mewin/glslang
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

SPV: Reduce spurious type generation by removing intermediate types in the middle of access chains.

Browse Source 
This generally simplifies access chain generation, with far fewer  type conversions.
It is particularly important to future SPIR-V changes where there is less aggregate
type uniqueness due to carrying different layout information with the type.
This commit is contained in:
John Kessenich
2015-09-13 14:46:30 -06:00
parent c9a808319a
commit fa668dad99
8 changed files with 144 additions and 137 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
SPIRV/SpvBuilder.cpp
View File

@@ -1957,18 +1957,23 @@ void Builder::createBranchToLoopHeaderFromInside(const Loop& loop)
void Builder::clearAccessChain()
{
accessChain.base = 0;
accessChain.base = NoResult;
accessChain.indexChain.clear();
accessChain.instr = 0;
accessChain.instr = NoResult;
accessChain.swizzle.clear();
accessChain.component = 0;
accessChain.resultType = NoType;
accessChain.component = NoResult;
accessChain.preSwizzleBaseType = NoType;
accessChain.isRValue = false;
}
// Comments in header
void Builder::accessChainPushSwizzle(std::vector<unsigned>& swizzle)
void Builder::accessChainPushSwizzle(std::vector<unsigned>& swizzle, Id preSwizzleBaseType)
{
// swizzles can be stacked in GLSL, but simplified to a single
// one here; the base type doesn't change
if (accessChain.preSwizzleBaseType == NoType)
accessChain.preSwizzleBaseType = preSwizzleBaseType;
// if needed, propagate the swizzle for the current access chain
if (accessChain.swizzle.size()) {
std::vector<unsigned> oldSwizzle = accessChain.swizzle;
@@ -1990,7 +1995,7 @@ void Builder::accessChainStore(Id rvalue)
Id base = collapseAccessChain();
if (accessChain.swizzle.size() && accessChain.component)
if (accessChain.swizzle.size() && accessChain.component != NoResult)
MissingFunctionality("simultaneous l-value swizzle and dynamic component selection");
// If swizzle exists, it is out-of-order or not full, we must load the target vector,
@@ -2002,7 +2007,7 @@ void Builder::accessChainStore(Id rvalue)
}
// dynamic component selection
if (accessChain.component) {
if (accessChain.component != NoResult) {
Id tempBaseId = (source == NoResult) ? createLoad(base) : source;
source = createVectorInsertDynamic(tempBaseId, getTypeId(tempBaseId), rvalue, accessChain.component);
}
@@ -2014,13 +2019,15 @@ void Builder::accessChainStore(Id rvalue)
}
// Comments in header
Id Builder::accessChainLoad(Decoration /*precision*/)
Id Builder::accessChainLoad(Id resultType)
{
Id id;
if (accessChain.isRValue) {
if (accessChain.indexChain.size() > 0) {
mergeAccessChainSwizzle(); // TODO: optimization: look at applying this optimization more widely
Id swizzleBase = accessChain.preSwizzleBaseType != NoType ? accessChain.preSwizzleBaseType : resultType;
// if all the accesses are constants, we can use OpCompositeExtract
std::vector<unsigned> indexes;
bool constant = true;
@@ -2034,7 +2041,7 @@ Id Builder::accessChainLoad(Decoration /*precision*/)
}
if (constant)
id = createCompositeExtract(accessChain.base, accessChain.resultType, indexes);
id = createCompositeExtract(accessChain.base, swizzleBase, indexes);
else {
// make a new function variable for this r-value
Id lValue = createVariable(StorageClassFunction, getTypeId(accessChain.base), "indexable");
@@ -2057,24 +2064,22 @@ Id Builder::accessChainLoad(Decoration /*precision*/)
}
// Done, unless there are swizzles to do
if (accessChain.swizzle.size() == 0 && accessChain.component == 0)
if (accessChain.swizzle.size() == 0 && accessChain.component == NoResult)
return id;
Id componentType = getScalarTypeId(accessChain.resultType);
// Do remaining swizzling
// First, static swizzling
if (accessChain.swizzle.size()) {
// static swizzle
Id resultType = componentType;
Id swizzledType = getScalarTypeId(getTypeId(id));
if (accessChain.swizzle.size() > 1)
resultType = makeVectorType(componentType, (int)accessChain.swizzle.size());
id = createRvalueSwizzle(resultType, id, accessChain.swizzle);
swizzledType = makeVectorType(swizzledType, (int)accessChain.swizzle.size());
id = createRvalueSwizzle(swizzledType, id, accessChain.swizzle);
}
// dynamic single-component selection
if (accessChain.component)
id = createVectorExtractDynamic(id, componentType, accessChain.component);
if (accessChain.component != NoResult)
id = createVectorExtractDynamic(id, resultType, accessChain.component);
return id;
}
@@ -2089,7 +2094,7 @@ Id Builder::accessChainGetLValue()
// extract and insert elements to perform writeMask and/or swizzle. This does not
// go with getting a direct l-value pointer.
assert(accessChain.swizzle.size() == 0);
assert(accessChain.component == spv::NoResult);
assert(accessChain.component == NoResult);
return lvalue;
}
@@ -2170,7 +2175,7 @@ void Builder::simplifyAccessChainSwizzle()
{
// If the swizzle has fewer components than the vector, it is subsetting, and must stay
// to preserve that fact.
if (getNumTypeComponents(accessChain.resultType) > (int)accessChain.swizzle.size())
if (getNumTypeComponents(accessChain.preSwizzleBaseType) > (int)accessChain.swizzle.size())
return;
// if components are out of order, it is a swizzle
@@ -2181,6 +2186,8 @@ void Builder::simplifyAccessChainSwizzle()
// otherwise, there is no need to track this swizzle
accessChain.swizzle.clear();
if (accessChain.component == NoResult)
accessChain.preSwizzleBaseType = NoType;
}
// clear out swizzle if it can become part of the indexes
@@ -2188,12 +2195,12 @@ void Builder::mergeAccessChainSwizzle()
{
// is there even a chance of doing something? Need a single-component swizzle
if ((accessChain.swizzle.size() > 1) ||
(accessChain.swizzle.size() == 0 && accessChain.component == 0))
(accessChain.swizzle.size() == 0 && accessChain.component == NoResult))
return;
// TODO: optimization: remove this, but for now confine this to non-dynamic accesses
// (the above test is correct when this is removed.)
if (accessChain.component)
if (accessChain.component != NoResult)
return;
// move the swizzle over to the indexes
@@ -2201,10 +2208,10 @@ void Builder::mergeAccessChainSwizzle()
accessChain.indexChain.push_back(makeUintConstant(accessChain.swizzle.front()));
else
accessChain.indexChain.push_back(accessChain.component);
accessChain.resultType = getScalarTypeId(accessChain.resultType);
// now there is no need to track this swizzle
accessChain.component = NoResult;
accessChain.preSwizzleBaseType = NoType;
accessChain.swizzle.clear();
}