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#![allow(unreachable_code)]
use crate::float::Float;
use crate::int::Int;
#[derive(Clone, Copy)]
enum Result {
Less,
Equal,
Greater,
Unordered,
}
impl Result {
fn to_le_abi(self) -> i32 {
match self {
Result::Less => -1,
Result::Equal => 0,
Result::Greater => 1,
Result::Unordered => 1,
}
}
fn to_ge_abi(self) -> i32 {
match self {
Result::Less => -1,
Result::Equal => 0,
Result::Greater => 1,
Result::Unordered => -1,
}
}
}
fn cmp<F: Float>(a: F, b: F) -> Result {
let one = F::Int::ONE;
let zero = F::Int::ZERO;
let szero = F::SignedInt::ZERO;
let sign_bit = F::SIGN_MASK as F::Int;
let abs_mask = sign_bit - one;
let exponent_mask = F::EXPONENT_MASK;
let inf_rep = exponent_mask;
let a_rep = a.repr();
let b_rep = b.repr();
let a_abs = a_rep & abs_mask;
let b_abs = b_rep & abs_mask;
// If either a or b is NaN, they are unordered.
if a_abs > inf_rep || b_abs > inf_rep {
return Result::Unordered;
}
// If a and b are both zeros, they are equal.
if a_abs | b_abs == zero {
return Result::Equal;
}
let a_srep = a.signed_repr();
let b_srep = b.signed_repr();
// If at least one of a and b is positive, we get the same result comparing
// a and b as signed integers as we would with a fp_ting-point compare.
if a_srep & b_srep >= szero {
if a_srep < b_srep {
Result::Less
} else if a_srep == b_srep {
Result::Equal
} else {
Result::Greater
}
// Otherwise, both are negative, so we need to flip the sense of the
// comparison to get the correct result. (This assumes a twos- or ones-
// complement integer representation; if integers are represented in a
// sign-magnitude representation, then this flip is incorrect).
} else if a_srep > b_srep {
Result::Less
} else if a_srep == b_srep {
Result::Equal
} else {
Result::Greater
}
}
fn unord<F: Float>(a: F, b: F) -> bool {
let one = F::Int::ONE;
let sign_bit = F::SIGN_MASK as F::Int;
let abs_mask = sign_bit - one;
let exponent_mask = F::EXPONENT_MASK;
let inf_rep = exponent_mask;
let a_rep = a.repr();
let b_rep = b.repr();
let a_abs = a_rep & abs_mask;
let b_abs = b_rep & abs_mask;
a_abs > inf_rep || b_abs > inf_rep
}
intrinsics! {
#[avr_skip]
pub extern "C" fn __lesf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __gesf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_ge_abi()
}
#[avr_skip]
#[arm_aeabi_alias = __aeabi_fcmpun]
pub extern "C" fn __unordsf2(a: f32, b: f32) -> i32 {
unord(a, b) as i32
}
#[avr_skip]
pub extern "C" fn __eqsf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __ltsf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __nesf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __gtsf2(a: f32, b: f32) -> i32 {
cmp(a, b).to_ge_abi()
}
#[avr_skip]
pub extern "C" fn __ledf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __gedf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_ge_abi()
}
#[avr_skip]
#[arm_aeabi_alias = __aeabi_dcmpun]
pub extern "C" fn __unorddf2(a: f64, b: f64) -> i32 {
unord(a, b) as i32
}
#[avr_skip]
pub extern "C" fn __eqdf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __ltdf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __nedf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_le_abi()
}
#[avr_skip]
pub extern "C" fn __gtdf2(a: f64, b: f64) -> i32 {
cmp(a, b).to_ge_abi()
}
}
#[cfg(target_arch = "arm")]
intrinsics! {
pub extern "aapcs" fn __aeabi_fcmple(a: f32, b: f32) -> i32 {
(__lesf2(a, b) <= 0) as i32
}
pub extern "aapcs" fn __aeabi_fcmpge(a: f32, b: f32) -> i32 {
(__gesf2(a, b) >= 0) as i32
}
pub extern "aapcs" fn __aeabi_fcmpeq(a: f32, b: f32) -> i32 {
(__eqsf2(a, b) == 0) as i32
}
pub extern "aapcs" fn __aeabi_fcmplt(a: f32, b: f32) -> i32 {
(__ltsf2(a, b) < 0) as i32
}
pub extern "aapcs" fn __aeabi_fcmpgt(a: f32, b: f32) -> i32 {
(__gtsf2(a, b) > 0) as i32
}
pub extern "aapcs" fn __aeabi_dcmple(a: f64, b: f64) -> i32 {
(__ledf2(a, b) <= 0) as i32
}
pub extern "aapcs" fn __aeabi_dcmpge(a: f64, b: f64) -> i32 {
(__gedf2(a, b) >= 0) as i32
}
pub extern "aapcs" fn __aeabi_dcmpeq(a: f64, b: f64) -> i32 {
(__eqdf2(a, b) == 0) as i32
}
pub extern "aapcs" fn __aeabi_dcmplt(a: f64, b: f64) -> i32 {
(__ltdf2(a, b) < 0) as i32
}
pub extern "aapcs" fn __aeabi_dcmpgt(a: f64, b: f64) -> i32 {
(__gtdf2(a, b) > 0) as i32
}
// On hard-float targets LLVM will use native instructions
// for all VFP intrinsics below
pub extern "C" fn __gesf2vfp(a: f32, b: f32) -> i32 {
(a >= b) as i32
}
pub extern "C" fn __gedf2vfp(a: f64, b: f64) -> i32 {
(a >= b) as i32
}
pub extern "C" fn __gtsf2vfp(a: f32, b: f32) -> i32 {
(a > b) as i32
}
pub extern "C" fn __gtdf2vfp(a: f64, b: f64) -> i32 {
(a > b) as i32
}
pub extern "C" fn __ltsf2vfp(a: f32, b: f32) -> i32 {
(a < b) as i32
}
pub extern "C" fn __ltdf2vfp(a: f64, b: f64) -> i32 {
(a < b) as i32
}
pub extern "C" fn __lesf2vfp(a: f32, b: f32) -> i32 {
(a <= b) as i32
}
pub extern "C" fn __ledf2vfp(a: f64, b: f64) -> i32 {
(a <= b) as i32
}
pub extern "C" fn __nesf2vfp(a: f32, b: f32) -> i32 {
(a != b) as i32
}
pub extern "C" fn __nedf2vfp(a: f64, b: f64) -> i32 {
(a != b) as i32
}
pub extern "C" fn __eqsf2vfp(a: f32, b: f32) -> i32 {
(a == b) as i32
}
pub extern "C" fn __eqdf2vfp(a: f64, b: f64) -> i32 {
(a == b) as i32
}
}
|
