tinycc/lib/armeabi.c
Thomas Preud'homme 88c9f1bb4e Round mode of ll -> float conversion to nearest
Change rounding mode of long long to float conversion to nearest in
libtcc1.
2014-02-05 20:56:36 +08:00

469 lines
26 KiB
C

#include <limits.h>
/* We rely on the little endianness and EABI calling convention for this to
work */
typedef struct double_unsigned_struct {
unsigned low;
unsigned high;
} double_unsigned_struct;
typedef struct unsigned_int_struct {
unsigned low;
int high;
} unsigned_int_struct;
#define REGS_RETURN(name, type) \
void name ## _return(type ret) {}
/* Float helper functions */
#define FLOAT_EXP_BITS 8
#define FLOAT_FRAC_BITS 23
#define DOUBLE_EXP_BITS 11
#define DOUBLE_FRAC_BITS 52
#define ONE_EXP(type) ((1 << (type ## _EXP_BITS - 1)) - 1)
REGS_RETURN(unsigned_int_struct, unsigned_int_struct)
REGS_RETURN(double_unsigned_struct, double_unsigned_struct)
/* float -> integer: (sign) 1.fraction x 2^(exponent - exp_for_one) */
/* float to [unsigned] long long conversion */
#define DEFINE__AEABI_F2XLZ(name, with_sign) \
void __aeabi_ ## name(unsigned val) \
{ \
int exp, high_shift, sign; \
double_unsigned_struct ret; \
\
/* compute sign */ \
sign = val >> 31; \
\
/* compute real exponent */ \
exp = val >> FLOAT_FRAC_BITS; \
exp &= (1 << FLOAT_EXP_BITS) - 1; \
exp -= ONE_EXP(FLOAT); \
\
/* undefined behavior if truncated value cannot be represented */ \
if (with_sign) { \
if (exp > 62) /* |val| too big, double cannot represent LLONG_MAX */ \
return; \
} else { \
if ((sign && exp >= 0) || exp > 63) /* if val < 0 || val too big */ \
return; \
} \
\
val &= (1 << FLOAT_FRAC_BITS) - 1; \
if (exp >= 32) { \
ret.high = 1 << (exp - 32); \
if (exp - 32 >= FLOAT_FRAC_BITS) { \
ret.high |= val << (exp - 32 - FLOAT_FRAC_BITS); \
ret.low = 0; \
} else { \
high_shift = FLOAT_FRAC_BITS - (exp - 32); \
ret.high |= val >> high_shift; \
ret.low = val << (32 - high_shift); \
} \
} else { \
ret.high = 0; \
ret.low = 1 << exp; \
if (exp > FLOAT_FRAC_BITS) \
ret.low |= val << (exp - FLOAT_FRAC_BITS); \
else \
ret.low |= val >> (FLOAT_FRAC_BITS - exp); \
} \
\
/* encode negative integer using 2's complement */ \
if (with_sign && sign) { \
ret.low = ~ret.low; \
ret.high = ~ret.high; \
if (ret.low == UINT_MAX) { \
ret.low = 0; \
ret.high++; \
} else \
ret.low++; \
} \
\
double_unsigned_struct_return(ret); \
}
/* float to unsigned long long conversion */
DEFINE__AEABI_F2XLZ(f2ulz, 0)
/* float to long long conversion */
DEFINE__AEABI_F2XLZ(f2lz, 1)
/* double to [unsigned] long long conversion */
#define DEFINE__AEABI_D2XLZ(name, with_sign) \
void __aeabi_ ## name(double_unsigned_struct val) \
{ \
int exp, high_shift, sign; \
double_unsigned_struct ret; \
\
/* compute sign */ \
sign = val.high >> 31; \
\
/* compute real exponent */ \
exp = (val.high >> (DOUBLE_FRAC_BITS - 32)); \
