[WebAssembly] Fix byval for empty types.

llvm-svn: 260740

2 files changed, 20 insertions, 2 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 779e23f7773..7d63d89f17e 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -308,9 +308,8 @@ SDValue WebAssemblyTargetLowering::LowerCall(
       fail(DL, DAG, "WebAssembly hasn't implemented cons regs arguments");
     if (Out.Flags.isInConsecutiveRegsLast())
       fail(DL, DAG, "WebAssembly hasn't implemented cons regs last arguments");
-    if (Out.Flags.isByVal()) {
+    if (Out.Flags.isByVal() && Out.Flags.getByValSize() != 0) {
       auto *MFI = MF.getFrameInfo();
-      assert(Out.Flags.getByValSize() && "Zero-size byval?");
       int FI = MFI->CreateStackObject(Out.Flags.getByValSize(),
                                       Out.Flags.getByValAlign(),
                                       /*isSS=*/false);
diff --git a/llvm/test/CodeGen/WebAssembly/byval.ll b/llvm/test/CodeGen/WebAssembly/byval.ll
index 5bb350215db..9a9ab6500c8 100644
--- a/llvm/test/CodeGen/WebAssembly/byval.ll
+++ b/llvm/test/CodeGen/WebAssembly/byval.ll
@@ -8,14 +8,17 @@ target triple = "wasm32-unknown-unknown"
 %OddStruct = type { i32, i8, i32 }
 %AlignedStruct = type { double, double }
 %BigStruct = type { double, double, double, double, double, double, double, double, double, double, double, i8, i8, i8 }
+%EmptyStruct = type { }
 
 %BigArray = type { [33 x i8] }
 
 declare void @ext_func(%SmallStruct*)
+declare void @ext_func_empty(%EmptyStruct* byval)
 declare void @ext_byval_func(%SmallStruct* byval)
 declare void @ext_byval_func_align8(%SmallStruct* byval align 8)
 declare void @ext_byval_func_alignedstruct(%AlignedStruct* byval)
 declare void @ext_byval_func_bigarray(%BigArray* byval)
+declare void @ext_byval_func_empty(%EmptyStruct* byval)
 
 ; CHECK-LABEL: byval_arg
 define void @byval_arg(%SmallStruct* %ptr) {
@@ -103,3 +106,19 @@ define void @byval_param(%SmallStruct* byval align 32 %ptr) {
  call void @ext_func(%SmallStruct* %ptr)
  ret void
 }
+
+; CHECK-LABEL: byval_empty_caller
+define void @byval_empty_caller(%EmptyStruct* %ptr) {
+ ; CHECK: .param i32
+ ; CHECK: call ext_byval_func_empty@FUNCTION, $0
+ call void @ext_byval_func_empty(%EmptyStruct* byval %ptr)
+ ret void
+}
+
+; CHECK-LABEL: byval_empty_callee
+define void @byval_empty_callee(%EmptyStruct* byval %ptr) {
+ ; CHECK: .param i32
+ ; CHECK: call ext_func_empty@FUNCTION, $0
+ call void @ext_func_empty(%EmptyStruct* %ptr)
+ ret void
+}