chromium / native_client / nacl-gcc / f80d6b9ee7f94755c697ffb7194fb01dd0c537dd / . / gcc / convert.c

/* Utility routines for data type conversion for GCC. | |

Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997, 1998, | |

2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |

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/>. */ | |

/* These routines are somewhat language-independent utility function | |

intended to be called by the language-specific convert () functions. */ | |

#include "config.h" | |

#include "system.h" | |

#include "coretypes.h" | |

#include "tm.h" | |

#include "tree.h" | |

#include "flags.h" | |

#include "convert.h" | |

#include "toplev.h" | |

#include "langhooks.h" | |

#include "real.h" | |

#include "fixed-value.h" | |

/* Convert EXPR to some pointer or reference type TYPE. | |

EXPR must be pointer, reference, integer, enumeral, or literal zero; | |

in other cases error is called. */ | |

tree | |

convert_to_pointer (tree type, tree expr) | |

{ | |

if (TREE_TYPE (expr) == type) | |

return expr; | |

/* Propagate overflow to the NULL pointer. */ | |

if (integer_zerop (expr)) | |

return force_fit_type_double (type, 0, 0, 0, TREE_OVERFLOW (expr)); | |

switch (TREE_CODE (TREE_TYPE (expr))) | |

{ | |

case POINTER_TYPE: | |

case REFERENCE_TYPE: | |

return fold_build1 (NOP_EXPR, type, expr); | |

case INTEGER_TYPE: | |

case ENUMERAL_TYPE: | |

case BOOLEAN_TYPE: | |

if (TYPE_PRECISION (TREE_TYPE (expr)) != POINTER_SIZE) | |

expr = fold_build1 (NOP_EXPR, | |

lang_hooks.types.type_for_size (POINTER_SIZE, 0), | |

expr); | |

return fold_build1 (CONVERT_EXPR, type, expr); | |

default: | |

error ("cannot convert to a pointer type"); | |

return convert_to_pointer (type, integer_zero_node); | |

} | |

} | |

/* Avoid any floating point extensions from EXP. */ | |

tree | |

strip_float_extensions (tree exp) | |

{ | |

tree sub, expt, subt; | |

/* For floating point constant look up the narrowest type that can hold | |

it properly and handle it like (type)(narrowest_type)constant. | |

This way we can optimize for instance a=a*2.0 where "a" is float | |

but 2.0 is double constant. */ | |

if (TREE_CODE (exp) == REAL_CST && !DECIMAL_FLOAT_TYPE_P (TREE_TYPE (exp))) | |

{ | |

REAL_VALUE_TYPE orig; | |

tree type = NULL; | |

orig = TREE_REAL_CST (exp); | |

if (TYPE_PRECISION (TREE_TYPE (exp)) > TYPE_PRECISION (float_type_node) | |

&& exact_real_truncate (TYPE_MODE (float_type_node), &orig)) | |

type = float_type_node; | |

else if (TYPE_PRECISION (TREE_TYPE (exp)) | |

> TYPE_PRECISION (double_type_node) | |

&& exact_real_truncate (TYPE_MODE (double_type_node), &orig)) | |

type = double_type_node; | |

if (type) | |

return build_real (type, real_value_truncate (TYPE_MODE (type), orig)); | |

} | |

if (!CONVERT_EXPR_P (exp)) | |

return exp; | |

sub = TREE_OPERAND (exp, 0); | |

subt = TREE_TYPE (sub); | |

expt = TREE_TYPE (exp); | |

if (!FLOAT_TYPE_P (subt)) | |

return exp; | |

if (DECIMAL_FLOAT_TYPE_P (expt) != DECIMAL_FLOAT_TYPE_P (subt)) | |

return exp; | |

if (TYPE_PRECISION (subt) > TYPE_PRECISION (expt)) | |

return exp; | |

return strip_float_extensions (sub); | |

} | |

/* Convert EXPR to some floating-point type TYPE. | |

EXPR must be float, fixed-point, integer, or enumeral; | |

in other cases error is called. */ | |

