src/pkg/runtime/alg.goc

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runtime
#include "runtime.h"
#include "type.h"
#include "../../cmd/ld/textflag.h"

bool runtime·use_aeshash;

void
runtime·memequal(bool *eq, uintptr s, void *a, void *b)
{
	if(a == b) {
		*eq = 1;
		return;
	}
	*eq = runtime·memeq(a, b, s);
}

void
runtime·memprint(uintptr s, void *a)
{
	uint64 v;

	v = 0xbadb00b;
	switch(s) {
	case 1:
		v = *(uint8*)a;
		break;
	case 2:
		v = *(uint16*)a;
		break;
	case 4:
		v = *(uint32*)a;
		break;
	case 8:
		v = *(uint64*)a;
		break;
	}
	runtime·printint_c(v);
}

void
runtime·memcopy(uintptr s, void *a, void *b)
{
	if(b == nil) {
		runtime·memclr(a, s);
		return;
	}
	runtime·memmove(a, b, s);
}

void
runtime·memequal0(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	USED(a);
	USED(b);
	*eq = true;
}

void
runtime·memcopy0(uintptr s, void *a, void *b)
{
	USED(s);
	USED(a);
	USED(b);
}

void
runtime·memequal8(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(uint8*)a == *(uint8*)b;
}

void
runtime·memcopy8(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		*(uint8*)a = 0;
		return;
	}
	*(uint8*)a = *(uint8*)b;
}

void
runtime·memequal16(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(uint16*)a == *(uint16*)b;
}

void
runtime·memcopy16(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		*(uint16*)a = 0;
		return;
	}
	*(uint16*)a = *(uint16*)b;
}

void
runtime·memequal32(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(uint32*)a == *(uint32*)b;
}

void
runtime·memcopy32(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		*(uint32*)a = 0;
		return;
	}
	*(uint32*)a = *(uint32*)b;
}

void
runtime·memequal64(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(uint64*)a == *(uint64*)b;
}

void
runtime·memcopy64(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		*(uint64*)a = 0;
		return;
	}
	*(uint64*)a = *(uint64*)b;
}

void
runtime·memequal128(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = ((uint64*)a)[0] == ((uint64*)b)[0] && ((uint64*)a)[1] == ((uint64*)b)[1];
}

void
runtime·memcopy128(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		((uint64*)a)[0] = 0;
		((uint64*)a)[1] = 0;
		return;
	}
	((uint64*)a)[0] = ((uint64*)b)[0];
	((uint64*)a)[1] = ((uint64*)b)[1];
}

void
runtime·f32equal(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(float32*)a == *(float32*)b;
}

void
runtime·f64equal(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = *(float64*)a == *(float64*)b;
}

void
runtime·c64equal(bool *eq, uintptr s, void *a, void *b)
{	
	Complex64 *ca, *cb;
	
	USED(s);
	ca = a;
	cb = b;
	*eq = ca->real == cb->real && ca->imag == cb->imag;
}

void
runtime·c128equal(bool *eq, uintptr s, void *a, void *b)
{	
	Complex128 *ca, *cb;
	
	USED(s);
	ca = a;
	cb = b;
	*eq = ca->real == cb->real && ca->imag == cb->imag;
}

void
runtime·algslicecopy(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		((Slice*)a)->array = 0;
		((Slice*)a)->len = 0;
		((Slice*)a)->cap = 0;
		return;
	}
	((Slice*)a)->array = ((Slice*)b)->array;
	((Slice*)a)->len = ((Slice*)b)->len;
	((Slice*)a)->cap = ((Slice*)b)->cap;
}

void
runtime·strequal(bool *eq, uintptr s, void *a, void *b)
{
	intgo alen;
	byte *s1, *s2;

	USED(s);
	alen = ((String*)a)->len;
	if(alen != ((String*)b)->len) {
		*eq = false;
		return;
	}
	s1 = ((String*)a)->str;
	s2 = ((String*)b)->str;
	if(s1 == s2) {
		*eq = true;
		return;
	}
	*eq = runtime·memeq(s1, s2, alen);
}

void
runtime·strprint(uintptr s, void *a)
{
	USED(s);
	runtime·printstring_c(*(String*)a);
}

void
runtime·strcopy(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		((String*)a)->str = 0;
		((String*)a)->len = 0;
		return;
	}
	((String*)a)->str = ((String*)b)->str;
	((String*)a)->len = ((String*)b)->len;
}

void
runtime·interprint(uintptr s, void *a)
{
	USED(s);
	runtime·printiface_c(*(Iface*)a);
}

void
runtime·interequal(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = runtime·ifaceeq_c(*(Iface*)a, *(Iface*)b);
}

void
runtime·intercopy(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		((Iface*)a)->tab = 0;
		((Iface*)a)->data = 0;
		return;
	}
	((Iface*)a)->tab = ((Iface*)b)->tab;
	((Iface*)a)->data = ((Iface*)b)->data;
}

void
runtime·nilinterprint(uintptr s, void *a)
{
	USED(s);
	runtime·printeface_c(*(Eface*)a);
}

void
runtime·nilinterequal(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	*eq = runtime·efaceeq_c(*(Eface*)a, *(Eface*)b);
}

void
runtime·nilintercopy(uintptr s, void *a, void *b)
{
	USED(s);
	if(b == nil) {
		((Eface*)a)->type = 0;
		((Eface*)a)->data = 0;
		return;
	}
	((Eface*)a)->type = ((Eface*)b)->type;
	((Eface*)a)->data = ((Eface*)b)->data;
}

extern uintptr runtime·nohashcode;

