+2011-10-12 Richard Sandiford <richard.sandiford@linaro.org>
+
+ * expr.h (copy_blkmode_to_reg): Declare.
+ * expr.c (copy_blkmode_to_reg): New function.
+ (expand_assignment): Don't expand register RESULT_DECLs before
+ the lhs. Use copy_blkmode_to_reg to copy BLKmode values into a
+ RESULT_DECL register.
+ (expand_expr_real_1): Handle BLKmode decls when looking for promotion.
+ * stmt.c (expand_return): Move BLKmode-to-register code into
+ copy_blkmode_to_reg.
+
2011-10-11 Eric Botcazou <ebotcazou@adacore.com>
PR target/49965
return tgtblk;
}
+/* Copy BLKmode value SRC into a register of mode MODE. Return the
+ register if it contains any data, otherwise return null.
+
+ This is used on targets that return BLKmode values in registers. */
+
+rtx
+copy_blkmode_to_reg (enum machine_mode mode, tree src)
+{
+ int i, n_regs;
+ unsigned HOST_WIDE_INT bitpos, xbitpos, padding_correction = 0, bytes;
+ unsigned int bitsize;
+ rtx *dst_words, dst, x, src_word = NULL_RTX, dst_word = NULL_RTX;
+ enum machine_mode dst_mode;
+
+ gcc_assert (TYPE_MODE (TREE_TYPE (src)) == BLKmode);
+
+ x = expand_normal (src);
+
+ bytes = int_size_in_bytes (TREE_TYPE (src));
+ if (bytes == 0)
+ return NULL_RTX;
+
+ /* If the structure doesn't take up a whole number of words, see
+ whether the register value should be padded on the left or on
+ the right. Set PADDING_CORRECTION to the number of padding
+ bits needed on the left side.
+
+ In most ABIs, the structure will be returned at the least end of
+ the register, which translates to right padding on little-endian
+ targets and left padding on big-endian targets. The opposite
+ holds if the structure is returned at the most significant
+ end of the register. */
+ if (bytes % UNITS_PER_WORD != 0
+ && (targetm.calls.return_in_msb (TREE_TYPE (src))
+ ? !BYTES_BIG_ENDIAN
+ : BYTES_BIG_ENDIAN))
+ padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
+ * BITS_PER_UNIT));
+
+ n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
+ dst_words = XALLOCAVEC (rtx, n_regs);
+ bitsize = MIN (TYPE_ALIGN (TREE_TYPE (src)), BITS_PER_WORD);
+
+ /* Copy the structure BITSIZE bits at a time. */
+ for (bitpos = 0, xbitpos = padding_correction;
+ bitpos < bytes * BITS_PER_UNIT;
+ bitpos += bitsize, xbitpos += bitsize)
+ {
+ /* We need a new destination pseudo each time xbitpos is
+ on a word boundary and when xbitpos == padding_correction
+ (the first time through). */
+ if (xbitpos % BITS_PER_WORD == 0
+ || xbitpos == padding_correction)
+ {
+ /* Generate an appropriate register. */
+ dst_word = gen_reg_rtx (word_mode);
+ dst_words[xbitpos / BITS_PER_WORD] = dst_word;
+
+ /* Clear the destination before we move anything into it. */
+ emit_move_insn (dst_word, CONST0_RTX (word_mode));
+ }
+
+ /* We need a new source operand each time bitpos is on a word
+ boundary. */
+ if (bitpos % BITS_PER_WORD == 0)
+ src_word = operand_subword_force (x, bitpos / BITS_PER_WORD, BLKmode);
+
+ /* Use bitpos for the source extraction (left justified) and
+ xbitpos for the destination store (right justified). */
+ store_bit_field (dst_word, bitsize, xbitpos % BITS_PER_WORD,
+ 0, 0, word_mode,
+ extract_bit_field (src_word, bitsize,
+ bitpos % BITS_PER_WORD, 1, false,
+ NULL_RTX, word_mode, word_mode));
+ }
+
+ if (mode == BLKmode)
+ {
+ /* Find the smallest integer mode large enough to hold the
+ entire structure. */
+ for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
+ mode != VOIDmode;
+ mode = GET_MODE_WIDER_MODE (mode))
+ /* Have we found a large enough mode? */
+ if (GET_MODE_SIZE (mode) >= bytes)
+ break;
+
+ /* A suitable mode should have been found. */
+ gcc_assert (mode != VOIDmode);
+ }
+
+ if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (word_mode))
+ dst_mode = word_mode;