tree | |

convert_to_real (tree type, tree expr) | |

{ | |

enum built_in_function fcode = builtin_mathfn_code (expr); | |

tree itype = TREE_TYPE (expr); | |

/* Disable until we figure out how to decide whether the functions are | |

present in runtime. */ | |

/* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */ | |

if (optimize | |

&& (TYPE_MODE (type) == TYPE_MODE (double_type_node) | |

|| TYPE_MODE (type) == TYPE_MODE (float_type_node))) | |

{ | |

switch (fcode) | |

{ | |

#define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L: | |

CASE_MATHFN (COSH) | |

CASE_MATHFN (EXP) | |

CASE_MATHFN (EXP10) | |

CASE_MATHFN (EXP2) | |

CASE_MATHFN (EXPM1) | |

CASE_MATHFN (GAMMA) | |

CASE_MATHFN (J0) | |

CASE_MATHFN (J1) | |

CASE_MATHFN (LGAMMA) | |

CASE_MATHFN (POW10) | |

CASE_MATHFN (SINH) | |

CASE_MATHFN (TGAMMA) | |

CASE_MATHFN (Y0) | |

CASE_MATHFN (Y1) | |

/* The above functions may set errno differently with float | |

input or output so this transformation is not safe with | |

-fmath-errno. */ | |

if (flag_errno_math) | |

break; | |

CASE_MATHFN (ACOS) | |

CASE_MATHFN (ACOSH) | |

CASE_MATHFN (ASIN) | |

CASE_MATHFN (ASINH) | |

CASE_MATHFN (ATAN) | |

CASE_MATHFN (ATANH) | |

CASE_MATHFN (CBRT) | |

CASE_MATHFN (COS) | |

CASE_MATHFN (ERF) | |

CASE_MATHFN (ERFC) | |

CASE_MATHFN (FABS) | |

CASE_MATHFN (LOG) | |

CASE_MATHFN (LOG10) | |

CASE_MATHFN (LOG2) | |

CASE_MATHFN (LOG1P) | |

CASE_MATHFN (LOGB) | |

CASE_MATHFN (SIN) | |

CASE_MATHFN (SQRT) | |

CASE_MATHFN (TAN) | |

CASE_MATHFN (TANH) | |

#undef CASE_MATHFN | |

{ | |

tree arg0 = strip_float_extensions (CALL_EXPR_ARG (expr, 0)); | |

tree newtype = type; | |

/* We have (outertype)sqrt((innertype)x). Choose the wider mode from | |

the both as the safe type for operation. */ | |

if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (type)) | |

newtype = TREE_TYPE (arg0); | |

/* Be careful about integer to fp conversions. | |

These may overflow still. */ | |

if (FLOAT_TYPE_P (TREE_TYPE (arg0)) | |

&& TYPE_PRECISION (newtype) < TYPE_PRECISION (itype) | |

&& (TYPE_MODE (newtype) == TYPE_MODE (double_type_node) | |

|| TYPE_MODE (newtype) == TYPE_MODE (float_type_node))) | |

{ | |

tree fn = mathfn_built_in (newtype, fcode); | |

if (fn) | |

{ | |

tree arg = fold (convert_to_real (newtype, arg0)); | |

expr = build_call_expr (fn, 1, arg); | |

if (newtype == type) | |

return expr; | |

} | |

} | |

} | |

default: | |

break; | |

} | |

} | |

if (optimize | |

&& (((fcode == BUILT_IN_FLOORL | |

|| fcode == BUILT_IN_CEILL | |

|| fcode == BUILT_IN_ROUNDL | |

|| fcode == BUILT_IN_RINTL | |

|| fcode == BUILT_IN_TRUNCL | |

|| fcode == BUILT_IN_NEARBYINTL) | |

&& (TYPE_MODE (type) == TYPE_MODE (double_type_node) | |

|| TYPE_MODE (type) == TYPE_MODE (float_type_node))) | |

|| ((fcode == BUILT_IN_FLOOR | |

|| fcode == BUILT_IN_CEIL | |

|| fcode == BUILT_IN_ROUND | |

|| fcode == BUILT_IN_RINT | |

|| fcode == BUILT_IN_TRUNC | |

|| fcode == BUILT_IN_NEARBYINT) | |

&& (TYPE_MODE (type) == TYPE_MODE (float_type_node))))) | |

{ | |

tree fn = mathfn_built_in (type, fcode); | |

if (fn) | |

{ | |

tree arg = strip_float_extensions (CALL_EXPR_ARG (expr, 0)); | |

/* Make sure (type)arg0 is an extension, otherwise we could end up | |

changing (float)floor(double d) into floorf((float)d), which is | |

