calls.c (emit_library_call_value_1): Support padding for libcall arguments and return...

	gcc/
	* calls.c (emit_library_call_value_1): Support padding for libcall
	arguments and return values.
	* config/arm/arm.c (arm_pad_arg_upward): Pad half-float values
	downwards in big-endian mode.

From-SVN: r177022

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 76fe48cff39ea79a523736257d177565fe88462f..417807a970b180775c3f1bcfdee1a9c80637d440 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2011-08-01  Julian Brown  <julian@codesourcery.com>
+
+       * calls.c (emit_library_call_value_1): Support padding for libcall
+       arguments and return values.
+       * config/arm/arm.c (arm_pad_arg_upward): Pad half-float values
+       downwards in big-endian mode.
+
 2011-08-01  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
        PR debug/49887

diff --git a/gcc/calls.c b/gcc/calls.c
index dfa9ceb556332eadc4b2a8ccd8c1ac1cf2898a42..7ad30b4245c135f6f90772d2930d144db3f44305 100644 (file)
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -3829,13 +3829,41 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
       rtx val = argvec[argnum].value;
       rtx reg = argvec[argnum].reg;
       int partial = argvec[argnum].partial;
-
+      int size = 0;
+      
       /* Handle calls that pass values in multiple non-contiguous
         locations.  The PA64 has examples of this for library calls.  */
       if (reg != 0 && GET_CODE (reg) == PARALLEL)
        emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
       else if (reg != 0 && partial == 0)
-       emit_move_insn (reg, val);
+        {
+         emit_move_insn (reg, val);
+#ifdef BLOCK_REG_PADDING
+         size = GET_MODE_SIZE (argvec[argnum].mode);
+
+         /* Copied from load_register_parameters.  */
+
+         /* Handle case where we have a value that needs shifting
+            up to the msb.  eg. a QImode value and we're padding
+            upward on a BYTES_BIG_ENDIAN machine.  */
+         if (size < UNITS_PER_WORD
+             && (argvec[argnum].locate.where_pad
+                 == (BYTES_BIG_ENDIAN ? upward : downward)))
+           {
+             rtx x;
+             int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
+
+             /* Assigning REG here rather than a temp makes CALL_FUSAGE
+                report the whole reg as used.  Strictly speaking, the
+                call only uses SIZE bytes at the msb end, but it doesn't
+                seem worth generating rtl to say that.  */
+             reg = gen_rtx_REG (word_mode, REGNO (reg));
+             x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
+             if (x != reg)
+               emit_move_insn (reg, x);
+           }
+#endif
+       }
 
       NO_DEFER_POP;
     }
@@ -3901,6 +3929,15 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
               valreg,
               old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
 
+  /* Right-shift returned value if necessary.  */
+  if (!pcc_struct_value
+      && TYPE_MODE (tfom) != BLKmode
+      && targetm.calls.return_in_msb (tfom))
+    {
+      shift_return_value (TYPE_MODE (tfom), false, valreg);
+      valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
+    }
+
   /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
      that it should complain if nonvolatile values are live.  For
      functions that cannot return, inform flow that control does not

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 4193515b3421115e00a1ca02f4ff70ae94b7c1d1..e0b8c3dd4a03cae6d23edbafc63e715790eedf0e 100644 (file)
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -11261,6 +11261,15 @@ arm_pad_arg_upward (enum machine_mode mode, const_tree type)
   if (type && BYTES_BIG_ENDIAN && INTEGRAL_TYPE_P (type))
     return false;
 
+  /* Half-float values are only passed to libcalls, not regular functions.
+     They should be passed and returned as "short"s (see RTABI).  To achieve
+     that effect in big-endian mode, pad downwards so the value is passed in
+     the least-significant end of the register.  ??? This needs to be here
+     rather than in arm_pad_reg_upward due to peculiarity in the handling of
+     libcall arguments.  */
+  if (BYTES_BIG_ENDIAN && mode == HFmode)
+    return false;
+
   return true;
 }