Add fast memory copy function for x86-64

This commit is contained in:
Eugen Wissner 2017-07-29 10:08:44 +02:00
parent 51ade45108
commit 5d145f524c

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@ -0,0 +1,65 @@
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* Copyright: Eugene Wissner 2017.
* License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
* Mozilla Public License, v. 2.0).
* Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
*/
module tanya.memory.arch.x86_64;
version (D_InlineAsm_X86_64):
package void copy(const void[] src, void[] dst)
pure nothrow @system @nogc
{
asm pure nothrow @nogc
{
naked;
// RDX - src length.
// RCX - src data.
// RDI - dst length.
// RSI - dst data.
// RDI and RSI should be preserved.
mov RAX, RDI;
mov R8, RSI;
// Set the registers for movsb/movsq.
mov RDI, RSI;
mov RSI, RCX;
cmp RDX, 0x08;
jc aligned_8;
test EDI, 0x07;
jz aligned_8;
naligned:
movsb;
dec RDX;
test EDI, 0x07;
jnz naligned;
aligned_8:
mov RCX, RDX;
shr RCX, 0x03;
rep;
movsq;
and EDX, 0x07;
jz end;
// Write remaining bytes.
mov RCX, RDX;
rep;
movsb;
end: // Restore registers.
mov RSI, R8;
mov RDI, RAX;
ret;
}
}