diff options
Diffstat (limited to 'gcc/stmt.c')
| -rw-r--r-- | gcc/stmt.c | 159 |
1 files changed, 127 insertions, 32 deletions
diff --git a/gcc/stmt.c b/gcc/stmt.c index 718f2558e7d..7b388dd6c1d 100644 --- a/gcc/stmt.c +++ b/gcc/stmt.c @@ -403,6 +403,7 @@ static bool check_unique_operand_names (tree, tree); static char *resolve_operand_name_1 (char *, tree, tree); static void expand_null_return_1 (rtx); static enum br_predictor return_prediction (rtx); +static rtx shift_return_value (rtx); static void expand_value_return (rtx); static int tail_recursion_args (tree, tree); static void expand_cleanups (tree, int, int); @@ -646,6 +647,13 @@ expand_goto (tree label) else #endif { + emit_insn (gen_rtx_CLOBBER (VOIDmode, + gen_rtx_MEM (BLKmode, + gen_rtx_SCRATCH (VOIDmode)))); + emit_insn (gen_rtx_CLOBBER (VOIDmode, + gen_rtx_MEM (BLKmode, + hard_frame_pointer_rtx))); + /* Restore frame pointer for containing function. This sets the actual hard register used for the frame pointer to the location of the function's incoming static chain info. @@ -1246,6 +1254,9 @@ parse_output_constraint (const char **constraint_p, int operand_num, break; } + if (*is_inout && !*allows_reg) + warning ("read-write constraint does not allow a register"); + return true; } @@ -1261,6 +1272,7 @@ parse_input_constraint (const char **constraint_p, int input_num, const char *orig_constraint = constraint; size_t c_len = strlen (constraint); size_t j; + bool saw_match = false; /* Assume the constraint doesn't allow the use of either a register or memory. */ @@ -1312,6 +1324,8 @@ parse_input_constraint (const char **constraint_p, int input_num, char *end; unsigned long match; + saw_match = true; + match = strtoul (constraint + j, &end, 10); if (match >= (unsigned long) noutputs) { @@ -1376,6 +1390,9 @@ parse_input_constraint (const char **constraint_p, int input_num, break; } + if (saw_match && !*allows_reg) + warning ("matching constraint does not allow a register"); + return true; } @@ -1704,13 +1721,16 @@ expand_asm_operands (tree string, tree outputs, tree inputs, if (CONSTANT_P (op)) { - op = force_const_mem (TYPE_MODE (type), op); - op = validize_mem (op); + rtx mem = force_const_mem (TYPE_MODE (type), op); + if (mem) + op = validize_mem (mem); + else + op = force_reg (TYPE_MODE (type), op); } - else if (GET_CODE (op) == REG - || GET_CODE (op) == SUBREG - || GET_CODE (op) == ADDRESSOF - || GET_CODE (op) == CONCAT) + if (GET_CODE (op) == REG + || GET_CODE (op) == SUBREG + || GET_CODE (op) == ADDRESSOF + || GET_CODE (op) == CONCAT) { tree qual_type = build_qualified_type (type, (TYPE_QUALS (type) @@ -2874,6 +2894,26 @@ expand_null_return (void) expand_null_return_1 (last_insn); } +/* Generate RTL to return directly from the current function. + (That is, we bypass any return value.) */ + +void +expand_naked_return (void) +{ + rtx last_insn, end_label; + + last_insn = get_last_insn (); + end_label = naked_return_label; + + clear_pending_stack_adjust (); + do_pending_stack_adjust (); + clear_last_expr (); + + if (end_label == 0) + end_label = naked_return_label = gen_label_rtx (); + expand_goto_internal (NULL_TREE, end_label, last_insn); +} + /* Try to guess whether the value of return means error code. */ static enum br_predictor return_prediction (rtx val) @@ -2902,6 +2942,34 @@ return_prediction (rtx val) return PRED_NO_PREDICTION; } + +/* If the current function returns values in the most significant part + of a register, shift return value VAL appropriately. The mode of + the function's return type is known not to be BLKmode. */ + +static rtx +shift_return_value (rtx val) +{ + tree type; + + type = TREE_TYPE (DECL_RESULT (current_function_decl)); + if (targetm.calls.return_in_msb (type)) + { + rtx target; + HOST_WIDE_INT shift; + + target = DECL_RTL (DECL_RESULT (current_function_decl)); + shift = (GET_MODE_BITSIZE (GET_MODE (target)) + - BITS_PER_UNIT * int_size_in_bytes (type)); + if (shift > 0) + val = expand_binop (GET_MODE (target), ashl_optab, + gen_lowpart (GET_MODE (target), val), + GEN_INT (shift), target, 1, OPTAB_WIDEN); + } + return val; +} + + /* Generate RTL to return from the current function, with value VAL. */ static void @@ -3066,7 +3134,7 @@ expand_return (tree retval) { int i; unsigned HOST_WIDE_INT bitpos, xbitpos; - unsigned HOST_WIDE_INT big_endian_correction = 0; + 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; @@ -3083,25 +3151,33 @@ expand_return (tree retval) return; } - /* Structures whose size is not a multiple of a word are aligned - to the least significant byte (to the right). On a BYTES_BIG_ENDIAN - machine, this means we must skip the empty high order bytes when - calculating the bit offset. */ - if (BYTES_BIG_ENDIAN - && bytes % UNITS_PER_WORD) - big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) - * BITS_PER_UNIT)); + /* 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 = big_endian_correction; + 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 == big_endian_correction + on a word boundary and when xbitpos == padding_correction (the first time through). */ if (xbitpos % BITS_PER_WORD == 0 - || xbitpos == big_endian_correction) + || xbitpos == padding_correction) { /* Generate an appropriate register. */ dst = gen_reg_rtx (word_mode); @@ -3128,21 +3204,25 @@ expand_return (tree retval) BITS_PER_WORD); } - /* 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; + 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; - /* No suitable mode found. */ - if (tmpmode == VOIDmode) - abort (); + /* No suitable mode found. */ + if (tmpmode == VOIDmode) + abort (); - PUT_MODE (result_rtl, tmpmode); + PUT_MODE (result_rtl, tmpmode); + } if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) result_reg_mode = word_mode; @@ -3175,7 +3255,7 @@ expand_return (tree retval) val = force_not_mem (val); emit_queue (); /* Return the calculated value, doing cleanups first. */ - expand_value_return (val); + expand_value_return (shift_return_value (val)); } else { @@ -3487,6 +3567,14 @@ expand_nl_handler_label (rtx slot, rtx before_insn) static void expand_nl_goto_receiver (void) { + /* Clobber the FP when we get here, so we have to make sure it's + marked as used by this function. */ + emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); + + /* Mark the static chain as clobbered here so life information + doesn't get messed up for it. */ + emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx)); + #ifdef HAVE_nonlocal_goto if (! HAVE_nonlocal_goto) #endif @@ -3535,6 +3623,13 @@ expand_nl_goto_receiver (void) if (HAVE_nonlocal_goto_receiver) emit_insn (gen_nonlocal_goto_receiver ()); #endif + + /* @@@ This is a kludge. Not all machine descriptions define a blockage + insn, but we must not allow the code we just generated to be reordered + by scheduling. Specifically, the update of the frame pointer must + happen immediately, not later. So emit an ASM_INPUT to act as blockage + insn. */ + emit_insn (gen_rtx_ASM_INPUT (VOIDmode, "")); } /* Make handlers for nonlocal gotos taking place in the function calls in |