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MobileGL/MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LowerClipDistanceForEsslPass.cpp
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// MobileGL - MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LowerClipDistanceForEsslPass.cpp
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
// https://www.gnu.org/licenses/gpl-3.0.txt
// https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header
#include "LowerClipDistanceForEsslPass.h"
#include "spirv.hpp"
#include "source/opt/basic_block.h"
#include "source/opt/constants.h"
#include "source/opt/def_use_manager.h"
#include "source/opt/instruction.h"
#include "source/opt/ir_context.h"
#include "source/opt/module.h"
#include "source/opt/type_manager.h"
#include "source/opt/types.h"
#include "source/util/make_unique.h"
#include <memory>
#include <vector>
namespace MobileGL {
namespace MG_Util {
namespace ShaderTranspiler {
namespace {
using spvtools::opt::BasicBlock;
using spvtools::opt::Function;
using spvtools::opt::Instruction;
using spvtools::opt::IRContext;
using spvtools::opt::Operand;
namespace analysis = spvtools::opt::analysis;
spv::ExecutionModel EntryExecutionModel(IRContext* ctx) {
for (Instruction& ep : ctx->module()->entry_points()) {
return static_cast<spv::ExecutionModel>(ep.GetSingleWordInOperand(0));
}
return spv::ExecutionModel::Max;
}
uint32_t EntryFunctionId(IRContext* ctx) {
for (Instruction& ep : ctx->module()->entry_points()) {
// OpEntryPoint <model> <function> "name" <interface...>
return ep.GetSingleWordInOperand(1);
}
return 0;
}
uint32_t VariablePointeeType(IRContext* ctx, Instruction* var) {
Instruction* ptrType = ctx->get_def_use_mgr()->GetDef(var->type_id());
// OpTypePointer <storage-class> <pointee>
return ptrType->GetSingleWordInOperand(1);
}
uint32_t PointerTypeTo(IRContext* ctx, uint32_t pointeeId, spv::StorageClass sc) {
analysis::Type* pointee = ctx->get_type_mgr()->GetType(pointeeId);
analysis::Pointer ptr(pointee, sc);
return ctx->get_type_mgr()->GetTypeInstruction(&ptr);
}
uint32_t IntConstant(IRContext* ctx, bool isSigned, uint32_t value) {
analysis::Integer i(32, isSigned);
analysis::Type* reg = ctx->get_type_mgr()->GetRegisteredType(&i);
const analysis::Constant* c = ctx->get_constant_mgr()->GetConstant(reg, {value});
return ctx->get_constant_mgr()->GetDefiningInstruction(c)->result_id();
}
uint32_t UintType(IRContext* ctx) {
analysis::Integer i(32, false);
return ctx->get_type_mgr()->GetTypeInstruction(&i);
}
uint32_t BoolType(IRContext* ctx) {
analysis::Bool b;
return ctx->get_type_mgr()->GetTypeInstruction(&b);
}
// Constant length of OpTypeArray |arrayTypeId| (0 when not a sized constant).
uint32_t ArrayLength(IRContext* ctx, uint32_t arrayTypeId) {
Instruction* arrayType = ctx->get_def_use_mgr()->GetDef(arrayTypeId);
if (arrayType == nullptr || arrayType->opcode() != spv::Op::OpTypeArray) {
return 0;
}
Instruction* length = ctx->get_def_use_mgr()->GetDef(arrayType->GetSingleWordInOperand(1));
if (length == nullptr || length->opcode() != spv::Op::OpConstant) {
return 0;
}
return length->GetSingleWordInOperand(0);
}
bool IsConstantWithValue(IRContext* ctx, uint32_t id, uint32_t value) {
Instruction* def = ctx->get_def_use_mgr()->GetDef(id);
return def != nullptr && def->opcode() == spv::Op::OpConstant &&
def->GetSingleWordInOperand(0) == value;
}
bool IsAccessChain(const Instruction* inst) {
return inst->opcode() == spv::Op::OpAccessChain ||
inst->opcode() == spv::Op::OpInBoundsAccessChain;
}
Instruction* AddPrivateVariable(IRContext* ctx, uint32_t pointeeTypeId, const char* name) {
const uint32_t ptrType = PointerTypeTo(ctx, pointeeTypeId, spv::StorageClass::Private);
const uint32_t varId = ctx->TakeNextId();
ctx->AddGlobalValue(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpVariable, ptrType, varId,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_STORAGE_CLASS,
{static_cast<uint32_t>(spv::StorageClass::Private)}}}));
ctx->AddDebug2Inst(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpName, 0, 0,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_ID, {varId}},
{SPV_OPERAND_TYPE_LITERAL_STRING, spvtools::utils::MakeVector(name)}}));
return ctx->get_def_use_mgr()->GetDef(varId);
}
// Retargets |chain| onto |newBaseId|, dropping the first |dropIndexCount| index
// operands and switching the result pointer's storage class to Private.
