runtime: add more specialized type algorithms

The change adds specialized type algorithms
for slices and types of size 8/16/32/64/128.
It significantly accelerates chan and map operations
for most builtin types as well as user structs.

benchmark                   old,ns/op   new,ns/op
BenchmarkChanUncontended          226          94
(on Intel Xeon E5620, 2.4GHz, Linux 64 bit)

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4815087

src/cmd/gc/go.h

@@ -40,7 +40,17 @@ enum
 	ASTRING,
 	AINTER,
 	ANILINTER,
-	AMEMWORD,
+	ASLICE,
+	AMEM8,
+	AMEM16,
+	AMEM32,
+	AMEM64,
+	AMEM128,
+	ANOEQ8,
+	ANOEQ16,
+	ANOEQ32,
+	ANOEQ64,
+	ANOEQ128,
 
 	BADWIDTH	= -1000000000,
 };

src/cmd/gc/subr.c

@@ -493,8 +493,16 @@ algtype(Type *t)
 
 	if(issimple[t->etype] || isptr[t->etype] ||
 		t->etype == TCHAN || t->etype == TFUNC || t->etype == TMAP) {
-		if(t->width == widthptr)
+		if(t->width == 1)
-			a = AMEMWORD;
+			a = AMEM8;
+		else if(t->width == 2)
+			a = AMEM16;
+		else if(t->width == 4)
+			a = AMEM32;
+		else if(t->width == 8)
+			a = AMEM64;
+		else if(t->width == 16)
+			a = AMEM128;
 		else
 			a = AMEM;	// just bytes (int, ptr, etc)
 	} else if(t->etype == TSTRING)
@@ -503,8 +511,22 @@ algtype(Type *t)
 		a = ANILINTER;	// nil interface
 	else if(t->etype == TINTER)
 		a = AINTER;	// interface
-	else
+	else if(isslice(t))
-		a = ANOEQ;	// just bytes, but no hash/eq
+		a = ASLICE;	// slice
+	else {
+		if(t->width == 1)
+			a = ANOEQ8;
+		else if(t->width == 2)
+			a = ANOEQ16;
+		else if(t->width == 4)
+			a = ANOEQ32;
+		else if(t->width == 8)
+			a = ANOEQ64;
+		else if(t->width == 16)
+			a = ANOEQ128;
+		else
+			a = ANOEQ;	// just bytes, but no hash/eq
+	}
 	return a;
 }
 

src/pkg/runtime/runtime.c

@@ -398,21 +398,110 @@ memcopy(uint32 s, void *a, void *b)
 }
 
 static uint32
-memwordequal(uint32 s, void *a, void *b)
+memequal8(uint32 s, uint8 *a, uint8 *b)
 {
 	USED(s);
-	return *(uintptr*)(a) == *(uintptr*)(b);
+	return *a == *b;
 }
 
 static void
-memwordcopy(uint32 s, void *a, void *b)
+memcopy8(uint32 s, uint8 *a, uint8 *b)
 {
 	USED(s);
-	if (b == nil) {
+	if(b == nil) {
-		*(uintptr*)(a) = 0;
+		*a = 0;
 		return;
 	}
-	*(uintptr*)(a) = *(uintptr*)(b);
+	*a = *b;
+}
+
+static uint32
+memequal16(uint32 s, uint16 *a, uint16 *b)
+{
+	USED(s);
+	return *a == *b;
+}
+
+static void
+memcopy16(uint32 s, uint16 *a, uint16 *b)
+{
+	USED(s);
+	if(b == nil) {
+		*a = 0;
+		return;
+	}
+	*a = *b;
+}
+
+static uint32
+memequal32(uint32 s, uint32 *a, uint32 *b)
+{
+	USED(s);
+	return *a == *b;
+}
+
+static void
+memcopy32(uint32 s, uint32 *a, uint32 *b)
+{
+	USED(s);
+	if(b == nil) {
+		*a = 0;
+		return;
+	}
+	*a = *b;
+}
+
+static uint32
+memequal64(uint32 s, uint64 *a, uint64 *b)
+{
+	USED(s);
+	return *a == *b;
+}
+
+static void
+memcopy64(uint32 s, uint64 *a, uint64 *b)
+{
+	USED(s);
+	if(b == nil) {
+		*a = 0;
+		return;
+	}
+	*a = *b;
+}
+
+static uint32
+memequal128(uint32 s, uint64 *a, uint64 *b)
+{
+	USED(s);
+	return a[0] == b[0] && a[1] == b[1];
+}
+
+static void
+memcopy128(uint32 s, uint64 *a, uint64 *b)
+{
+	USED(s);
+	if(b == nil) {
+		a[0] = 0;
+		a[1] = 0;
+		return;
+	}
+	a[0] = b[0];
+	a[1] = b[1];
+}
+
+static void
+slicecopy(uint32 s, Slice *a, Slice *b)
+{
+	USED(s);
+	if(b == nil) {
+		a->array = 0;
+		a->len = 0;
+		a->cap = 0;
+		return;
+	}
+	a->array = b->array;
+	a->len = b->len;
+	a->cap = b->cap;
 }
 