void
runtime·noequal(bool *eq, uintptr s, void *a, void *b)
{
	USED(s);
	USED(a);
	USED(b);
	USED(eq);
	runtime·panicstring("comparing uncomparable types");
}

static FuncVal memhashfunc = {(void*)runtime·memhash};
static FuncVal nohashfunc = {(void*)runtime·nohash};
static FuncVal strhashfunc = {(void*)runtime·strhash};
static FuncVal interhashfunc = {(void*)runtime·interhash};
static FuncVal nilinterhashfunc = {(void*)runtime·nilinterhash};
static FuncVal f32hashfunc = {(void*)runtime·f32hash};
static FuncVal f64hashfunc = {(void*)runtime·f64hash};
static FuncVal c64hashfunc = {(void*)runtime·c64hash};
static FuncVal c128hashfunc = {(void*)runtime·c128hash};

static FuncVal aeshashfunc = {(void*)runtime·aeshash};
static FuncVal aeshash32func = {(void*)runtime·aeshash32};
static FuncVal aeshash64func = {(void*)runtime·aeshash64};
static FuncVal aeshashstrfunc = {(void*)runtime·aeshashstr};

Alg
runtime·algarray[] =
{
[AMEM]		{ &memhashfunc, runtime·memequal, runtime·memprint, runtime·memcopy },
[ANOEQ]		{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy },
[ASTRING]	{ &strhashfunc, runtime·strequal, runtime·strprint, runtime·strcopy },
[AINTER]	{ &interhashfunc, runtime·interequal, runtime·interprint, runtime·intercopy },
[ANILINTER]	{ &nilinterhashfunc, runtime·nilinterequal, runtime·nilinterprint, runtime·nilintercopy },
[ASLICE]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·algslicecopy },
[AFLOAT32]	{ &f32hashfunc, runtime·f32equal, runtime·memprint, runtime·memcopy },
[AFLOAT64]	{ &f64hashfunc, runtime·f64equal, runtime·memprint, runtime·memcopy },
[ACPLX64]	{ &c64hashfunc, runtime·c64equal, runtime·memprint, runtime·memcopy },
[ACPLX128]	{ &c128hashfunc, runtime·c128equal, runtime·memprint, runtime·memcopy },
[AMEM0]		{ &memhashfunc, runtime·memequal0, runtime·memprint, runtime·memcopy0 },
[AMEM8]		{ &memhashfunc, runtime·memequal8, runtime·memprint, runtime·memcopy8 },
[AMEM16]	{ &memhashfunc, runtime·memequal16, runtime·memprint, runtime·memcopy16 },
[AMEM32]	{ &memhashfunc, runtime·memequal32, runtime·memprint, runtime·memcopy32 },
[AMEM64]	{ &memhashfunc, runtime·memequal64, runtime·memprint, runtime·memcopy64 },
[AMEM128]	{ &memhashfunc, runtime·memequal128, runtime·memprint, runtime·memcopy128 },
[ANOEQ0]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy0 },
[ANOEQ8]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy8 },
[ANOEQ16]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy16 },
[ANOEQ32]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy32 },
[ANOEQ64]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy64 },
[ANOEQ128]	{ &nohashfunc, runtime·noequal, runtime·memprint, runtime·memcopy128 },
};

// Runtime helpers.

// used in asm_{386,amd64}.s
#pragma dataflag NOPTR
byte runtime·aeskeysched[HashRandomBytes];

void
runtime·hashinit(void)
{
	runtime·nohashcode = (uintptr)runtime·nohash;
        if(NaCl)
                return;

	// Install aes hash algorithm if we have the instructions we need
	if((runtime·cpuid_ecx & (1 << 25)) != 0 &&  // aes (aesenc)
	   (runtime·cpuid_ecx & (1 << 9)) != 0 &&   // sse3 (pshufb)
	   (runtime·cpuid_ecx & (1 << 19)) != 0) {  // sse4.1 (pinsr{d,q})
		byte *rnd;
		int32 n;
		runtime·use_aeshash = true;
		runtime·algarray[AMEM].hash = &aeshashfunc;
		runtime·algarray[AMEM8].hash = &aeshashfunc;
		runtime·algarray[AMEM16].hash = &aeshashfunc;
		runtime·algarray[AMEM32].hash = &aeshash32func;
		runtime·algarray[AMEM64].hash = &aeshash64func;
		runtime·algarray[AMEM128].hash = &aeshashfunc;
		runtime·algarray[ASTRING].hash = &aeshashstrfunc;
		// Initialize with random data so hash collisions will be hard to engineer.
		runtime·get_random_data(&rnd, &n);
		if(n > HashRandomBytes)
			n = HashRandomBytes;
		runtime·memmove(runtime·aeskeysched, rnd, n);
		if(n < HashRandomBytes) {
			// Not very random, but better than nothing.
			int64 t = runtime·nanotime();
			while (n < HashRandomBytes) {
				runtime·aeskeysched[n++] = (int8)(t >> (8 * (n % 8)));
			}
		}
	}
}

// func equal(t *Type, x T, y T) (ret bool)
#pragma textflag NOSPLIT
void
runtime·equal(Type *t, ...)
{
	byte *x, *y;
	bool *ret;
	
	x = (byte*)ROUND((uintptr)(&t+1), t->align);
	y = x + t->size;
	ret = (bool*)ROUND((uintptr)(y+t->size), Structrnd);
	t->alg->equal(ret, t->size, x, y);
}

// Testing adapter for memclr
func memclrBytes(s Slice) {
	runtime·memclr(s.array, s.len);
}