void RetargetChainToPrivate(IRContext* ctx, Instruction* chain, uint32_t newBaseId,
uint32_t dropIndexCount) {
Instruction* chainPtrType = ctx->get_def_use_mgr()->GetDef(chain->type_id());
const uint32_t pointeeId = chainPtrType->GetSingleWordInOperand(1);
const uint32_t newPtrType = PointerTypeTo(ctx, pointeeId, spv::StorageClass::Private);
ctx->ForgetUses(chain);
std::vector<Operand> newOperands;
newOperands.push_back({SPV_OPERAND_TYPE_ID, {newBaseId}});
for (uint32_t i = 1 + dropIndexCount; i < chain->NumInOperands(); ++i) {
newOperands.push_back(chain->GetInOperand(i));
}
chain->SetResultType(newPtrType);
chain->SetInOperands(std::move(newOperands));
ctx->AnalyzeUses(chain);
}
// ---- Output side --------------------------------------------------------------
struct OutputTarget {
Instruction* var = nullptr; // Output gl_PerVertex block or standalone builtin
bool isBlockMember = false;
uint32_t memberIndex = 0; // valid when isBlockMember
uint32_t arrayTypeId = 0; // float[N]
uint32_t elemTypeId = 0; // float
uint32_t arrayLen = 0; // N
};
// Inserts "gl_ClipDistance[k] = mg_ClipDistance[k]" for every literal k before
// |before|. Constant-index writes are the only write shape Adreno links correctly.
void InsertFlushBefore(IRContext* ctx, Instruction* before, const OutputTarget& target,
uint32_t mgVarId) {
const uint32_t ptrPrivElem =
PointerTypeTo(ctx, target.elemTypeId, spv::StorageClass::Private);
const uint32_t ptrOutElem =
PointerTypeTo(ctx, target.elemTypeId, spv::StorageClass::Output);
for (uint32_t k = 0; k < target.arrayLen; ++k) {
const uint32_t kConst = IntConstant(ctx, true, k);
const uint32_t srcChainId = ctx->TakeNextId();
before->InsertBefore(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpAccessChain, ptrPrivElem, srcChainId,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {mgVarId}},
{SPV_OPERAND_TYPE_ID, {kConst}}}));
const uint32_t valId = ctx->TakeNextId();
before->InsertBefore(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpLoad, target.elemTypeId, valId,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {srcChainId}}}));
const uint32_t dstChainId = ctx->TakeNextId();
std::vector<Operand> dstOperands;
dstOperands.push_back({SPV_OPERAND_TYPE_ID, {target.var->result_id()}});
if (target.isBlockMember) {
dstOperands.push_back(
{SPV_OPERAND_TYPE_ID, {IntConstant(ctx, true, target.memberIndex)}});
}
dstOperands.push_back({SPV_OPERAND_TYPE_ID, {kConst}});
before->InsertBefore(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpAccessChain, ptrOutElem, dstChainId, dstOperands));
before->InsertBefore(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpStore, 0, 0,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {dstChainId}},
{SPV_OPERAND_TYPE_ID, {valId}}}));
}
}
bool LowerOutputClipDistance(IRContext* ctx, bool isGeometry) {
auto* defUse = ctx->get_def_use_mgr();
// Collect (struct type, member) pairs decorated BuiltIn ClipDistance and
// standalone variables decorated BuiltIn ClipDistance.
