diff -Naur gcc-4.5.3.orig/gcc/expr.c gcc-4.5.3/gcc/expr.c --- gcc-4.5.3.orig/gcc/expr.c 2012-01-04 21:09:23.416616230 -0500 +++ gcc-4.5.3/gcc/expr.c 2012-01-04 21:08:24.396616331 -0500 @@ -2220,6 +2220,111 @@ 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, word_mode, + extract_bit_field (src_word, bitsize, + bitpos % BITS_PER_WORD, 1, + 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. */ @@ -4380,7 +4485,9 @@ 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)) { @@ -4426,12 +4533,15 @@ 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); @@ -8517,11 +8627,14 @@ 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 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; diff -Naur gcc-4.5.3.orig/gcc/expr.h gcc-4.5.3/gcc/expr.h --- gcc-4.5.3.orig/gcc/expr.h 2012-01-04 21:03:22.207868400 -0500 +++ gcc-4.5.3/gcc/expr.h 2012-01-04 21:04:07.207866645 -0500 @@ -460,6 +460,8 @@ /* Copy BLKmode object from a set of registers. */ extern rtx copy_blkmode_from_reg (rtx, rtx, tree); +extern rtx copy_blkmode_to_reg (enum machine_mode, tree); + /* Mark REG as holding a parameter for the next CALL_INSN. */ extern void use_reg (rtx *, rtx);