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emulator: opengl: 'large' buffer optimization

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This patch modifies the guest encoding libraries to avoid
un-necessary copies when sending large buffers (e.g. pixels)
to the host. Instead, the data is sent directly through a
new IOStream method (writeFully()).

On my machine, this improves the NenaMark2 benchmark
(from 50.8 to 57.1 fps). More importantly, this speeds up
the display of non-GL surfaces too, which are sent through
the special rcUpdateColorBuffer() function in gralloc_goldfish.

This is noticeable in many parts of the UI (e.g. when scrolling
through lists).

To tag a given parameter, use the new 'isLarge' variable flag
in the protocol .attrib file.

Implemented for the following encoding functions:

  rcUpdateColorBuffer
  glTexSubImage2D
  glTexImage2Di
  glBufferData
  glBufferSubData
  glCompressedTexImage2D
  glCompressedTexSubImage2D
  glTexImage3DOES
  glTexSubImage3DOES
  glCompressedTexImage3DOES
  glCompressedTexSubImage3DOES

+ Optimize the auto-generated encoder functions to avoid
  repeated function calls (for size computations).

Change-Id: I13a02607b606c40cd05984cd2051b1f3424bc2d0
This commit is contained in:
David 'Digit' Turner
2011-09-19 18:47:26 +02:00
parent e72ed049a8
commit 5d7f0875e9
11 changed files with 302 additions and 109 deletions
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314
tools/emulator/opengl/host/tools/emugen/ApiGen.cpp
View File

