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Diffstat (limited to 'gcc/explow.cc')
| -rw-r--r-- | gcc/explow.cc | 2321 |
1 files changed, 2321 insertions, 0 deletions
diff --git a/gcc/explow.cc b/gcc/explow.cc new file mode 100644 index 0000000..e2f4fd6 --- /dev/null +++ b/gcc/explow.cc @@ -0,0 +1,2321 @@ +/* Subroutines for manipulating rtx's in semantically interesting ways. + Copyright (C) 1987-2022 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "function.h" +#include "rtl.h" +#include "tree.h" +#include "memmodel.h" +#include "tm_p.h" +#include "optabs.h" +#include "expmed.h" +#include "profile-count.h" +#include "emit-rtl.h" +#include "recog.h" +#include "diagnostic-core.h" +#include "stor-layout.h" +#include "langhooks.h" +#include "except.h" +#include "dojump.h" +#include "explow.h" +#include "expr.h" +#include "stringpool.h" +#include "common/common-target.h" +#include "output.h" + +static rtx break_out_memory_refs (rtx); + + +/* Truncate and perhaps sign-extend C as appropriate for MODE. */ + +HOST_WIDE_INT +trunc_int_for_mode (HOST_WIDE_INT c, machine_mode mode) +{ + /* Not scalar_int_mode because we also allow pointer bound modes. */ + scalar_mode smode = as_a <scalar_mode> (mode); + int width = GET_MODE_PRECISION (smode); + + /* You want to truncate to a _what_? */ + gcc_assert (SCALAR_INT_MODE_P (mode)); + + /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */ + if (smode == BImode) + return c & 1 ? STORE_FLAG_VALUE : 0; + + /* Sign-extend for the requested mode. */ + + if (width < HOST_BITS_PER_WIDE_INT) + { + HOST_WIDE_INT sign = 1; + sign <<= width - 1; + c &= (sign << 1) - 1; + c ^= sign; + c -= sign; + } + + return c; +} + +/* Likewise for polynomial values, using the sign-extended representation + for each individual coefficient. */ + +poly_int64 +trunc_int_for_mode (poly_int64 x, machine_mode mode) +{ + for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i) + x.coeffs[i] = trunc_int_for_mode (x.coeffs[i], mode); + return x; +} + +/* Return an rtx for the sum of X and the integer C, given that X has + mode MODE. INPLACE is true if X can be modified inplace or false + if it must be treated as immutable. */ + +rtx +plus_constant (machine_mode mode, rtx x, poly_int64 c, bool inplace) +{ + RTX_CODE code; + rtx y; + rtx tem; + int all_constant = 0; + + gcc_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode); + + if (known_eq (c, 0)) + return x; + + restart: + + code = GET_CODE (x); + y = x; + + switch (code) + { + CASE_CONST_SCALAR_INT: + return immed_wide_int_const (wi::add (rtx_mode_t (x, mode), c), mode); + case MEM: + /* If this is a reference to the constant pool, try replacing it with + a reference to a new constant. If the resulting address isn't + valid, don't return it because we have no way to validize it. */ + if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF + && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) + { + rtx cst = get_pool_constant (XEXP (x, 0)); + + if (GET_CODE (cst) == CONST_VECTOR + && GET_MODE_INNER (GET_MODE (cst)) == mode) + { + cst = gen_lowpart (mode, cst); + gcc_assert (cst); + } + else if (GET_MODE (cst) == VOIDmode + && get_pool_mode (XEXP (x, 0)) != mode) + break; + if (GET_MODE (cst) == VOIDmode || GET_MODE (cst) == mode) + { + tem = plus_constant (mode, cst, c); + tem = force_const_mem (GET_MODE (x), tem); + /* Targets may disallow some constants in the constant pool, thus + force_const_mem may return NULL_RTX. */ + if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0))) + return tem; + } + } + break; + + case CONST: + /* If adding to something entirely constant, set a flag + so that we can add a CONST around the result. */ + if (inplace && shared_const_p (x)) + inplace = false; + x = XEXP (x, 0); + all_constant = 1; + goto restart; + + case SYMBOL_REF: + case LABEL_REF: + all_constant = 1; + break; + + case PLUS: + /* The interesting case is adding the integer to a sum. Look + for constant term in the sum and combine with C. For an + integer constant term or a constant term that is not an + explicit integer, we combine or group them together anyway. + + We may not immediately return from the recursive call here, lest + all_constant gets lost. */ + + if (CONSTANT_P (XEXP (x, 1))) + { + rtx term = plus_constant (mode, XEXP (x, 1), c, inplace); + if (term == const0_rtx) + x = XEXP (x, 0); + else if (inplace) + XEXP (x, 1) = term; + else + x = gen_rtx_PLUS (mode, XEXP (x, 0), term); + c = 0; + } + else if (rtx *const_loc = find_constant_term_loc (&y)) + { + if (!inplace) + { + /* We need to be careful since X may be shared and we can't + modify it in place. */ + x = copy_rtx (x); + const_loc = find_constant_term_loc (&x); + } + *const_loc = plus_constant (mode, *const_loc, c, true); + c = 0; + } + break; + + default: + if (CONST_POLY_INT_P (x)) + return immed_wide_int_const (const_poly_int_value (x) + c, mode); + break; + } + + if (maybe_ne (c, 0)) + x = gen_rtx_PLUS (mode, x, gen_int_mode (c, mode)); + + if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF) + return x; + else if (all_constant) + return gen_rtx_CONST (mode, x); + else + return x; +} + +/* If X is a sum, return a new sum like X but lacking any constant terms. + Add all the removed constant terms into *CONSTPTR. + X itself is not altered. The result != X if and only if + it is not isomorphic to X. */ + +rtx +eliminate_constant_term (rtx x, rtx *constptr) +{ + rtx x0, x1; + rtx tem; + + if (GET_CODE (x) != PLUS) + return x; + + /* First handle constants appearing at this level explicitly. */ + if (CONST_INT_P (XEXP (x, 1)) + && (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr, + XEXP (x, 1))) != 0 + && CONST_INT_P (tem)) + { + *constptr = tem; + return eliminate_constant_term (XEXP (x, 0), constptr); + } + + tem = const0_rtx; + x0 = eliminate_constant_term (XEXP (x, 0), &tem); + x1 = eliminate_constant_term (XEXP (x, 1), &tem); + if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0)) + && (tem = simplify_binary_operation (PLUS, GET_MODE (x), + *constptr, tem)) != 0 + && CONST_INT_P (tem)) + { + *constptr = tem; + return gen_rtx_PLUS (GET_MODE (x), x0, x1); + } + + return x; +} + + +/* Return a copy of X in which all memory references + and all constants that involve symbol refs + have been replaced with new temporary registers. + Also emit code to load the memory locations and constants + into those registers. + + If X contains no such constants or memory references, + X itself (not a copy) is returned. + + If a constant is found in the address that is not a legitimate constant + in an insn, it is left alone in the hope that it might be valid in the + address. + + X may contain no arithmetic except addition, subtraction and multiplication. + Values returned by expand_expr with 1 for sum_ok fit this constraint. */ + +static rtx +break_out_memory_refs (rtx x) +{ + if (MEM_P (x) + || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x) + && GET_MODE (x) != VOIDmode)) + x = force_reg (GET_MODE (x), x); + else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS + || GET_CODE (x) == MULT) + { + rtx op0 = break_out_memory_refs (XEXP (x, 0)); + rtx op1 = break_out_memory_refs (XEXP (x, 1)); + + if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) + x = simplify_gen_binary (GET_CODE (x), GET_MODE (x), op0, op1); + } + + return x; +} + +/* Given X, a memory address in address space AS' pointer mode, convert it to + an address in the address space's address mode, or vice versa (TO_MODE says + which way). We take advantage of the fact that pointers are not allowed to + overflow by commuting arithmetic operations over conversions so that address + arithmetic insns can be used. IN_CONST is true if this conversion is inside + a CONST. NO_EMIT is true if no insns should be emitted, and instead + it should return NULL if it can't be simplified without emitting insns. */ + +rtx +convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED, + rtx x, addr_space_t as ATTRIBUTE_UNUSED, + bool in_const ATTRIBUTE_UNUSED, + bool no_emit ATTRIBUTE_UNUSED) +{ +#ifndef POINTERS_EXTEND_UNSIGNED + gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode); + return x; +#else /* defined(POINTERS_EXTEND_UNSIGNED) */ + scalar_int_mode pointer_mode, address_mode, from_mode; + rtx temp; + enum rtx_code code; + + /* If X already has the right mode, just return it. */ + if (GET_MODE (x) == to_mode) + return x; + + pointer_mode = targetm.addr_space.pointer_mode (as); + address_mode = targetm.addr_space.address_mode (as); + from_mode = to_mode == pointer_mode ? address_mode : pointer_mode; + + /* Here we handle some special cases. If none of them apply, fall through + to the default case. */ + switch (GET_CODE (x)) + { + CASE_CONST_SCALAR_INT: + if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)) + code = TRUNCATE; + else if (POINTERS_EXTEND_UNSIGNED < 0) + break; + else if (POINTERS_EXTEND_UNSIGNED > 0) + code = ZERO_EXTEND; + else + code = SIGN_EXTEND; + temp = simplify_unary_operation (code, to_mode, x, from_mode); + if (temp) + return temp; + break; + + case SUBREG: + if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x))) + && GET_MODE (SUBREG_REG (x)) == to_mode) + return SUBREG_REG (x); + break; + + case LABEL_REF: + temp = gen_rtx_LABEL_REF (to_mode, label_ref_label (x)); + LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x); + return temp; + + case SYMBOL_REF: + temp = shallow_copy_rtx (x); + PUT_MODE (temp, to_mode); + return temp; + + case CONST: + temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, + true, no_emit); + return temp ? gen_rtx_CONST (to_mode, temp) : temp; + + case PLUS: + case MULT: + /* For addition we can safely permute the conversion and addition + operation if one operand is a constant and converting the constant + does not change it or if one operand is a constant and we are + using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0). + We can always safely permute them if we are making the address + narrower. Inside a CONST RTL, this is safe for both pointers + zero or sign extended as pointers cannot wrap. */ + if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode) + || (GET_CODE (x) == PLUS + && CONST_INT_P (XEXP (x, 1)) + && ((in_const && POINTERS_EXTEND_UNSIGNED != 0) + || XEXP (x, 1) == convert_memory_address_addr_space_1 + (to_mode, XEXP (x, 1), as, in_const, + no_emit) + || POINTERS_EXTEND_UNSIGNED < 0))) + { + temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), + as, in_const, no_emit); + return (temp ? gen_rtx_fmt_ee (GET_CODE (x), to_mode, + temp, XEXP (x, 1)) + : temp); + } + break; + + case UNSPEC: + /* Assume that all UNSPECs in a constant address can be converted + operand-by-operand. We could add a target hook if some targets + require different behavior. */ + if (in_const && GET_MODE (x) == from_mode) + { + unsigned int n = XVECLEN (x, 0); + rtvec v = gen_rtvec (n); + for (unsigned int i = 0; i < n; ++i) + { + rtx op = XVECEXP (x, 0, i); + if (GET_MODE (op) == from_mode) + op = convert_memory_address_addr_space_1 (to_mode, op, as, + in_const, no_emit); + RTVEC_ELT (v, i) = op; + } + return gen_rtx_UNSPEC (to_mode, v, XINT (x, 1)); + } + break; + + default: + break; + } + + if (no_emit) + return NULL_RTX; + + return convert_modes (to_mode, from_mode, + x, POINTERS_EXTEND_UNSIGNED); +#endif /* defined(POINTERS_EXTEND_UNSIGNED) */ +} + +/* Given X, a memory address in address space AS' pointer mode, convert it to + an address in the address space's address mode, or vice versa (TO_MODE says + which way). We take advantage of the fact that pointers are not allowed to + overflow by commuting arithmetic operations over conversions so that address + arithmetic insns can be used. */ + +rtx +convert_memory_address_addr_space (scalar_int_mode to_mode, rtx x, + addr_space_t as) +{ + return convert_memory_address_addr_space_1 (to_mode, x, as, false, false); +} + + +/* Return something equivalent to X but valid as a memory address for something + of mode MODE in the named address space AS. When X is not itself valid, + this works by copying X or subexpressions of it into registers. */ + +rtx +memory_address_addr_space (machine_mode mode, rtx x, addr_space_t as) +{ + rtx oldx = x; + scalar_int_mode address_mode = targetm.addr_space.address_mode (as); + + x = convert_memory_address_addr_space (address_mode, x, as); + + /* By passing constant addresses through registers + we get a chance to cse them. */ + if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)) + x = force_reg (address_mode, x); + + /* We get better cse by rejecting indirect addressing at this stage. + Let the combiner create indirect addresses where appropriate. + For now, generate the code so that the subexpressions useful to share + are visible. But not if cse won't be done! */ + else + { + if (! cse_not_expected && !REG_P (x)) + x = break_out_memory_refs (x); + + /* At this point, any valid address is accepted. */ + if (memory_address_addr_space_p (mode, x, as)) + goto done; + + /* If it was valid before but breaking out memory refs invalidated it, + use it the old way. */ + if (memory_address_addr_space_p (mode, oldx, as)) + { + x = oldx; + goto done; + } + + /* Perform machine-dependent transformations on X + in certain cases. This is not necessary since the code + below can handle all possible cases, but machine-dependent + transformations can make better code. */ + { + rtx orig_x = x; + x = targetm.addr_space.legitimize_address (x, oldx, mode, as); + if (orig_x != x && memory_address_addr_space_p (mode, x, as)) + goto done; + } + + /* PLUS and MULT can appear in special ways + as the result of attempts to make an address usable for indexing. + Usually they are dealt with by calling force_operand, below. + But a sum containing constant terms is special + if removing them makes the sum a valid address: + then we generate that address in a register + and index off of it. We do this because it often makes + shorter code, and because the addresses thus generated + in registers often become common subexpressions. */ + if (GET_CODE (x) == PLUS) + { + rtx constant_term = const0_rtx; + rtx y = eliminate_constant_term (x, &constant_term); + if (constant_term == const0_rtx + || ! memory_address_addr_space_p (mode, y, as)) + x = force_operand (x, NULL_RTX); + else + { + y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term); + if (! memory_address_addr_space_p (mode, y, as)) + x = force_operand (x, NULL_RTX); + else + x = y; + } + } + + else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS) + x = force_operand (x, NULL_RTX); + + /* If we have a register that's an invalid address, + it must be a hard reg of the wrong class. Copy it to a pseudo. */ + else if (REG_P (x)) + x = copy_to_reg (x); + + /* Last resort: copy the value to a register, since + the register is a valid address. */ + else + x = force_reg (address_mode, x); + } + + done: + + gcc_assert (memory_address_addr_space_p (mode, x, as)); + /* If we didn't change the address, we are done. Otherwise, mark + a reg as a pointer if we have REG or REG + CONST_INT. */ + if (oldx == x) + return x; + else if (REG_P (x)) + mark_reg_pointer (x, BITS_PER_UNIT); + else if (GET_CODE (x) == PLUS + && REG_P (XEXP (x, 0)) + && CONST_INT_P (XEXP (x, 1))) + mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT); + + /* OLDX may have been the address on a temporary. Update the address + to indicate that X is now used. */ + update_temp_slot_address (oldx, x); + + return x; +} + +/* Convert a mem ref into one with a valid memory address. + Pass through anything else unchanged. */ + +rtx +validize_mem (rtx ref) +{ + if (!MEM_P (ref)) + return ref; + ref = use_anchored_address (ref); + if (memory_address_addr_space_p (GET_MODE (ref), XEXP (ref, 0), + MEM_ADDR_SPACE (ref))) + return ref; + + /* Don't alter REF itself, since that is probably a stack slot. */ + return replace_equiv_address (ref, XEXP (ref, 0)); +} + +/* If X is a memory reference to a member of an object block, try rewriting + it to use an anchor instead. Return the new memory reference on success + and the old one on failure. */ + +rtx +use_anchored_address (rtx x) +{ + rtx base; + HOST_WIDE_INT offset; + machine_mode mode; + + if (!flag_section_anchors) + return x; + + if (!MEM_P (x)) + return x; + + /* Split the address into a base and offset. */ + base = XEXP (x, 0); + offset = 0; + if (GET_CODE (base) == CONST + && GET_CODE (XEXP (base, 0)) == PLUS + && CONST_INT_P (XEXP (XEXP (base, 0), 1))) + { + offset += INTVAL (XEXP (XEXP (base, 0), 1)); + base = XEXP (XEXP (base, 0), 0); + } + + /* Check whether BASE is suitable for anchors. */ + if (GET_CODE (base) != SYMBOL_REF + || !SYMBOL_REF_HAS_BLOCK_INFO_P (base) + || SYMBOL_REF_ANCHOR_P (base) + || SYMBOL_REF_BLOCK (base) == NULL + || !targetm.use_anchors_for_symbol_p (base)) + return x; + + /* Decide where BASE is going to be. */ + place_block_symbol (base); + + /* Get the anchor we need to use. */ + offset += SYMBOL_REF_BLOCK_OFFSET (base); + base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset, + SYMBOL_REF_TLS_MODEL (base)); + + /* Work out the offset from the anchor. */ + offset -= SYMBOL_REF_BLOCK_OFFSET (base); + + /* If we're going to run a CSE pass, force the anchor into a register. + We will then be able to reuse registers for several accesses, if the + target costs say that that's worthwhile. */ + mode = GET_MODE (base); + if (!cse_not_expected) + base = force_reg (mode, base); + + return replace_equiv_address (x, plus_constant (mode, base, offset)); +} + +/* Copy the value or contents of X to a new temp reg and return that reg. */ + +rtx +copy_to_reg (rtx x) +{ + rtx temp = gen_reg_rtx (GET_MODE (x)); + + /* If not an operand, must be an address with PLUS and MULT so + do the computation. */ + if (! general_operand (x, VOIDmode)) + x = force_operand (x, temp); + + if (x != temp) + emit_move_insn (temp, x); + + return temp; +} + +/* Like copy_to_reg but always give the new register mode Pmode + in case X is a constant. */ + +rtx +copy_addr_to_reg (rtx x) +{ + return copy_to_mode_reg (Pmode, x); +} + +/* Like copy_to_reg but always give the new register mode MODE + in case X is a constant. */ + +rtx +copy_to_mode_reg (machine_mode mode, rtx x) +{ + rtx temp = gen_reg_rtx (mode); + + /* If not an operand, must be an address with PLUS and MULT so + do the computation. */ + if (! general_operand (x, VOIDmode)) + x = force_operand (x, temp); + + gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode); + if (x != temp) + emit_move_insn (temp, x); + return temp; +} + +/* Load X into a register if it is not already one. + Use mode MODE for the register. + X should be valid for mode MODE, but it may be a constant which + is valid for all integer modes; that's why caller must specify MODE. + + The caller must not alter the value in the register we return, + since we mark it as a "constant" register. */ + +rtx +force_reg (machine_mode mode, rtx x) +{ + rtx temp, set; + rtx_insn *insn; + + if (REG_P (x)) + return x; + + if (general_operand (x, mode)) + { + temp = gen_reg_rtx (mode); + insn = emit_move_insn (temp, x); + } + else + { + temp = force_operand (x, NULL_RTX); + if (REG_P (temp)) + insn = get_last_insn (); + else + { + rtx temp2 = gen_reg_rtx (mode); + insn = emit_move_insn (temp2, temp); + temp = temp2; + } + } + + /* Let optimizers know that TEMP's value never changes + and that X can be substituted for it. Don't get confused + if INSN set something else (such as a SUBREG of TEMP). */ + if (CONSTANT_P (x) + && (set = single_set (insn)) != 0 + && SET_DEST (set) == temp + && ! rtx_equal_p (x, SET_SRC (set))) + set_unique_reg_note (insn, REG_EQUAL, x); + + /* Let optimizers know that TEMP is a pointer, and if so, the + known alignment of that pointer. */ + { + unsigned align = 0; + if (GET_CODE (x) == SYMBOL_REF) + { + align = BITS_PER_UNIT; + if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x))) + align = DECL_ALIGN (SYMBOL_REF_DECL (x)); + } + else if (GET_CODE (x) == LABEL_REF) + align = BITS_PER_UNIT; + else if (GET_CODE (x) == CONST + && GET_CODE (XEXP (x, 0)) == PLUS + && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF + && CONST_INT_P (XEXP (XEXP (x, 0), 1))) + { + rtx s = XEXP (XEXP (x, 0), 0); + rtx c = XEXP (XEXP (x, 0), 1); + unsigned sa, ca; + + sa = BITS_PER_UNIT; + if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s))) + sa = DECL_ALIGN (SYMBOL_REF_DECL (s)); + + if (INTVAL (c) == 0) + align = sa; + else + { + ca = ctz_hwi (INTVAL (c)) * BITS_PER_UNIT; + align = MIN (sa, ca); + } + } + + if (align || (MEM_P (x) && MEM_POINTER (x))) + mark_reg_pointer (temp, align); + } + + return temp; +} + +/* If X is a memory ref, copy its contents to a new temp reg and return + that reg. Otherwise, return X. */ + +rtx +force_not_mem (rtx x) +{ + rtx temp; + + if (!MEM_P (x) || GET_MODE (x) == BLKmode) + return x; + + temp = gen_reg_rtx (GET_MODE (x)); + + if (MEM_POINTER (x)) + REG_POINTER (temp) = 1; + + emit_move_insn (temp, x); + return temp; +} + +/* Copy X to TARGET (if it's nonzero and a reg) + or to a new temp reg and return that reg. + MODE is the mode to use for X in case it is a constant. */ + +rtx +copy_to_suggested_reg (rtx x, rtx target, machine_mode mode) +{ + rtx temp; + + if (target && REG_P (target)) + temp = target; + else + temp = gen_reg_rtx (mode); + + emit_move_insn (temp, x); + return temp; +} + +/* Return the mode to use to pass or return a scalar of TYPE and MODE. + PUNSIGNEDP points to the signedness of the type and may be adjusted + to show what signedness to use on extension operations. + + FOR_RETURN is nonzero if the caller is promoting the return value + of FNDECL, else it is for promoting args. */ + +machine_mode +promote_function_mode (const_tree type, machine_mode mode, int *punsignedp, + const_tree funtype, int for_return) +{ + /* Called without a type node for a libcall. */ + if (type == NULL_TREE) + { + if (INTEGRAL_MODE_P (mode)) + return targetm.calls.promote_function_mode (NULL_TREE, mode, + punsignedp, funtype, + for_return); + else + return mode; + } + + switch (TREE_CODE (type)) + { + case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: + case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE: + case POINTER_TYPE: case REFERENCE_TYPE: + return targetm.calls.promote_function_mode (type, mode, punsignedp, funtype, + for_return); + + default: + return mode; + } +} +/* Return the mode to use to store a scalar of TYPE and MODE. + PUNSIGNEDP points to the signedness of the type and may be adjusted + to show what signedness to use on extension operations. */ + +machine_mode +promote_mode (const_tree type ATTRIBUTE_UNUSED, machine_mode mode, + int *punsignedp ATTRIBUTE_UNUSED) +{ +#ifdef PROMOTE_MODE + enum tree_code code; + int unsignedp; + scalar_mode smode; +#endif + + /* For libcalls this is invoked without TYPE from the backends + TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that + case. */ + if (type == NULL_TREE) + return mode; + + /* FIXME: this is the same logic that was there until GCC 4.4, but we + probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE + is not defined. The affected targets are M32C, S390, SPARC. */ +#ifdef PROMOTE_MODE + code = TREE_CODE (type); + unsignedp = *punsignedp; + + switch (code) + { + case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: + case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE: + /* Values of these types always have scalar mode. */ + smode = as_a <scalar_mode> (mode); + PROMOTE_MODE (smode, unsignedp, type); + *punsignedp = unsignedp; + return smode; + +#ifdef POINTERS_EXTEND_UNSIGNED + case REFERENCE_TYPE: + case POINTER_TYPE: + *punsignedp = POINTERS_EXTEND_UNSIGNED; + return targetm.addr_space.address_mode + (TYPE_ADDR_SPACE (TREE_TYPE (type))); +#endif + + default: + return mode; + } +#else + return mode; +#endif +} + + +/* Use one of promote_mode or promote_function_mode to find the promoted + mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness + of DECL after promotion. */ + +machine_mode +promote_decl_mode (const_tree decl, int *punsignedp) +{ + tree type = TREE_TYPE (decl); + int unsignedp = TYPE_UNSIGNED (type); + machine_mode mode = DECL_MODE (decl); + machine_mode pmode; + + if (TREE_CODE (decl) == RESULT_DECL && !DECL_BY_REFERENCE (decl)) + pmode = promote_function_mode (type, mode, &unsignedp, + TREE_TYPE (current_function_decl), 1); + else if (TREE_CODE (decl) == RESULT_DECL || TREE_CODE (decl) == PARM_DECL) + pmode = promote_function_mode (type, mode, &unsignedp, + TREE_TYPE (current_function_decl), 2); + else + pmode = promote_mode (type, mode, &unsignedp); + + if (punsignedp) + *punsignedp = unsignedp; + return pmode; +} + +/* Return the promoted mode for name. If it is a named SSA_NAME, it + is the same as promote_decl_mode. Otherwise, it is the promoted + mode of a temp decl of same type as the SSA_NAME, if we had created + one. */ + +machine_mode +promote_ssa_mode (const_tree name, int *punsignedp) +{ + gcc_assert (TREE_CODE (name) == SSA_NAME); + + /* Partitions holding parms and results must be promoted as expected + by function.c. */ + if (SSA_NAME_VAR (name) + && (TREE_CODE (SSA_NAME_VAR (name)) == PARM_DECL + || TREE_CODE (SSA_NAME_VAR (name)) == RESULT_DECL)) + { + machine_mode mode = promote_decl_mode (SSA_NAME_VAR (name), punsignedp); + if (mode != BLKmode) + return mode; + } + + tree type = TREE_TYPE (name); + int unsignedp = TYPE_UNSIGNED (type); + machine_mode pmode = promote_mode (type, TYPE_MODE (type), &unsignedp); + if (punsignedp) + *punsignedp = unsignedp; + + return pmode; +} + + + +/* Controls the behavior of {anti_,}adjust_stack. */ +static bool suppress_reg_args_size; + +/* A helper for adjust_stack and anti_adjust_stack. */ + +static void +adjust_stack_1 (rtx adjust, bool anti_p) +{ + rtx temp; + rtx_insn *insn; + + /* Hereafter anti_p means subtract_p. */ + if (!STACK_GROWS_DOWNWARD) + anti_p = !anti_p; + + temp = expand_binop (Pmode, + anti_p ? sub_optab : add_optab, + stack_pointer_rtx, adjust, stack_pointer_rtx, 0, + OPTAB_LIB_WIDEN); + + if (temp != stack_pointer_rtx) + insn = emit_move_insn (stack_pointer_rtx, temp); + else + { + insn = get_last_insn (); + temp = single_set (insn); + gcc_assert (temp != NULL && SET_DEST (temp) == stack_pointer_rtx); + } + + if (!suppress_reg_args_size) + add_args_size_note (insn, stack_pointer_delta); +} + +/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes). + This pops when ADJUST is positive. ADJUST need not be constant. */ + +void +adjust_stack (rtx adjust) +{ + if (adjust == const0_rtx) + return; + + /* We expect all variable sized adjustments to be multiple of + PREFERRED_STACK_BOUNDARY. */ + poly_int64 const_adjust; + if (poly_int_rtx_p (adjust, &const_adjust)) + stack_pointer_delta -= const_adjust; + + adjust_stack_1 (adjust, false); +} + +/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes). + This pushes when ADJUST is positive. ADJUST need not be constant. */ + +void +anti_adjust_stack (rtx adjust) +{ + if (adjust == const0_rtx) + return; + + /* We expect all variable sized adjustments to be multiple of + PREFERRED_STACK_BOUNDARY. */ + poly_int64 const_adjust; + if (poly_int_rtx_p (adjust, &const_adjust)) + stack_pointer_delta += const_adjust; + + adjust_stack_1 (adjust, true); +} + +/* Round the size of a block to be pushed up to the boundary required + by this machine. SIZE is the desired size, which need not be constant. */ + +static rtx +round_push (rtx size) +{ + rtx align_rtx, alignm1_rtx; + + if (!SUPPORTS_STACK_ALIGNMENT + || crtl->preferred_stack_boundary == MAX_SUPPORTED_STACK_ALIGNMENT) + { + int align = crtl->preferred_stack_boundary / BITS_PER_UNIT; + + if (align == 1) + return size; + + if (CONST_INT_P (size)) + { + HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align; + + if (INTVAL (size) != new_size) + size = GEN_INT (new_size); + return size; + } + + align_rtx = GEN_INT (align); + alignm1_rtx = GEN_INT (align - 1); + } + else + { + /* If crtl->preferred_stack_boundary might still grow, use + virtual_preferred_stack_boundary_rtx instead. This will be + substituted by the right value in vregs pass and optimized + during combine. */ + align_rtx = virtual_preferred_stack_boundary_rtx; + alignm1_rtx = force_operand (plus_constant (Pmode, align_rtx, -1), + NULL_RTX); + } + + /* CEIL_DIV_EXPR needs to worry about the addition overflowing, + but we know it can't. So add ourselves and then do + TRUNC_DIV_EXPR. */ + size = expand_binop (Pmode, add_optab, size, alignm1_rtx, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, align_rtx, + NULL_RTX, 1); + size = expand_mult (Pmode, size, align_rtx, NULL_RTX, 1); + + return size; +} + +/* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer + to a previously-created save area. If no save area has been allocated, + this function will allocate one. If a save area is specified, it + must be of the proper mode. */ + +void +emit_stack_save (enum save_level save_level, rtx *psave) +{ + rtx sa = *psave; + /* The default is that we use a move insn and save in a Pmode object. */ + rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn; + machine_mode mode = STACK_SAVEAREA_MODE (save_level); + + /* See if this machine has anything special to do for this kind of save. */ + switch (save_level) + { + case SAVE_BLOCK: + if (targetm.have_save_stack_block ()) + fcn = targetm.gen_save_stack_block; + break; + case SAVE_FUNCTION: + if (targetm.have_save_stack_function ()) + fcn = targetm.gen_save_stack_function; + break; + case SAVE_NONLOCAL: + if (targetm.have_save_stack_nonlocal ()) + fcn = targetm.gen_save_stack_nonlocal; + break; + default: + break; + } + + /* If there is no save area and we have to allocate one, do so. Otherwise + verify the save area is the proper mode. */ + + if (sa == 0) + { + if (mode != VOIDmode) + { + if (save_level == SAVE_NONLOCAL) + *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); + else + *psave = sa = gen_reg_rtx (mode); + } + } + + do_pending_stack_adjust (); + if (sa != 0) + sa = validize_mem (sa); + emit_insn (fcn (sa, stack_pointer_rtx)); +} + +/* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save + area made by emit_stack_save. If it is zero, we have nothing to do. */ + +void +emit_stack_restore (enum save_level save_level, rtx sa) +{ + /* The default is that we use a move insn. */ + rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn; + + /* If stack_realign_drap, the x86 backend emits a prologue that aligns both + STACK_POINTER and HARD_FRAME_POINTER. + If stack_realign_fp, the x86 backend emits a prologue that aligns only + STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing + aligned variables, which is reflected in ix86_can_eliminate. + We normally still have the realigned STACK_POINTER that we can use. + But if there is a stack restore still present at reload, it can trigger + mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate + FRAME_POINTER into a hard reg. + To prevent this situation, we force need_drap if we emit a stack + restore. */ + if (SUPPORTS_STACK_ALIGNMENT) + crtl->need_drap = true; + + /* See if this machine has anything special to do for this kind of save. */ + switch (save_level) + { + case SAVE_BLOCK: + if (targetm.have_restore_stack_block ()) + fcn = targetm.gen_restore_stack_block; + break; + case SAVE_FUNCTION: + if (targetm.have_restore_stack_function ()) + fcn = targetm.gen_restore_stack_function; + break; + case SAVE_NONLOCAL: + if (targetm.have_restore_stack_nonlocal ()) + fcn = targetm.gen_restore_stack_nonlocal; + break; + default: + break; + } + + if (sa != 0) + { + sa = validize_mem (sa); + /* These clobbers prevent the scheduler from moving + references to variable arrays below the code + that deletes (pops) the arrays. */ + emit_clobber (gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))); + emit_clobber (gen_rtx_MEM (BLKmode, stack_pointer_rtx)); + } + + discard_pending_stack_adjust (); + + emit_insn (fcn (stack_pointer_rtx, sa)); +} + +/* Invoke emit_stack_save on the nonlocal_goto_save_area for the current + function. This should be called whenever we allocate or deallocate + dynamic stack space. */ + +void +update_nonlocal_goto_save_area (void) +{ + tree t_save; + rtx r_save; + + /* The nonlocal_goto_save_area object is an array of N pointers. The + first one is used for the frame pointer save; the rest are sized by + STACK_SAVEAREA_MODE. Create a reference to array index 1, the first + of the stack save area slots. */ + t_save = build4 (ARRAY_REF, + TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)), + cfun->nonlocal_goto_save_area, + integer_one_node, NULL_TREE, NULL_TREE); + r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE); + + emit_stack_save (SAVE_NONLOCAL, &r_save); +} + +/* Record a new stack level for the current function. This should be called + whenever we allocate or deallocate dynamic stack space. */ + +void +record_new_stack_level (void) +{ + /* Record the new stack level for nonlocal gotos. */ + if (cfun->nonlocal_goto_save_area) + update_nonlocal_goto_save_area (); + + /* Record the new stack level for SJLJ exceptions. */ + if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) + update_sjlj_context (); +} + +/* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */ + +rtx +align_dynamic_address (rtx target, unsigned required_align) +{ + /* CEIL_DIV_EXPR needs to worry about the addition overflowing, + but we know it can't. So add ourselves and then do + TRUNC_DIV_EXPR. */ + target = expand_binop (Pmode, add_optab, target, + gen_int_mode (required_align / BITS_PER_UNIT - 1, + Pmode), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target, + gen_int_mode (required_align / BITS_PER_UNIT, + Pmode), + NULL_RTX, 1); + target = expand_mult (Pmode, target, + gen_int_mode (required_align / BITS_PER_UNIT, + Pmode), + NULL_RTX, 1); + + return target; +} + +/* Return an rtx through *PSIZE, representing the size of an area of memory to + be dynamically pushed on the stack. + + *PSIZE is an