[mlir] Support translating function linkage between MLIR and LLVM IR

Linkage support is already present in the LLVM dialect, and is being translated
for globals other than functions. Translation support has been missing for
functions because their conversion goes through a different code path than
other globals.

Differential Revision: https://reviews.llvm.org/D84149

diff --git a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
index c6a58a8..9754c61 100644 (file)
--- a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
+++ b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
@@ -846,8 +846,9 @@ LogicalResult Importer::processFunction(llvm::Function *f) {
     return failure();
 
   b.setInsertionPoint(module.getBody(), getFuncInsertPt());
-  LLVMFuncOp fop = b.create<LLVMFuncOp>(UnknownLoc::get(context), f->getName(),
-                                        functionType);
+  LLVMFuncOp fop =
+      b.create<LLVMFuncOp>(UnknownLoc::get(context), f->getName(), functionType,
+                           convertLinkageFromLLVM(f->getLinkage()));
 
   if (FlatSymbolRefAttr personality = getPersonalityAsAttr(f))
     fop.setAttr(b.getIdentifier("personality"), personality);

diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 0defea6..12d3d40 100644 (file)
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -884,6 +884,7 @@ LogicalResult ModuleTranslation::convertFunctionSignatures() {
         function.getName(),
         cast<llvm::FunctionType>(function.getType().getUnderlyingType()));
     llvm::Function *llvmFunc = cast<llvm::Function>(llvmFuncCst.getCallee());
+    llvmFunc->setLinkage(convertLinkageToLLVM(function.linkage()));
     functionMapping[function.getName()] = llvmFunc;
 
     // Forward the pass-through attributes to LLVM.

diff --git a/mlir/test/Target/import.ll b/mlir/test/Target/import.ll
index 4f4e822..24b4a0b 100644 (file)
--- a/mlir/test/Target/import.ll
+++ b/mlir/test/Target/import.ll
@@ -64,11 +64,20 @@
 ; CHECK: llvm.mlir.global internal constant @nested_array_vector(dense<[{{\[}}[1, 2], [3, 4]]]> : vector<1x2x2xi32>) : !llvm<"[1 x [2 x <2 x i32>]]">
 @nested_array_vector = internal constant [1 x [2 x <2 x i32>]] [[2 x <2 x i32>] [<2 x i32> <i32 1, i32 2>, <2 x i32> <i32 3, i32 4>]]
 
+;
+; Linkage on functions.
+;
+
+; CHECK: llvm.func internal @func_internal
+define internal void @func_internal() {
+  ret void
+}
+
 ; CHECK: llvm.func @fe(!llvm.i32) -> !llvm.float
 declare float @fe(i32)
 
 ; FIXME: function attributes.
-; CHECK-LABEL: llvm.func @f1(%arg0: !llvm.i64) -> !llvm.i32 {
+; CHECK-LABEL: llvm.func internal @f1(%arg0: !llvm.i64) -> !llvm.i32 {
 ; CHECK-DAG: %[[c2:[0-9]+]] = llvm.mlir.constant(2 : i32) : !llvm.i32
 ; CHECK-DAG: %[[c42:[0-9]+]] = llvm.mlir.constant(42 : i32) : !llvm.i32
 ; CHECK-DAG: %[[c1:[0-9]+]] = llvm.mlir.constant(true) : !llvm.i1

diff --git a/mlir/test/Target/llvmir.mlir b/mlir/test/Target/llvmir.mlir
index 05b8ef1..566212a 100644 (file)
--- a/mlir/test/Target/llvmir.mlir
+++ b/mlir/test/Target/llvmir.mlir
@@ -61,7 +61,8 @@ llvm.mlir.global external @external() : !llvm.i32
 
 
 //
-// Declarations of the allocation functions to be linked against.
+// Declarations of the allocation functions to be linked against. These are
+// inserted before other functions in the module.
 //
 
 // CHECK: declare i8* @malloc(i64)
@@ -390,6 +391,17 @@ llvm.func @more_imperfectly_nested_loops() {
   llvm.return
 }
 
+
+//
+// Check that linkage is translated for functions. No need to check all linkage
+// flags since the logic is the same as for globals.
+//
+
+// CHECK: define internal void @func_internal
+llvm.func internal @func_internal() {
+  llvm.return
+}
+
 //
 // MemRef type conversion, allocation and communication with functions.
 //