Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -19575,6 +19575,77 @@
This function returns the same values as the libm ``trunc`` functions
would and handles error conditions in the same way.
+.. _int_experimental_noalias_scope_decl:
+
+'``llvm.experimental.noalias.scope.decl``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+
+::
+
+ declare void @llvm.experimental.noalias.scope.decl(metadata !id.scope)
+
+Overview:
+"""""""""
+
+The ``llvm.experimental.noalias.scope.decl`` intrinsic identifies where a
+noalias scope is declared. When the intrinsic is duplicated, also a decision
+must be made about the scope: depending on the reason of the duplication,
+sometimes the scope must be duplicated as well.
+
+
+Arguments:
+""""""""""
+
+The ``!id.scope`` argument is metadata that is a list of ``noalias``
+metadata references. The format is identical to that required for ``noalias``
+metadata. This list must have exactly one element.
+
+Semantics:
+""""""""""
+
+The ``llvm.experimental.noalias.scope.decl`` intrinsic identifies where a
+noalias scope is declared. When the intrinsic is duplicated, also a decision
+must be made about the scope: depending on the reason of the duplication,
+sometimes the scope must be duplicated as well.
+
+For example, when the intrinsic is used inside a loop body, and that loop is
+unrolled, it is an indication that the associate noalias scope must also
+be duplicated. Otherwise, the noalias property it signifies would spill
+across loop iterations, whereas it was only valid within a single iteration.
+
+.. code-block:: llvm
+
+ ; This examples shows two possible positions for noalias.decl:
+ ; If it is outside the loop (version 1), then %a and %b are noalias across *all* iterations.
+ ; If it is inside the loop (version 2), then %a and %b are noalias only within *one* iteration.
+ declare void @decl_in_loop(i8* %a.base, i8* %b.base) {
+ entry:
+ ; call void @llvm.experimental.noalias.scope.decl(metadata !2) ; Version 1: noalias decl outside loop
+ br label %loop
+
+ loop:
+ %a = phi i8* [ %a.base, %entry ], [ %a.inc, %loop ]
+ %b = phi i8* [ %b.base, %entry ], [ %b.inc, %loop ]
+ ; call void @llvm.experimental.noalias.scope.decl(metadata !2) ; Version 2: noalias decl inside loop
+ %val = load i8, i8* %a, !alias.scope !2
+ store i8 %val, i8* %b, !noalias !2
+ %a.inc = getelementptr inbounds i8, i8* %a, i64 1
+ %b.inc = getelementptr inbounds i8, i8* %a, i64 1
+ %cond = call i1 @cond()
+ br i1 %cond, label %loop, label %exit
+
+ exit:
+ ret void
+ }
+
+ !0 = !{!0} ; domain
+ !1 = !{!1, !0} ; scope
+ !2 = !{!1} ; scope list
+
Floating Point Environment Manipulation intrinsics
--------------------------------------------------
Index: llvm/include/llvm/IR/IRBuilder.h
===================================================================
--- llvm/include/llvm/IR/IRBuilder.h
+++ llvm/include/llvm/IR/IRBuilder.h
@@ -858,6 +858,13 @@
CallInst *CreateAssumption(Value *Cond,
ArrayRef<OperandBundleDef> OpBundles = llvm::None);
+ /// Create a llvm.experimental.noalias.scope.decl intrinsic call.
+ Instruction *CreateNoAliasScopeDeclaration(Value *Scope);
+ Instruction *CreateNoAliasScopeDeclaration(MDNode *ScopeTag) {
+ return CreateNoAliasScopeDeclaration(
+ MetadataAsValue::get(Context, ScopeTag));
+ }
+
/// Create a call to the experimental.gc.statepoint intrinsic to
/// start a new statepoint sequence.
