Merge pull request #521 from ethcore/bigint-u512-opt

U512 add/sub optimize
This commit is contained in:
Gav Wood 2016-02-26 23:46:47 +01:00
commit 07b9f9f6f3
2 changed files with 178 additions and 21 deletions

View File

@ -38,7 +38,6 @@ fn u256_add(b: &mut Bencher) {
});
}
#[bench]
fn u256_sub(b: &mut Bencher) {
b.iter(|| {
@ -47,6 +46,25 @@ fn u256_sub(b: &mut Bencher) {
});
}
#[bench]
fn u512_sub(b: &mut Bencher) {
b.iter(|| {
let n = black_box(10000);
(0..n).fold(U512([rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(),
rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>()]),
|old, new| { old.overflowing_sub(U512([0, 0, 0, 0, 0, 0, 0, new])).0 })
});
}
#[bench]
fn u512_add(b: &mut Bencher) {
b.iter(|| {
let n = black_box(10000);
(0..n).fold(U512([0, 0, 0, 0, 0, 0, 0, 0]),
|old, new| { old.overflowing_add(U512([new, new, new, new, new, new, new, new])).0 })
});
}
#[bench]
fn u256_mul(b: &mut Bencher) {
b.iter(|| {

View File

@ -99,7 +99,7 @@ macro_rules! uint_overflowing_add {
let overflow: u8;
unsafe {
asm!("
adc $9, $0
add $9, $0
adc $10, $1
adc $11, $2
adc $12, $3
@ -114,6 +114,52 @@ macro_rules! uint_overflowing_add {
}
(U256(result), overflow != 0)
});
(U512, $n_words: expr, $self_expr: expr, $other: expr) => ({
let mut result: [u64; 8] = unsafe { mem::uninitialized() };
let self_t: &[u64; 8] = unsafe { &mem::transmute($self_expr) };
let other_t: &[u64; 8] = unsafe { &mem::transmute($other) };
let overflow: u8;
unsafe {
asm!("
add $15, $0
adc $16, $1
adc $17, $2
adc $18, $3
lodsq
adc $11, %rax
stosq
lodsq
adc $12, %rax
stosq
lodsq
adc $13, %rax
stosq
lodsq
adc $14, %rax
stosq
setc %al
": "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]),
"={al}"(overflow) /* $0 - $4 */
: "{rdi}"(&result[4] as *const u64) /* $5 */
"{rsi}"(&other_t[4] as *const u64) /* $6 */
"0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]),
"m"(self_t[4]), "m"(self_t[5]), "m"(self_t[6]), "m"(self_t[7]),
/* $7 - $14 */
"mr"(other_t[0]), "mr"(other_t[1]), "mr"(other_t[2]), "mr"(other_t[3]),
"m"(other_t[4]), "m"(other_t[5]), "m"(other_t[6]), "m"(other_t[7]) /* $15 - $22 */
: "rdi", "rsi"
:
);
}
(U512(result), overflow != 0)
});
($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => (
uint_overflowing_add_reg!($name, $n_words, $self_expr, $other)
)
@ -138,11 +184,12 @@ macro_rules! uint_overflowing_sub {
let overflow: u8;
unsafe {
asm!("
sbb $9, $0
sub $9, $0
sbb $10, $1
sbb $11, $2
sbb $12, $3
setb %al"
setb %al
"
: "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]), "={al}"(overflow)
: "0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]), "mr"(other_t[0]), "mr"(other_t[1]), "mr"(other_t[2]), "mr"(other_t[3])
:
@ -151,6 +198,51 @@ macro_rules! uint_overflowing_sub {
}
(U256(result), overflow != 0)
});
(U512, $n_words: expr, $self_expr: expr, $other: expr) => ({
let mut result: [u64; 8] = unsafe { mem::uninitialized() };
let self_t: &[u64; 8] = unsafe { &mem::transmute($self_expr) };
let other_t: &[u64; 8] = unsafe { &mem::transmute($other) };
let overflow: u8;
unsafe {
asm!("
sub $15, $0
sbb $16, $1
sbb $17, $2
sbb $18, $3
lodsq
sbb $19, %rax
stosq
lodsq
sbb $20, %rax
stosq
lodsq
sbb $21, %rax
stosq
lodsq
sbb $22, %rax
stosq
setb %al
"
: "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]),
"={al}"(overflow) /* $0 - $4 */
: "{rdi}"(&result[4] as *const u64) /* $5 */
"{rsi}"(&self_t[4] as *const u64) /* $6 */
"0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]),
"m"(self_t[4]), "m"(self_t[5]), "m"(self_t[6]), "m"(self_t[7]),
/* $7 - $14 */
"m"(other_t[0]), "m"(other_t[1]), "m"(other_t[2]), "m"(other_t[3]),
"m"(other_t[4]), "m"(other_t[5]), "m"(other_t[6]), "m"(other_t[7]) /* $15 - $22 */
: "rdi", "rsi"
:
);
}
(U512(result), overflow != 0)
});
($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
let res = overflowing!((!$other).overflowing_add(From::from(1u64)));
let res = overflowing!($self_expr.overflowing_add(res));
@ -1483,6 +1575,38 @@ mod tests {
assert_eq!(format!("{}", U256::from(0)), "0");
}
#[test]
fn u512_multi_adds() {
let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 0]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 0]));
assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 0]));
let (result, _) = U512([1, 0, 0, 0, 0, 0, 0, 1]).overflowing_add(U512([1, 0, 0, 0, 0, 0, 0, 1]));
assert_eq!(result, U512([2, 0, 0, 0, 0, 0, 0, 2]));
let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 1]));
assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 2]));
let (result, _) = U512([0, 0, 0, 0, 0, 0, 2, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 3, 1]));
assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 5, 2]));
let (result, _) = U512([1, 2, 3, 4, 5, 6, 7, 8]).overflowing_add(U512([9, 10, 11, 12, 13, 14, 15, 16]));
assert_eq!(result, U512([10, 12, 14, 16, 18, 20, 22, 24]));
let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 2, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 3, 1]));
assert!(!overflow);
let (_, overflow) = U512([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX])
.overflowing_add(U512([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX]));
assert!(overflow);
let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX])
.overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX]));
assert!(overflow);
let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX])
.overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 0]));
assert!(!overflow);
}
#[test]
fn u256_multi_adds() {
@ -1531,6 +1655,21 @@ mod tests {
}
#[test]
fn u512_multi_subs() {
let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 0]).overflowing_sub(U512([0, 0, 0, 0, 0, 0, 0, 0]));
assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 0]));
let (result, _) = U512([10, 9, 8, 7, 6, 5, 4, 3]).overflowing_sub(U512([9, 8, 7, 6, 5, 4, 3, 2]));
assert_eq!(result, U512([1, 1, 1, 1, 1, 1, 1, 1]));
let (_, overflow) = U512([10, 9, 8, 7, 6, 5, 4, 3]).overflowing_sub(U512([9, 8, 7, 6, 5, 4, 3, 2]));
assert!(!overflow);
let (_, overflow) = U512([9, 8, 7, 6, 5, 4, 3, 2]).overflowing_sub(U512([10, 9, 8, 7, 6, 5, 4, 3]));
assert!(overflow);
}
#[test]
fn u256_multi_muls() {
let (result, _) = U256([0, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, 0]));