rtx representing the size of the area. + + SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This + parameter may be zero. If so, a proper value will be extracted + from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed. + + REQUIRED_ALIGN is the alignment (in bits) required for the region + of memory. + + If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for + the additional size returned. */ +void +get_dynamic_stack_size (rtx *psize, unsigned size_align, + unsigned required_align, + HOST_WIDE_INT *pstack_usage_size) +{ + rtx size = *psize; + + /* Ensure the size is in the proper mode. */ + if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) + size = convert_to_mode (Pmode, size, 1); + + if (CONST_INT_P (size)) + { + unsigned HOST_WIDE_INT lsb; + + lsb = INTVAL (size); + lsb &= -lsb; + + /* Watch out for overflow truncating to "unsigned". */ + if (lsb > UINT_MAX / BITS_PER_UNIT) + size_align = 1u << (HOST_BITS_PER_INT - 1); + else + size_align = (unsigned)lsb * BITS_PER_UNIT; + } + else if (size_align < BITS_PER_UNIT) + size_align = BITS_PER_UNIT; + + /* We can't attempt to minimize alignment necessary, because we don't + know the final value of preferred_stack_boundary yet while executing + this code. */ + if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) + crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; + + /* We will need to ensure that the address we return is aligned to + REQUIRED_ALIGN. At this point in the compilation, we don't always + know the final value of the STACK_DYNAMIC_OFFSET used in function.c + (it might depend on the size of the outgoing parameter lists, for + example), so we must preventively align the value. We leave space + in SIZE for the hole that might result from the alignment operation. */ + + unsigned known_align = REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM); + if (known_align == 0) + known_align = BITS_PER_UNIT; + if (required_align > known_align) + { + unsigned extra = (required_align - known_align) / BITS_PER_UNIT; + size = plus_constant (Pmode, size, extra); + size = force_operand (size, NULL_RTX); + if (size_align > known_align) + size_align = known_align; + + if (flag_stack_usage_info && pstack_usage_size) + *pstack_usage_size += extra; + } + + /* Round the size to a multiple of the required stack alignment. + Since the stack is presumed to be rounded before this allocation, + this will maintain the required alignment. + + If the stack grows downward, we could save an insn by subtracting + SIZE from the stack pointer and then aligning the stack pointer. + The problem with this is that the stack pointer may be unaligned + between the execution of the subtraction and alignment insns and + some machines do not allow this. Even on those that do, some + signal handlers malfunction if a signal should occur between those + insns. Since this is an extremely rare event, we have no reliable + way of knowing which systems have this problem. So we avoid even + momentarily mis-aligning the stack. */ + if (size_align % MAX_SUPPORTED_STACK_ALIGNMENT != 0) + { + size = round_push (size); + + if (flag_stack_usage_info && pstack_usage_size) + { + int align = crtl->preferred_stack_boundary / BITS_PER_UNIT; + *pstack_usage_size = + (*pstack_usage_size + align - 1) / align * align; + } + } + + *psize = size; +} + +/* Return the number of bytes to "protect" on the stack for -fstack-check. + + "protect" in the context of -fstack-check means how many bytes we need + to always ensure are available on the stack; as a consequence, this is + also how many bytes are first skipped when probing the stack. + + On some targets we want to reuse the -fstack-check prologue support + to give a degree of protection against stack clashing style attacks. + + In that scenario we do not want to skip bytes before probing as that + would render the stack clash protections useless. + + So we never use STACK_CHECK_PROTECT directly. Instead we indirectly + use it through this helper, which allows to provide different values + for -fstack-check and -fstack-clash-protection. */ + +HOST_WIDE_INT +get_stack_check_protect (void) +{ + if (flag_stack_clash_protection) + return 0; + + return STACK_CHECK_PROTECT; +} + +/* Return an rtx representing the address of an area of memory dynamically + pushed on the stack. + + Any required stack pointer alignment is preserved. + + SIZE is an rtx representing the size of the area. + + SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This + parameter may be zero. If so, a proper value will be extracted + from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed. + + REQUIRED_ALIGN is the alignment (in bits) required for the region + of memory. + + MAX_SIZE is an upper bound for SIZE, if SIZE is not constant, or -1 if + no such upper bound is known. + + If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the + stack space allocated by the generated code cannot be added with itself + in the course of the execution of the function. It is always safe to + pass FALSE here and the following criterion is sufficient in order to + pass TRUE: every path in the CFG that starts at the allocation point and + loops to it executes the associated deallocation code. */ + +rtx +allocate_dynamic_stack_space (rtx size, unsigned size_align, + unsigned required_align, + HOST_WIDE_INT max_size, + bool cannot_accumulate) +{ + HOST_WIDE_INT stack_usage_size = -1; + rtx_code_label *final_label; + rtx final_target, target; + + /* If we're asking for zero bytes, it doesn't matter what we point + to since we can't dereference it. But return a reasonable + address anyway. */ + if (size == const0_rtx) + return virtual_stack_dynamic_rtx; + + /* Otherwise, show we're calling alloca or equivalent. */ + cfun->calls_alloca = 1; + + /* If stack usage info is requested, look into the size we are passed. + We need to do so this early to avoid the obfuscation that may be + introduced later by the various alignment operations. */ + if (flag_stack_usage_info) + { + if (CONST_INT_P (size)) + stack_usage_size = INTVAL (size); + else if (REG_P (size)) + { + /* Look into the last emitted insn and see if we can deduce + something for the register. */ + rtx_insn *insn; + rtx set, note; + insn = get_last_insn (); + if ((set = single_set (insn)) && rtx_equal_p (SET_DEST (set), size)) + { + if (CONST_INT_P (SET_SRC (set))) + stack_usage_size = INTVAL (SET_SRC (set)); + else if ((note = find_reg_equal_equiv_note (insn)) + && CONST_INT_P (XEXP (note, 0))) + stack_usage_size = INTVAL (XEXP (note, 0)); + } + } + + /* If the size is not constant, try the maximum size. */ + if (stack_usage_size < 0) + stack_usage_size = max_size; + + /* If the size is still not constant, we can't say anything. */ + if (stack_usage_size < 0) + { + current_function_has_unbounded_dynamic_stack_size = 1; + stack_usage_size = 0; + } + } + + get_dynamic_stack_size (&size, size_align, required_align, &stack_usage_size); + + target = gen_reg_rtx (Pmode); + + /* The size is supposed to be fully adjusted at this point so record it + if stack usage info is requested. */ + if (flag_stack_usage_info) + { + current_function_dynamic_stack_size += stack_usage_size; + + /* ??? This is gross but the only safe stance in the absence + of stack usage oriented flow analysis. */ + if (!cannot_accumulate) + current_function_has_unbounded_dynamic_stack_size = 1; + } + + do_pending_stack_adjust (); + + final_label = NULL; + final_target = NULL_RTX; + + /* If we are splitting the stack, we need to ask the backend whether + there is enough room on the current stack. If there isn't, or if + the backend doesn't know how to tell is, then we need to call a + function to allocate memory in some other way. This memory will + be released when we release the current stack segment. The + effect is that stack allocation becomes less efficient, but at + least it doesn't cause a stack overflow. */ + if (flag_split_stack) + { + rtx_code_label *available_label; + rtx ask, space, func; + + available_label = NULL; + + if (targetm.have_split_stack_space_check ()) + { + available_label = gen_label_rtx (); + + /* This instruction will branch to AVAILABLE_LABEL if there + are SIZE bytes available on the stack. */ + emit_insn (targetm.gen_split_stack_space_check + (size, available_label)); + } + + /* The __morestack_allocate_stack_space function will allocate + memory using malloc. If the alignment of the memory returned + by malloc does not meet REQUIRED_ALIGN, we increase SIZE to + make