+ else
+ dst_mode = mode;
+ dst = gen_reg_rtx (dst_mode);
+
+ for (i = 0; i < n_regs; i++)
+ emit_move_insn (operand_subword (dst, i, 0, dst_mode), dst_words[i]);
+
+ if (mode != dst_mode)
+ dst = gen_lowpart (mode, dst);
+
+ return dst;
+}
+
/* Add a USE expression for REG to the (possibly empty) list pointed
to by CALL_FUSAGE. REG must denote a hard register. */
if (TREE_CODE (from) == CALL_EXPR && ! aggregate_value_p (from, from)
&& COMPLETE_TYPE_P (TREE_TYPE (from))
&& TREE_CODE (TYPE_SIZE (TREE_TYPE (from))) == INTEGER_CST
- && ! (((TREE_CODE (to) == VAR_DECL || TREE_CODE (to) == PARM_DECL)
+ && ! (((TREE_CODE (to) == VAR_DECL
+ || TREE_CODE (to) == PARM_DECL
+ || TREE_CODE (to) == RESULT_DECL)
&& REG_P (DECL_RTL (to)))
|| TREE_CODE (to) == SSA_NAME))
{
rtx temp;
push_temp_slots ();
- temp = expand_expr (from, NULL_RTX, GET_MODE (to_rtx), EXPAND_NORMAL);
+ if (REG_P (to_rtx) && TYPE_MODE (TREE_TYPE (from)) == BLKmode)
+ temp = copy_blkmode_to_reg (GET_MODE (to_rtx), from);
+ else
+ temp = expand_expr (from, NULL_RTX, GET_MODE (to_rtx), EXPAND_NORMAL);
if (GET_CODE (to_rtx) == PARALLEL)
emit_group_load (to_rtx, temp, TREE_TYPE (from),
int_size_in_bytes (TREE_TYPE (from)));
- else
+ else if (temp)
emit_move_insn (to_rtx, temp);
preserve_temp_slots (to_rtx);
return temp;
}
- /* If the mode of DECL_RTL does not match that of the decl, it
- must be a promoted value. We return a SUBREG of the wanted mode,
- but mark it so that we know that it was already extended. */
- if (REG_P (decl_rtl) && GET_MODE (decl_rtl) != DECL_MODE (exp))
+ /* If the mode of DECL_RTL does not match that of the decl,
+ there are two cases: we are dealing with a BLKmode value
+ that is returned in a register, or we are dealing with
+ a promoted value. In the latter case, return a SUBREG
+ of the wanted mode, but mark it so that we know that it
+ was already extended. */
+ if (REG_P (decl_rtl)
+ && DECL_MODE (exp) != BLKmode
+ && GET_MODE (decl_rtl) != DECL_MODE (exp))
{
enum machine_mode pmode;
Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
extern void use_reg_mode (rtx *, rtx, enum machine_mode);
+extern rtx copy_blkmode_to_reg (enum machine_mode, tree);
+
/* Mark REG as holding a parameter for the next CALL_INSN. */
static inline void
use_reg (rtx *fusage, rtx reg)
expand_value_return (result_rtl);
/* If the result is an aggregate that is being returned in one (or more)
- registers, load the registers here. The compiler currently can't handle
- copying a BLKmode value into registers. We could put this code in a
- more general area (for use by everyone instead of just function
- call/return), but until this feature is generally usable it is kept here
- (and in expand_call). */
+ registers, load the registers here. */
else if (retval_rhs != 0
&& TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
&& REG_P (result_rtl))
{
- int i;
- unsigned HOST_WIDE_INT bitpos, xbitpos;
- unsigned HOST_WIDE_INT padding_correction = 0;
- unsigned HOST_WIDE_INT bytes
- = int_size_in_bytes (TREE_TYPE (retval_rhs));
- int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
- unsigned int bitsize
- = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
- rtx *result_pseudos = XALLOCAVEC (rtx, n_regs);
- rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
- rtx result_val = expand_normal (retval_rhs);
- enum machine_mode tmpmode, result_reg_mode;
-
- if (bytes == 0)
+ val = copy_blkmode_to_reg (GET_MODE (result_rtl), retval_rhs);
+ if (val)
{
- expand_null_return ();
- return;
- }
-
- /* If the structure doesn't take up a whole number of words, see
- whether the register value should be padded on the left or on
- the right. Set PADDING_CORRECTION to the number of padding
- bits needed on the left side.