exp &= (1 << DOUBLE_EXP_BITS) - 1; \
exp -= ONE_EXP(DOUBLE); \
\
/* undefined behavior if truncated value cannot be represented */ \
if (with_sign) { \
if (exp > 62) /* |val| too big, double cannot represent LLONG_MAX */ \
return; \
} else { \
if ((sign && exp >= 0) || exp > 63) /* if val < 0 || val too big */ \
return; \
} \
\
val.high &= (1 << (DOUBLE_FRAC_BITS - 32)) - 1; \
if (exp >= 32) { \
ret.high = 1 << (exp - 32); \
if (exp >= DOUBLE_FRAC_BITS) { \
high_shift = exp - DOUBLE_FRAC_BITS; \
ret.high |= val.high << high_shift; \
ret.high |= val.low >> (32 - high_shift); \
ret.low = val.low << high_shift; \
} else { \
high_shift = DOUBLE_FRAC_BITS - exp; \
ret.high |= val.high >> high_shift; \
ret.low = val.high << (32 - high_shift); \
ret.low |= val.low >> high_shift; \
} \
} else { \
ret.high = 0; \
ret.low = 1 << exp; \
if (exp > DOUBLE_FRAC_BITS - 32) { \
high_shift = exp - DOUBLE_FRAC_BITS - 32; \
ret.low |= val.high << high_shift; \
ret.low |= val.low >> (32 - high_shift); \
} else \
ret.low |= val.high >> (DOUBLE_FRAC_BITS - 32 - exp); \
} \
\
/* encode negative integer using 2's complement */ \
if (with_sign && sign) { \
ret.low = ~ret.low; \
ret.high = ~ret.high; \
if (ret.low == UINT_MAX) { \
ret.low = 0; \
ret.high++; \
} else \
ret.low++; \
} \
\
double_unsigned_struct_return(ret); \
}
/* double to unsigned long long conversion */
DEFINE__AEABI_D2XLZ(d2ulz, 0)
/* double to long long conversion */
DEFINE__AEABI_D2XLZ(d2lz, 1)
/* long long to float conversion */
#define DEFINE__AEABI_XL2F(name, with_sign) \
unsigned __aeabi_ ## name(unsigned long long v) \
{ \
int s /* shift */, flb /* first lost bit */, sign = 0; \
unsigned p = 0 /* power */, ret; \
double_unsigned_struct val; \
\
/* fraction in negative float is encoded in 1's complement */ \
if (with_sign && (v & (1ULL << 63))) { \
sign = 1; \
v = ~v + 1; \
} \
val.low = v; \
val.high = v >> 32; \
/* fill fraction bits */ \
for (s = 31, p = 1 << 31; p && !(val.high & p); s--, p >>= 1); \
if (p) { \
ret = val.high & (p - 1); \
if (s < FLOAT_FRAC_BITS) { \
ret <<= FLOAT_FRAC_BITS - s; \
ret |= val.low >> (32 - (FLOAT_FRAC_BITS - s)); \
flb = (val.low >> (32 - (FLOAT_FRAC_BITS - s - 1))) & 1; \
} else { \
flb = (ret >> (s - FLOAT_FRAC_BITS - 1)) & 1; \
ret >>= s - FLOAT_FRAC_BITS; \
} \
s += 32; \
} else { \
for (s = 31, p = 1 << 31; p && !(val.low & p); s--, p >>= 1); \
if (p) { \
ret = val.low & (p - 1); \
if (s <= FLOAT_FRAC_BITS) { \
ret <<= FLOAT_FRAC_BITS - s; \
flb = 0; \
} else { \
flb = (ret >> (s - FLOAT_FRAC_BITS - 1)) & 1; \
ret >>= s - FLOAT_FRAC_BITS; \
} \
} else \
return 0; \
} \
if (flb) \
ret++; \
\
/* fill exponent bits */ \
ret |= (s + ONE_EXP(FLOAT)) << FLOAT_FRAC_BITS; \
\
/* fill sign bit */ \
ret |= sign << 31; \
\
return ret; \
}
/* unsigned long long to float conversion */