sure we allocate enough space. */ + if (MALLOC_ABI_ALIGNMENT >= required_align) + ask = size; + else + ask = expand_binop (Pmode, add_optab, size, + gen_int_mode (required_align / BITS_PER_UNIT - 1, + Pmode), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + + func = init_one_libfunc ("__morestack_allocate_stack_space"); + + space = emit_library_call_value (func, target, LCT_NORMAL, Pmode, + ask, Pmode); + + if (available_label == NULL_RTX) + return space; + + final_target = gen_reg_rtx (Pmode); + + emit_move_insn (final_target, space); + + final_label = gen_label_rtx (); + emit_jump (final_label); + + emit_label (available_label); + } + + /* We ought to be called always on the toplevel and stack ought to be aligned + properly. */ + gcc_assert (multiple_p (stack_pointer_delta, + PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)); + + /* If needed, check that we have the required amount of stack. Take into + account what has already been checked. */ + if (STACK_CHECK_MOVING_SP) + ; + else if (flag_stack_check == GENERIC_STACK_CHECK) + probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE, + size); + else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK) + probe_stack_range (get_stack_check_protect (), size); + + /* Don't let anti_adjust_stack emit notes. */ + suppress_reg_args_size = true; + + /* Perform the required allocation from the stack. Some systems do + this differently than simply incrementing/decrementing from the + stack pointer, such as acquiring the space by calling malloc(). */ + if (targetm.have_allocate_stack ()) + { + class expand_operand ops[2]; + /* We don't have to check against the predicate for operand 0 since + TARGET is known to be a pseudo of the proper mode, which must + be valid for the operand. */ + create_fixed_operand (&ops[0], target); + create_convert_operand_to (&ops[1], size, STACK_SIZE_MODE, true); + expand_insn (targetm.code_for_allocate_stack, 2, ops); + } + else + { + poly_int64 saved_stack_pointer_delta; + + if (!STACK_GROWS_DOWNWARD) + emit_move_insn (target, virtual_stack_dynamic_rtx); + + /* Check stack bounds if necessary. */ + if (crtl->limit_stack) + { + rtx available; + rtx_code_label *space_available = gen_label_rtx (); + if (STACK_GROWS_DOWNWARD) + available = expand_binop (Pmode, sub_optab, + stack_pointer_rtx, stack_limit_rtx, + NULL_RTX, 1, OPTAB_WIDEN); + else + available = expand_binop (Pmode, sub_optab, + stack_limit_rtx, stack_pointer_rtx, + NULL_RTX, 1, OPTAB_WIDEN); + + emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1, + space_available); + if (targetm.have_trap ()) + emit_insn (targetm.gen_trap ()); + else + error ("stack limits not supported on this target"); + emit_barrier (); + emit_label (space_available); + } + + saved_stack_pointer_delta = stack_pointer_delta; + + /* If stack checking or stack clash protection is requested, + then probe the stack while allocating space from it. */ + if (flag_stack_check && STACK_CHECK_MOVING_SP) + anti_adjust_stack_and_probe (size, false); + else if (flag_stack_clash_protection) + anti_adjust_stack_and_probe_stack_clash (size); + else + anti_adjust_stack (size); + + /* Even if size is constant, don't modify stack_pointer_delta. + The constant size alloca should preserve + crtl->preferred_stack_boundary alignment. */ + stack_pointer_delta = saved_stack_pointer_delta; + + if (STACK_GROWS_DOWNWARD) + emit_move_insn (target, virtual_stack_dynamic_rtx); + } + + suppress_reg_args_size = false; + + /* Finish up the split stack handling. */ + if (final_label != NULL_RTX) + { + gcc_assert (flag_split_stack); + emit_move_insn (final_target, target); + emit_label (final_label); + target = final_target; + } + + target = align_dynamic_address (target, required_align); + + /* Now that we've committed to a return value, mark its alignment. */ + mark_reg_pointer (target, required_align); + + /* Record the new stack level. */ + record_new_stack_level (); + + return target; +} + +/* Return an rtx representing the address of an area of memory already + statically pushed onto the stack in the virtual stack vars area. (It is + assumed that the area is allocated in the function prologue.) + + Any required stack pointer alignment is preserved. + + OFFSET is the offset of the area into the virtual stack vars area. + + REQUIRED_ALIGN is the alignment (in bits) required for the region + of memory. + + BASE is the rtx of the base of this virtual stack vars area. + The only time this is not `virtual_stack_vars_rtx` is when tagging pointers + on the stack. */ + +rtx +get_dynamic_stack_base (poly_int64 offset, unsigned required_align, rtx base) +{ + rtx target; + + if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) + crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; + + target = gen_reg_rtx (Pmode); + emit_move_insn (target, base); + target = expand_binop (Pmode, add_optab, target, + gen_int_mode (offset, Pmode), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + target = align_dynamic_address (target, required_align); + + /* Now that we've committed to a return value, mark its alignment. */ + mark_reg_pointer (target, required_align); + + return target; +} + +/* A front end may want to override GCC's stack checking by providing a + run-time routine to call to check the stack, so provide a mechanism for + calling that routine. */ + +static GTY(()) rtx stack_check_libfunc; + +void +set_stack_check_libfunc (const char *libfunc_name) +{ + gcc_assert (stack_check_libfunc == NULL_RTX); + stack_check_libfunc = gen_rtx_SYMBOL_REF (Pmode, libfunc_name); + tree ptype + = Pmode == ptr_mode + ? ptr_type_node + : lang_hooks.types.type_for_mode (Pmode, 1); + tree ftype + = build_function_type_list (void_type_node, ptype, NULL_TREE); + tree decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, + get_identifier (libfunc_name), ftype); + DECL_EXTERNAL (decl) = 1; + SET_SYMBOL_REF_DECL (stack_check_libfunc, decl); +} + +/* Emit one stack probe at ADDRESS, an address within the stack. */ + +void +emit_stack_probe (rtx address) +{ + if (targetm.have_probe_stack_address ()) + { + class expand_operand ops[1]; + insn_code icode = targetm.code_for_probe_stack_address; + create_address_operand (ops, address); + maybe_legitimize_operands (icode, 0, 1, ops); + expand_insn (icode, 1, ops); + } + else + { + rtx memref = gen_rtx_MEM (word_mode, address); + + MEM_VOLATILE_P (memref) = 1; + memref = validize_mem (memref); + + /* See if we have an insn to probe the stack. */ + if (targetm.have_probe_stack ()) + emit_insn (targetm.gen_probe_stack (memref)); + else + emit_move_insn (memref, const0_rtx); + } +} + +/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive. + FIRST is a constant and size is a Pmode RTX. These are offsets from + the current stack pointer. STACK_GROWS_DOWNWARD says whether to add + or subtract them from the stack pointer. */ + +#define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP) + +#if STACK_GROWS_DOWNWARD +#define STACK_GROW_OP MINUS +#define STACK_GROW_OPTAB sub_optab +#define STACK_GROW_OFF(off) -(off) +#else +#define STACK_GROW_OP PLUS +#define STACK_GROW_OPTAB add_optab +#define STACK_GROW_OFF(off) (off) +#endif + +void +probe_stack_range (HOST_WIDE_INT first, rtx size) +{ + /* First ensure SIZE is Pmode. */ + if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) + size = convert_to_mode (Pmode, size, 1); + + /* Next see if we have a function to check the stack. */ + if (stack_check_libfunc) + { + rtx addr = memory_address (Pmode, + gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + plus_constant (Pmode, + size, first))); + emit_library_call (stack_check_libfunc, LCT_THROW, VOIDmode, + addr, Pmode); + } + + /* Next see if we have an insn to check the stack. */ + else if (targetm.have_check_stack ()) + { + class expand_operand ops[1]; + rtx addr = memory_address (Pmode, + gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + plus_constant (Pmode, + size, first))); + bool success; + create_input_operand (&ops[0], addr, Pmode); + success = maybe_expand_insn (targetm.code_for_check_stack, 1, ops); + gcc_assert (success); + } + + /* Otherwise we have to generate explicit probes. If we have a constant + small number of them to generate, that's the easy case. */ + else if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL) + { + HOST_WIDE_INT isize = INTVAL (size), i; + rtx addr; + + /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until + it exceeds SIZE. If only one probe is needed, this will not + generate any