diff --git a/gen/abi/aarch64.cpp b/gen/abi/aarch64.cpp
index 2a9f58639e..144312ff07 100644
--- a/gen/abi/aarch64.cpp
+++ b/gen/abi/aarch64.cpp
@@ -84,14 +84,7 @@ struct AArch64TargetABI : TargetABI {
   bool passByVal(TypeFunction *, Type *) override { return false; }
 
   void rewriteFunctionType(IrFuncTy &fty) override {
-    if (!skipReturnValueRewrite(fty)) {
-      rewriteArgument(fty, *fty.ret, /*isReturnVal=*/true);
-    }
-
-    for (auto arg : fty.args) {
-      if (!arg->byref)
-        rewriteArgument(fty, *arg, /*isReturnVal=*/false);
-    }
+    TargetABI::rewriteFunctionType(fty);
 
     // remove 0-sized args (static arrays with 0 elements) and, for Darwin,
     // empty POD structs too
@@ -122,15 +115,13 @@ struct AArch64TargetABI : TargetABI {
   }
 
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
-    return rewriteArgument(fty, arg, /*isReturnVal=*/false);
-  }
-
-  void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg, bool isReturnVal) {
     Type *t = arg.type->toBasetype();
 
     if (!isAggregate(t))
       return;
 
+    const bool isReturnVal = &arg == fty.ret;
+
     // compiler magic: pass va_list args implicitly by reference
     if (!isReturnVal && isAAPCS64VaList(t)) {
       arg.byref = true;
diff --git a/gen/abi/abi.cpp b/gen/abi/abi.cpp
index b034f65072..4050964041 100644
--- a/gen/abi/abi.cpp
+++ b/gen/abi/abi.cpp
@@ -164,6 +164,16 @@ bool TargetABI::preferPassByRef(Type *t) {
 
 //////////////////////////////////////////////////////////////////////////////
 
+void TargetABI::rewriteFunctionType(IrFuncTy &fty) {
+  if (!skipReturnValueRewrite(fty))
+    rewriteArgument(fty, *fty.ret);
+
+  for (auto arg : fty.args) {
+    if (!arg->byref)
+      rewriteArgument(fty, *arg);
+  }
+}
+
 void TargetABI::rewriteVarargs(IrFuncTy &fty,
                                std::vector<IrFuncTyArg *> &args) {
   for (auto arg : args) {
@@ -231,10 +241,6 @@ struct UnknownTargetABI : TargetABI {
   bool passByVal(TypeFunction *, Type *t) override {
     return DtoIsInMemoryOnly(t);
   }
-
-  void rewriteFunctionType(IrFuncTy &) override {
-    // why?
-  }
 };
 
 //////////////////////////////////////////////////////////////////////////////
@@ -305,32 +311,6 @@ struct IntrinsicABI : TargetABI {
       remove_padding.applyTo(arg, abiTy);
     }
   }
-
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    if (!fty.arg_sret) {
-      Type *rt = fty.ret->type->toBasetype();
-      if (rt->ty == TY::Tstruct) {
-        Logger::println("Intrinsic ABI: Transforming return type");
-        rewriteArgument(fty, *fty.ret);
-      }
-    }
-
-    Logger::println("Intrinsic ABI: Transforming arguments");
-    LOG_SCOPE;
-
-    for (auto arg : fty.args) {
-      IF_LOG Logger::cout() << "Arg: " << arg->type->toChars() << '\n';
-
-      // Arguments that are in memory are of no interest to us.
-      if (arg->byref) {
-        continue;
-      }
-
-      rewriteArgument(fty, *arg);
-
-      IF_LOG Logger::cout() << "New arg type: " << *arg->ltype << '\n';
-    }
-  }
 };
 
 TargetABI *TargetABI::getIntrinsic() {
diff --git a/gen/abi/abi.h b/gen/abi/abi.h
index 3545fb531a..48a42e51bb 100644
--- a/gen/abi/abi.h
+++ b/gen/abi/abi.h
@@ -154,7 +154,7 @@ struct TargetABI {
   virtual bool passThisBeforeSret(TypeFunction *tf) { return false; }
 
