diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2351,6 +2351,10 @@
 
 def mharden_sls_EQ : Joined<["-"], "mharden-sls=">,
   HelpText<"Select straight-line speculation hardening scope">;
+def msve_vector_bits : Joined<["-"], "msve-vector-bits=">,
+  Group<m_aarch64_Features_Group>,
+  HelpText<"Specify the size in bits of an SVE vector register."
+           " Has no effect unless SVE is enabled. (Default is \"scalable\")">;
 
 def msimd128 : Flag<["-"], "msimd128">, Group<m_wasm_Features_Group>;
 def munimplemented_simd128 : Flag<["-"], "munimplemented-simd128">, Group<m_wasm_Features_Group>;
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1715,6 +1715,22 @@
     if (IndirectBranches)
       CmdArgs.push_back("-mbranch-target-enforce");
   }
+
+  if (any_of(CmdArgs, [](const char *Arg) {
+        return (strcmp(Arg, "+sve") == 0 || strcmp(Arg, "+sve2") == 0);
+      })) {
+    if (Arg *A = Args.getLastArg(options::OPT_msve_vector_bits)) {
+      StringRef Bits = A->getValue();
+      if (Bits != "scalable") {
+        CmdArgs.push_back("-mllvm");
+        CmdArgs.push_back(
+            Args.MakeArgString("-aarch64-sve-vector-bits-min=" + Bits));
+        // CmdArgs.push_back("-mllvm");
+        // CmdArgs.push_back(
+        //    Args.MakeArgString("-aarch64-sve-vector-bits-max=" + Bits));
+      }
+    }
+  }
 }
 
 void Clang::AddMIPSTargetArgs(const ArgList &Args,
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -1819,7 +1819,7 @@
         if (FPOffsetFits && CanUseBP) // Both are ok. Pick the best.
           UseFP = PreferFP;
         else if (!CanUseBP) { // Can't use BP. Forced to use FP.
-          assert(!SVEStackSize && "Expected BP to be available");
+          // assert(!SVEStackSize && "Expected BP to be available");
           UseFP = true;
         }
         // else we can use BP and FP, but the offset from FP won't fit.