diff --git a/cranelift/filetests/filetests/runtests/isubbin.clif b/cranelift/filetests/filetests/runtests/isubbin.clif
new file mode 100644
index 0000000000..304d118d6a
--- /dev/null
+++ b/cranelift/filetests/filetests/runtests/isubbin.clif
@@ -0,0 +1,49 @@
+test interpret
+
+function %isubbin_i8(i8, i8, b1) -> i8 {
+block0(v0: i8, v1: i8, v2: b1):
+    v3 = isub_bin v0, v1, v2
+    return v3
+}
+; run: %isubbin_i8(0, 1, true) == -2
+; run: %isubbin_i8(0, 1, false) == -1
+; run: %isubbin_i8(100, 20, true) == 79
+; run: %isubbin_i8(100, 20, false) == 80
+; run: %isubbin_i8(-128, 1, true) == 126
+; run: %isubbin_i8(-128, 1, false) == 127
+
+function %isubbin_i16(i16, i16, b1) -> i16 {
+block0(v0: i16, v1: i16, v2: b1):
+    v3 = isub_bin v0, v1, v2
+    return v3
+}
+; run: %isubbin_i16(0, 1, true) == -2
+; run: %isubbin_i16(0, 1, false) == -1
+; run: %isubbin_i16(100, 20, true) == 79
+; run: %isubbin_i16(100, 20, false) == 80
+; run: %isubbin_i16(-32768, 1, true) == 32766
+; run: %isubbin_i16(-32768, 1, false) == 32767
+
+function %isubbin_i32(i32, i32, b1) -> i32 {
+block0(v0: i32, v1: i32, v2: b1):
+    v3 = isub_bin v0, v1, v2
+    return v3
+}
+; run: %isubbin_i32(0, 1, true) == -2
+; run: %isubbin_i32(0, 1, false) == -1
+; run: %isubbin_i32(100, 20, true) == 79
+; run: %isubbin_i32(100, 20, false) == 80
+; run: %isubbin_i32(-2147483648, 1, true) == 2147483646
+; run: %isubbin_i32(-2147483648, 1, false) == 2147483647
+
+function %isubbin_i64(i64, i64, b1) -> i64 {
+block0(v0: i64, v1: i64, v2: b1):
+    v3 = isub_bin v0, v1, v2
+    return v3
+}
+; run: %isubbin_i64(0, 1, true) == -2
+; run: %isubbin_i64(0, 1, false) == -1
+; run: %isubbin_i64(100, 20, true) == 79
+; run: %isubbin_i64(100, 20, false) == 80
+; run: %isubbin_i64(-2147483648, 1, true) == -2147483650
+; run: %isubbin_i64(-2147483648, 1, false) == -2147483649
\ No newline at end of file
diff --git a/cranelift/filetests/filetests/runtests/isubborrow.clif b/cranelift/filetests/filetests/runtests/isubborrow.clif
new file mode 100644
index 0000000000..cf1f2fd5a3
--- /dev/null
+++ b/cranelift/filetests/filetests/runtests/isubborrow.clif
@@ -0,0 +1,98 @@
+test interpret
+
+function %isubborrow_i8_v(i8, i8, b1) -> i8 {
+block0(v0: i8, v1: i8, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v3
+}
+; run: %isubborrow_i8_v(0, 1, true) == -2
+; run: %isubborrow_i8_v(0, 1, false) == -1
+; run: %isubborrow_i8_v(100, 20, true) == 79
+; run: %isubborrow_i8_v(100, 20, false) == 80
+; run: %isubborrow_i8_v(127, 127, true) == -1
+; run: %isubborrow_i8_v(127, 127, false) == 0
+
+function %isubborrow_i8_c(i8, i8, b1) -> b1 {
+block0(v0: i8, v1: i8, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v4
+}
+; run: %isubborrow_i8_c(0, 1, true) == true
+; run: %isubborrow_i8_c(0, 1, false) == true
+; run: %isubborrow_i8_c(100, 20, true) == false
+; run: %isubborrow_i8_c(100, 20, false) == false
+; run: %isubborrow_i8_c(127, 127, true) == false
+; run: %isubborrow_i8_c(127, 127, false) == false
+
+function %isubborrow_i16_v(i16, i16, b1) -> i16 {
+block0(v0: i16, v1: i16, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v3
+}
+; run: %isubborrow_i16_v(0, 1, true) == -2
+; run: %isubborrow_i16_v(0, 1, false) == -1
+; run: %isubborrow_i16_v(100, 20, true) == 79
+; run: %isubborrow_i16_v(100, 20, false) == 80
+; run: %isubborrow_i16_v(-32000, 768, true) == 32767
+; run: %isubborrow_i16_v(-32000, 768, false) == -32768
+