CallInst *CreateGCStatepointCall(uint64_t ID, uint32_t NumPatchBytes,
Index: llvm/include/llvm/IR/Intrinsics.h
===================================================================
--- llvm/include/llvm/IR/Intrinsics.h
+++ llvm/include/llvm/IR/Intrinsics.h
@@ -34,6 +34,9 @@
/// function known by LLVM. The enum values are returned by
/// Function::getIntrinsicID().
namespace Intrinsic {
+ // Abstraction for the arguments of the noalias intrinsics
+ static const int NoAliasScopeDeclScopeArg = 0;
+
// Intrinsic ID type. This is an opaque typedef to facilitate splitting up
// the enum into target-specific enums.
typedef unsigned ID;
Index: llvm/include/llvm/IR/Intrinsics.td
===================================================================
--- llvm/include/llvm/IR/Intrinsics.td
+++ llvm/include/llvm/IR/Intrinsics.td
@@ -539,6 +539,16 @@
def int_assume : DefaultAttrsIntrinsic<[], [llvm_i1_ty], [IntrWillReturn,
NoUndef<ArgIndex<0>>]>;
+// 'llvm.experimental.noalias.scope.decl' intrinsic: Inserted at the location of
+// noalias scope declaration. Makes it possible to identify that a noalias scope
+// is only valid inside the body of a loop.
+//
+// Purpose of the different arguments:
+// - arg0: id.scope: metadata representing the scope declaration.
+def int_experimental_noalias_scope_decl
+ : DefaultAttrsIntrinsic<[], [llvm_metadata_ty],
+ [IntrInaccessibleMemOnly]>; // blocks LICM and some more
+
// Stack Protector Intrinsic - The stackprotector intrinsic writes the stack
// guard to the correct place on the stack frame.
def int_stackprotector : DefaultAttrsIntrinsic<[], [llvm_ptr_ty, llvm_ptrptr_ty], []>;
Index: llvm/lib/CodeGen/IntrinsicLowering.cpp
===================================================================
--- llvm/lib/CodeGen/IntrinsicLowering.cpp
+++ llvm/lib/CodeGen/IntrinsicLowering.cpp
@@ -329,6 +329,7 @@
break;
case Intrinsic::assume:
+ case Intrinsic::experimental_noalias_scope_decl:
case Intrinsic::var_annotation:
break; // Strip out these intrinsics
Index: llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1375,6 +1375,8 @@
case Intrinsic::sideeffect:
// Neither does the assume intrinsic; it's also OK not to codegen its operand.
case Intrinsic::assume:
+ // Neither does the llvm.experimental.noalias.scope.decl intrinsic
+ case Intrinsic::experimental_noalias_scope_decl:
return true;
case Intrinsic::dbg_declare: {
const DbgDeclareInst *DI = cast<DbgDeclareInst>(II);
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6404,7 +6404,7 @@
return;
}
case Intrinsic::stackprotector: {
- // Emit code into the DAG to store the stack guard onto the stack.
+ // Emit code into the DAG tostore the stack guard onto the stack.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
SDValue Src, Chain = getRoot();
@@ -6444,10 +6444,13 @@
// Drop the intrinsic, but forward the value
setValue(&I, getValue(I.getOperand(0)));
return;
+
case Intrinsic::assume:
+ case Intrinsic::experimental_noalias_scope_decl:
case Intrinsic::var_annotation:
case Intrinsic::sideeffect:
- // Discard annotate attributes, assumptions, and artificial side-effects.
+ // Discard annotate attributes, noalias scope declarations, assumptions, and
+ // artificial side-effects.
return;
case Intrinsic::codeview_annotation: {
Index: llvm/lib/IR/IRBuilder.cpp
===================================================================
--- llvm/lib/IR/IRBuilder.cpp
+++ llvm/lib/IR/IRBuilder.cpp
@@ -452,6 +452,15 @@
return createCallHelper(FnAssume, Ops, this, "", nullptr, OpBundles);
}
+Instruction *IRBuilderBase::CreateNoAliasScopeDeclaration(Value *Scope) {
+ SmallVector<Value *, 1> Ops = {Scope};
+
+ Module *M = BB->getModule();
+ auto *FnIntrinsic = Intrinsic::getDeclaration(
+ M, Intrinsic::experimental_noalias_scope_decl, {});
+ return createCallHelper(FnIntrinsic, Ops, this);
+}
+
/// Create a call to a Masked Load intrinsic.
/// \p Ptr - base pointer for the load
/// \p Alignment - alignment of the source location