   /// Called to give ABI the chance to rewrite the types
-  virtual void rewriteFunctionType(IrFuncTy &fty) = 0;
+  virtual void rewriteFunctionType(IrFuncTy &fty);
   virtual void rewriteVarargs(IrFuncTy &fty, std::vector<IrFuncTyArg *> &args);
   virtual void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) {}
 
diff --git a/gen/abi/arm.cpp b/gen/abi/arm.cpp
index ed4c311a22..3b5ee7b58e 100644
--- a/gen/abi/arm.cpp
+++ b/gen/abi/arm.cpp
@@ -69,24 +69,6 @@ struct ArmTargetABI : TargetABI {
     // problem is better understood.
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    Type *retTy = fty.ret->type->toBasetype();
-    if (!fty.ret->byref && retTy->ty == TY::Tstruct) {
-      // Rewrite HFAs only because union HFAs are turned into IR types that are
-      // non-HFA and messes up register selection
-      if (isHFVA(retTy, hfvaToArray.maxElements, &fty.ret->ltype)) {
-        hfvaToArray.applyTo(*fty.ret, fty.ret->ltype);
-      } else {
-        integerRewrite.applyTo(*fty.ret);
-      }
-    }
-
-    for (auto arg : fty.args) {
-      if (!arg->byref)
-        rewriteArgument(fty, *arg);
-    }
-  }
-
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
     // structs and arrays need rewrite as i32 arrays.  This keeps data layout
     // unchanged when passed in registers r0-r3 and is necessary to match C ABI
@@ -95,6 +77,8 @@ struct ArmTargetABI : TargetABI {
     // r0, where before it consumed r0-r3.
     Type *ty = arg.type->toBasetype();
 
+    const bool isReturnValue = &arg == fty.ret;
+
     // TODO: want to also rewrite Tsarray as i32 arrays, but sometimes
     // llvm selects an aligned ldrd instruction even though the ptr is
     // unaligned (e.g. walking through members of array char[5][]).
@@ -104,6 +88,8 @@ struct ArmTargetABI : TargetABI {
       // non-HFA and messes up register selection
       if (isHFVA(ty, hfvaToArray.maxElements, &arg.ltype)) {
         hfvaToArray.applyTo(arg, arg.ltype);
+      } else if (isReturnValue) {
+        integerRewrite.applyTo(arg);
       } else if (DtoAlignment(ty) <= 4) {
         compositeToArray32.applyTo(arg);
       } else {
diff --git a/gen/abi/loongarch64.cpp b/gen/abi/loongarch64.cpp
index b27a7b89be..639a5d1f13 100644
--- a/gen/abi/loongarch64.cpp
+++ b/gen/abi/loongarch64.cpp
@@ -136,35 +136,22 @@ struct LoongArch64TargetABI : TargetABI {
     return size(t) > 16;
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    if (!skipReturnValueRewrite(fty)) {
-      if (requireHardfloatRewrite(fty.ret->type)) {
-        // rewrite here because we should not apply this to variadic arguments
-        hardfloatRewrite.applyTo(*fty.ret);
-      } else {
-        rewriteArgument(fty, *fty.ret);
-      }
-    }
-
-    for (auto arg : fty.args) {
-      if (!arg->byref) {
-        if (requireHardfloatRewrite(arg->type)) {
-          // rewrite here because we should not apply this to variadic arguments
-          hardfloatRewrite.applyTo(*arg);
-        } else {
-          rewriteArgument(fty, *arg);
-        }
-      }
-    }
+  void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
+    rewriteArgument(fty, arg, /*isVararg=*/ false);
   }
 
-  void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
+  void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg, bool isVararg) {
     if (!isPOD(arg.type)) {
       // non-PODs should be passed in memory
       indirectByvalRewrite.applyTo(arg);
       return;
     }
 