+function %isubborrow_i16_c(i16, i16, b1) -> b1 {
+block0(v0: i16, v1: i16, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v4
+}
+; run: %isubborrow_i16_c(0, 1, true) == true
+; run: %isubborrow_i16_c(0, 1, false) == true
+; run: %isubborrow_i16_c(100, 20, true) == false
+; run: %isubborrow_i16_c(100, 20, false) == false
+; run: %isubborrow_i16_c(-32000, 768, true) == true
+; run: %isubborrow_i16_c(-32000, 768, false) == true
+
+function %isubborrow_i32_v(i32, i32, b1) -> i32 {
+block0(v0: i32, v1: i32, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v3
+}
+; run: %isubborrow_i32_v(0, 1, true) == -2
+; run: %isubborrow_i32_v(0, 1, false) == -1
+; run: %isubborrow_i32_v(100, 20, true) == 79
+; run: %isubborrow_i32_v(100, 20, false) == 80
+; run: %isubborrow_i32_v(-2147483640, 8, true) == 2147483647
+; run: %isubborrow_i32_v(-2147483640, 8, false) == -2147483648
+
+function %isubborrow_i32_c(i32, i32, b1) -> b1 {
+block0(v0: i32, v1: i32, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v4
+}
+; run: %isubborrow_i32_c(0, 1, true) == true
+; run: %isubborrow_i32_c(0, 1, false) == true
+; run: %isubborrow_i32_c(100, 20, true) == false
+; run: %isubborrow_i32_c(100, 20, false) == false
+; run: %isubborrow_i32_c(-2147483640, 8, true) == true
+; run: %isubborrow_i32_c(-2147483640, 8, false) == true
+
+
+function %isubborrow_i64_v(i64, i64, b1) -> i64 {
+block0(v0: i64, v1: i64, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v3
+}
+; run: %isubborrow_i64_v(0, 1, true) == -2
+; run: %isubborrow_i64_v(0, 1, false) == -1
+; run: %isubborrow_i64_v(100, 20, true) == 79
+; run: %isubborrow_i64_v(100, 20, false) == 80
+; run: %isubborrow_i64_v(-9223372036854775800, 8, true) == 9223372036854775807
+; run: %isubborrow_i64_v(-9223372036854775800, 8, false) == -9223372036854775808
+
+function %isubborrow_i64_c(i64, i64, b1) -> b1 {
+block0(v0: i64, v1: i64, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v4
+}
+; run: %isubborrow_i64_c(0, 1, true) == true
+; run: %isubborrow_i64_c(0, 1, false) == true
+; run: %isubborrow_i64_c(100, 20, true) == false
+; run: %isubborrow_i64_c(100, 20, false) == false
+; run: %isubborrow_i64_c(-9223372036854775800, 8, true) == true
+; run: %isubborrow_i64_c(-9223372036854775800, 8, false) == true
diff --git a/cranelift/filetests/filetests/runtests/isubbout.clif b/cranelift/filetests/filetests/runtests/isubbout.clif
new file mode 100644
index 0000000000..db07b1a6f3
--- /dev/null
+++ b/cranelift/filetests/filetests/runtests/isubbout.clif
@@ -0,0 +1,87 @@
+test interpret
+
+function %isubbout_i8_v(i8, i8) -> i8 {
+block0(v0: i8, v1: i8):
+    v2, v3 = isub_bout v0, v1
+    return v2
+}
+; run: %isubbout_i8_v(0, 1) == -1
+; run: %isubbout_i8_v(100, 20) == 80
+; run: %isubbout_i8_v(100, -20) == 120
+; run: %isubbout_i8_v(-128, 1) == 127
+
+function %isubbout_i8_c(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    v2, v3 = isub_bout v0, v1
+    return v3
+}
+; run: %isubbout_i8_c(0, 1) == true
+; run: %isubbout_i8_c(100, 20) == false
+; run: %isubbout_i8_c(100, -20) == false
+; run: %isubbout_i8_c(-128, 1) == true
+
+function %isubbout_i16_v(i16, i16) -> i16 {
+block0(v0: i16, v1: i16):
+    v2, v3 = isub_bout v0, v1
+    return v2
+}
+; run: %isubbout_i16_v(0, 1) == -1
+; run: %isubbout_i16_v(100, 20) == 80
+; run: %isubbout_i16_v(100, -28) == 128
+; run: %isubbout_i16_v(-32000, 768) == -32768
+; run: %isubbout_i16_v(-32000, 769) == 32767
+