incorrect because (float)d uses round-to-nearest and can round | |

up to the next integer. */ | |

if (TYPE_PRECISION (type) >= TYPE_PRECISION (TREE_TYPE (arg))) | |

return build_call_expr (fn, 1, fold (convert_to_real (type, arg))); | |

} | |

} | |

/* Propagate the cast into the operation. */ | |

if (itype != type && FLOAT_TYPE_P (type)) | |

switch (TREE_CODE (expr)) | |

{ | |

/* Convert (float)-x into -(float)x. This is safe for | |

round-to-nearest rounding mode. */ | |

case ABS_EXPR: | |

case NEGATE_EXPR: | |

if (!flag_rounding_math | |

&& TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (expr))) | |

return build1 (TREE_CODE (expr), type, | |

fold (convert_to_real (type, | |

TREE_OPERAND (expr, 0)))); | |

break; | |

/* Convert (outertype)((innertype0)a+(innertype1)b) | |

into ((newtype)a+(newtype)b) where newtype | |

is the widest mode from all of these. */ | |

case PLUS_EXPR: | |

case MINUS_EXPR: | |

case MULT_EXPR: | |

case RDIV_EXPR: | |

{ | |

tree arg0 = strip_float_extensions (TREE_OPERAND (expr, 0)); | |

tree arg1 = strip_float_extensions (TREE_OPERAND (expr, 1)); | |

if (FLOAT_TYPE_P (TREE_TYPE (arg0)) | |

&& FLOAT_TYPE_P (TREE_TYPE (arg1)) | |

&& DECIMAL_FLOAT_TYPE_P (itype) == DECIMAL_FLOAT_TYPE_P (type)) | |

{ | |

tree newtype = type; | |

if (TYPE_MODE (TREE_TYPE (arg0)) == SDmode | |

|| TYPE_MODE (TREE_TYPE (arg1)) == SDmode | |

|| TYPE_MODE (type) == SDmode) | |

newtype = dfloat32_type_node; | |

if (TYPE_MODE (TREE_TYPE (arg0)) == DDmode | |

|| TYPE_MODE (TREE_TYPE (arg1)) == DDmode | |

|| TYPE_MODE (type) == DDmode) | |

newtype = dfloat64_type_node; | |

if (TYPE_MODE (TREE_TYPE (arg0)) == TDmode | |

|| TYPE_MODE (TREE_TYPE (arg1)) == TDmode | |

|| TYPE_MODE (type) == TDmode) | |

newtype = dfloat128_type_node; | |

if (newtype == dfloat32_type_node | |

|| newtype == dfloat64_type_node | |

|| newtype == dfloat128_type_node) | |

{ | |

expr = build2 (TREE_CODE (expr), newtype, | |

fold (convert_to_real (newtype, arg0)), | |

fold (convert_to_real (newtype, arg1))); | |

if (newtype == type) | |

return expr; | |

break; | |

} | |

if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (newtype)) | |

newtype = TREE_TYPE (arg0); | |

if (TYPE_PRECISION (TREE_TYPE (arg1)) > TYPE_PRECISION (newtype)) | |

newtype = TREE_TYPE (arg1); | |

/* Sometimes this transformation is safe (cannot | |

change results through affecting double rounding | |

cases) and sometimes it is not. If NEWTYPE is | |

wider than TYPE, e.g. (float)((long double)double | |

+ (long double)double) converted to | |

(float)(double + double), the transformation is | |

unsafe regardless of the details of the types | |

involved; double rounding can arise if the result | |

of NEWTYPE arithmetic is a NEWTYPE value half way | |

between two representable TYPE values but the | |

exact value is sufficiently different (in the | |

right direction) for this difference to be | |

visible in ITYPE arithmetic. If NEWTYPE is the | |

same as TYPE, however, the transformation may be | |

safe depending on the types involved: it is safe | |

if the ITYPE has strictly more than twice as many | |

mantissa bits as TYPE, can represent infinities | |

and NaNs if the TYPE can, and has sufficient | |

exponent range for the product or ratio of two | |

values representable in the TYPE to be within the | |