std::vector<std::pair<uint32_t, uint32_t>> memberTargets; // (structId, member)
std::vector<uint32_t> plainTargets; // variable ids
for (Instruction& ann : ctx->annotations()) {
if (ann.opcode() == spv::Op::OpMemberDecorate && ann.NumInOperands() >= 4 &&
static_cast<spv::Decoration>(ann.GetSingleWordInOperand(2)) ==
spv::Decoration::BuiltIn &&
static_cast<spv::BuiltIn>(ann.GetSingleWordInOperand(3)) ==
spv::BuiltIn::ClipDistance) {
memberTargets.emplace_back(ann.GetSingleWordInOperand(0),
ann.GetSingleWordInOperand(1));
} else if (ann.opcode() == spv::Op::OpDecorate && ann.NumInOperands() >= 3 &&
static_cast<spv::Decoration>(ann.GetSingleWordInOperand(1)) ==
spv::Decoration::BuiltIn &&
static_cast<spv::BuiltIn>(ann.GetSingleWordInOperand(2)) ==
spv::BuiltIn::ClipDistance) {
plainTargets.push_back(ann.GetSingleWordInOperand(0));
}
}
std::vector<OutputTarget> targets;
for (Instruction& inst : ctx->module()->types_values()) {
if (inst.opcode() != spv::Op::OpVariable ||
static_cast<spv::StorageClass>(inst.GetSingleWordInOperand(0)) !=
spv::StorageClass::Output) {
continue;
}
const uint32_t pointee = VariablePointeeType(ctx, &inst);
for (const auto& [structId, member] : memberTargets) {
if (pointee != structId) continue;
Instruction* structType = defUse->GetDef(structId);
if (structType == nullptr || member >= structType->NumInOperands()) continue;
OutputTarget target;
target.var = &inst;
target.isBlockMember = true;
target.memberIndex = member;
target.arrayTypeId = structType->GetSingleWordInOperand(member);
target.arrayLen = ArrayLength(ctx, target.arrayTypeId);
targets.push_back(target);
}
for (const uint32_t varId : plainTargets) {
if (inst.result_id() != varId) continue;
OutputTarget target;
target.var = &inst;
target.isBlockMember = false;
target.arrayTypeId = pointee;
target.arrayLen = ArrayLength(ctx, target.arrayTypeId);
targets.push_back(target);
}
}
bool changed = false;
for (OutputTarget& target : targets) {
if (target.arrayLen == 0) continue;
Instruction* arrayType = defUse->GetDef(target.arrayTypeId);
target.elemTypeId = arrayType->GetSingleWordInOperand(0);
// Collect the accesses to redirect. For the block form only chains whose
// leading index selects the ClipDistance member count; for the standalone
// form every chain plus whole-variable loads/stores.
std::vector<Instruction*> chains;
std::vector<Instruction*> directAccesses;
bool unsupportedUse = false;
defUse->ForEachUser(target.var, [&](Instruction* user) {
if (IsAccessChain(user) &&
user->GetSingleWordInOperand(0) == target.var->result_id()) {
if (target.isBlockMember) {
if (user->NumInOperands() >= 2 &&
IsConstantWithValue(ctx, user->GetSingleWordInOperand(1),
target.memberIndex)) {
chains.push_back(user);
}
} else {
chains.push_back(user);
}
} else if (!target.isBlockMember) {
if (user->opcode() == spv::Op::OpLoad ||
(user->opcode() == spv::Op::OpStore &&
user->GetSingleWordInOperand(0) == target.var->result_id())) {
directAccesses.push_back(user);
} else if (user->opcode() == spv::Op::OpCopyMemory) {
unsupportedUse = true;
}
}
});
if (unsupportedUse || (chains.empty() && directAccesses.empty())) {
continue;
}
Instruction* mgVar = AddPrivateVariable(ctx, target.arrayTypeId, "mg_ClipDistance");
const uint32_t mgVarId = mgVar->result_id();
for (Instruction* chain : chains) {
const uint32_t dropCount = target.isBlockMember ? 1u : 0u;
if (chain->NumInOperands() == 1 + dropCount) {
// Pointer to the whole float[N]: reuse the private variable itself.