-
- In most ABIs, the structure will be returned at the least end of
- the register, which translates to right padding on little-endian
- targets and left padding on big-endian targets. The opposite
- holds if the structure is returned at the most significant
- end of the register. */
- if (bytes % UNITS_PER_WORD != 0
- && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
- ? !BYTES_BIG_ENDIAN
- : BYTES_BIG_ENDIAN))
- padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
- * BITS_PER_UNIT));
-
- /* Copy the structure BITSIZE bits at a time. */
- for (bitpos = 0, xbitpos = padding_correction;
- bitpos < bytes * BITS_PER_UNIT;
- bitpos += bitsize, xbitpos += bitsize)
- {
- /* We need a new destination pseudo each time xbitpos is
- on a word boundary and when xbitpos == padding_correction
- (the first time through). */
- if (xbitpos % BITS_PER_WORD == 0
- || xbitpos == padding_correction)
- {
- /* Generate an appropriate register. */
- dst = gen_reg_rtx (word_mode);
- result_pseudos[xbitpos / BITS_PER_WORD] = dst;
-
- /* Clear the destination before we move anything into it. */
- emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
- }
-
- /* We need a new source operand each time bitpos is on a word
- boundary. */
- if (bitpos % BITS_PER_WORD == 0)
- src = operand_subword_force (result_val,
- bitpos / BITS_PER_WORD,
- BLKmode);
-
- /* Use bitpos for the source extraction (left justified) and
- xbitpos for the destination store (right justified). */
- store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD,
- 0, 0, word_mode,
- extract_bit_field (src, bitsize,
- bitpos % BITS_PER_WORD, 1, false,
- NULL_RTX, word_mode, word_mode));
- }
-
- tmpmode = GET_MODE (result_rtl);
- if (tmpmode == BLKmode)
- {
- /* Find the smallest integer mode large enough to hold the
- entire structure and use that mode instead of BLKmode
- on the USE insn for the return register. */
- for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
- tmpmode != VOIDmode;
- tmpmode = GET_MODE_WIDER_MODE (tmpmode))
- /* Have we found a large enough mode? */
- if (GET_MODE_SIZE (tmpmode) >= bytes)
- break;
-
- /* A suitable mode should have been found. */
- gcc_assert (tmpmode != VOIDmode);
-
- PUT_MODE (result_rtl, tmpmode);
+ /* Use the mode of the result value on the return register. */
+ PUT_MODE (result_rtl, GET_MODE (val));
+ expand_value_return (val);
}
-
- if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
- result_reg_mode = word_mode;
else
- result_reg_mode = tmpmode;
- result_reg = gen_reg_rtx (result_reg_mode);
-
- for (i = 0; i < n_regs; i++)
- emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
- result_pseudos[i]);
-
- if (tmpmode != result_reg_mode)
- result_reg = gen_lowpart (tmpmode, result_reg);
-
- expand_value_return (result_reg);
+ expand_null_return ();
}
else if (retval_rhs != 0
&& !VOID_TYPE_P (TREE_TYPE (retval_rhs))
--- /dev/null
+template<int N> struct val { char a[N]; };
+
+class Base
+{
+public:
+ virtual val<1> get1() const = 0;
+ virtual val<2> get2() const = 0;
+ virtual val<3> get3() const = 0;
+ virtual val<4> get4() const = 0;
+};
+
+class Derived : public virtual Base
+{
+public:
+ virtual val<1> get1() const { return foo->get1(); }
+ virtual val<2> get2() const { return foo->get2(); }
+ virtual val<3> get3() const { return foo->get3(); }
+ virtual val<4> get4() const { return foo->get4(); }
+ Base *foo;
+};
+
+Base* make() { return new Derived; }