range of normal values of ITYPE. */ | |

if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype) | |

&& (flag_unsafe_math_optimizations | |

|| (TYPE_PRECISION (newtype) == TYPE_PRECISION (type) | |

&& real_can_shorten_arithmetic (TYPE_MODE (itype), | |

TYPE_MODE (type))))) | |

{ | |

expr = build2 (TREE_CODE (expr), newtype, | |

fold (convert_to_real (newtype, arg0)), | |

fold (convert_to_real (newtype, arg1))); | |

if (newtype == type) | |

return expr; | |

} | |

} | |

} | |

break; | |

default: | |

break; | |

} | |

switch (TREE_CODE (TREE_TYPE (expr))) | |

{ | |

case REAL_TYPE: | |

/* Ignore the conversion if we don't need to store intermediate | |

results and neither type is a decimal float. */ | |

return build1 ((flag_float_store | |

|| DECIMAL_FLOAT_TYPE_P (type) | |

|| DECIMAL_FLOAT_TYPE_P (itype)) | |

? CONVERT_EXPR : NOP_EXPR, type, expr); | |

case INTEGER_TYPE: | |

case ENUMERAL_TYPE: | |

case BOOLEAN_TYPE: | |

return build1 (FLOAT_EXPR, type, expr); | |

case FIXED_POINT_TYPE: | |

return build1 (FIXED_CONVERT_EXPR, type, expr); | |

case COMPLEX_TYPE: | |

return convert (type, | |

fold_build1 (REALPART_EXPR, | |

TREE_TYPE (TREE_TYPE (expr)), expr)); | |

case POINTER_TYPE: | |

case REFERENCE_TYPE: | |

error ("pointer value used where a floating point value was expected"); | |

return convert_to_real (type, integer_zero_node); | |

default: | |

error ("aggregate value used where a float was expected"); | |

return convert_to_real (type, integer_zero_node); | |

} | |

} | |

/* Convert EXPR to some integer (or enum) type TYPE. | |

EXPR must be pointer, integer, discrete (enum, char, or bool), float, | |

fixed-point or vector; in other cases error is called. | |

The result of this is always supposed to be a newly created tree node | |

not in use in any existing structure. */ | |

tree | |

convert_to_integer (tree type, tree expr) | |

{ | |

enum tree_code ex_form = TREE_CODE (expr); | |

tree intype = TREE_TYPE (expr); | |

unsigned int inprec = TYPE_PRECISION (intype); | |

unsigned int outprec = TYPE_PRECISION (type); | |

/* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can | |

be. Consider `enum E = { a, b = (enum E) 3 };'. */ | |

if (!COMPLETE_TYPE_P (type)) | |

{ | |

error ("conversion to incomplete type"); | |

return error_mark_node; | |

} | |

/* Convert e.g. (long)round(d) -> lround(d). */ | |

/* If we're converting to char, we may encounter differing behavior | |

between converting from double->char vs double->long->char. | |

We're in "undefined" territory but we prefer to be conservative, | |

so only proceed in "unsafe" math mode. */ | |

if (optimize | |

&& (flag_unsafe_math_optimizations | |

|| (long_integer_type_node | |

&& outprec >= TYPE_PRECISION (long_integer_type_node)))) | |

{ | |

tree s_expr = strip_float_extensions (expr); | |

tree s_intype = TREE_TYPE (s_expr); | |

const enum built_in_function fcode = builtin_mathfn_code (s_expr); | |

tree fn = 0; | |

switch (fcode) | |

{ | |

CASE_FLT_FN (BUILT_IN_CEIL): | |

/* Only convert in ISO C99 mode. */ | |

if (!TARGET_C99_FUNCTIONS) | |

break; | |

if (outprec < TYPE_PRECISION (long_integer_type_node) | |

|| (outprec == TYPE_PRECISION (long_integer_type_node) | |

&& !TYPE_UNSIGNED (type))) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LCEIL); | |

