diff --git a/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp b/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
--- a/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
@@ -736,6 +736,12 @@
         continue;
 
       if (Use->getParent()->getParent() == &F) {
+        // Do not promote alloca to static LDS if this function uses any dynamic shared memory
+        // since mixed static/dynamic LDS is not fully supported yet.
+        uint64_t AllocSize = DL.getTypeAllocSize(GV.getValueType());
+        if (AllocSize == 0)
+          return false;
+
         unsigned Align = GV.getAlignment();
         if (Align == 0)
           Align = DL.getABITypeAlignment(GV.getValueType());
@@ -744,7 +750,6 @@
         // determined from the inverse order of uses in the function. I'm not
         // sure if the use list order is in any way connected to this, so the
         // total reported size is likely incorrect.
-        uint64_t AllocSize = DL.getTypeAllocSize(GV.getValueType());
         CurrentLocalMemUsage = alignTo(CurrentLocalMemUsage, Align);
         CurrentLocalMemUsage += AllocSize;
         break;