Replace the dummy definition of FUNCTION_ARG_PASS_BY_REFERENCE(). The new

definition forces variable-sized types to always be passed by reference.

Update the varargs code to cope with this.

gcc.c-torture/execute/20020412-1 finally passes.

3 files changed, 74 insertions, 10 deletions

diff --git a/gnu/usr.bin/gcc/gcc/config/m88k/m88k-protos.h b/gnu/usr.bin/gcc/gcc/config/m88k/m88k-protos.h
index f97cadd9222..69880cc0973 100644
--- a/gnu/usr.bin/gcc/gcc/config/m88k/m88k-protos.h
+++ b/gnu/usr.bin/gcc/gcc/config/m88k/m88k-protos.h
@@ -94,6 +94,9 @@ extern struct rtx_def *m88k_function_arg PARAMS ((CUMULATIVE_ARGS,
 						  int));
 extern void m88k_function_arg_advance PARAMS ((CUMULATIVE_ARGS *,
 					       enum machine_mode, tree, int));
+extern int m88k_function_arg_pass_by_reference PARAMS ((CUMULATIVE_ARGS *,
+							enum machine_mode,
+							tree, int));
 extern struct rtx_def *m88k_va_arg PARAMS ((tree, tree));
 extern tree m88k_build_va_list PARAMS ((void));
 #endif /* TREE_CODE */
diff --git a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.c b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.c
index 3654d228dfa..07cb561b2ae 100644
--- a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.c
+++ b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.c
@@ -2243,6 +2243,17 @@ m88k_function_arg (args_so_far, mode, type, named)
     abort ();	/* m88k_function_arg argument `type' is NULL for BLKmode. */
 
   bytes = (mode != BLKmode) ? GET_MODE_SIZE (mode) : int_size_in_bytes (type);
+
+  /* Variable-sized types get passed by reference, which can be passed
+     in registers.  */
+  if (bytes < 0)
+    {
+      if (args_so_far > 8 - (POINTER_SIZE / BITS_PER_WORD))
+	return (rtx) 0;
+
+      return gen_rtx_REG (Pmode, 2 + args_so_far);
+    }
+
   words = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
 
   if ((args_so_far & 1) != 0
@@ -2280,6 +2291,18 @@ m88k_function_arg_advance (args_so_far, mode, type, named)
     mode = BLKmode;
 
   bytes = (mode != BLKmode) ? GET_MODE_SIZE (mode) : int_size_in_bytes (type);
+  asf = *args_so_far;
+
+  /* Variable-sized types get passed by reference, which can be passed
+     in registers.  */
+  if (bytes < 0)
+    {
+      if (asf <= 8 - (POINTER_SIZE / BITS_PER_WORD))
+	*args_so_far += POINTER_SIZE / BITS_PER_WORD;
+
+      return;
+    }
+
   words = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
 
   /* Struct and unions which are not exactly the size of a register are to be
@@ -2288,7 +2311,6 @@ m88k_function_arg_advance (args_so_far, mode, type, named)
       && (TYPE_ALIGN (type) != BITS_PER_WORD || bytes != UNITS_PER_WORD))
     return;
 
-  asf = *args_so_far;
   /* Align arguments requiring more than word alignment to a double-word
      boundary (or an even register number if the argument will get passed
      in registers).  */
@@ -2303,10 +2325,29 @@ m88k_function_arg_advance (args_so_far, mode, type, named)
   (*args_so_far) = asf + words;
 }
 
+/* A C expression that indicates when an argument must be passed by
+   reference.  If nonzero for an argument, a copy of that argument is
+   made in memory and a pointer to the argument is passed instead of
+   the argument itself.  The pointer is passed in whatever way is
+   appropriate for passing a pointer to that type.
+
+   On m88k, only variable sized types are passed by reference.  */
+
+int
+m88k_function_arg_pass_by_reference (cum, mode, type, named)
+     CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED;
+     enum machine_mode mode ATTRIBUTE_UNUSED;
+     tree type;
+     int named ATTRIBUTE_UNUSED;
+{
+  return type != 0 && int_size_in_bytes (type) < 0;
+}
+
 /* Perform any needed actions needed for a function that is receiving a
    variable number of arguments.
 