else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |

&& !TYPE_UNSIGNED (type)) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL); | |

break; | |

CASE_FLT_FN (BUILT_IN_FLOOR): | |

/* Only convert in ISO C99 mode. */ | |

if (!TARGET_C99_FUNCTIONS) | |

break; | |

if (outprec < TYPE_PRECISION (long_integer_type_node) | |

|| (outprec == TYPE_PRECISION (long_integer_type_node) | |

&& !TYPE_UNSIGNED (type))) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LFLOOR); | |

else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |

&& !TYPE_UNSIGNED (type)) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR); | |

break; | |

CASE_FLT_FN (BUILT_IN_ROUND): | |

if (outprec < TYPE_PRECISION (long_integer_type_node) | |

|| (outprec == TYPE_PRECISION (long_integer_type_node) | |

&& !TYPE_UNSIGNED (type))) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LROUND); | |

else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |

&& !TYPE_UNSIGNED (type)) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND); | |

break; | |

CASE_FLT_FN (BUILT_IN_NEARBYINT): | |

/* Only convert nearbyint* if we can ignore math exceptions. */ | |

if (flag_trapping_math) | |

break; | |

/* ... Fall through ... */ | |

CASE_FLT_FN (BUILT_IN_RINT): | |

if (outprec < TYPE_PRECISION (long_integer_type_node) | |

|| (outprec == TYPE_PRECISION (long_integer_type_node) | |

&& !TYPE_UNSIGNED (type))) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LRINT); | |