ctx->ReplaceAllUsesWith(chain->result_id(), mgVarId);
ctx->KillInst(chain);
} else {
RetargetChainToPrivate(ctx, chain, mgVarId, dropCount);
}
}
for (Instruction* access : directAccesses) {
ctx->ForgetUses(access);
access->SetInOperand(0, {mgVarId});
ctx->AnalyzeUses(access);
}
// Flush the shadow into the real builtin: geometry right before every
// EmitVertex, vertex before every return of the entry point. The flush is
// also what keeps the builtin statically used for cross-stage IO matching.
std::vector<Instruction*> flushSites;
if (isGeometry) {
for (Function& function : *ctx->module()) {
function.ForEachInst([&](Instruction* inst) {
if (inst->opcode() == spv::Op::OpEmitVertex) {
flushSites.push_back(inst);
}
});
}
} else {
const uint32_t entryFuncId = EntryFunctionId(ctx);
for (Function& function : *ctx->module()) {
if (function.result_id() != entryFuncId) continue;
function.ForEachInst([&](Instruction* inst) {
if (inst->opcode() == spv::Op::OpReturn ||
inst->opcode() == spv::Op::OpReturnValue) {
flushSites.push_back(inst);
}
});
}
}
for (Instruction* site : flushSites) {
InsertFlushBefore(ctx, site, target, mgVarId);
}
changed = true;
}
return changed;
}
// ---- Input side (geometry gl_in) ----------------------------------------------
bool LowerInputClipDistance(IRContext* ctx) {
auto* defUse = ctx->get_def_use_mgr();
auto* typeMgr = ctx->get_type_mgr();
// Locate the gl_in block member decorated ClipDistance.
Instruction* glInVar = nullptr;
uint32_t memberIndex = 0;
uint32_t arrayTypeId = 0; // float[N]
for (Instruction& ann : ctx->annotations()) {
if (ann.opcode() != spv::Op::OpMemberDecorate || ann.NumInOperands() < 4 ||
static_cast<spv::Decoration>(ann.GetSingleWordInOperand(2)) !=
spv::Decoration::BuiltIn ||
static_cast<spv::BuiltIn>(ann.GetSingleWordInOperand(3)) !=
spv::BuiltIn::ClipDistance) {
continue;
}
const uint32_t structId = ann.GetSingleWordInOperand(0);
const uint32_t member = ann.GetSingleWordInOperand(1);
for (Instruction& inst : ctx->module()->types_values()) {
if (inst.opcode() != spv::Op::OpVariable ||
static_cast<spv::StorageClass>(inst.GetSingleWordInOperand(0)) !=
spv::StorageClass::Input) {
continue;
}
const uint32_t pointee = VariablePointeeType(ctx, &inst);
Instruction* pointeeType = defUse->GetDef(pointee);
if (pointeeType == nullptr || pointeeType->opcode() != spv::Op::OpTypeArray ||
pointeeType->GetSingleWordInOperand(0) != structId) {
continue;
}
Instruction* structType = defUse->GetDef(structId);
if (structType == nullptr || member >= structType->NumInOperands()) continue;
glInVar = &inst;
memberIndex = member;
arrayTypeId = structType->GetSingleWordInOperand(member);
break;
}
if (glInVar != nullptr) break;
}
if (glInVar == nullptr) {
return false;
}
const uint32_t clipCount = ArrayLength(ctx, arrayTypeId);
const uint32_t vertexCount = ArrayLength(ctx, VariablePointeeType(ctx, glInVar));
if (clipCount == 0 || vertexCount == 0) {
return false;
}
// Every gl_in chain that selects the ClipDistance member:
// (vertex, member) yields a whole float[N], (vertex, member, k) an element.