+function %isubbout_i16_c(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    v2, v3 = isub_bout v0, v1
+    return v3
+}
+; run: %isubbout_i16_c(0, 1) == true
+; run: %isubbout_i16_c(100, 20) == false
+; run: %isubbout_i16_c(100, -28) == false
+; run: %isubbout_i16_c(-32000, 768) == true
+; run: %isubbout_i16_c(-32000, 769) == true
+
+function %isubbout_i32_v(i32, i32) -> i32 {
+block0(v0: i32, v1: i32):
+    v2, v3 = isub_bout v0, v1
+    return v2
+}
+; run: %isubbout_i32_v(0, 1) == -1
+; run: %isubbout_i32_v(100, 20) == 80
+; run: %isubbout_i32_v(100, -28) == 128
+; run: %isubbout_i32_v(-2147483640, 8) == -2147483648
+; run: %isubbout_i32_v(-2147483640, 9) == 2147483647
+
+function %isubbout_i32_c(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    v2, v3 = isub_bout v0, v1
+    return v3
+}
+; run: %isubbout_i32_c(0, 1) == true
+; run: %isubbout_i32_c(100, 20) == false
+; run: %isubbout_i32_c(100, -28) == false
+; run: %isubbout_i32_c(-2147483640, 8) == true
+; run: %isubbout_i32_c(-2147483640, 9) == true
+
+function %isubbout_i64_v(i64, i64) -> i64 {
+block0(v0: i64, v1: i64):
+    v2, v3 = isub_bout v0, v1
+    return v2
+}
+; run: %isubbout_i64_v(0, 1) == -1
+; run: %isubbout_i64_v(100, 20) == 80
+; run: %isubbout_i64_v(100, -28) == 128
+; run: %isubbout_i64_v(-2147483640, 8) == -2147483648
+; run: %isubbout_i64_v(-2147483640, 9) == -2147483649
+
+function %isubbout_i64_c(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    v2, v3 = isub_bout v0, v1
+    return v3
+}
+; run: %isubbout_i64_c(0, 1) == true
+; run: %isubbout_i64_c(100, 20) == false
+; run: %isubbout_i64_c(100, -28) == false
+; run: %isubbout_i64_c(-2147483640, 8) == true
+; run: %isubbout_i64_c(-2147483640, 9) == true
\ No newline at end of file
diff --git a/cranelift/interpreter/src/step.rs b/cranelift/interpreter/src/step.rs
index f9dd882357..277ad1db0b 100644
--- a/cranelift/interpreter/src/step.rs
+++ b/cranelift/interpreter/src/step.rs
@@ -550,11 +550,28 @@ where
             assign_multiple(&[sum, Value::bool(carry, types::B1)?])
         }
         Opcode::IaddIfcarry => unimplemented!("IaddIfcarry"),
-        Opcode::IsubBin => unimplemented!("IsubBin"),
+        Opcode::IsubBin => choose(
+            Value::into_bool(arg(2)?)?,
+            Value::sub(arg(0)?, Value::add(arg(1)?, Value::int(1, ctrl_ty)?)?)?,
+            Value::sub(arg(0)?, arg(1)?)?,
+        ),
         Opcode::IsubIfbin => unimplemented!("IsubIfbin"),
-        Opcode::IsubBout => unimplemented!("IsubBout"),
+        Opcode::IsubBout => {
+            let sum = Value::sub(arg(0)?, arg(1)?)?;
+            let borrow = Value::lt(&arg(0)?, &arg(1)?)?;
+            assign_multiple(&[sum, Value::bool(borrow, types::B1)?])
+        }
         Opcode::IsubIfbout => unimplemented!("IsubIfbout"),
-        Opcode::IsubBorrow => unimplemented!("IsubBorrow"),
+        Opcode::IsubBorrow => {
+            let rhs = if Value::into_bool(arg(2)?)? {
+                Value::add(arg(1)?, Value::int(1, ctrl_ty)?)?
+            } else {
+                arg(1)?
+            };
+            let borrow = Value::lt(&arg(0)?, &rhs)?;
+            let sum = Value::sub(arg(0)?, rhs)?;
+            assign_multiple(&[sum, Value::bool(borrow, types::B1)?])
+        }
         Opcode::IsubIfborrow => unimplemented!("IsubIfborrow"),
         Opcode::Band => binary(Value::and, arg(0)?, arg(1)?)?,
         Opcode::Bor => binary(Value::or, arg(0)?, arg(1)?)?,