else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |

&& !TYPE_UNSIGNED (type)) | |

fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT); | |

break; | |

CASE_FLT_FN (BUILT_IN_TRUNC): | |

return convert_to_integer (type, CALL_EXPR_ARG (s_expr, 0)); | |

default: | |

break; | |

} | |

if (fn) | |

{ | |

tree newexpr = build_call_expr (fn, 1, CALL_EXPR_ARG (s_expr, 0)); | |

return convert_to_integer (type, newexpr); | |

} | |

} | |

switch (TREE_CODE (intype)) | |

{ | |

case POINTER_TYPE: | |

case REFERENCE_TYPE: | |

if (integer_zerop (expr)) | |

return build_int_cst (type, 0); | |

/* Convert to an unsigned integer of the correct width first, | |

and from there widen/truncate to the required type. */ | |

expr = fold_build1 (CONVERT_EXPR, | |

lang_hooks.types.type_for_size (POINTER_SIZE, 0), | |

expr); | |

return fold_convert (type, expr); | |

case INTEGER_TYPE: | |

case ENUMERAL_TYPE: | |

case BOOLEAN_TYPE: | |

case OFFSET_TYPE: | |

/* If this is a logical operation, which just returns 0 or 1, we can | |

change the type of the expression. */ | |

if (TREE_CODE_CLASS (ex_form) == tcc_comparison) | |

{ | |

expr = copy_node (expr); | |

TREE_TYPE (expr) = type; | |

return expr; | |

} | |

/* If we are widening the type, put in an explicit conversion. | |

Similarly if we are not changing the width. After this, we know | |

we are truncating EXPR. */ | |

else if (outprec >= inprec) | |

{ | |

enum tree_code code; | |

tree tem; | |

/* If the precision of the EXPR's type is K bits and the | |

destination mode has more bits, and the sign is changing, | |

it is not safe to use a NOP_EXPR. For example, suppose | |

that EXPR's type is a 3-bit unsigned integer type, the | |

TYPE is a 3-bit signed integer type, and the machine mode | |

for the types is 8-bit QImode. In that case, the | |

conversion necessitates an explicit sign-extension. In | |

the signed-to-unsigned case the high-order bits have to | |

be cleared. */ | |

if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (TREE_TYPE (expr)) | |

&& (TYPE_PRECISION (TREE_TYPE (expr)) | |

!= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr))))) | |

code = CONVERT_EXPR; | |

else | |

code = NOP_EXPR; | |

tem = fold_unary (code, type, expr); | |

if (tem) | |

return tem; | |

tem = build1 (code, type, expr); | |

TREE_NO_WARNING (tem) = 1; | |

return tem; | |

} | |

/* If TYPE is an enumeral type or a type with a precision less | |

than the number of bits in its mode, do the conversion to the | |

type corresponding to its mode, then do a nop conversion | |

to TYPE. */ | |

else if (TREE_CODE (type) == ENUMERAL_TYPE | |

|| outprec != GET_MODE_BITSIZE (TYPE_MODE (type))) | |

return build1 (NOP_EXPR, type, | |

convert (lang_hooks.types.type_for_mode | |

(TYPE_MODE (type), TYPE_UNSIGNED (type)), | |

expr)); | |

/* Here detect when we can distribute the truncation down past some | |

arithmetic. For example, if adding two longs and converting to an | |

int, we can equally well convert both to ints and then add. | |

For the operations handled here, such truncation distribution | |

is always safe. | |

It is desirable in these cases: | |

1) when truncating down to full-word from a larger size | |

2) when truncating takes no work. | |

3) when at least one operand of the arithmetic has been extended | |

(as by C's default conversions). In this case we need two conversions | |

if we do the arithmetic as already requested, so we might as well | |

truncate both and then combine. Perhaps that way we need only one. | |

Note that in general we cannot do the arithmetic in a type | |

shorter than the desired result of conversion, even if the operands | |

are both extended from a shorter type, because they might overflow | |

if combined in that type. The exceptions to this--the times when | |

two narrow values can be combined in their narrow type even to | |

make a wider result--are handled by "shorten" in build_binary_op. */ | |

switch (ex_form) | |

{ | |

case RSHIFT_EXPR: | |

/* We can pass truncation down through right shifting | |

when the shift count is a nonpositive constant. */ | |

if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST | |

&& tree_int_cst_sgn (TREE_OPERAND (expr, 1)) <= 0) | |

goto trunc1; | |

break; | |

case LSHIFT_EXPR: | |

/* We can pass truncation down through left shifting | |

when the shift count is a nonnegative constant and | |

the target type is unsigned. */ | |

if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST | |

&& tree_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0 | |

&& TYPE_UNSIGNED (type) | |

&& TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST) | |