std::vector<Instruction*> chains;
defUse->ForEachUser(glInVar, [&](Instruction* user) {
if (IsAccessChain(user) && user->GetSingleWordInOperand(0) == glInVar->result_id() &&
user->NumInOperands() >= 3 &&
IsConstantWithValue(ctx, user->GetSingleWordInOperand(2), memberIndex)) {
chains.push_back(user);
}
});
if (chains.empty()) {
return false;
}
Instruction* arrayTypeInst = defUse->GetDef(arrayTypeId);
const uint32_t elemTypeId = arrayTypeInst->GetSingleWordInOperand(0);
// Private mg_ClipDistanceIn = float[vertexCount][clipCount].
const uint32_t vertexCountConst = IntConstant(ctx, false, vertexCount);
analysis::Type* innerType = typeMgr->GetType(arrayTypeId);
analysis::Array outerArray(
innerType, analysis::Array::LengthInfo{
vertexCountConst,
{analysis::Array::LengthInfo::kConstant, vertexCount}});
const uint32_t outerArrayTypeId = typeMgr->GetTypeInstruction(&outerArray);
Instruction* mgInVar = AddPrivateVariable(ctx, outerArrayTypeId, "mg_ClipDistanceIn");
const uint32_t mgInVarId = mgInVar->result_id();
// Copy loop at the top of the entry point:
// for (uint t = 0; t < vertexCount * clipCount; ++t)
// mg_ClipDistanceIn[t / clipCount][t % clipCount] =
// gl_in[t / clipCount].gl_ClipDistance[t % clipCount];
// Both gl_in indices are loop-derived (dynamic): constant-index element reads
// miscompile and whole-array reads crash the Adreno compiler.
const uint32_t entryFuncId = EntryFunctionId(ctx);
Function* entryFn = nullptr;
for (Function& function : *ctx->module()) {
if (function.result_id() == entryFuncId) {
entryFn = &function;
break;
}
}
if (entryFn == nullptr || entryFn->begin() == entryFn->end()) {
return false;
}
const uint32_t uintTypeId = UintType(ctx);
const uint32_t boolTypeId = BoolType(ctx);
const uint32_t ptrFnUint = PointerTypeTo(ctx, uintTypeId, spv::StorageClass::Function);
const uint32_t ptrInElem = PointerTypeTo(ctx, elemTypeId, spv::StorageClass::Input);
const uint32_t ptrPrivElem = PointerTypeTo(ctx, elemTypeId, spv::StorageClass::Private);
const uint32_t uint0 = IntConstant(ctx, false, 0);
const uint32_t uint1 = IntConstant(ctx, false, 1);
const uint32_t uintN = IntConstant(ctx, false, clipCount);
const uint32_t uintTotal = IntConstant(ctx, false, vertexCount * clipCount);
const uint32_t memberConst = IntConstant(ctx, true, memberIndex);
BasicBlock* entryBlock = &*entryFn->begin();
auto splitPoint = entryBlock->begin();
while (splitPoint != entryBlock->end() &&
splitPoint->opcode() == spv::Op::OpVariable) {
++splitPoint;
}
// Loop counter lives with the other function-local variables.
const uint32_t counterVarId = ctx->TakeNextId();
splitPoint->InsertBefore(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpVariable, ptrFnUint, counterVarId,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_STORAGE_CLASS,
{static_cast<uint32_t>(spv::StorageClass::Function)}}}));
const uint32_t restLabelId = ctx->TakeNextId();
BasicBlock* restBlock = entryBlock->SplitBasicBlock(ctx, restLabelId, splitPoint);
const uint32_t headerLabelId = ctx->TakeNextId();
const uint32_t checkLabelId = ctx->TakeNextId();
const uint32_t bodyLabelId = ctx->TakeNextId();
const uint32_t continueLabelId = ctx->TakeNextId();
auto makeBlock = [&](uint32_t labelId) {
return spvtools::MakeUnique<BasicBlock>(spvtools::MakeUnique<Instruction>(
ctx, spv::Op::OpLabel, 0, labelId, std::initializer_list<Operand>{}));
};
auto addInst = [&](BasicBlock* block, spv::Op opcode, uint32_t typeId,
uint32_t resultId, std::vector<Operand> operands) {
block->AddInstruction(spvtools::MakeUnique<Instruction>(
ctx, opcode, typeId, resultId, std::move(operands)));
};
// entry: t = 0; branch header
addInst(entryBlock, spv::Op::OpStore, 0, 0,
{{SPV_OPERAND_TYPE_ID, {counterVarId}}, {SPV_OPERAND_TYPE_ID, {uint0}}});
addInst(entryBlock, spv::Op::OpBranch, 0, 0, {{SPV_OPERAND_TYPE_ID, {headerLabelId}}});
// header: structured loop header
auto headerBlock = makeBlock(headerLabelId);
addInst(headerBlock.get(), spv::Op::OpLoopMerge, 0, 0,
{{SPV_OPERAND_TYPE_ID, {restLabelId}},
{SPV_OPERAND_TYPE_ID, {continueLabelId}},
{SPV_OPERAND_TYPE_LOOP_CONTROL,
{static_cast<uint32_t>(spv::LoopControlMask::MaskNone)}}});
addInst(headerBlock.get(), spv::Op::OpBranch, 0, 0,
{{SPV_OPERAND_TYPE_ID, {checkLabelId}}});
// check: t < vertexCount * clipCount ?
