Index: lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
===================================================================
--- lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -359,8 +359,11 @@
 
   unsigned NumBytes = CCInfo.getAlignedCallFrameSize();
 
-  auto NB = DAG.getConstant(NumBytes, DL, PtrVT, true);
-  Chain = DAG.getCALLSEQ_START(Chain, NB, DL);
+  SDValue NB;
+  if (NumBytes) {
+    NB = DAG.getConstant(NumBytes, DL, PtrVT, true);
+    Chain = DAG.getCALLSEQ_START(Chain, NB, DL);
+  }
 
   if (IsVarArg) {
     // For non-fixed arguments, next emit stores to store the argument values
@@ -420,8 +423,10 @@
     Chain = Res.getValue(1);
   }
 
-  SDValue Unused = DAG.getUNDEF(PtrVT);
-  Chain = DAG.getCALLSEQ_END(Chain, NB, Unused, SDValue(), DL);
+  if (NumBytes) {
+    SDValue Unused = DAG.getUNDEF(PtrVT);
+    Chain = DAG.getCALLSEQ_END(Chain, NB, Unused, SDValue(), DL);
+  }
 
   return Chain;
 }
Index: lib/Target/WebAssembly/WebAssemblyInstrCall.td
===================================================================
--- lib/Target/WebAssembly/WebAssemblyInstrCall.td
+++ lib/Target/WebAssembly/WebAssemblyInstrCall.td
@@ -18,7 +18,7 @@
 
 // Call sequence markers. These have an immediate which represents the amount of
 // stack space to allocate or free, which is used for varargs lowering.
-let isCodeGenOnly = 1 in {
+let Uses = [SP32, SP64], Defs = [SP32, SP64], isCodeGenOnly = 1 in {
 def ADJCALLSTACKDOWN : I<(outs), (ins i32imm:$amt),
                          [(WebAssemblycallseq_start timm:$amt)]>;
 def ADJCALLSTACKUP : I<(outs), (ins i32imm:$amt),