int float_to_half(float f) {
unsigned int sign_mask = 0x80000000u;
int o;
int fint = FloatToBits(f);
int sign = fint & sign_mask;
fint ^= sign;
// NOTE all the integer compares in this function can be safely
// compiled into signed compares since all operands are below
// 0x80000000. Important if you want fast straight SSE2 code (since
// there's no unsigned PCMPGTD).
// Inf or NaN (all exponent bits set)
// NaN->qNaN and Inf->Inf
// unconditional assignment here, will override with right value for
// the regular case below.
int f32infty = 255ul << 23;
o = (fint > f32infty) ? 0x7e00u : 0x7c00u;
// (De)normalized number or zero
// update fint unconditionally to save the blending; we don't need it
// anymore for the Inf/NaN case anyway.
const unsigned int round_mask = ~0xfffu;
const uint32_t magic = 15ul << 23;
const int f16infty = 31ul << 23;
int fint2 = FloatToBits(BitsToFloat(fint & round_mask) * BitsToFloat(magic)) -
round_mask;
// Clamp to signed infinity if overflowed
fint2 = (fint2 > f16infty) ? f16infty : fint2;
if (fint < f32infty)
o = fint2 >> 13; // Take the bits!
return (o | (sign >> 16));
}
bool isInlinableLiteral32(int32_t Literal, bool IsVI) {
if (Literal >= -16 && Literal <= 64)
return true;
float F = BitsToFloat(Literal);
if (F == 0.5 || F == -0.5 ||
F == 1.0 || F == -1.0 ||
F == 2.0 || F == -2.0 ||
F == 4.0 || F == -4.0)
return true;
if (IsVI && Literal == 0x3e22f983)
return true;
return false;
}
