* reg-stack.c (convert_regs_1): Handle EH edges specially.

From-SVN: r30336

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 33c48e6ef129a5ecb96a684594e41597372392a8..4ce7c3c5a658b8a01a381bf7799e7189be1962bc 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+Mon Nov  1 18:09:14 1999  Richard Henderson  <rth@cygnus.com>
+
+       * reg-stack.c (convert_regs_1): Handle EH edges specially.
+
 Mon Nov  1 15:41:01 1999  Mark P. Mitchell  <mark@codesourcery.com>
 
        * bitmap.h (BITMAP_XMALLOC): New macro.

diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c
index c30d709fed104bb85ce0b9127b4a278569b29893..e20e92e859568bd7e487d71aefb055e4fd0d83f2 100644 (file)
--- a/gcc/reg-stack.c
+++ b/gcc/reg-stack.c
@@ -2514,12 +2514,34 @@ convert_regs_1 (file, block)
            }
        }
 
+      /* Care for EH edges specially.  The normal return path may return
+        a value in st(0), but the EH path will not, and there's no need
+        to add popping code to the edge.  */
+      if (e->flags & EDGE_EH)
+       {
+         /* Assert that the lifetimes are as we expect -- one value
+            live at st(0) on the end of the source block, and no
+            values live at the beginning of the destination block.  */
+         HARD_REG_SET tmp;
+
+         CLEAR_HARD_REG_SET (tmp);
+         GO_IF_HARD_REG_EQUAL (BLOCK_INFO (e->dest)->stack_in.reg_set,
+                               tmp, eh1);
+         abort();
+       eh1:
+
+         SET_HARD_REG_BIT (tmp, FIRST_STACK_REG);
+         GO_IF_HARD_REG_EQUAL (BLOCK_INFO (e->src)->out_reg_set, tmp, eh2);
+         abort();
+       eh2:;
+       }
+
       /* It is better to output directly to the end of the block
         instead of to the edge, because emit_swap can do minimal
         insn scheduling.  We can do this when there is only one
         edge out, and it is not abnormal.  */
-      if (block->succ->succ_next == NULL
-         && ! (e->flags & EDGE_ABNORMAL))
+      else if (block->succ->succ_next == NULL
+              && ! (e->flags & EDGE_ABNORMAL))
        {
          /* change_stack kills values in regstack.  */
          tmpstack = regstack;
@@ -2532,9 +2554,9 @@ convert_regs_1 (file, block)
        {
          rtx seq, after;
 
-         /* We don't support abnormal edges.  Global takes
-            care to avoid any live register across them, so
-            we should never have to.  */
+         /* We don't support abnormal edges.  Global takes care to
+            avoid any live register across them, so we should never
+            have to insert instructions on such edges.  */
          if (e->flags & EDGE_ABNORMAL)
            abort ();