DEFINE__AEABI_XL2F(ul2f, 0)
/* long long to float conversion */
DEFINE__AEABI_XL2F(l2f, 1)
/* long long to double conversion */
#define __AEABI_XL2D(name, with_sign) \
void __aeabi_ ## name(unsigned long long v) \
{ \
int s /* shift */, high_shift, sign = 0; \
unsigned tmp, p = 0; \
double_unsigned_struct val, ret; \
\
/* fraction in negative float is encoded in 1's complement */ \
if (with_sign && (v & (1ULL << 63))) { \
sign = 1; \
v = ~v + 1; \
} \
val.low = v; \
val.high = v >> 32; \
\
/* fill fraction bits */ \
for (s = 31, p = 1 << 31; p && !(val.high & p); s--, p >>= 1); \
if (p) { \
tmp = val.high & (p - 1); \
if (s < DOUBLE_FRAC_BITS - 32) { \
high_shift = DOUBLE_FRAC_BITS - 32 - s; \
ret.high = tmp << high_shift; \
ret.high |= val.low >> (32 - high_shift); \
ret.low = val.low << high_shift; \
} else { \
high_shift = s - (DOUBLE_FRAC_BITS - 32); \
ret.high = tmp >> high_shift; \
ret.low = tmp << (32 - high_shift); \
ret.low |= val.low >> high_shift; \
if ((val.low >> (high_shift - 1)) & 1) { \
if (ret.low == UINT_MAX) { \
ret.high++; \
ret.low = 0; \
} else \
ret.low++; \
} \
} \
s += 32; \
} else { \
for (s = 31, p = 1 << 31; p && !(val.low & p); s--, p >>= 1); \
if (p) { \
tmp = val.low & (p - 1); \
if (s <= DOUBLE_FRAC_BITS - 32) { \
high_shift = DOUBLE_FRAC_BITS - 32 - s; \
ret.high = tmp << high_shift; \
ret.low = 0; \
} else { \
high_shift = s - (DOUBLE_FRAC_BITS - 32); \
ret.high = tmp >> high_shift; \
ret.low = tmp << (32 - high_shift); \
} \
} else { \
ret.high = ret.low = 0; \
double_unsigned_struct_return(ret); \
} \
} \
\
/* fill exponent bits */ \
ret.high |= (s + ONE_EXP(DOUBLE)) << (DOUBLE_FRAC_BITS - 32); \
\
/* fill sign bit */ \
ret.high |= sign << 31; \
\
double_unsigned_struct_return(ret); \
}
/* unsigned long long to double conversion */
__AEABI_XL2D(ul2d, 0)
/* long long to double conversion */
__AEABI_XL2D(l2d, 1)
/* Long long helper functions */
/* TODO: add error in case of den == 0 (see §4.3.1 and §4.3.2) */
#define define_aeabi_xdivmod_signed_type(basetype, type) \
typedef struct type { \
basetype quot; \
unsigned basetype rem; \
} type
#define define_aeabi_xdivmod_unsigned_type(basetype, type) \
typedef struct type { \
basetype quot; \
basetype rem; \
} type
#define AEABI_UXDIVMOD(name,type, rettype, typemacro) \
static inline rettype aeabi_ ## name (type num, type den) \
{ \
rettype ret; \
type quot = 0; \
\
/* Increase quotient while it is less than numerator */ \
while (num >= den) { \
type q = 1; \
\
/* Find closest power of two */ \
while ((q << 1) * den <= num && q * den <= typemacro ## _MAX / 2) \
q <<= 1; \
\
/* Compute difference between current quotient and numerator */ \
num -= q * den; \
quot += q; \
} \
ret.quot = quot; \
ret.rem = num; \
return ret; \
}
#define __AEABI_XDIVMOD(name, type, uiname, rettype, urettype, typemacro) \