{ | |

/* If shift count is less than the width of the truncated type, | |

really shift. */ | |

if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type))) | |

/* In this case, shifting is like multiplication. */ | |

goto trunc1; | |

else | |

{ | |

/* If it is >= that width, result is zero. | |

Handling this with trunc1 would give the wrong result: | |

(int) ((long long) a << 32) is well defined (as 0) | |

but (int) a << 32 is undefined and would get a | |

warning. */ | |

tree t = build_int_cst (type, 0); | |

/* If the original expression had side-effects, we must | |

preserve it. */ | |

if (TREE_SIDE_EFFECTS (expr)) | |

return build2 (COMPOUND_EXPR, type, expr, t); | |

else | |

return t; | |

} | |

} | |

break; | |

case MAX_EXPR: | |

case MIN_EXPR: | |

case MULT_EXPR: | |

{ | |

tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); | |

tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); | |

/* Don't distribute unless the output precision is at least as big | |

as the actual inputs. Otherwise, the comparison of the | |

truncated values will be wrong. */ | |

if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0)) | |

&& outprec >= TYPE_PRECISION (TREE_TYPE (arg1)) | |

/* If signedness of arg0 and arg1 don't match, | |

we can't necessarily find a type to compare them in. */ | |

&& (TYPE_UNSIGNED (TREE_TYPE (arg0)) | |

== TYPE_UNSIGNED (TREE_TYPE (arg1)))) | |

goto trunc1; | |

break; | |

} | |

case PLUS_EXPR: | |

case MINUS_EXPR: | |

case BIT_AND_EXPR: | |

case BIT_IOR_EXPR: | |

case BIT_XOR_EXPR: | |

trunc1: | |

{ | |

tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); | |

tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); | |

if (outprec >= BITS_PER_WORD | |

|| TRULY_NOOP_TRUNCATION (outprec, inprec) | |

|| inprec > TYPE_PRECISION (TREE_TYPE (arg0)) | |

|| inprec > TYPE_PRECISION (TREE_TYPE (arg1))) | |

{ | |

/* Do the arithmetic in type TYPEX, | |

then convert result to TYPE. */ | |

tree typex = type; | |

/* Can't do arithmetic in enumeral types | |

so use an integer type that will hold the values. */ | |

if (TREE_CODE (typex) == ENUMERAL_TYPE) | |

typex = lang_hooks.types.type_for_size | |

(TYPE_PRECISION (typex), TYPE_UNSIGNED (typex)); | |

/* But now perhaps TYPEX is as wide as INPREC. | |

In that case, do nothing special here. | |

(Otherwise would recurse infinitely in convert. */ | |

if (TYPE_PRECISION (typex) != inprec) | |

{ | |

/* Don't do unsigned arithmetic where signed was wanted, | |

or vice versa. | |

Exception: if both of the original operands were | |

unsigned then we can safely do the work as unsigned. | |

Exception: shift operations take their type solely | |

from the first argument. | |

Exception: the LSHIFT_EXPR case above requires that | |

we perform this operation unsigned lest we produce | |

signed-overflow undefinedness. | |

And we may need to do it as unsigned | |

if we truncate to the original size. */ | |

if (TYPE_UNSIGNED (TREE_TYPE (expr)) | |

|| (TYPE_UNSIGNED (TREE_TYPE (arg0)) | |

&& (TYPE_UNSIGNED (TREE_TYPE (arg1)) | |

|| ex_form == LSHIFT_EXPR | |

|| ex_form == RSHIFT_EXPR | |

|| ex_form == LROTATE_EXPR | |

|| ex_form == RROTATE_EXPR)) | |

|| ex_form == LSHIFT_EXPR | |

/* If we have !flag_wrapv, and either ARG0 or | |

ARG1 is of a signed type, we have to do | |

PLUS_EXPR or MINUS_EXPR in an unsigned | |

type. Otherwise, we would introduce | |

signed-overflow undefinedness. */ | |

|| ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0)) | |

|| !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1))) | |

&& (ex_form == PLUS_EXPR | |

|| ex_form == MINUS_EXPR))) | |

typex = unsigned_type_for (typex); | |

else | |

typex = signed_type_for (typex); | |

return convert (type, | |

fold_build2 (ex_form, typex, | |

convert (typex, arg0), | |

convert (typex, arg1))); | |

} | |

} | |

} | |

break; | |

case NEGATE_EXPR: | |

case BIT_NOT_EXPR: | |

/* This is not correct for ABS_EXPR, | |

since we must test the sign before truncation. */ | |

{ | |

tree typex; | |

/* Don't do unsigned arithmetic where signed was wanted, | |

or vice versa. */ | |

if (TYPE_UNSIGNED (TREE_TYPE (expr))) | |

typex = unsigned_type_for (type); | |

else | |

typex = signed_type_for (type); | |

return convert (type, | |

fold_build1 (ex_form, typex, | |

convert (typex, | |

TREE_OPERAND (expr, 0)))); | |

} | |

case NOP_EXPR: | |

/* Don't introduce a | |

"can't convert between vector values of different size" error. */ | |

if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == VECTOR_TYPE | |

&& (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))) | |

