flow.c (init_propagate_block_info): Protect the rtx stored in mem_set_list from modif...

        * flow.c (init_propagate_block_info): Protect the rtx stored in
        mem_set_list from modification by find_auto_inc.
        (mark_set_1): Likewise.

From-SVN: r37330

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ef955ac66f8a77c622b403b0af3edcdade9c00f2..e28acbc3d896a04ebfb5631ff37ae0ab68c8ad29 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2000-11-08  Richard Henderson  <rth@redhat.com>
+
+       * flow.c (init_propagate_block_info): Protect the rtx stored in
+       mem_set_list from modification by find_auto_inc.
+       (mark_set_1): Likewise.
+
 2000-11-08  Neil Booth  <neilb@earthling.net>
 
         Move directive handling into the lexer itself.

diff --git a/gcc/flow.c b/gcc/flow.c
index d286f91e2b3465695012a9bb1e6dceda3ffa8579..b855114d47bf3dee26a52159e8634660bff4240b 100644 (file)
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -3930,7 +3930,21 @@ init_propagate_block_info (bb, live, local_set, flags)
                || (GET_CODE (XEXP (mem, 0)) == PLUS
                    && XEXP (XEXP (mem, 0), 0) == frame_pointer_rtx
                    && GET_CODE (XEXP (XEXP (mem, 0), 1)) == CONST_INT))
-             pbi->mem_set_list = alloc_EXPR_LIST (0, mem, pbi->mem_set_list);
+             {
+#ifdef AUTO_INC_DEC
+               /* Store a copy of mem, otherwise the address may be scrogged
+                  by find_auto_inc.  This matters because insn_dead_p uses
+                  an rtx_equal_p check to determine if two addresses are
+                  the same.  This works before find_auto_inc, but fails
+                  after find_auto_inc, causing discrepencies between the
+                  set of live registers calculated during the
+                  calculate_global_regs_live phase and what actually exists
+                  after flow completes, leading to aborts.  */
+               if (flags & PROP_AUTOINC)
+                 mem = shallow_copy_rtx (mem);
+#endif
+               pbi->mem_set_list = alloc_EXPR_LIST (0, mem, pbi->mem_set_list);
+             }
          }
     }
 
@@ -4561,7 +4575,15 @@ mark_set_1 (pbi, code, reg, cond, insn, flags)
             everything that invalidates it.  To be safe, don't eliminate any
             stores though SP; none of them should be redundant anyway.  */
          && ! reg_mentioned_p (stack_pointer_rtx, reg))
-       pbi->mem_set_list = alloc_EXPR_LIST (0, reg, pbi->mem_set_list);
+       {
+#ifdef AUTO_INC_DEC
+         /* Store a copy of mem, otherwise the address may be
+            scrogged by find_auto_inc.  */
+         if (flags & PROP_AUTOINC)
+           reg = shallow_copy_rtx (reg);
+#endif
+         pbi->mem_set_list = alloc_EXPR_LIST (0, reg, pbi->mem_set_list);
+       }
     }
 
   if (GET_CODE (reg) == REG