rtlanal.c (rtx_addr_can_trap_p): Virtual registers cannot trap.

        * rtlanal.c (rtx_addr_can_trap_p): Virtual registers cannot trap.
        Auto-inc addresses trap only if their base register does.

From-SVN: r40914

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d5164f8b5c9bfa2b29b98e55132dda1dd4497238..0b0379dee4bc324f78359e4547285b6abb23b5ac 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,8 @@
 2001-03-27  Richard Henderson  <rth@redhat.com>
 
+       * rtlanal.c (rtx_addr_can_trap_p): Virtual registers cannot trap.
+       Auto-inc addresses trap only if their base register does.
+
        * except.c (can_throw_internal): Rename from can_throw.
        * except.h, resource.c: Update references.
 

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index be9374e68ebfadcb81cdf3a3288180ad0e8cfd46..db8e696801024908df3fc145b5abf66d2b326ca1 100644 (file)
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -216,10 +216,16 @@ rtx_addr_can_trap_p (x)
 
     case REG:
       /* As in rtx_varies_p, we have to use the actual rtx, not reg number.  */
-      return ! (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
-               || x == stack_pointer_rtx
-               /* The arg pointer varies if it is not a fixed register.  */
-               || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]));
+      if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
+         || x == stack_pointer_rtx
+         /* The arg pointer varies if it is not a fixed register.  */
+         || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
+       return 0;
+      /* All of the virtual frame registers are stack references.  */
+      if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
+         && REGNO (x) <= LAST_VIRTUAL_REGISTER)
+       return 0;
+      return 1;
 
     case CONST:
       return rtx_addr_can_trap_p (XEXP (x, 0));
@@ -234,8 +240,16 @@ rtx_addr_can_trap_p (x)
                    && CONSTANT_P (XEXP (x, 1))));
 
     case LO_SUM:
+    case PRE_MODIFY:
       return rtx_addr_can_trap_p (XEXP (x, 1));
-      
+
+    case PRE_DEC:
+    case PRE_INC:
+    case POST_DEC:
+    case POST_INC:
+    case POST_MODIFY:
+      return rtx_addr_can_trap_p (XEXP (x, 0));
+
     default:
       break;
     }