[mlir][LLVM] Add support for invariant group related intrinsics (llvm#115877)

This PR adds support for the following LLVM intrinsics:
- `llvm.launder.invariant.group`
- `llvm.strip.invariant.group`

Author: Lancern

mlir/include/mlir/Dialect/LLVMIR/LLVMIntrinsicOps.td

@@ -346,6 +346,24 @@ def LLVM_InvariantEndOp : LLVM_ZeroResultIntrOp<"invariant.end", [2],
       "qualified(type($ptr))";
 }
 
+def LLVM_LaunderInvariantGroupOp
+    : LLVM_OneResultIntrOp<"launder.invariant.group", [], [0],
+        [DeclareOpInterfaceMethods<PromotableOpInterface>,
+         SameOperandsAndResultType]> {
+  let arguments = (ins LLVM_AnyPointer:$ptr);
+  let results = (outs LLVM_AnyPointer:$res);
+  let assemblyFormat = "$ptr attr-dict `:` qualified(type($ptr))";
+}
+
+def LLVM_StripInvariantGroupOp
+    : LLVM_OneResultIntrOp<"strip.invariant.group", [], [0],
+        [DeclareOpInterfaceMethods<PromotableOpInterface>,
+         SameOperandsAndResultType]> {
+  let arguments = (ins LLVM_AnyPointer:$ptr);
+  let results = (outs LLVM_AnyPointer:$res);
+  let assemblyFormat = "$ptr attr-dict `:` qualified(type($ptr))";
+}
+
 // Constrained Floating-Point Intrinsics.
 
 class LLVM_ConstrainedIntr<string mnem, int numArgs,

mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp

@@ -590,6 +590,30 @@ DeletionKind LLVM::InvariantEndOp::removeBlockingUses(
   return DeletionKind::Delete;
 }
 
+bool LLVM::LaunderInvariantGroupOp::canUsesBeRemoved(
+    const SmallPtrSetImpl<OpOperand *> &blockingUses,
+    SmallVectorImpl<OpOperand *> &newBlockingUses,
+    const DataLayout &dataLayout) {
+  return forwardToUsers(*this, newBlockingUses);
+}
+
+DeletionKind LLVM::LaunderInvariantGroupOp::removeBlockingUses(
+    const SmallPtrSetImpl<OpOperand *> &blockingUses, OpBuilder &builder) {
+  return DeletionKind::Delete;
+}
+
+bool LLVM::StripInvariantGroupOp::canUsesBeRemoved(
+    const SmallPtrSetImpl<OpOperand *> &blockingUses,
+    SmallVectorImpl<OpOperand *> &newBlockingUses,
+    const DataLayout &dataLayout) {
+  return forwardToUsers(*this, newBlockingUses);
+}
+
+DeletionKind LLVM::StripInvariantGroupOp::removeBlockingUses(
+    const SmallPtrSetImpl<OpOperand *> &blockingUses, OpBuilder &builder) {
+  return DeletionKind::Delete;
+}
+
 bool LLVM::DbgDeclareOp::canUsesBeRemoved(
     const SmallPtrSetImpl<OpOperand *> &blockingUses,
     SmallVectorImpl<OpOperand *> &newBlockingUses,

mlir/test/Dialect/LLVMIR/mem2reg.mlir

@@ -414,6 +414,18 @@ llvm.func @ignore_lifetime() {
 
 // -----
 
+// CHECK-LABEL: llvm.func @ignore_invariant_group
+// CHECK-NOT: llvm.alloca
+llvm.func @ignore_invariant_group() {
+  %0 = llvm.mlir.constant(1 : i32) : i32
+  %1 = llvm.alloca %0 x i32 {alignment = 4 : i64} : (i32) -> !llvm.ptr
+  %2 = llvm.intr.launder.invariant.group %1 : !llvm.ptr
+  %3 = llvm.intr.strip.invariant.group %2 : !llvm.ptr
+  llvm.return
+}
+
+// -----
+
 // CHECK-LABEL: llvm.func @ignore_discardable_tree
 // CHECK-NOT: = llvm.alloca
 llvm.func @ignore_discardable_tree() {

mlir/test/Dialect/LLVMIR/roundtrip.mlir

@@ -686,6 +686,16 @@ llvm.func @invariant(%p: !llvm.ptr) {
   llvm.return
 }
 
+// CHECK-LABEL: @invariant_group_intrinsics
+// CHECK-SAME: %[[P:.+]]: !llvm.ptr
+llvm.func @invariant_group_intrinsics(%p: !llvm.ptr) {
+  // CHECK: %{{.+}} = llvm.intr.launder.invariant.group %[[P]] : !llvm.ptr
+  %1 = llvm.intr.launder.invariant.group %p : !llvm.ptr
+  // CHECK: %{{.+}} = llvm.intr.strip.invariant.group %[[P]] : !llvm.ptr
+  %2 = llvm.intr.strip.invariant.group %p : !llvm.ptr
+  llvm.return
+}
+
 // CHECK-LABEL: @vararg_func
 llvm.func @vararg_func(%arg0: i32, ...) {
   // CHECK: %[[C:.*]] = llvm.mlir.constant(1 : i32)

mlir/test/Target/LLVMIR/Import/intrinsic.ll

@@ -806,6 +806,15 @@ define void @invariant(ptr %0) {
   ret void
 }
 
+; CHECK-LABEL: llvm.func @invariant_group
+define void @invariant_group(ptr %0) {
+  ; CHECK: %{{.+}} = llvm.intr.launder.invariant.group %{{.*}} : !llvm.ptr
+  %2 = call ptr @llvm.launder.invariant.group.p0(ptr %0)
+  ; CHECK: %{{.+}} = llvm.intr.strip.invariant.group %{{.*}} : !llvm.ptr
+  %3 = call ptr @llvm.strip.invariant.group.p0(ptr %0)
+  ret void
+}
+
 ; CHECK-LABEL: llvm.func @vector_insert
 define void @vector_insert(<vscale x 4 x float> %0, <4 x float> %1) {
   ; CHECK: llvm.intr.vector.insert %{{.*}}, %{{.*}}[4] : vector<4xf32> into !llvm.vec<? x 4 x  f32>
@@ -1195,6 +1204,8 @@ declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture)
 declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture)
 declare ptr @llvm.invariant.start.p0(i64 immarg, ptr nocapture)
 declare void @llvm.invariant.end.p0(ptr, i64 immarg, ptr nocapture)
+declare ptr @llvm.launder.invariant.group.p0(ptr nocapture)
+declare ptr @llvm.strip.invariant.group.p0(ptr nocapture)
 
 declare void @llvm.assume(i1)
 declare float @llvm.ssa.copy.f32(float returned)

mlir/test/Target/LLVMIR/llvmir-intrinsics.mlir

@@ -1024,6 +1024,15 @@ llvm.func @invariant(%p: !llvm.ptr) {
   llvm.return
 }
 
+// CHECK-LABEL: @invariant_group
+llvm.func @invariant_group(%p: !llvm.ptr) {
+  // CHECK: call ptr @llvm.launder.invariant.group
+  %1 = llvm.intr.launder.invariant.group %p : !llvm.ptr
+  // CHECK: call ptr @llvm.strip.invariant.group
+  %2 = llvm.intr.strip.invariant.group %p : !llvm.ptr
+  llvm.return
+}
+
 // CHECK-LABEL: @ssa_copy
 llvm.func @ssa_copy(%arg: f32) -> f32 {
   // CHECK: call float @llvm.ssa.copy