 static uintptr
@@ -441,6 +530,19 @@ strprint(uint32 s, String *a)
 	runtime·printstring(*a);
 }
 
+static void
+strcopy(uint32 s, String *a, String *b)
+{
+	USED(s);
+	if(b == nil) {
+		a->str = 0;
+		a->len = 0;
+		return;
+	}
+	a->str = b->str;
+	a->len = b->len;
+}
+
 static uintptr
 interhash(uint32 s, Iface *a)
 {
@@ -462,6 +564,19 @@ interequal(uint32 s, Iface *a, Iface *b)
 	return runtime·ifaceeq_c(*a, *b);
 }
 
+static void
+intercopy(uint32 s, Iface *a, Iface *b)
+{
+	USED(s);
+	if(b == nil) {
+		a->tab = 0;
+		a->data = 0;
+		return;
+	}
+	a->tab = b->tab;
+	a->data = b->data;
+}
+
 static uintptr
 nilinterhash(uint32 s, Eface *a)
 {
@@ -483,6 +598,19 @@ nilinterequal(uint32 s, Eface *a, Eface *b)
 	return runtime·efaceeq_c(*a, *b);
 }
 
+static void
+nilintercopy(uint32 s, Eface *a, Eface *b)
+{
+	USED(s);
+	if(b == nil) {
+		a->type = 0;
+		a->data = 0;
+		return;
+	}
+	a->type = b->type;
+	a->data = b->data;
+}
+
 uintptr
 runtime·nohash(uint32 s, void *a)
 {
@@ -507,10 +635,20 @@ runtime·algarray[] =
 {
 [AMEM]	{ memhash, memequal, memprint, memcopy },
 [ANOEQ]	{ runtime·nohash, runtime·noequal, memprint, memcopy },
-[ASTRING]	{ strhash, strequal, strprint, memcopy },
+[ASTRING]	{ strhash, strequal, strprint, strcopy },
-[AINTER]		{ interhash, interequal, interprint, memcopy },
+[AINTER]		{ interhash, interequal, interprint, intercopy },
-[ANILINTER]	{ nilinterhash, nilinterequal, nilinterprint, memcopy },
+[ANILINTER]	{ nilinterhash, nilinterequal, nilinterprint, nilintercopy },
-[AMEMWORD] { memhash, memwordequal, memprint, memwordcopy },
+[ASLICE]	{ runtime·nohash, runtime·noequal, memprint, slicecopy },
+[AMEM8]		{ memhash, memequal8, memprint, memcopy8 },
+[AMEM16]	{ memhash, memequal16, memprint, memcopy16 },
+[AMEM32]	{ memhash, memequal32, memprint, memcopy32 },
+[AMEM64]	{ memhash, memequal64, memprint, memcopy64 },
+[AMEM128]	{ memhash, memequal128, memprint, memcopy128 },
+[ANOEQ8]	{ runtime·nohash, runtime·noequal, memprint, memcopy8 },
+[ANOEQ16]	{ runtime·nohash, runtime·noequal, memprint, memcopy16 },
+[ANOEQ32]	{ runtime·nohash, runtime·noequal, memprint, memcopy32 },
+[ANOEQ64]	{ runtime·nohash, runtime·noequal, memprint, memcopy64 },
+[ANOEQ128]	{ runtime·nohash, runtime·noequal, memprint, memcopy128 },
 };
 
 int64

src/pkg/runtime/runtime.h

@@ -335,7 +335,17 @@ enum
 	ASTRING,
 	AINTER,
 	ANILINTER,
-	AMEMWORD,
+	ASLICE,
+	AMEM8,
+	AMEM16,
+	AMEM32,
+	AMEM64,
+	AMEM128,
+	ANOEQ8,
+	ANOEQ16,
+	ANOEQ32,
+	ANOEQ64,
+	ANOEQ128,
 	Amax
 };