Generate REG_FRAME_RELATED_EXPR notes that are compatible with

dwarf2out_frame_debug_expt.

From-SVN: r35233

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1796e08..eb65aa7 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2000-07-24  Nick Clifton  <nickc@cygnus.com>
+
+       * config/arm/arm.c (emit_multi_reg_push): Generate a
+       REG_FRAME_RELEATED_NOTE that is compatable with the code in
+       dwarf2out_debug_frame_expr.
+
 2000-07-24  Jason Merrill  <jason@redhat.com>
 
        * dwarf2out.c: Complain if DWARF2_DEBUGGING_INFO is defined without

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 6a37bf8..ec80863 100644 (file)
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -93,6 +93,7 @@ static Mfix *    create_fix_barrier           PARAMS ((Mfix *, Hint));
 static void     push_minipool_barrier          PARAMS ((rtx, Hint));
 static void     push_minipool_fix              PARAMS ((rtx, Hint, rtx *, Mmode, rtx));
 static void     note_invalid_constants         PARAMS ((rtx, Hint));
+static int       current_file_function_operand PARAMS ((rtx));
 \f
 #undef Hint
 #undef Mmode
@@ -1822,7 +1823,7 @@ arm_is_longcall_p (sym_ref, call_cookie, call_symbol)
   if (TARGET_LONG_CALLS && flag_function_sections)
     return 1;
   
-  if (current_file_function_operand (sym_ref, VOIDmode))
+  if (current_file_function_operand (sym_ref))
     return 0;
   
   return (call_cookie & CALL_LONG)
@@ -7067,6 +7068,7 @@ emit_multi_reg_push (mask)
   int i, j;
   rtx par;
   rtx dwarf;
+  int dwarf_par_index;
   rtx tmp, reg;
 
   for (i = 0; i <= LAST_ARM_REGNUM; i++)
@@ -7076,9 +7078,42 @@ emit_multi_reg_push (mask)
   if (num_regs == 0 || num_regs > 16)
     abort ();
 
+  /* For the body of the insn we are going to generate an UNSPEC in
+     parallel with several USEs.  This allows the insn to be recognised
+     by the push_multi pattern in the arm.md file.  The insn looks
+     something like this:
+
+       (parallel [ 
+           (set (mem:BLK (pre_dec:BLK (reg:SI sp))) (unspec:BLK [(reg:SI r4)] 2))
+           (use (reg:SI 11 fp))
+           (use (reg:SI 12 ip))
+           (use (reg:SI 14 lr))
+           (use (reg:SI 15 pc))
+        ])
+
+     For the frame note however, we try to be more explicit and actually
+     show each register being stored into the stack frame, plus a (single)
+     decrement of the stack pointer.  We do it this way in order to be
+     friendly to the stack unwinding code, which only wants to see a single
+     stack decrement per instruction.  The RTL we generate for the note looks
+     something like this:
+
+      (sequence [ 
+           (set (reg:SI sp) (plus:SI (reg:SI sp) (const_int -20)))
+           (set (mem:SI (reg:SI sp)) (reg:SI r4))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 4))) (reg:SI fp))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 8))) (reg:SI ip))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 12))) (reg:SI lr))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 16))) (reg:SI pc))
+        ])
+
+      This sequence is used both by the code to support stack unwinding for
+      exceptions handlers and the code to generate dwarf2 frame debugging.  */
+  
   par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num_regs));
-  dwarf = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num_regs));
+  dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (num_regs + 1));
   RTX_FRAME_RELATED_P (dwarf) = 1;
+  dwarf_par_index = 1;
 
   for (i = 0; i <= LAST_ARM_REGNUM; i++)
     {
@@ -7096,12 +7131,11 @@ emit_multi_reg_push (mask)
                                           2));
 
          tmp = gen_rtx_SET (VOIDmode,
-                            gen_rtx_MEM (SImode,
-                                         gen_rtx_PRE_DEC (BLKmode,
-                                                          stack_pointer_rtx)),
+                            gen_rtx_MEM (SImode, stack_pointer_rtx),
                             reg);
          RTX_FRAME_RELATED_P (tmp) = 1;
-         XVECEXP (dwarf, 0, num_regs - 1) = tmp;         
+         XVECEXP (dwarf, 0, dwarf_par_index) = tmp;
+         dwarf_par_index ++;
 
          break;
        }
@@ -7117,17 +7151,27 @@ emit_multi_reg_push (mask)
 
          tmp = gen_rtx_SET (VOIDmode,
                             gen_rtx_MEM (SImode,
-                                         gen_rtx_PRE_DEC (BLKmode,
-                                                          stack_pointer_rtx)),
+                                         gen_rtx_PLUS (SImode,
+                                                       stack_pointer_rtx,
+                                                       GEN_INT (4 * j))),
                             reg);
          RTX_FRAME_RELATED_P (tmp) = 1;
-         XVECEXP (dwarf, 0, num_regs - j - 1) = tmp;
+         XVECEXP (dwarf, 0, dwarf_par_index ++) = tmp;
                           
          j++;
        }
     }
 
   par = emit_insn (par);
+  
+  tmp = gen_rtx_SET (SImode,
+                    stack_pointer_rtx,
+                    gen_rtx_PLUS (SImode,
+                                  stack_pointer_rtx,
+                                  GEN_INT (-4 * num_regs)));
+  RTX_FRAME_RELATED_P (tmp) = 1;
+  XVECEXP (dwarf, 0, 0) = tmp;
+  
   REG_NOTES (par) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                       REG_NOTES (par));
   return par;