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Optimize some std mem methods by replacing expensive rem operations to fast bit logic #24

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Merged
merged 2 commits into from
Feb 12, 2018
Merged

Optimize some std mem methods by replacing expensive rem operations to fast bit logic #24

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88a7bbc
Optimize some std mem operation by replacing expensive rem ops
MaxGraey Feb 8, 2018
bd8a733
Self add to contributors in NOTICE
MaxGraey Feb 12, 2018
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1 change: 1 addition & 0 deletions NOTICE
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@ The following authors have all licensed their contributions to AssemblyScript
under the licensing terms detailed in LICENSE.

* Daniel Wirtz <[email protected]>
* Max Graey <[email protected]>

================================================================================

Expand Down
20 changes: 10 additions & 10 deletions std/assembly/memory.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -5,13 +5,13 @@ function copy_memory(dest: usize, src: usize, n: usize): void {
var w: u32, x: u32;

// copy 1 byte each until src is aligned to 4 bytes
while (n && src % 4) {
while (n && (src & 3)) {
store<u8>(dest++, load<u8>(src++));
n--;
}

// if dst is aligned to 4 bytes as well, copy 4 bytes each
if (dest % 4 == 0) {
if ((dest & 3) == 0) {
while (n >= 16) {
store<u32>(dest , load<u32>(src ));
store<u32>(dest + 4, load<u32>(src + 4));
Expand Down Expand Up @@ -41,7 +41,7 @@ function copy_memory(dest: usize, src: usize, n: usize): void {
// if dst is not aligned to 4 bytes, use alternating shifts to copy 4 bytes each
// doing shifts if faster when copying enough bytes (here: 32 or more)
if (n >= 32) {
switch (dest % 4) {
switch (dest & 3) {
// known to be != 0
case 1:
w = load<u32>(src);
Expand Down Expand Up @@ -152,27 +152,27 @@ export function move_memory(dest: usize, src: usize, n: usize): void {
return;
}
if (dest < src) {
if (src % 8 == dest % 8) {
while (dest % 8) {
if ((src & 7) == (dest & 7)) {
while (dest & 7) {
if (!n)
return;
--n;
store<u8>(dest++, load<u8>(src++));
}
while (n >= 8) {
store<u64>(dest, load<u64>(src));
n -= 8;
n -= 8;
dest += 8;
src += 8;
src += 8;
}
}
while (n) {
store<u8>(dest++, load<u8>(src++));
--n;
}
} else {
if (src % 8 == dest % 8) {
while ((dest + n) % 8) {
if ((src & 7) == (dest & 7)) {
while ((dest + n) & 7) {
if (!n)
return;
store<u8>(dest + --n, load<u8>(src + n));
Expand Down Expand Up @@ -217,7 +217,7 @@ export function set_memory(dest: usize, c: u8, n: usize): void {
n -= k;
n &= -4;

var c32: u32 = -1 / 255 * c;
var c32: u32 = (-1 / 255) * c;

