diff --git a/mlir/include/mlir/Interfaces/SideEffectInterfaces.h b/mlir/include/mlir/Interfaces/SideEffectInterfaces.h
--- a/mlir/include/mlir/Interfaces/SideEffectInterfaces.h
+++ b/mlir/include/mlir/Interfaces/SideEffectInterfaces.h
@@ -337,6 +337,12 @@
 /// getSpeculatability hook in the ConditionallySpeculatable op interface.
 bool isSpeculatable(Operation *op);
 
+/// Returns true if the given operation is pure, i.e., is speculatable that does
+/// not touch memory.
+///
+/// This function is the C++ equivalent of the `Pure` trait.
+bool isPure(Operation *op);
+
 } // namespace mlir
 
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -20,6 +20,7 @@
 #include "mlir/IR/FunctionImplementation.h"
 #include "mlir/IR/MLIRContext.h"
 #include "mlir/IR/Matchers.h"
+#include "mlir/Transforms/InliningUtils.h"
 
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/AsmParser/Parser.h"
@@ -2583,6 +2584,22 @@
 };
 } // namespace
 
+//===----------------------------------------------------------------------===//
+// DialectInlinerInterface
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct LLVMInlinerInterface : public DialectInlinerInterface {
+  using DialectInlinerInterface::DialectInlinerInterface;
+
+  /// Conservatively only allow inlining of pure ops.
+  bool isLegalToInline(Operation *op, Region *, bool,
+                       BlockAndValueMapping &) const final {
+    return isPure(op);
+  }
+};
+} // end anonymous namespace
+
 //===----------------------------------------------------------------------===//
 // LLVMDialect initialization, type parsing, and registration.
 //===----------------------------------------------------------------------===//
@@ -2611,7 +2628,10 @@
 
   // Support unknown operations because not all LLVM operations are registered.
   allowUnknownOperations();
-  addInterfaces<LLVMOpAsmDialectInterface>();
+  // clang-format off
+  addInterfaces<LLVMOpAsmDialectInterface,
+                LLVMInlinerInterface>();
+  // clang-format on
 }
 
 #define GET_OP_CLASSES
diff --git a/mlir/lib/Interfaces/SideEffectInterfaces.cpp b/mlir/lib/Interfaces/SideEffectInterfaces.cpp
--- a/mlir/lib/Interfaces/SideEffectInterfaces.cpp
+++ b/mlir/lib/Interfaces/SideEffectInterfaces.cpp
@@ -202,3 +202,9 @@
 
   llvm_unreachable("Unhandled enum in mlir::isSpeculatable!");
 }
+
+/// The implementation of this function replicates the `def Pure : TraitList`
+/// in `SideEffectInterfaces.td` and has to be kept in sync manually.
+bool mlir::isPure(Operation *op) {
+  return isSpeculatable(op) && isMemoryEffectFree(op);
+}
diff --git a/mlir/test/Dialect/LLVMIR/inlining.mlir b/mlir/test/Dialect/LLVMIR/inlining.mlir
new file mode 100644
--- /dev/null
+++ b/mlir/test/Dialect/LLVMIR/inlining.mlir
@@ -0,0 +1,28 @@
+// RUN: mlir-opt %s -inline | FileCheck %s
+
+// CHECK-LABEL: func.func @test_inline() -> i32 {
+// CHECK-NEXT: %[[RES:.*]] = llvm.mlir.constant(42 : i32) : i32
+// CHECK-NEXT: return %[[RES]] : i32
+func.func @test_inline() -> i32 {
+  %0 = call @inner_func_inlinable() : () -> i32
+  return %0 : i32
+}
+
+func.func @inner_func_inlinable() -> i32 {
+  %0 = llvm.mlir.constant(42 : i32) : i32
+  return %0 : i32
+}
+
+// CHECK-LABEL: func.func @test_not_inline() -> !llvm.ptr<f64> {
+// CHECK-NEXT: %[[RES:.*]] = call @inner_func_not_inlinable() : () -> !llvm.ptr<f64>
+// CHECK-NEXT: return %[[RES]] : !llvm.ptr<f64>
+func.func @test_not_inline() -> !llvm.ptr<f64> {
+  %0 = call @inner_func_not_inlinable() : () -> !llvm.ptr<f64>
+  return %0 : !llvm.ptr<f64>
+}
+
+func.func @inner_func_not_inlinable() -> !llvm.ptr<f64> {
+  %0 = llvm.mlir.constant(0 : i32) : i32
+  %1 = llvm.alloca %0 x f64 : (i32) -> !llvm.ptr<f64>
+  return %1 : !llvm.ptr<f64>
+}