@@ -21,6 +21,15 @@
#include <errno.h>
#include <sys/types.h>
/* Define this to 1 to enable support for the 'isLarge' variable flag
* that instructs the encoder to send large data buffers by a direct
* write through the pipe (i.e. without copying it into a temporary
* buffer. This has definite performance benefits when using a QEMU Pipe.
*
* Set to 0 otherwise.
*/
#define WITH_LARGE_SUPPORT 1
EntryPoint * ApiGen::findEntryByName(const std::string & name)
{
EntryPoint * entry = NULL;
@@ -338,6 +347,99 @@ int ApiGen::genEncoderHeader(const std::string &filename)
return 0;
}
// Format the byte length expression for a given variable into a user-provided buffer
// If the variable type is not a pointer, this is simply its size as a decimal constant
// If the variable is a pointer, this will be an expression provided by the .attrib file
// through the 'len' attribute.
//
// Returns 1 if the variable is a pointer, 0 otherwise
//
static int getVarEncodingSizeExpression(Var& var, EntryPoint* e, char* buff, size_t bufflen)
{
int ret = 0;
if (!var.isPointer()) {
snprintf(buff, bufflen, "%u", (unsigned int) var.type()->bytes());
} else {
ret = 1;
const char* lenExpr = var.lenExpression().c_str();
const char* varname = var.name().c_str();
if (e != NULL && lenExpr[0] == '\0') {
fprintf(stderr, "%s: data len is undefined for '%s'\n",
e->name().c_str(), varname);
}
if (var.nullAllowed()) {
snprintf(buff, bufflen, "((%s != NULL) ? %s : 0)", varname, lenExpr);
} else {
snprintf(buff, bufflen, "%s", lenExpr);
}
}
return ret;
}
static int writeVarEncodingSize(Var& var, FILE* fp)
{
int ret = 0;
if (!var.isPointer()) {
fprintf(fp, "%u", (unsigned int) var.type()->bytes());
} else {
ret = 1;
fprintf(fp, "__size_%s", var.name().c_str());
}
return ret;
}
static void writeVarEncodingExpression(Var& var, FILE* fp)
{
const char* varname = var.name().c_str();
if (var.isPointer()) {
// encode a pointer header
fprintf(fp, "\t*(unsigned int *)(ptr) = __size_%s; ptr += 4;\n", varname);
Var::PointerDir dir = var.pointerDir();
if (dir == Var::POINTER_INOUT || dir == Var::POINTER_IN) {
if (var.nullAllowed()) {
fprintf(fp, "\tif (%s != NULL) ", varname);
} else {
fprintf(fp, "\t");
}
if (var.packExpression().size() != 0) {
fprintf(fp, "%s;", var.packExpression().c_str());
} else {
fprintf(fp, "memcpy(ptr, %s, __size_%s);",
varname, varname);
}
fprintf(fp, "ptr += __size_%s;\n", varname);
}
} else {
// encode a non pointer variable
if (!var.isVoid()) {
fprintf(fp, "\t*(%s *) (ptr) = %s; ptr += %u;\n",
var.type()->name().c_str(), varname,
(uint) var.type()->bytes());
}
}
}
#if WITH_LARGE_SUPPORT
static void writeVarLargeEncodingExpression(Var& var, FILE* fp)
{
const char* varname = var.name().c_str();
fprintf(fp, "\tstream->writeFully(&__size_%s,4);\n", varname);
if (var.nullAllowed()) {
fprintf(fp, "\tif (%s != NULL) ", varname);
} else {
fprintf(fp, "\t");
}
fprintf(fp, "stream->writeFully(%s, __size_%s);\n", varname, varname);
}
#endif /* WITH_LARGE_SUPPORT */
int ApiGen::genEncoderImpl(const std::string &filename)
{
FILE *fp = fopen(filename.c_str(), "wt");
@@ -368,46 +470,139 @@ int ApiGen::genEncoderImpl(const std::string &filename)
fprintf(fp, "{\n");
// fprintf(fp, "\n\tDBG(\">>>> %s\\n\");\n", e->name().c_str());
fprintf(fp, "\n\t%s *ctx = (%s *)self;\n\n",
fprintf(fp, "\n\t%s *ctx = (%s *)self;\n",
classname.c_str(),
classname.c_str());
// size calculation ;
fprintf(fp, "\t size_t packetSize = ");
fprintf(fp, "\tIOStream *stream = ctx->m_stream;\n\n");
VarsArray & evars = e->vars();
size_t maxvars = evars.size();
size_t j;
char buff[256];
// Define the __size_XXX variables that contain the size of data
// associated with pointers.
for (j = 0; j < maxvars; j++) {
Var& var = evars[j];
if (!var.isPointer())
continue;
const char* varname = var.name().c_str();
fprintf(fp, "\tconst unsigned int __size_%s = ", varname);
getVarEncodingSizeExpression(var, e, buff, sizeof(buff));
fprintf(fp, "%s;\n", buff);
}
#if WITH_LARGE_SUPPORT
// We need to take care of 'isLarge' variable in a special way
// Anything before an isLarge variable can be packed into a single
// buffer, which is then commited. Each isLarge variable is a pointer
// to data that can be written to directly through the pipe, which
// will be instant when using a QEMU pipe
size_t nvars = 0;
size_t npointers = 0;
// First, compute the total size, 8 bytes for the opcode + payload size
fprintf(fp, "\t unsigned char *ptr;\n");
fprintf(fp, "\t const size_t packetSize = 8");
for (j = 0; j < maxvars; j++) {
fprintf(fp, " + ");
npointers += writeVarEncodingSize(evars[j], fp);
}
if (npointers > 0) {
fprintf(fp, " + %u*4", npointers);
}
fprintf(fp, ";\n");
// We need to divide the packet into fragments. Each fragment contains
// either copied arguments to a temporary buffer, or direct writes for
// large variables.
//
// The first fragment must also contain the opcode+payload_size
//
nvars = 0;
while (nvars < maxvars || maxvars == 0) {
// Skip over non-large fields
for (j = nvars; j < maxvars; j++) {
if (evars[j].isLarge())
break;
}
// Write a fragment if needed.
if (nvars == 0 || j > nvars) {
const char* plus = "";
if (nvars == 0 && j == maxvars) {
