2021-03-04  Jakub Jelinek  <jakub@redhat.com>

	PR debug/99388
	* dwarf2out.c (insert_float): Change return type from void to
	unsigned, handle GET_MODE_SIZE (mode) == 2 and return element size.
	(mem_loc_descriptor, loc_descriptor, add_const_value_attribute):
	Adjust callers.

--- gcc/dwarf2out.c.jj	2021-03-03 09:53:55.391191719 +0100
+++ gcc/dwarf2out.c	2021-03-04 15:51:23.174396552 +0100
@@ -3825,7 +3825,7 @@ static void add_data_member_location_att
 static bool add_const_value_attribute (dw_die_ref, rtx);
 static void insert_int (HOST_WIDE_INT, unsigned, unsigned char *);
 static void insert_wide_int (const wide_int &, unsigned char *, int);
-static void insert_float (const_rtx, unsigned char *);
+static unsigned insert_float (const_rtx, unsigned char *);
 static rtx rtl_for_decl_location (tree);
 static bool add_location_or_const_value_attribute (dw_die_ref, tree, bool);
 static bool tree_add_const_value_attribute (dw_die_ref, tree);
@@ -16292,11 +16292,12 @@ mem_loc_descriptor (rtx rtl, machine_mod
 	      scalar_float_mode float_mode = as_a <scalar_float_mode> (mode);
 	      unsigned int length = GET_MODE_SIZE (float_mode);
 	      unsigned char *array = ggc_vec_alloc<unsigned char> (length);
+	      unsigned int elt_size = insert_float (rtl, array);
 
-	      insert_float (rtl, array);
 	      mem_loc_result->dw_loc_oprnd2.val_class = dw_val_class_vec;
-	      mem_loc_result->dw_loc_oprnd2.v.val_vec.length = length / 4;
-	      mem_loc_result->dw_loc_oprnd2.v.val_vec.elt_size = 4;
+	      mem_loc_result->dw_loc_oprnd2.v.val_vec.length
+		= length / elt_size;
+	      mem_loc_result->dw_loc_oprnd2.v.val_vec.elt_size = elt_size;
 	      mem_loc_result->dw_loc_oprnd2.v.val_vec.array = array;
 	    }
 	}
@@ -16866,11 +16867,11 @@ loc_descriptor (rtx rtl, machine_mode mo
 	    {
 	      unsigned int length = GET_MODE_SIZE (smode);
 	      unsigned char *array = ggc_vec_alloc<unsigned char> (length);
+	      unsigned int elt_size = insert_float (rtl, array);
 
-	      insert_float (rtl, array);
 	      loc_result->dw_loc_oprnd2.val_class = dw_val_class_vec;
-	      loc_result->dw_loc_oprnd2.v.val_vec.length = length / 4;
-	      loc_result->dw_loc_oprnd2.v.val_vec.elt_size = 4;
+	      loc_result->dw_loc_oprnd2.v.val_vec.length = length / elt_size;
+	      loc_result->dw_loc_oprnd2.v.val_vec.elt_size = elt_size;
 	      loc_result->dw_loc_oprnd2.v.val_vec.array = array;
 	    }
 	}
@@ -19689,7 +19690,7 @@ insert_wide_int (const wide_int &val, un
 
 /* Writes floating point values to dw_vec_const array.  */
 
-static void
+static unsigned
 insert_float (const_rtx rtl, unsigned char *array)
 {
   long val[4];
@@ -19699,11 +19700,19 @@ insert_float (const_rtx rtl, unsigned ch
   real_to_target (val, CONST_DOUBLE_REAL_VALUE (rtl), mode);
 
   /* real_to_target puts 32-bit pieces in each long.  Pack them.  */
+  if (GET_MODE_SIZE (mode) < 4)
+    {
+      gcc_assert (GET_MODE_SIZE (mode) == 2);
+      insert_int (val[0], 2, array);
+      return 2;
+    }
+
   for (i = 0; i < GET_MODE_SIZE (mode) / 4; i++)
     {
       insert_int (val[i], 4, array);
       array += 4;
     }
+  return 4;
 }
 
 /* Attach a DW_AT_const_value attribute for a variable or a parameter which
@@ -19752,9 +19761,10 @@ add_const_value_attribute (dw_die_ref di
 	  scalar_float_mode mode = as_a <scalar_float_mode> (GET_MODE (rtl));
 	  unsigned int length = GET_MODE_SIZE (mode);
 	  unsigned char *array = ggc_vec_alloc<unsigned char> (length);
+	  unsigned int elt_size = insert_float (rtl, array);
 
-	  insert_float (rtl, array);
-	  add_AT_vec (die, DW_AT_const_value, length / 4, 4, array);
+	  add_AT_vec (die, DW_AT_const_value, length / elt_size, elt_size,
+		      array);
 	}
       return true;