mips.c (mips_va_arg): When using the struct version of the EABI va_list...

	* config/mips/mips.c (mips_va_arg): When using the struct version
	of the EABI va_list, allow arguments in the register save area to
	take up less room than a stack argument.

From-SVN: r52125

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f6e47a8a8b87f66708ee280d28051967c78c0527..5ce2348093c185a73537c9280daedaf770a993e6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2002-04-10  Richard Sandiford  <rsandifo@redhat.com>
+
+       * config/mips/mips.c (mips_va_arg): When using the struct version
+       of the EABI va_list, allow arguments in the register save area to
+       take up less room than a stack argument.
+
 2002-04-10  Richard Henderson  <rth@redhat.com>
 
        * expr.c (expand_expr) [INTEGER_CST]: Don't force into registers

diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index c04b0546a53e13a994bad7f3aba4ff99dcfc3b72..8188c7bbc1fb81a03c79313b21cb92dd13df2efb 100644 (file)
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -4582,6 +4582,7 @@ mips_va_arg (valist, type)
          tree f_ovfl, f_gtop, f_ftop, f_goff, f_foff;
          tree ovfl, top, off;
          rtx lab_over = NULL_RTX, lab_false;
+         HOST_WIDE_INT osize;
 
          f_ovfl = TYPE_FIELDS (va_list_type_node);
          f_gtop = TREE_CHAIN (f_ovfl);
@@ -4596,7 +4597,11 @@ mips_va_arg (valist, type)
                 TOP be the top of the register save area;
                 OFF be the offset from TOP of the next register;
                 ADDR_RTX be the address of the argument; and
-                RSIZE be the number of bytes used to store the argument.
+                RSIZE be the number of bytes used to store the argument
+                  when it's in the register save area
+                OSIZE be the number of bytes used to store it when it's
+                  in the stack overflow area
+                PADDING be (BYTES_BIG_ENDIAN ? OSIZE - RSIZE : 0)
 
             The code we want is:
 
@@ -4608,10 +4613,10 @@ mips_va_arg (valist, type)
                  6:   }
                  7: else
                  8:   {
-                 9:     ovfl += ((intptr_t) ovfl + rsize - 1) & -rsize;
-                10:     addr_rtx = ovfl;
-                11:     ovfl += rsize;
-                12:   }
+                 9:     ovfl += ((intptr_t) ovfl + osize - 1) & -osize;
+                10:     addr_rtx = ovfl + PADDING;
+                11:     ovfl += osize;
+                14:   }
 
             [1] and [9] can sometimes be optimized away.  */
 
@@ -4643,6 +4648,13 @@ mips_va_arg (valist, type)
                  expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
                }
            }
+         /* Every overflow argument must take up at least UNITS_PER_WORD
+            bytes (= PARM_BOUNDARY bits).  RSIZE can sometimes be smaller
+            than that, such as in the combination -mgp64 -msingle-float
+            -fshort-double.  Doubles passed in registers will then take
+            up UNITS_PER_FPVALUE bytes, but those passed on the stack
+            take up UNITS_PER_WORD bytes.  */
+         osize = MAX (rsize, UNITS_PER_WORD);
 
          /* [2] Emit code to branch if off == 0.  */
          r = expand_expr (off, NULL_RTX, TYPE_MODE (TREE_TYPE (off)),
@@ -4668,21 +4680,25 @@ mips_va_arg (valist, type)
          emit_barrier ();
          emit_label (lab_false);
 
-         if (rsize > UNITS_PER_WORD)
+         if (osize > UNITS_PER_WORD)
            {
-             /* [9] Emit: ovfl += ((intptr_t) ovfl + rsize - 1) & -rsize.  */
+             /* [9] Emit: ovfl += ((intptr_t) ovfl + osize - 1) & -osize.  */
              t = build (PLUS_EXPR, TREE_TYPE (ovfl), ovfl,
-                        build_int_2 (rsize - 1, 0));
+                        build_int_2 (osize - 1, 0));
              t = build (BIT_AND_EXPR, TREE_TYPE (ovfl), t,
-                        build_int_2 (-rsize, -1));
+                        build_int_2 (-osize, -1));
              t = build (MODIFY_EXPR, TREE_TYPE (ovfl), ovfl, t);
              expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
            }
 
          /* [10, 11].  Emit code to store ovfl in addr_rtx, then
-            post-increment ovfl by rsize.  */
+            post-increment ovfl by osize.  On big-endian machines,
+            the argument has OSIZE - RSIZE bytes of leading padding.  */
          t = build (POSTINCREMENT_EXPR, TREE_TYPE (ovfl), ovfl,
-                    size_int (rsize));
+                    size_int (osize));
+         if (BYTES_BIG_ENDIAN && osize > rsize)
+           t = build (PLUS_EXPR, TREE_TYPE (t), t,
+                      build_int_2 (osize - rsize, 0));
          r = expand_expr (t, addr_rtx, Pmode, EXPAND_NORMAL);
          if (r != addr_rtx)
            emit_move_insn (addr_rtx, r);