-   CUM is as above.
+   CUM is a variable of type CUMULATIVE_ARGS which gives info about
+    the preceding args and about the function being called.
 
    MODE and TYPE are the mode and type of the current parameter.
 
@@ -2478,7 +2519,7 @@ m88k_va_arg (valist, type)
      tree valist, type;
 {
   tree field_reg, field_stk, field_arg;
-  int size, wsize, align, reg_p;
+  int indirect_p, size, wsize, align, reg_p;
   rtx addr_rtx;
   rtx lab_done;
 
@@ -2487,10 +2528,22 @@ m88k_va_arg (valist, type)
   field_reg = TREE_CHAIN (field_stk);
 
   size = int_size_in_bytes (type);
-  wsize = (size + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
-  reg_p = (AGGREGATE_TYPE_P (type)
-	   ? size == UNITS_PER_WORD && TYPE_ALIGN (type) == BITS_PER_WORD
-	   : size <= 2*UNITS_PER_WORD);
+  /* Variable sized types are passed by reference.  */
+  if (size < 0)
+    {
+      indirect_p = 1;
+      wsize = POINTER_SIZE / BITS_PER_WORD;
+      type = 0;
+      reg_p = 1;
+    }
+  else
+    {
+      indirect_p = 0;
+      wsize = (size + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
+      reg_p = (AGGREGATE_TYPE_P (type)
+	       ? size == UNITS_PER_WORD && TYPE_ALIGN (type) == BITS_PER_WORD
+	       : size <= 2*UNITS_PER_WORD);
+    }
 
   addr_rtx = gen_reg_rtx (Pmode);
   lab_done = gen_label_rtx ();
@@ -2507,7 +2560,7 @@ m88k_va_arg (valist, type)
 
     /* Align __va_arg to a doubleword boundary if necessary.  */
     arg = build (COMPONENT_REF, TREE_TYPE (field_arg), valist, field_arg);
-    align = TYPE_ALIGN (type) / BITS_PER_WORD;
+    align = type == 0 ? 0 : TYPE_ALIGN (type) / BITS_PER_WORD;
     if (align > 1)
       {
 	t = build (PLUS_EXPR, TREE_TYPE (arg), arg, build_int_2 (align - 1, 0));
@@ -2558,7 +2611,7 @@ m88k_va_arg (valist, type)
     stk = build (COMPONENT_REF, TREE_TYPE (field_stk), valist, field_stk);
 
     /* Align __va_stk to the type boundary if necessary.  */
-    align = TYPE_ALIGN (type) / BITS_PER_UNIT;
+    align = type == 0 ? 0 : TYPE_ALIGN (type) / BITS_PER_UNIT;
     if (align > UNITS_PER_WORD)
       {
         t = build (PLUS_EXPR, TREE_TYPE (stk), stk, build_int_2 (align - 1, 0));
@@ -2583,6 +2636,13 @@ m88k_va_arg (valist, type)
 
   emit_label (lab_done);
 
+  if (indirect_p)
+    {
+      rtx r = gen_rtx_MEM (Pmode, addr_rtx);
+      set_mem_alias_set (r, get_varargs_alias_set ());
+      emit_move_insn (addr_rtx, r);
+    }
+
   return addr_rtx;
 }
 
diff --git a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.h b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.h
index 12d38735eea..16f874a6125 100644
--- a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.h
+++ b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.h
@@ -848,7 +848,8 @@ enum reg_class { NO_REGS, AP_REG, XRF_REGS, GENERAL_REGS, AGRF_REGS,
    made in memory and a pointer to the argument is passed instead of the
    argument itself.  The pointer is passed in whatever way is appropriate
    for passing a pointer to that type.  */
-#define FUNCTION_ARG_PASS_BY_REFERENCE(CUM, MODE, TYPE, NAMED) (0)
+#define FUNCTION_ARG_PASS_BY_REFERENCE(CUM, MODE, TYPE, NAMED) \
+  m88k_function_arg_pass_by_reference(&CUM, MODE, TYPE, NAMED)
 
 /* A C type for declaring a variable that is used as the first argument
    of `FUNCTION_ARG' and other related values.  It suffices to count