code. Then probe at FIRST + SIZE. */ + for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL) + { + addr = memory_address (Pmode, + plus_constant (Pmode, stack_pointer_rtx, + STACK_GROW_OFF (first + i))); + emit_stack_probe (addr); + } + + addr = memory_address (Pmode, + plus_constant (Pmode, stack_pointer_rtx, + STACK_GROW_OFF (first + isize))); + emit_stack_probe (addr); + } + + /* In the variable case, do the same as above, but in a loop. Note that we + must be extra careful with variables wrapping around because we might be + at the very top (or the very bottom) of the address space and we have to + be able to handle this case properly; in particular, we use an equality + test for the loop condition. */ + else + { + rtx rounded_size, rounded_size_op, test_addr, last_addr, temp; + rtx_code_label *loop_lab = gen_label_rtx (); + rtx_code_label *end_lab = gen_label_rtx (); + + /* Step 1: round SIZE to the previous multiple of the interval. */ + + /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */ + rounded_size + = simplify_gen_binary (AND, Pmode, size, + gen_int_mode (-PROBE_INTERVAL, Pmode)); + rounded_size_op = force_operand (rounded_size, NULL_RTX); + + + /* Step 2: compute initial and final value of the loop counter. */ + + /* TEST_ADDR = SP + FIRST. */ + test_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + gen_int_mode (first, Pmode)), + NULL_RTX); + + /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */ + last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + test_addr, + rounded_size_op), NULL_RTX); + + + /* Step 3: the loop + + while (TEST_ADDR != LAST_ADDR) + { + TEST_ADDR = TEST_ADDR + PROBE_INTERVAL + probe at TEST_ADDR + } + + probes at FIRST + N * PROBE_INTERVAL for values of N from 1 + until it is equal to ROUNDED_SIZE. */ + + emit_label (loop_lab); + + /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */ + emit_cmp_and_jump_insns (test_addr, last_addr, EQ, NULL_RTX, Pmode, 1, + end_lab); + + /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */ + temp = expand_binop (Pmode, STACK_GROW_OPTAB, test_addr, + gen_int_mode (PROBE_INTERVAL, Pmode), test_addr, + 1, OPTAB_WIDEN); + + gcc_assert (temp == test_addr); + + /* Probe at TEST_ADDR. */ + emit_stack_probe (test_addr); + + emit_jump (loop_lab); + + emit_label (end_lab); + + + /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time + that SIZE is equal to ROUNDED_SIZE. */ + + /* TEMP = SIZE - ROUNDED_SIZE. */ + temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size); + if (temp != const0_rtx) + { + rtx addr; + + if (CONST_INT_P (temp)) + { + /* Use [base + disp} addressing mode if supported. */ + HOST_WIDE_INT offset = INTVAL (temp); + addr = memory_address (Pmode, + plus_constant (Pmode, last_addr, + STACK_GROW_OFF (offset))); + } + else + { + /* Manual CSE if the difference is not known at compile-time. */ + temp = gen_rtx_MINUS (Pmode, size, rounded_size_op); + addr = memory_address (Pmode, + gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + last_addr, temp)); + } + + emit_stack_probe (addr); + } + } + + /* Make sure nothing is scheduled before we are done. */ + emit_insn (gen_blockage ()); +} + +/* Compute parameters for stack clash probing a dynamic stack + allocation of SIZE bytes. + + We compute ROUNDED_SIZE, LAST_ADDR, RESIDUAL and PROBE_INTERVAL. + + Additionally we conditionally dump the type of probing that will + be needed given the values computed. */ + +void +compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr, + rtx *residual, + HOST_WIDE_INT *probe_interval, + rtx size) +{ + /* Round SIZE down to STACK_CLASH_PROTECTION_PROBE_INTERVAL */ + *probe_interval + = 1 << param_stack_clash_protection_probe_interval; + *rounded_size = simplify_gen_binary (AND, Pmode, size, + GEN_INT (-*probe_interval)); + + /* Compute the value of the stack pointer for the last iteration. + It's just SP + ROUNDED_SIZE. */ + rtx rounded_size_op = force_operand (*rounded_size, NULL_RTX); + *last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + rounded_size_op), + NULL_RTX); + + /* Compute any residuals not allocated by the loop above. Residuals + are just the ROUNDED_SIZE - SIZE. */ + *residual = simplify_gen_binary (MINUS, Pmode, size, *rounded_size); + + /* Dump key information to make writing tests easy. */ + if (dump_file) + { + if (*rounded_size == CONST0_RTX (Pmode)) + fprintf (dump_file, + "Stack clash skipped dynamic allocation and probing loop.\n"); + else if (CONST_INT_P (*rounded_size) + && INTVAL (*rounded_size) <= 4 * *probe_interval) + fprintf (dump_file, + "Stack clash dynamic allocation and probing inline.\n"); + else if (CONST_INT_P (*rounded_size)) + fprintf (dump_file, + "Stack clash dynamic allocation and probing in " + "rotated loop.\n"); + else + fprintf (dump_file, + "Stack clash dynamic allocation and probing in loop.\n"); + + if (*residual != CONST0_RTX (Pmode)) + fprintf (dump_file, + "Stack clash dynamic allocation and probing residuals.\n"); + else + fprintf (dump_file, + "Stack clash skipped dynamic allocation and " + "probing residuals.\n"); + } +} + +/* Emit the start of an allocate/probe loop for stack + clash protection. + + LOOP_LAB and END_LAB are returned for use when we emit the + end of the loop. + + LAST addr is the value for SP which stops the loop. */ +void +emit_stack_clash_protection_probe_loop_start (rtx *loop_lab, + rtx *end_lab, + rtx last_addr, + bool rotated) +{ + /* Essentially we want to emit any setup code, the top of loop + label and the comparison at the top of the loop. */ + *loop_lab = gen_label_rtx (); + *end_lab = gen_label_rtx (); + + emit_label (*loop_lab); + if (!rotated) + emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX, + Pmode, 1, *end_lab); +} + +/* Emit the end of a stack clash probing loop. + + This consists of just the jump back to LOOP_LAB and + emitting END_LOOP after the loop. */ + +void +emit_stack_clash_protection_probe_loop_end (rtx loop_lab, rtx end_loop, + rtx last_addr, bool rotated) +{ + if (rotated) + emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, NE, NULL_RTX, + Pmode, 1, loop_lab); + else + emit_jump (loop_lab); + + emit_label (end_loop); + +} + +/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes) + while probing it. This pushes when SIZE is positive. SIZE need not + be constant. + + This is subtly different than anti_adjust_stack_and_probe to try and + prevent stack-clash attacks + + 1. It must assume no knowledge of the probing state, any allocation + must probe. + + Consider the case of a 1 byte alloca in a loop. If the sum of the + allocations is large, then this could be used to jump the guard if + probes were not emitted. + + 2. It never skips probes, whereas anti_adjust_stack_and_probe will + skip the probe on the first PROBE_INTERVAL on the assumption it + was already done in the prologue and in previous allocations. + + 3. It only allocates and probes SIZE bytes, it does not need to + allocate/probe beyond that because this probing style does not + guarantee signal handling capability if the guard is hit. */ + +void +anti_adjust_stack_and_probe_stack_clash (rtx size) +{ + /* First ensure SIZE is Pmode. */ + if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) + size = convert_to_mode (Pmode, size, 1); + + /* We can get here with a constant size on some targets. */ + rtx rounded_size, last_addr, residual; + HOST_WIDE_INT probe_interval, probe_range; + bool target_probe_range_p = false; + compute_stack_clash_protection_loop_data (&rounded_size, &last_addr, + &residual, &probe_interval, size); + + /* Get the back-end specific probe ranges. */ + probe_range = targetm.stack_clash_protection_alloca_probe_range (); + target_probe_range_p = probe_range != 0; + gcc_assert (probe_range >= 0); + + /* If no back-end specific range defined, default to the top of the newly + allocated range. */ + if (probe_range == 0) + probe_range = probe_interval - GET_MODE_SIZE (word_mode); + + if (rounded_size != CONST0_RTX (Pmode)) + { + if (CONST_INT_P (rounded_size) + && INTVAL (rounded_size) <= 4 * probe_interval) + { + for (HOST_WIDE_INT i = 0; + i < INTVAL (rounded_size); + i += probe_interval) + { + anti_adjust_stack (GEN_INT (probe_interval)); + /* The prologue does not probe residuals. Thus the offset + here to probe just beyond what the prologue had already + allocated. */ + emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, + probe_range)); + + emit_insn (gen_blockage ()); + } + } + else + { + rtx loop_lab, end_loop; + bool rotate_loop = CONST_INT_P (rounded_size); + emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop, + last_addr, rotate_loop); + + anti_adjust_stack (GEN_INT (probe_interval)); + + /* The prologue does not probe residuals. Thus the offset here + to probe just beyond what the prologue had already + allocated. */ + emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, + probe_range)); + + emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop, + last_addr, rotate_loop); + emit_insn (gen_blockage ()); + } + } + + if (residual != CONST0_RTX (Pmode)) + { + rtx label = NULL_RTX; + /* RESIDUAL could be zero at runtime and in that case *sp could + hold live data. Furthermore, we do not want to probe into the + red zone. + + If TARGET_PROBE_RANGE_P then the target has promised it's safe to + probe at offset 0. In which case we no longer have to check for + RESIDUAL == 0. However we still need to probe at the right offset + when RESIDUAL > PROBE_RANGE, in which case we probe at PROBE_RANGE. + + If !TARGET_PROBE_RANGE_P then go ahead and just guard the probe at *sp + on RESIDUAL != 0 at runtime if RESIDUAL is not a compile time constant. + */ + anti_adjust_stack (residual); + + if (!CONST_INT_P (residual)) + { + label = gen_label_rtx (); + rtx_code op = target_probe_range_p ? LT : EQ; + rtx probe_cmp_value = target_probe_range_p + ? gen_rtx_CONST_INT (GET_MODE (residual), probe_range) + : CONST0_RTX (GET_MODE (residual)); + + if (target_probe_range_p) + emit_stack_probe (stack_pointer_rtx); + + emit_cmp_and_jump_insns (residual, probe_cmp_value, + op, NULL_RTX, Pmode, 1, label); + } + + rtx x = NULL_RTX; + + /* If RESIDUAL isn't a constant and TARGET_PROBE_RANGE_P then we probe up + by the ABI defined safe value. */ + if (!CONST_INT_P (residual) && target_probe_range_p) + x = GEN_INT (probe_range); + /* If RESIDUAL is a constant but smaller than the ABI defined safe value, + we still want to probe up, but the safest amount if a word. */ + else if (target_probe_range_p) + { + if (INTVAL (residual) <= probe_range) + x = GEN_INT (GET_MODE_SIZE (word_mode)); + else + x = GEN_INT (probe_range); + } + else + /* If nothing else, probe at the top of the new allocation. */ + x = plus_constant (Pmode, residual, -GET_MODE_SIZE (word_mode)); + + emit_stack_probe (gen_rtx_PLUS (Pmode, stack_pointer_rtx, x)); + + emit_insn (gen_blockage ()); + if (!CONST_INT_P (residual)) + emit_label (label); + } +} + + +/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes) + while probing it. This pushes when SIZE is positive. SIZE need not + be constant. If ADJUST_BACK is true, adjust back the stack pointer + by plus SIZE at the end. */ + +void +anti_adjust_stack_and_probe (rtx size, bool adjust_back) +{ + /* We skip the probe for the first interval + a small dope of 4 words and + probe that many bytes past the specified size to maintain a protection + area at the botton of the stack. */ + const int dope = 4 * UNITS_PER_WORD; + + /* First ensure SIZE is Pmode. */ + if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) + size = convert_to_mode (Pmode, size, 1); + + /* If we have a constant small number of probes to generate, that's the + easy case. */ + if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL) + { + HOST_WIDE_INT isize = INTVAL (size), i; + bool first_probe = true; + + /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for + values of N from 1 until it exceeds SIZE. If only one probe is + needed, this will not generate any code. Then adjust and probe + to PROBE_INTERVAL + SIZE. */ + for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL) + { + if (first_probe) + { + anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL + dope)); + first_probe = false; + } + else + anti_adjust_stack (GEN_INT (PROBE_INTERVAL)); + emit_stack_probe (stack_pointer_rtx); + } + + if (first_probe) + anti_adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL + dope)); + else + anti_adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL - i)); + emit_stack_probe (stack_pointer_rtx); + } + + /* In the variable case, do the same as above, but in a loop. Note that we + must be extra careful with variables wrapping around because we might be + at the very top (or the very bottom) of the address space and we have to + be able to handle this case properly; in particular, we use an equality + test for the loop condition. */ + else + { + rtx rounded_size, rounded_size_op, last_addr, temp; + rtx_code_label *loop_lab = gen_label_rtx (); + rtx_code_label *end_lab = gen_label_rtx (); + + + /* Step 1: round SIZE to the previous multiple of the interval. */ + + /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */ + rounded_size + = simplify_gen_binary (AND, Pmode, size, + gen_int_mode (-PROBE_INTERVAL, Pmode)); + rounded_size_op = force_operand (rounded_size, NULL_RTX); + + + /* Step 2: compute initial and final value of the loop counter. */ + + /* SP = SP_0 + PROBE_INTERVAL. */ + anti_adjust_stack (GEN_INT (PROBE_INTERVAL + dope)); + + /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */ + last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + rounded_size_op), NULL_RTX); + + + /* Step 3: the loop + + while (SP != LAST_ADDR) + { + SP = SP + PROBE_INTERVAL + probe at SP + } + + adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for + values of N from 1 until it is equal to ROUNDED_SIZE. */ + + emit_label (loop_lab); + + /* Jump to END_LAB if SP == LAST_ADDR. */ + emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX, + Pmode, 1, end_lab); + + /* SP = SP + PROBE_INTERVAL and probe at SP. */ + anti_adjust_stack (GEN_INT (PROBE_INTERVAL)); + emit_stack_probe (stack_pointer_rtx); + + emit_jump (loop_lab); + + emit_label (end_lab); + + + /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot + assert at compile-time that SIZE is equal to ROUNDED_SIZE. */ + + /* TEMP = SIZE - ROUNDED_SIZE. */ + temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size); + if (temp != const0_rtx) + { + /* Manual CSE if the difference is not known at compile-time. */ + if (GET_CODE (temp) != CONST_INT) + temp = gen_rtx_MINUS (Pmode, size, rounded_size_op); + anti_adjust_stack (temp); + emit_stack_probe (stack_pointer_rtx); + } + } + + /* Adjust back and account for the additional first interval. */ + if (adjust_back) + adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL + dope)); + else + adjust_stack (GEN_INT (PROBE_INTERVAL + dope)); +} + +/* Return an rtx representing the register or memory location + in which a scalar value of data type VALTYPE + was returned by a function call to function FUNC. + FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise + function is known, otherwise 0. + OUTGOING is 1 if on a machine with register windows this function + should return the register in which the function will put its result + and 0 otherwise. */ + +rtx +hard_function_value (const_tree valtype, const_tree func, const_tree fntype, + int outgoing ATTRIBUTE_UNUSED) +{ + rtx val; + + val = targetm.calls.function_value (valtype, func ? func : fntype, outgoing); + + if (REG_P (val) + && GET_MODE (val) == BLKmode) + { + unsigned HOST_WIDE_INT bytes = arg_int_size_in_bytes (valtype); + opt_scalar_int_mode tmpmode; + + /* int_size_in_bytes can return -1. We don't need a check here + since the value of bytes will then be large enough that no + mode will match anyway. */ + + FOR_EACH_MODE_IN_CLASS (tmpmode, MODE_INT) + { + /* Have we found a large enough mode? */ + if (GET_MODE_SIZE (tmpmode.require ()) >= bytes) + break; + } + + PUT_MODE (val, tmpmode.require ()); + } + return val; +} + +/* Return an rtx representing the register or memory location + in which a scalar value of mode MODE was returned by a library call. */ + +rtx +hard_libcall_value (machine_mode mode, rtx fun) +{ + return targetm.calls.libcall_value (mode, fun); +} + +/* Look up the tree code for a given rtx code + to provide the arithmetic operation for real_arithmetic. + The function returns an int because the caller may not know + what `enum tree_code' means. */ + +int +rtx_to_tree_code (enum rtx_code code) +{ + enum tree_code tcode; + + switch (code) + { + case PLUS: + tcode = PLUS_EXPR; + break; + case MINUS: + tcode = MINUS_EXPR; + break; + case MULT: + tcode = MULT_EXPR; + break; + case DIV: + tcode = RDIV_EXPR; + break; + case SMIN: + tcode = MIN_EXPR; + break; + case SMAX: + tcode = MAX_EXPR; + break; + default: + tcode = LAST_AND_UNUSED_TREE_CODE; + break; + } + return ((int) tcode); +} + +#include "gt-explow.h" |