maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[LoopInfo][Refactor] Make SetLoopAlreadyUnrolled a member function of the Loop Pass, NFC. 

This avoid code duplication and allow us to add the disable unroll metadata elsewhere.

Differential Revision: https://reviews.llvm.org/D38928

llvm-svn: 315850
This commit is contained in:
Hongbin Zheng 2017-10-15 07:31:02 +00:00
parent a9cd59fb5d
commit 73f650435b
4 changed files with 43 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
llvm/include/llvm/Analysis/LoopInfo.h
View File

@ -520,6 +520,14 @@ public:
/// operand should be the node itself.
void setLoopID(MDNode *LoopID) const;
/// Add llvm.loop.unroll.disable to this loop's loop id metadata.
///
/// Remove existing unroll metadata and add unroll disable metadata to
/// indicate the loop has already been unrolled. This prevents a loop
/// from being unrolled more than is directed by a pragma if the loop
/// unrolling pass is run more than once (which it generally is).
void setLoopAlreadyUnrolled();
/// Return true if no exit block for the loop has a predecessor that is
/// outside the loop.
bool hasDedicatedExits() const;

33
llvm/lib/Analysis/LoopInfo.cpp
View File

@ -268,6 +268,39 @@ void Loop::setLoopID(MDNode *LoopID) const {
}
}
void Loop::setLoopAlreadyUnrolled() {
MDNode *LoopID = getLoopID();
// First remove any existing loop unrolling metadata.
SmallVector<Metadata *, 4> MDs;
// Reserve first location for self reference to the LoopID metadata node.
MDs.push_back(nullptr);
if (LoopID) {
for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
bool IsUnrollMetadata = false;
MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
if (MD) {
const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
IsUnrollMetadata = S && S->getString().startswith("llvm.loop.unroll.");
}
if (!IsUnrollMetadata)
MDs.push_back(LoopID->getOperand(i));
}
}
// Add unroll(disable) metadata to disable future unrolling.
LLVMContext &Context = getHeader()->getContext();
SmallVector<Metadata *, 1> DisableOperands;
DisableOperands.push_back(MDString::get(Context, "llvm.loop.unroll.disable"));
MDNode *DisableNode = MDNode::get(Context, DisableOperands);
MDs.push_back(DisableNode);
MDNode *NewLoopID = MDNode::get(Context, MDs);
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
setLoopID(NewLoopID);
}
bool Loop::isAnnotatedParallel() const {
MDNode *DesiredLoopIdMetadata = getLoopID();

39
llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
View File

@ -649,43 +649,6 @@ static unsigned UnrollCountPragmaValue(const Loop *L) {
return 0;
}
// Remove existing unroll metadata and add unroll disable metadata to
// indicate the loop has already been unrolled. This prevents a loop
// from being unrolled more than is directed by a pragma if the loop
// unrolling pass is run more than once (which it generally is).
static void SetLoopAlreadyUnrolled(Loop *L) {
MDNode *LoopID = L->getLoopID();
// First remove any existing loop unrolling metadata.
SmallVector<Metadata *, 4> MDs;
// Reserve first location for self reference to the LoopID metadata node.
MDs.push_back(nullptr);
if (LoopID) {
for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
bool IsUnrollMetadata = false;
MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
if (MD) {
const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
IsUnrollMetadata = S && S->getString().startswith("llvm.loop.unroll.");
}
if (!IsUnrollMetadata)
MDs.push_back(LoopID->getOperand(i));
}
}
// Add unroll(disable) metadata to disable future unrolling.
LLVMContext &Context = L->getHeader()->getContext();
SmallVector<Metadata *, 1> DisableOperands;
DisableOperands.push_back(MDString::get(Context, "llvm.loop.unroll.disable"));
MDNode *DisableNode = MDNode::get(Context, DisableOperands);
MDs.push_back(DisableNode);
MDNode *NewLoopID = MDNode::get(Context, MDs);
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
L->setLoopID(NewLoopID);
}
// Computes the boosting factor for complete unrolling.
// If fully unrolling the loop would save a lot of RolledDynamicCost, it would
// be beneficial to fully unroll the loop even if unrolledcost is large. We
@ -1068,7 +1031,7 @@ static LoopUnrollResult tryToUnrollLoop(
// we had, so we don't want to unroll or peel again.
if (UnrollResult != LoopUnrollResult::FullyUnrolled &&
(IsCountSetExplicitly || UP.PeelCount))
SetLoopAlreadyUnrolled(L);
L->setLoopAlreadyUnrolled();
return UnrollResult;
}

30
llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
View File

@ -401,35 +401,7 @@ CloneLoopBlocks(Loop *L, Value *NewIter, const bool CreateRemainderLoop,
return NewLoop;
// Add unroll disable metadata to disable future unrolling for this loop.
SmallVector<Metadata *, 4> MDs;
// Reserve first location for self reference to the LoopID metadata node.
MDs.push_back(nullptr);
MDNode *LoopID = NewLoop->getLoopID();
if (LoopID) {
// First remove any existing loop unrolling metadata.
for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
bool IsUnrollMetadata = false;
MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
if (MD) {
const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
IsUnrollMetadata = S && S->getString().startswith("llvm.loop.unroll.");
}
if (!IsUnrollMetadata)
MDs.push_back(LoopID->getOperand(i));
}
}
LLVMContext &Context = NewLoop->getHeader()->getContext();
SmallVector<Metadata *, 1> DisableOperands;
DisableOperands.push_back(MDString::get(Context,
"llvm.loop.unroll.disable"));
MDNode *DisableNode = MDNode::get(Context, DisableOperands);
MDs.push_back(DisableNode);
MDNode *NewLoopID = MDNode::get(Context, MDs);
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
NewLoop->setLoopID(NewLoopID);
NewLoop->setLoopAlreadyUnrolled();
return NewLoop;
}
else