+    if (!isVararg && requireHardfloatRewrite(arg.type)) {
+      hardfloatRewrite.applyTo(arg);
+      return;
+    }
+
     Type *ty = arg.type->toBasetype();
     if (ty->isintegral() && (ty->ty == TY::Tint32 || ty->ty == TY::Tuns32 ||
                              ty->ty == TY::Tdchar)) {
diff --git a/gen/abi/mips64.cpp b/gen/abi/mips64.cpp
index 478f12ad58..84d42624d4 100644
--- a/gen/abi/mips64.cpp
+++ b/gen/abi/mips64.cpp
@@ -46,18 +46,6 @@ struct MIPS64TargetABI : TargetABI {
     return ty == TY::Tstruct || ty == TY::Tsarray;
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    if (!fty.ret->byref) {
-      rewriteArgument(fty, *fty.ret);
-    }
-
-    for (auto arg : fty.args) {
-      if (!arg->byref) {
-        rewriteArgument(fty, *arg);
-      }
-    }
-  }
-
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
     // FIXME
   }
diff --git a/gen/abi/nvptx.cpp b/gen/abi/nvptx.cpp
index 7c4878aaea..e85b86db1f 100644
--- a/gen/abi/nvptx.cpp
+++ b/gen/abi/nvptx.cpp
@@ -30,12 +30,6 @@ struct NVPTXTargetABI : TargetABI {
     t = t->toBasetype();
     return ((t->ty == TY::Tsarray || t->ty == TY::Tstruct) && size(t) > 64);
   }
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    for (auto arg : fty.args) {
-      if (!arg->byref)
-        rewriteArgument(fty, *arg);
-    }
-  }
   bool returnInArg(TypeFunction *tf, bool) override {
     return !tf->isref() && DtoIsInMemoryOnly(tf->next);
   }
diff --git a/gen/abi/ppc.cpp b/gen/abi/ppc.cpp
index 81b1c9ce1b..d2401b4425 100644
--- a/gen/abi/ppc.cpp
+++ b/gen/abi/ppc.cpp
@@ -59,20 +59,6 @@ struct PPCTargetABI : TargetABI {
            (!Is64Bit || size(t) > 64);
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    // return value
-    if (!fty.ret->byref) {
-      rewriteArgument(fty, *fty.ret);
-    }
-
-    // explicit parameters
-    for (auto arg : fty.args) {
-      if (!arg->byref) {
-        rewriteArgument(fty, *arg);
-      }
-    }
-  }
-
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
     Type *ty = arg.type->toBasetype();
 
diff --git a/gen/abi/ppc64le.cpp b/gen/abi/ppc64le.cpp
index 129e1719bc..f540f727d5 100644
--- a/gen/abi/ppc64le.cpp
+++ b/gen/abi/ppc64le.cpp
@@ -48,20 +48,6 @@ struct PPC64LETargetABI : TargetABI {
                                     !isHFVA(t, hfvaToArray.maxElements));
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    // return value
-    if (!fty.ret->byref) {
-      rewriteArgument(fty, *fty.ret);
-    }
-
-    // explicit parameters
-    for (auto arg : fty.args) {
-      if (!arg->byref) {
-        rewriteArgument(fty, *arg);
-      }
-    }
-  }
-
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
     Type *ty = arg.type->toBasetype();
     if (ty->ty == TY::Tstruct || ty->ty == TY::Tsarray) {
diff --git a/gen/abi/riscv64.cpp b/gen/abi/riscv64.cpp
index 158bfaeba2..cac1c2958a 100644
--- a/gen/abi/riscv64.cpp
+++ b/gen/abi/riscv64.cpp
@@ -182,32 +182,22 @@ struct RISCV64TargetABI : TargetABI {
     }
     return size(t) > 16;
   }
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    if (!fty.ret->byref) {
-      if (!skipReturnValueRewrite(fty)) {
-        if (!fty.ret->byref && isPOD(fty.ret->type) &&
-            requireHardfloatRewrite(fty.ret->type)) {
-          // rewrite here because we should not apply this to variadic arguments
-          hardfloatRewrite.applyTo(*fty.ret);
-        } else {
-          rewriteArgument(fty, *fty.ret);
-        }
-      }
-    }
 