auto checkBlock = makeBlock(checkLabelId);
const uint32_t tCheckId = ctx->TakeNextId();
addInst(checkBlock.get(), spv::Op::OpLoad, uintTypeId, tCheckId,
{{SPV_OPERAND_TYPE_ID, {counterVarId}}});
const uint32_t condId = ctx->TakeNextId();
addInst(checkBlock.get(), spv::Op::OpULessThan, boolTypeId, condId,
{{SPV_OPERAND_TYPE_ID, {tCheckId}}, {SPV_OPERAND_TYPE_ID, {uintTotal}}});
addInst(checkBlock.get(), spv::Op::OpBranchConditional, 0, 0,
{{SPV_OPERAND_TYPE_ID, {condId}},
{SPV_OPERAND_TYPE_ID, {bodyLabelId}},
{SPV_OPERAND_TYPE_ID, {restLabelId}}});
// body: mg_ClipDistanceIn[t / N][t % N] = gl_in[t / N].gl_ClipDistance[t % N]
auto bodyBlock = makeBlock(bodyLabelId);
const uint32_t tBodyId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpLoad, uintTypeId, tBodyId,
{{SPV_OPERAND_TYPE_ID, {counterVarId}}});
const uint32_t vertexIdxId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpUDiv, uintTypeId, vertexIdxId,
{{SPV_OPERAND_TYPE_ID, {tBodyId}}, {SPV_OPERAND_TYPE_ID, {uintN}}});
const uint32_t clipIdxId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpUMod, uintTypeId, clipIdxId,
{{SPV_OPERAND_TYPE_ID, {tBodyId}}, {SPV_OPERAND_TYPE_ID, {uintN}}});
const uint32_t srcChainId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpAccessChain, ptrInElem, srcChainId,
{{SPV_OPERAND_TYPE_ID, {glInVar->result_id()}},
{SPV_OPERAND_TYPE_ID, {vertexIdxId}},
{SPV_OPERAND_TYPE_ID, {memberConst}},
{SPV_OPERAND_TYPE_ID, {clipIdxId}}});
const uint32_t valId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpLoad, elemTypeId, valId,
{{SPV_OPERAND_TYPE_ID, {srcChainId}}});
const uint32_t dstChainId = ctx->TakeNextId();
addInst(bodyBlock.get(), spv::Op::OpAccessChain, ptrPrivElem, dstChainId,
{{SPV_OPERAND_TYPE_ID, {mgInVarId}},
{SPV_OPERAND_TYPE_ID, {vertexIdxId}},
{SPV_OPERAND_TYPE_ID, {clipIdxId}}});
addInst(bodyBlock.get(), spv::Op::OpStore, 0, 0,
{{SPV_OPERAND_TYPE_ID, {dstChainId}}, {SPV_OPERAND_TYPE_ID, {valId}}});
addInst(bodyBlock.get(), spv::Op::OpBranch, 0, 0,
{{SPV_OPERAND_TYPE_ID, {continueLabelId}}});
// continue: ++t
auto continueBlock = makeBlock(continueLabelId);
const uint32_t tContinueId = ctx->TakeNextId();
addInst(continueBlock.get(), spv::Op::OpLoad, uintTypeId, tContinueId,
{{SPV_OPERAND_TYPE_ID, {counterVarId}}});
const uint32_t tIncId = ctx->TakeNextId();
addInst(continueBlock.get(), spv::Op::OpIAdd, uintTypeId, tIncId,
{{SPV_OPERAND_TYPE_ID, {tContinueId}}, {SPV_OPERAND_TYPE_ID, {uint1}}});
addInst(continueBlock.get(), spv::Op::OpStore, 0, 0,
{{SPV_OPERAND_TYPE_ID, {counterVarId}}, {SPV_OPERAND_TYPE_ID, {tIncId}}});
addInst(continueBlock.get(), spv::Op::OpBranch, 0, 0,