!= GET_MODE_SIZE (TYPE_MODE (type)))) | |

break; | |

/* If truncating after truncating, might as well do all at once. | |

If truncating after extending, we may get rid of wasted work. */ | |

return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type)); | |

case COND_EXPR: | |

/* It is sometimes worthwhile to push the narrowing down through | |

the conditional and never loses. A COND_EXPR may have a throw | |

as one operand, which then has void type. Just leave void | |

operands as they are. */ | |

return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0), | |

VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 1))) | |

? TREE_OPERAND (expr, 1) | |

: convert (type, TREE_OPERAND (expr, 1)), | |

VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 2))) | |

? TREE_OPERAND (expr, 2) | |

: convert (type, TREE_OPERAND (expr, 2))); | |

default: | |

break; | |

} | |

return build1 (CONVERT_EXPR, type, expr); | |

case REAL_TYPE: | |

return build1 (FIX_TRUNC_EXPR, type, expr); | |

case FIXED_POINT_TYPE: | |

return build1 (FIXED_CONVERT_EXPR, type, expr); | |

case COMPLEX_TYPE: | |

return convert (type, | |

fold_build1 (REALPART_EXPR, | |

TREE_TYPE (TREE_TYPE (expr)), expr)); | |

case VECTOR_TYPE: | |

if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr)))) | |

{ | |

error ("can't convert between vector values of different size"); | |

return error_mark_node; | |

} | |

return build1 (VIEW_CONVERT_EXPR, type, expr); | |

default: | |

error ("aggregate value used where an integer was expected"); | |

return convert (type, integer_zero_node); | |

} | |

} | |

/* Convert EXPR to the complex type TYPE in the usual ways. */ | |

tree | |

convert_to_complex (tree type, tree expr) | |

{ | |

tree subtype = TREE_TYPE (type); | |

switch (TREE_CODE (TREE_TYPE (expr))) | |

{ | |

case REAL_TYPE: | |

case FIXED_POINT_TYPE: | |

case INTEGER_TYPE: | |

case ENUMERAL_TYPE: | |

case BOOLEAN_TYPE: | |

return build2 (COMPLEX_EXPR, type, convert (subtype, expr), | |

convert (subtype, integer_zero_node)); | |

case COMPLEX_TYPE: | |

{ | |

tree elt_type = TREE_TYPE (TREE_TYPE (expr)); | |

if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype)) | |

return expr; | |

else if (TREE_CODE (expr) == COMPLEX_EXPR) | |

return fold_build2 (COMPLEX_EXPR, type, | |

convert (subtype, TREE_OPERAND (expr, 0)), | |

convert (subtype, TREE_OPERAND (expr, 1))); | |

else | |

{ | |

expr = save_expr (expr); | |

return | |

fold_build2 (COMPLEX_EXPR, type, | |

convert (subtype, | |

fold_build1 (REALPART_EXPR, | |

TREE_TYPE (TREE_TYPE (expr)), | |

expr)), | |

convert (subtype, | |

fold_build1 (IMAGPART_EXPR, | |

TREE_TYPE (TREE_TYPE (expr)), | |

expr))); | |

} | |

} | |

case POINTER_TYPE: | |

case REFERENCE_TYPE: | |

error ("pointer value used where a complex was expected"); | |

return convert_to_complex (type, integer_zero_node); | |

default: | |

error ("aggregate value used where a complex was expected"); | |

return convert_to_complex (type, integer_zero_node); | |

} | |

} | |

/* Convert EXPR to the vector type TYPE in the usual ways. */ | |

tree | |

convert_to_vector (tree type, tree expr) | |

{ | |

switch (TREE_CODE (TREE_TYPE (expr))) | |

{ | |

case INTEGER_TYPE: | |

case VECTOR_TYPE: | |

if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr)))) | |

{ | |

error ("can't convert between vector values of different size"); | |

return error_mark_node; | |

} | |

return build1 (VIEW_CONVERT_EXPR, type, expr); | |

default: | |

error ("can't convert value to a vector"); | |

return error_mark_node; | |

} | |

} | |

/* Convert EXPR to some fixed-point type TYPE. | |

EXPR must be fixed-point, float, integer, or enumeral; | |

in other cases error is called. */ | |

tree | |

convert_to_fixed (tree type, tree expr) | |

{ | |

if (integer_zerop (expr)) | |

{ | |

tree fixed_zero_node = build_fixed (type, FCONST0 (TYPE_MODE (type))); | |

return fixed_zero_node; | |

} | |

else if (integer_onep (expr) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type))) | |

{ | |

tree fixed_one_node = build_fixed (type, FCONST1 (TYPE_MODE (type))); | |

return fixed_one_node; | |

} | |

switch (TREE_CODE (TREE_TYPE (expr))) | |

{ | |

case FIXED_POINT_TYPE: | |

case INTEGER_TYPE: | |

case ENUMERAL_TYPE: | |

case BOOLEAN_TYPE: | |

case REAL_TYPE: | |

return build1 (FIXED_CONVERT_EXPR, type, expr); | |

case COMPLEX_TYPE: | |

return convert (type, | |

fold_build1 (REALPART_EXPR, | |

TREE_TYPE (TREE_TYPE (expr)), expr)); | |

default: | |

error ("aggregate value used where a fixed-point was expected"); | |

return error_mark_node; | |

} | |

} |