-    for (auto arg : fty.args) {
-      if (!arg->byref && isPOD(arg->type) &&
-          requireHardfloatRewrite(arg->type)) {
-        // rewrite here because we should not apply this to variadic arguments
-        hardfloatRewrite.applyTo(*arg);
-      } else {
-        rewriteArgument(fty, *arg);
-      }
+  void rewriteVarargs(IrFuncTy &fty,
+                      std::vector<IrFuncTyArg *> &args) override {
+    for (auto arg : args) {
+      if (!arg->byref)
+        rewriteArgument(fty, *arg, /*isVararg=*/true);
     }
   }
 
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
-    if (arg.byref) {
+    rewriteArgument(fty, arg, /*isVararg=*/false);
+  }
+
+  void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg, bool isVararg) {
+    if (!isVararg && isPOD(arg.type) && requireHardfloatRewrite(arg.type)) {
+      hardfloatRewrite.applyTo(arg);
       return;
     }
 
diff --git a/gen/abi/spirv.cpp b/gen/abi/spirv.cpp
index 1dd09f3cd8..22d5128a9b 100644
--- a/gen/abi/spirv.cpp
+++ b/gen/abi/spirv.cpp
@@ -30,14 +30,6 @@ struct SPIRVTargetABI : TargetABI {
     t = t->toBasetype();
     return ((t->ty == TY::Tsarray || t->ty == TY::Tstruct) && size(t) > 64);
   }
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    for (auto arg : fty.args) {
-      if (!arg->byref)
-        rewriteArgument(fty, *arg);
-    }
-    if (!skipReturnValueRewrite(fty))
-      rewriteArgument(fty, *fty.ret);
-  }
   bool returnInArg(TypeFunction *tf, bool) override {
     if (tf->isref())
       return false;
diff --git a/gen/abi/wasm.cpp b/gen/abi/wasm.cpp
index 52669a538d..5d5c44daa8 100644
--- a/gen/abi/wasm.cpp
+++ b/gen/abi/wasm.cpp
@@ -69,8 +69,6 @@ struct WasmTargetABI : TargetABI {
   bool passByVal(TypeFunction *, Type *t) override {
     return DtoIsInMemoryOnly(t) && !isDirectlyPassedAggregate(t);
   }
-
-  void rewriteFunctionType(IrFuncTy &) override {}
 };
 
 // The public getter for abi.cpp.
diff --git a/gen/abi/win64.cpp b/gen/abi/win64.cpp
index 631aeb1088..3a1fdc8df2 100644
--- a/gen/abi/win64.cpp
+++ b/gen/abi/win64.cpp
@@ -155,20 +155,6 @@ struct Win64TargetABI : TargetABI {
     return tf->linkage == LINK::cpp;
   }
 
-  void rewriteFunctionType(IrFuncTy &fty) override {
-    // return value
-    if (!skipReturnValueRewrite(fty)) {
-      rewrite(fty, *fty.ret, /*isReturnValue=*/true);
-    }
-
-    // explicit parameters
-    for (auto arg : fty.args) {
-      if (!arg->byref) {
-        rewriteArgument(fty, *arg);
-      }
-    }
-  }
-
   void rewriteVarargs(IrFuncTy &fty,
                       std::vector<IrFuncTyArg *> &args) override {
     for (auto arg : args) {
@@ -183,12 +169,9 @@ struct Win64TargetABI : TargetABI {
   }
 
   void rewriteArgument(IrFuncTy &fty, IrFuncTyArg &arg) override {
-    rewrite(fty, arg, /*isReturnValue=*/false);
-  }
-
-  void rewrite(IrFuncTy &fty, IrFuncTyArg &arg, bool isReturnValue) {
     Type *t = arg.type->toBasetype();
     LLType *originalLType = arg.ltype;
+    const bool isReturnValue = &arg == fty.ret;
 
     if (passPointerToHiddenCopy(t, isReturnValue, fty.type)) {
       // the caller allocates a hidden copy and passes a pointer to that copy