{{SPV_OPERAND_TYPE_ID, {headerLabelId}}});
BasicBlock* headerPtr = entryFn->InsertBasicBlockBefore(std::move(headerBlock), restBlock);
BasicBlock* checkPtr = entryFn->InsertBasicBlockAfter(std::move(checkBlock), headerPtr);
BasicBlock* bodyPtr = entryFn->InsertBasicBlockAfter(std::move(bodyBlock), checkPtr);
entryFn->InsertBasicBlockAfter(std::move(continueBlock), bodyPtr);
// Redirect the pre-existing accesses to the shadow copy.
for (Instruction* chain : chains) {
if (chain->NumInOperands() == 3) {
// (vertex, member): whole float[N] of one vertex.
Instruction* chainPtrType = defUse->GetDef(chain->type_id());
const uint32_t pointeeId = chainPtrType->GetSingleWordInOperand(1);
const uint32_t newPtrType =
PointerTypeTo(ctx, pointeeId, spv::StorageClass::Private);
ctx->ForgetUses(chain);
std::vector<Operand> newOperands;
newOperands.push_back({SPV_OPERAND_TYPE_ID, {mgInVarId}});
newOperands.push_back(chain->GetInOperand(1));
chain->SetResultType(newPtrType);
chain->SetInOperands(std::move(newOperands));
ctx->AnalyzeUses(chain);
} else {
// (vertex, member, k, ...): drop the member index.
Instruction* chainPtrType = defUse->GetDef(chain->type_id());
const uint32_t pointeeId = chainPtrType->GetSingleWordInOperand(1);
const uint32_t newPtrType =
PointerTypeTo(ctx, pointeeId, spv::StorageClass::Private);
ctx->ForgetUses(chain);
std::vector<Operand> newOperands;
newOperands.push_back({SPV_OPERAND_TYPE_ID, {mgInVarId}});
newOperands.push_back(chain->GetInOperand(1));
for (uint32_t i = 3; i < chain->NumInOperands(); ++i) {
newOperands.push_back(chain->GetInOperand(i));
}
chain->SetResultType(newPtrType);
chain->SetInOperands(std::move(newOperands));
ctx->AnalyzeUses(chain);
}
}
return true;
}
} // namespace
spvtools::opt::Pass::Status LowerClipDistanceForEsslPass::Process() {
auto* ctx = context();
const spv::ExecutionModel model = EntryExecutionModel(ctx);
const bool isVertex = model == spv::ExecutionModel::Vertex;
const bool isGeometry = model == spv::ExecutionModel::Geometry;
if (!isVertex && !isGeometry) {
return Status::SuccessWithoutChange;
}
bool changed = LowerOutputClipDistance(ctx, isGeometry);
if (isGeometry) {
changed |= LowerInputClipDistance(ctx);
}
if (!changed) {
return Status::SuccessWithoutChange;
}
ctx->InvalidateAnalysesExceptFor(spvtools::opt::IRContext::kAnalysisNone);
return Status::SuccessWithChange;
}
spvtools::Optimizer::PassToken
LowerClipDistanceForEsslPass::CreateLowerClipDistanceForEsslPass() {
return spvtools::Optimizer::PassToken(MakeUnique<LowerClipDistanceForEsslPass>());
}
} // namespace ShaderTranspiler
} // namespace MG_Util
} // namespace MobileGL