void __aeabi_ ## name(type numerator, type denominator) \
{ \
unsigned type num, den; \
urettype uxdiv_ret; \
rettype ret; \
\
if (numerator >= 0) \
num = numerator; \
else \
num = 0 - numerator; \
if (denominator >= 0) \
den = denominator; \
else \
den = 0 - denominator; \
uxdiv_ret = aeabi_ ## uiname(num, den); \
/* signs differ */ \
if ((numerator & typemacro ## _MIN) != (denominator & typemacro ## _MIN)) \
ret.quot = 0 - uxdiv_ret.quot; \
else \
ret.quot = uxdiv_ret.quot; \
if (numerator < 0) \
ret.rem = 0 - uxdiv_ret.rem; \
else \
ret.rem = uxdiv_ret.rem; \
\
rettype ## _return(ret); \
}
define_aeabi_xdivmod_signed_type(long long, lldiv_t);
define_aeabi_xdivmod_unsigned_type(unsigned long long, ulldiv_t);
define_aeabi_xdivmod_signed_type(int, idiv_t);
define_aeabi_xdivmod_unsigned_type(unsigned, uidiv_t);
REGS_RETURN(lldiv_t, lldiv_t)
REGS_RETURN(ulldiv_t, ulldiv_t)
REGS_RETURN(idiv_t, idiv_t)
REGS_RETURN(uidiv_t, uidiv_t)
AEABI_UXDIVMOD(uldivmod, unsigned long long, ulldiv_t, ULONG)
__AEABI_XDIVMOD(ldivmod, long long, uldivmod, lldiv_t, ulldiv_t, LLONG)
void __aeabi_uldivmod(unsigned long long num, unsigned long long den)
{
ulldiv_t_return(aeabi_uldivmod(num, den));
}
void __aeabi_llsl(double_unsigned_struct val, int shift)
{
double_unsigned_struct ret;
if (shift >= 32) {
val.high = val.low;
val.low = 0;
shift -= 32;
}
if (shift > 0) {
ret.low = val.low << shift;
ret.high = (val.high << shift) | (val.low >> (32 - shift));
double_unsigned_struct_return(ret);
return;
}
double_unsigned_struct_return(val);
}
#define aeabi_lsr(val, shift, fill, type) \
type ## _struct ret; \
\
if (shift >= 32) { \
val.low = val.high; \
val.high = fill; \
shift -= 32; \
} \
if (shift > 0) { \
ret.high = val.high >> shift; \
ret.low = (val.high << (32 - shift)) | (val.low >> shift); \
type ## _struct_return(ret); \
return; \
} \
type ## _struct_return(val);
void __aeabi_llsr(double_unsigned_struct val, int shift)
{
aeabi_lsr(val, shift, 0, double_unsigned);
}
void __aeabi_lasr(unsigned_int_struct val, int shift)
{
aeabi_lsr(val, shift, val.high >> 31, unsigned_int);
}
/* Integer division functions */
AEABI_UXDIVMOD(uidivmod, unsigned, uidiv_t, UINT)
int __aeabi_idiv(int numerator, int denominator)
{
unsigned num, den;
uidiv_t ret;
if (numerator >= 0)
num = numerator;
else
num = 0 - numerator;
if (denominator >= 0)
den = denominator;
else
den = 0 - denominator;
ret = aeabi_uidivmod(num, den);
if ((numerator & INT_MIN) != (denominator & INT_MIN)) /* signs differ */
ret.quot *= -1;
return ret.quot;
}
unsigned __aeabi_uidiv(unsigned num, unsigned den)
{
return aeabi_uidivmod(num, den).quot;
}
__AEABI_XDIVMOD(idivmod, int, uidivmod, idiv_t, uidiv_t, INT)
void __aeabi_uidivmod(unsigned num, unsigned den)
{
uidiv_t_return(aeabi_uidivmod(num, den));
}