 (file)
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -6290,8 +6290,22 @@ reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
           || GET_CODE (x) == CC0)
     return reg_mentioned_p (x, in);
   else if (GET_CODE (x) == PLUS)
-    return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
-           || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
+    {
+      /* We actually want to know if X is mentioned somewhere inside IN.
+        We must not say that (plus (sp) (const_int 124)) is in
+        (plus (sp) (const_int 64)), since that can lead to incorrect reload
+        allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
+        into a RELOAD_OTHER on behalf of another RELOAD_OTHER.  */
+      while (GET_CODE (in) == MEM)
+       in = XEXP (in, 0);
+      if (GET_CODE (in) == REG)
+       return 0;
+      else if (GET_CODE (in) == PLUS)
+       return (reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
+               || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
+      else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
+                  || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
+    }
   else
     abort ();