alpha.md (force_movdi): New insn.

        * config/alpha/alpha.md (force_movdi): New insn.
        * config/alpha/alpha.c (alpha_expand_prologue): Use it.
        Tweek FRP marking of VMS prologue insns.
        * config/alpha/vms.h (EPILOGUE_USES): New.

From-SVN: r44594

gcc/ChangeLog

+2001-08-03  Richard Henderson  <rth@redhat.com>
+
+	* config/alpha/alpha.md (force_movdi): New insn.
+	* config/alpha/alpha.c (alpha_expand_prologue): Use it.
+	Tweek FRP marking of VMS prologue insns.
+	* config/alpha/vms.h (EPILOGUE_USES): New.
+
 2001-08-02  Richard Henderson  <rth@redhat.com>
 
 	* Makefile.in, mklibgcc.in: Revert mkinstalldirs change.

gcc/config/alpha/alpha.c

@@ -4855,13 +4855,14 @@ alpha_expand_prologue ()
   if (TARGET_ABI_OPEN_VMS)
     {
       if (!vms_is_stack_procedure)
-	/* Register frame procedures fave the fp.  */
-	FRP (emit_move_insn (gen_rtx_REG (DImode, vms_save_fp_regno),
-			     hard_frame_pointer_rtx));
+	/* Register frame procedures save the fp.  */
+	/* ??? Ought to have a dwarf2 save for this.  */
+	emit_move_insn (gen_rtx_REG (DImode, vms_save_fp_regno),
+			hard_frame_pointer_rtx);
 
       if (vms_base_regno != REG_PV)
-	FRP (emit_move_insn (gen_rtx_REG (DImode, vms_base_regno),
-			     gen_rtx_REG (DImode, REG_PV)));
+	emit_insn (gen_force_movdi (gen_rtx_REG (DImode, vms_base_regno),
+				    gen_rtx_REG (DImode, REG_PV)));
 
       if (vms_unwind_regno == HARD_FRAME_POINTER_REGNUM)
 	FRP (emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx));

gcc/config/alpha/alpha.md

@@ -47,6 +47,7 @@
    (UNSPECV_MCOUNT	8)
    (UNSPECV_LDGP1	9)
    (UNSPECV_LDGP2	10)
+   (UNSPECV_FORCE_MOV	11)
   ])
 
 ;; Processor type -- this attribute must exactly match the processor_type
@@ -4880,6 +4881,18 @@ fadd,fmul,fcpys,fdiv,fsqrt,misc,mvi,ftoi,itof,multi"
    itoft %1,%0"
   [(set_attr "type" "ilog,iadd,iadd,ldsym,ild,ist,fcpys,fld,fst,ftoi,itof")])
 
+;; VMS needs to set up "vms_base_regno" for unwinding.  This move
+;; often appears dead to the life analysis code, at which point we
+;; abort for emitting dead prologue instructions.  Force this live.
+
+(define_insn "force_movdi"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(unspec_volatile:DI [(match_operand:DI 1 "register_operand" "r")]
+			    UNSPECV_FORCE_MOV))]
+  ""
+  "mov %1,%0"
+  [(set_attr "type" "ilog")])
+
 ;; We do three major things here: handle mem->mem, put 64-bit constants in
 ;; memory, and construct long 32-bit constants.
 

gcc/config/alpha/vms.h

@@ -111,6 +111,10 @@ Boston, MA 02111-1307, USA.  */
 #undef HARD_FRAME_POINTER_REGNUM
 #define HARD_FRAME_POINTER_REGNUM 29
 
+/* Define registers used by the epilogue and return instruction.  */
+#undef EPILOGUE_USES
+#define EPILOGUE_USES(REGNO)    ((REGNO) == 26 || (REGNO) == 29)
+
 #undef CAN_ELIMINATE
 #define CAN_ELIMINATE(FROM, TO)  \
 ((TO) != STACK_POINTER_REGNUM || ! alpha_using_fp ())