void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
const CapturedStmt *CS = cast<CapturedStmt>(S.getAssociatedStmt());
const Stmt *Body = CS->getCapturedStmt();
LoopStack.setParallel();
LoopStack.setVectorizerEnable(true);
for (auto C : S.clauses()) {
switch (C->getClauseKind()) {
case OMPC_safelen: {
RValue Len = EmitAnyExpr(cast<OMPSafelenClause>(C)->getSafelen(),
AggValueSlot::ignored(), true);
llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
LoopStack.setVectorizerWidth(Val->getZExtValue());
// In presence of finite 'safelen', it may be unsafe to mark all
// the memory instructions parallel, because loop-carried
// dependences of 'safelen' iterations are possible.
LoopStack.setParallel(false);
break;
}
default:
// Not handled yet
;
}
}
EmitStmt(Body);
}
void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
// Pragma 'simd' code depends on presence of 'lastprivate'.
// If present, we have to separate last iteration of the loop:
//
// if (LastIteration != 0) {
// for (IV in 0..LastIteration-1) BODY;
// BODY with updates of lastprivate vars;
// <Final counter/linear vars updates>;
// }
//
// otherwise (when there's no lastprivate):
//
// for (IV in 0..LastIteration) BODY;
// <Final counter/linear vars updates>;
//
// Walk clauses and process safelen/lastprivate.
bool SeparateIter = false;
LoopStack.setParallel();
LoopStack.setVectorizerEnable(true);
for (auto C : S.clauses()) {
switch (C->getClauseKind()) {
case OMPC_safelen: {
RValue Len = EmitAnyExpr(cast<OMPSafelenClause>(C)->getSafelen(),
AggValueSlot::ignored(), true);
llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
LoopStack.setVectorizerWidth(Val->getZExtValue());
// In presence of finite 'safelen', it may be unsafe to mark all
// the memory instructions parallel, because loop-carried
// dependences of 'safelen' iterations are possible.
LoopStack.setParallel(false);
break;
}
case OMPC_aligned:
EmitOMPAlignedClause(*this, CGM, cast<OMPAlignedClause>(*C));
break;
case OMPC_lastprivate:
SeparateIter = true;
break;
default:
// Not handled yet
;
}
}
RunCleanupsScope DirectiveScope(*this);
CGDebugInfo *DI = getDebugInfo();
if (DI)
DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
// Emit the loop iteration variable.
const Expr *IVExpr = S.getIterationVariable();
const VarDecl *IVDecl = cast<VarDecl>(cast<DeclRefExpr>(IVExpr)->getDecl());
EmitVarDecl(*IVDecl);
EmitIgnoredExpr(S.getInit());
// Emit the iterations count variable.
// If it is not a variable, Sema decided to calculate iterations count on each
// iteration (e.g., it is foldable into a constant).
if (auto LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
// Emit calculation of the iterations count.
EmitIgnoredExpr(S.getCalcLastIteration());
}
if (SeparateIter) {
// Emit: if (LastIteration > 0) - begin.
RegionCounter Cnt = getPGORegionCounter(&S);
auto ThenBlock = createBasicBlock("simd.if.then");
auto ContBlock = createBasicBlock("simd.if.end");
EmitBranchOnBoolExpr(S.getPreCond(), ThenBlock, ContBlock, Cnt.getCount());
EmitBlock(ThenBlock);
Cnt.beginRegion(Builder);
// Emit 'then' code.
{
OMPPrivateScope LoopScope(*this);
EmitPrivateLoopCounters(*this, LoopScope, S.counters());
EmitOMPInnerLoop(S, LoopScope, /* SeparateIter */ true);
EmitOMPLoopBody(S, /* SeparateIter */ true);
}
EmitOMPSimdFinal(S);
// Emit: if (LastIteration != 0) - end.
EmitBranch(ContBlock);
EmitBlock(ContBlock, true);
} else {
{
OMPPrivateScope LoopScope(*this);
EmitPrivateLoopCounters(*this, LoopScope, S.counters());
EmitOMPInnerLoop(S, LoopScope);
}
EmitOMPSimdFinal(S);
}
if (DI)
DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
}
