diff --git a/compiler/gen_dev/src/generic64/aarch64.rs b/compiler/gen_dev/src/generic64/aarch64.rs
index 6363ce14b5..890995c726 100644
--- a/compiler/gen_dev/src/generic64/aarch64.rs
+++ b/compiler/gen_dev/src/generic64/aarch64.rs
@@ -510,15 +510,6 @@ impl Assembler<AArch64GeneralReg, AArch64FloatReg> for AArch64Assembler {
         unimplemented!("registers less than not implemented yet for AArch64");
     }
 
-    #[inline(always)]
-    fn is_zero_reg64_reg64(
-        _buf: &mut Vec<'_, u8>,
-        _dst: AArch64GeneralReg,
-        _src: AArch64GeneralReg,
-    ) {
-        unimplemented!("registers is zero not implemented yet for AArch64");
-    }
-
     #[inline(always)]
     fn ret(buf: &mut Vec<'_, u8>) {
         ret_reg64(buf, AArch64GeneralReg::LR)
diff --git a/compiler/gen_dev/src/generic64/mod.rs b/compiler/gen_dev/src/generic64/mod.rs
index 563f9cd877..09cd28b4ee 100644
--- a/compiler/gen_dev/src/generic64/mod.rs
+++ b/compiler/gen_dev/src/generic64/mod.rs
@@ -187,8 +187,6 @@ pub trait Assembler<GeneralReg: RegTrait, FloatReg: RegTrait> {
         src2: GeneralReg,
     );
 
-    fn is_zero_reg64_reg64(buf: &mut Vec<'_, u8>, dst: GeneralReg, src: GeneralReg);
-
     fn ret(buf: &mut Vec<'_, u8>);
 }
 
@@ -897,23 +895,6 @@ impl<
         }
     }
 
-    fn build_num_is_zero(
-        &mut self,
-        dst: &Symbol,
-        src: &Symbol,
-        arg_layout: &Layout<'a>,
-    ) -> Result<(), String> {
-        match arg_layout {
-            Layout::Builtin(Builtin::Int(IntWidth::I64)) => {
-                let dst_reg = self.claim_general_reg(dst)?;
-                let src_reg = self.load_to_general_reg(src)?;
-                ASM::is_zero_reg64_reg64(&mut self.buf, dst_reg, src_reg);
-                Ok(())
-            }
-            x => Err(format!("NumIsZero: layout, {:?}, not implemented yet", x)),
-        }
-    }
-
     fn create_struct(
         &mut self,
         sym: &Symbol,
diff --git a/compiler/gen_dev/src/generic64/x86_64.rs b/compiler/gen_dev/src/generic64/x86_64.rs
index e9f1b1064a..5bc69e44e9 100644
--- a/compiler/gen_dev/src/generic64/x86_64.rs
+++ b/compiler/gen_dev/src/generic64/x86_64.rs
@@ -1119,12 +1119,6 @@ impl Assembler<X86_64GeneralReg, X86_64FloatReg> for X86_64Assembler {
         setl_reg64(buf, dst);
     }
 
-    #[inline(always)]
-    fn is_zero_reg64_reg64(buf: &mut Vec<'_, u8>, dst: X86_64GeneralReg, src: X86_64GeneralReg) {
-        test_reg64_reg64(buf, src, src);
-        sete_reg64(buf, dst);
-    }
-
     #[inline(always)]
     fn ret(buf: &mut Vec<'_, u8>) {
         ret(buf);
diff --git a/compiler/gen_dev/src/lib.rs b/compiler/gen_dev/src/lib.rs
index 0818122d1e..455faa56df 100644
--- a/compiler/gen_dev/src/lib.rs
+++ b/compiler/gen_dev/src/lib.rs
@@ -585,14 +585,6 @@ where
         arg_layout: &Layout<'a>,
     ) -> Result<(), String>;
 
-    /// build_num_is_zero stores the result of `src == 0` into dst.
-    fn build_num_is_zero(
-        &mut self,
-        dst: &Symbol,
-        src: &Symbol,
-        arg_layout: &Layout<'a>,
-    ) -> Result<(), String>;
-
     /// literal_map gets the map from symbol to literal, used for lazy loading and literal folding.
     fn literal_map(&mut self) -> &mut MutMap<Symbol, Literal<'a>>;