// fill head/tail up to 28 bytes each in preparation
store<u32>(dest, c32);
Expand Down
40 changes: 20 additions & 20 deletions tests/compiler/std/allocator_arena.optimized.wast
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Expand Up @@ -435,13 +435,13 @@
(local $4 i32)
(loop $continue|0
(if
(if (result i32)
(get_local $2)
(i32.rem_u
(select
(i32.and
(get_local $1)
(i32.const 4)
(i32.const 3)
)
(get_local $2)
(get_local $2)
)
(block
(set_local $0
Expand Down Expand Up @@ -480,9 +480,9 @@
)
(if
(i32.eqz
(i32.rem_u
(i32.and
(get_local $0)
(i32.const 4)
(i32.const 3)
)
)
(block
Expand Down Expand Up @@ -684,9 +684,9 @@
(block $tablify|0
(br_table $case0|2 $case1|2 $case2|2 $tablify|0
(i32.sub
(i32.rem_u
(i32.and
(get_local $0)
(i32.const 4)
(i32.const 3)
)
(i32.const 1)
)
Expand Down Expand Up @@ -2055,21 +2055,21 @@
(block
(if
(i32.eq
(i32.rem_u
(i32.and
(get_local $1)
(i32.const 8)
(i32.const 7)
)
(i32.rem_u
(i32.and
(get_local $0)
(i32.const 8)
(i32.const 7)
)
)
(block
(loop $continue|0
(if
(i32.rem_u
(i32.and
(get_local $0)
(i32.const 8)
(i32.const 7)
)
(block
(if
Expand Down Expand Up @@ -2191,24 +2191,24 @@
(block
(if
(i32.eq
(i32.rem_u
(i32.and
(get_local $1)
(i32.const 8)
(i32.const 7)
)
(i32.rem_u
(i32.and
(get_local $0)
(i32.const 8)
(i32.const 7)
)
)
(block
(loop $continue|3
(if
(i32.rem_u
(i32.and
(i32.add
(get_local $0)
(get_local $2)
)
(i32.const 8)
(i32.const 7)
)
(block
(if
Expand Down
77 changes: 42 additions & 35 deletions tests/compiler/std/allocator_arena.wast
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Original file line number Diff line number Diff line change
Expand Up @@ -348,15 +348,16 @@
;;@ (lib)/memory.ts:220:17
(i32.mul
(i32.div_u
;;@ (lib)/memory.ts:220:18
(i32.sub
(i32.const 0)
;;@ (lib)/memory.ts:220:18
;;@ (lib)/memory.ts:220:19
(i32.const 1)
)
;;@ (lib)/memory.ts:220:22
;;@ (lib)/memory.ts:220:23
(i32.const 255)
)
;;@ (lib)/memory.ts:220:28
;;@ (lib)/memory.ts:220:30
(get_local $1)
)
)
Expand Down Expand Up @@ -700,10 +701,11 @@
(i32.const 0)
)
;;@ (lib)/memory.ts:8:14
(i32.rem_u
(i32.and
;;@ (lib)/memory.ts:8:15
(get_local $1)
;;@ (lib)/memory.ts:8:20
(i32.const 4)
;;@ (lib)/memory.ts:8:21
(i32.const 3)
)
(get_local $2)
)
Expand Down Expand Up @@ -758,15 +760,16 @@
(if
;;@ (lib)/memory.ts:14:6
(i32.eq
(i32.rem_u
(i32.and
;;@ (lib)/memory.ts:14:7
(get_local $0)
;;@ (lib)/memory.ts:14:13
(i32.const 4)
;;@ (lib)/memory.ts:14:14
(i32.const 3)
)
;;@ (lib)/memory.ts:14:18
;;@ (lib)/memory.ts:14:20
(i32.const 0)
)
;;@ (lib)/memory.ts:14:21
;;@ (lib)/memory.ts:14:23
(block
(block $break|1
(loop $continue|1
Expand Down Expand Up @@ -1065,10 +1068,10 @@
(block $case0|2
(set_local $5
;;@ (lib)/memory.ts:44:12
(i32.rem_u
(i32.and
(get_local $0)
;;@ (lib)/memory.ts:44:19
(i32.const 4)
(i32.const 3)
)
)
(br_if $case0|2
Expand Down Expand Up @@ -3003,28 +3006,30 @@
(if
;;@ (lib)/memory.ts:155:8
(i32.eq
(i32.rem_u
(i32.and
;;@ (lib)/memory.ts:155:9
(get_local $1)
;;@ (lib)/memory.ts:155:14
(i32.const 8)
;;@ (lib)/memory.ts:155:15
(i32.const 7)
)
;;@ (lib)/memory.ts:155:19
(i32.rem_u
;;@ (lib)/memory.ts:155:21
(i32.and
;;@ (lib)/memory.ts:155:22
(get_local $0)
;;@ (lib)/memory.ts:155:26
(i32.const 8)
;;@ (lib)/memory.ts:155:29
(i32.const 7)
)
)
;;@ (lib)/memory.ts:155:29
;;@ (lib)/memory.ts:155:33
(block
(block $break|0
(loop $continue|0
(if
;;@ (lib)/memory.ts:156:13
(i32.rem_u
(i32.and
(get_local $0)
;;@ (lib)/memory.ts:156:20
(i32.const 8)
(i32.const 7)
)
(block
(block
Expand Down Expand Up @@ -3110,7 +3115,7 @@
(set_local $2
(i32.sub
(get_local $2)
;;@ (lib)/memory.ts:164:13
;;@ (lib)/memory.ts:164:16
(i32.const 8)
)
)
Expand All @@ -3126,7 +3131,7 @@
(set_local $1
(i32.add
(get_local $1)
;;@ (lib)/memory.ts:166:15
;;@ (lib)/memory.ts:166:16
(i32.const 8)
)
)
Expand Down Expand Up @@ -3199,33 +3204,35 @@
(if
;;@ (lib)/memory.ts:174:8
(i32.eq
(i32.rem_u
(i32.and
;;@ (lib)/memory.ts:174:9
(get_local $1)
;;@ (lib)/memory.ts:174:14
(i32.const 8)
;;@ (lib)/memory.ts:174:15
(i32.const 7)
)
;;@ (lib)/memory.ts:174:19
(i32.rem_u
;;@ (lib)/memory.ts:174:21
(i32.and
;;@ (lib)/memory.ts:174:22
(get_local $0)
;;@ (lib)/memory.ts:174:26
(i32.const 8)
;;@ (lib)/memory.ts:174:29
(i32.const 7)
)
)
;;@ (lib)/memory.ts:174:29
;;@ (lib)/memory.ts:174:33
(block
(block $break|3
(loop $continue|3
(if
;;@ (lib)/memory.ts:175:13
(i32.rem_u
(i32.and
(i32.add
;;@ (lib)/memory.ts:175:14
(get_local $0)
;;@ (lib)/memory.ts:175:21
(get_local $2)
)
;;@ (lib)/memory.ts:175:26
(i32.const 8)
(i32.const 7)
)
(block
(block
Expand Down
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