[Lowering] Support lowering of llvm.experimental.ptr.provenance.

[jeroen.dobbelaere]

Summary

Add support for lowering the llvm.experimental.ptr.provenance and optional ptr_provenance argument for load/store instructions.

For the llvm.experimental.ptr.provenance operand, this means following operand 0.
For the load/store instructions the ptr_provenance arguments is passed to the MachineMemOperand

[jeroen.dobbelaere]

• Rebased

[jeroen.dobbelaere]

Rebase to 49cb4fef02e635bf304906232214166c7531d753

[jeroen.dobbelaere]

NOTE: this should not be done here. The ptr_provenance Value in D107354 must still be able to see these intrinsics.

[jeroen.dobbelaere]

In D107356#3495880, @jeroen.dobbelaere wrote:

NOTE: this should not be done here. The ptr_provenance Value in D107354 must still be able to see these intrinsics.

Question: is 'IntrinsicLowering' used for codegen ? I only find it to be used for the interpreter. There it makes sense to handle the intrinsics.

[jeroen.dobbelaere]

Rebased to ffe262a198a9f9030991df6d3ddd812e74fa3523

Added support for passing ptr_provenance argument of load/store instructions to MachineMemOperand when lowering.

[jeroen.dobbelaere]

Rebased to ef545ef62a833152d8975ff16333b57cc41befcc (Jan 9, 2023)

[jeroen.dobbelaere]

Rebased to: 8c7cfa357280dd93d33b10bbba0fe33797e27d63 (Feb 14, 2023)

llvm/lib/CodeGen/IntrinsicLowering.cpp

case Intrinsic::ptr_annotation:
     CI->replaceAllUsesWith(CI->getOperand(0));
     break;
 
   case Intrinsic::assume:
   case Intrinsic::experimental_noalias_scope_decl:
   case Intrinsic::var_annotation:
     break;   // Strip out these intrinsics
 
+  case Intrinsic::experimental_ptr_provenance:
+    // Drop the provenance, but forward the value
+    CI->replaceAllUsesWith(CI->getOperand(0));
+    break;
+
   case Intrinsic::memcpy: {
     Type *IntPtr = DL.getIntPtrType(Context);
     Value *Size = Builder.CreateIntCast(CI->getArgOperand(2), IntPtr,
                                         /* isSigned */ false);
     Value *Ops[3];
     Ops[0] = CI->getArgOperand(0);
     Ops[1] = CI->getArgOperand(1);
     Ops[2] = Size;

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

#include "llvm/IR/VPIntrinsics.def"
 
   case Intrinsic::is_constant:
     llvm_unreachable("llvm.is.constant.* should have been lowered already");
 
   case Intrinsic::annotation:
   case Intrinsic::ptr_annotation:
   case Intrinsic::launder_invariant_group:
   case Intrinsic::strip_invariant_group:
+  case Intrinsic::experimental_ptr_provenance:
     // 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:

llvm/test/CodeGen/ptr_provenance.ll

+; RUN: llc < %s
+
+define i32* @test(i32* %p, i32* %p.provenance) {
+  %p.joined = call i32* @llvm.experimental.ptr.provenance.p0i32.p0i32(i32* %p, i32* %p.provenance)
+  ret i32* %p.joined
+}
+
+declare i32* @llvm.experimental.ptr.provenance.p0i32.p0i32(i32*, i32*) nounwind readnone