// Simple shortcut for the common case where we don't have large variables;
fprintf(fp, "\tptr = stream->alloc(packetSize);\n");
} else {
// allocate buffer from the stream until the first large variable
fprintf(fp, "\tptr = stream->alloc(");
plus = "";
if (nvars == 0) {
fprintf(fp,"8"); plus = " + ";
}
if (j > nvars) {
npointers = 0;
for (j = nvars; j < maxvars && !evars[j].isLarge(); j++) {
fprintf(fp, "%s", plus); plus = " + ";
npointers += writeVarEncodingSize(evars[j], fp);
}
if (npointers > 0) {
fprintf(fp, "%s%u*4", plus, npointers); plus = " + ";
}
}
fprintf(fp,");\n");
}
// encode packet header if needed.
if (nvars == 0) {
fprintf(fp, "\t*(unsigned int *)(ptr) = OP_%s; ptr += 4;\n", e->name().c_str());
fprintf(fp, "\t*(unsigned int *)(ptr) = (unsigned int) packetSize; ptr += 4;\n");
}
if (maxvars == 0)
break;
// encode non-large fields in this fragment
for (j = nvars; j < maxvars && !evars[j].isLarge(); j++) {
writeVarEncodingExpression(evars[j],fp);
}
// Ensure the fragment is commited if it is followed by a large variable
if (j < maxvars) {
fprintf(fp, "\tstream->flush();\n");
}
}
// If we have one or more large variables, write them directly.
// As size + data
for ( ; j < maxvars && evars[j].isLarge(); j++) {
writeVarLargeEncodingExpression(evars[j], fp);
}
nvars = j;
}
#else /* !WITH_LARGE_SUPPORT */
size_t nvars = evars.size();
size_t npointers = 0;
fprintf(fp, "\t const size_t packetSize = 8");
for (size_t j = 0; j < nvars; j++) {
fprintf(fp, "%s ", j == 0 ? "" : " +");
if (evars[j].isPointer()) {
npointers++;
if (evars[j].lenExpression() == "") {
fprintf(stderr, "%s: data len is undefined for '%s'\n",
e->name().c_str(), evars[j].name().c_str());
}
if (evars[j].nullAllowed()) {
fprintf(fp, "(%s != NULL ? %s : 0)",
evars[j].name().c_str(),
evars[j].lenExpression().c_str());
} else {
if (evars[j].pointerDir() == Var::POINTER_IN ||
evars[j].pointerDir() == Var::POINTER_INOUT) {
fprintf(fp, "%s", evars[j].lenExpression().c_str());
} else {
fprintf(fp, "0");
}
}
} else {
fprintf(fp, "%u", (unsigned int) evars[j].type()->bytes());
}
npointers += getVarEncodingSizeExpression(evars[j],e,buff,sizeof(buff));
fprintf(fp, " + %s", buff);
}
fprintf(fp, " %s 8 + %u * 4;\n", nvars != 0 ? "+" : "", (unsigned int) npointers);
fprintf(fp, " + %u * 4;\n", (unsigned int) npointers);
// allocate buffer from the stream;
fprintf(fp, "\t unsigned char *ptr = ctx->m_stream->alloc(packetSize);\n\n");
fprintf(fp, "\t unsigned char *ptr = stream->alloc(packetSize);\n\n");
// encode into the stream;
fprintf(fp, "\t*(unsigned int *)(ptr) = OP_%s; ptr += 4;\n", e->name().c_str());
@@ -415,62 +610,23 @@ int ApiGen::genEncoderImpl(const std::string &filename)
// out variables
for (size_t j = 0; j < nvars; j++) {
if (evars[j].isPointer()) {
// encode a pointer header
if (evars[j].nullAllowed()) {
fprintf(fp, "\t*(unsigned int *)(ptr) = (%s != NULL) ? %s : 0; ptr += 4; \n",
evars[j].name().c_str(), evars[j].lenExpression().c_str());
} else {
fprintf(fp, "\t*(unsigned int *)(ptr) = %s; ptr += 4; \n",
evars[j].lenExpression().c_str());
}
Var::PointerDir dir = evars[j].pointerDir();
if (dir == Var::POINTER_INOUT || dir == Var::POINTER_IN) {
if (evars[j].nullAllowed()) {
fprintf(fp, "\tif (%s != NULL) ", evars[j].name().c_str());
} else {
fprintf(fp, "\t");
}
if (evars[j].packExpression().size() != 0) {
fprintf(fp, "%s;", evars[j].packExpression().c_str());
} else {
fprintf(fp, "memcpy(ptr, %s, %s);",
evars[j].name().c_str(),
evars[j].lenExpression().c_str());
}
if (evars[j].nullAllowed()) {
fprintf(fp, "ptr += %s == NULL ? 0 : %s; \n", evars[j].name().c_str(), evars[j].lenExpression().c_str());
} else {
fprintf(fp, "ptr += %s;\n", evars[j].lenExpression().c_str());
}
}
} else {
// encode a non pointer variable
if (!evars[j].isVoid()) {
fprintf(fp, "\t*(%s *) (ptr) = %s; ptr += %u;\n",
evars[j].type()->name().c_str(), evars[j].name().c_str(),
(uint) evars[j].type()->bytes());
}
}
writeVarEncodingExpression(evars[j], fp);
}
#endif /* !WITH_LARGE_SUPPORT */
// in variables;
for (size_t j = 0; j < nvars; j++) {
if (evars[j].isPointer()) {
Var::PointerDir dir = evars[j].pointerDir();
if (dir == Var::POINTER_INOUT || dir == Var::POINTER_OUT) {
const char* varname = evars[j].name().c_str();
if (evars[j].nullAllowed()) {
fprintf(fp, "\tif (%s != NULL) ctx->m_stream->readback(%s, %s);\n",
evars[j].name().c_str(),
evars[j].name().c_str(),
evars[j].lenExpression().c_str());
fprintf(fp, "\tif (%s != NULL) ",varname);
} else {
fprintf(fp, "\tctx->m_stream->readback(%s, %s);\n",
evars[j].name().c_str(),
evars[j].lenExpression().c_str());
fprintf(fp, "\t");
}
fprintf(fp, "stream->readback(%s, __size_%s);\n",
varname, varname);
}
}
}
@@ -482,7 +638,7 @@ int ApiGen::genEncoderImpl(const std::string &filename)
fprintf(fp, "\t return NULL;\n");
} else if (e->retval().type()->name() != "void") {
fprintf(fp, "\n\t%s retval;\n", e->retval().type()->name().c_str());
fprintf(fp, "\tctx->m_stream->readback(&retval, %u);\n",(uint) e->retval().type()->bytes());
fprintf(fp, "\tstream->readback(&retval, %u);\n",(uint) e->retval().type()->bytes());
fprintf(fp, "\treturn retval;\n");
}
fprintf(fp, "}\n\n");