clarify inaccurate 32/16-bit `call/jmp [mem]` mem_size

3 files changed, 12 insertions, 2 deletions

diff --git a/test/long_mode/operand.rs b/test/long_mode/operand.rs
index 4cdaf35..a47e6c8 100644
--- a/test/long_mode/operand.rs
+++ b/test/long_mode/operand.rs
@@ -45,4 +45,7 @@ fn test_implied_memory_width() {
     assert_eq!(mem_size_of(&[0x66, 0x58]), Some(8));
     assert_eq!(mem_size_of(&[0xff, 0xf0]), Some(8));
     assert_eq!(mem_size_of(&[0x66, 0xff, 0xf0]), Some(2));
+    // operand-size prefixed call and jump still reads 8 bytes (prefix ignored)
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x10]), Some(8));
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x20]), Some(8));
 }
diff --git a/test/protected_mode/operand.rs b/test/protected_mode/operand.rs
index a114e69..6eb9ba5 100644
--- a/test/protected_mode/operand.rs
+++ b/test/protected_mode/operand.rs
@@ -43,4 +43,8 @@ fn test_implied_memory_width() {
     assert_eq!(mem_size_of(&[0x66, 0x58]), Some(4));
     assert_eq!(mem_size_of(&[0xff, 0xf0]), Some(4));
     assert_eq!(mem_size_of(&[0x66, 0xff, 0xf0]), Some(2));
+    // unlike 64-bit mode, operand-size prefixed call and jump do have a different size: they read
+    // two bytes.
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x10]), Some(2));
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x20]), Some(2));
 }
diff --git a/test/real_mode/operand.rs b/test/real_mode/operand.rs
index e037fee..7f2b72e 100644
--- a/test/real_mode/operand.rs
+++ b/test/real_mode/operand.rs
@@ -1,5 +1,4 @@
-use yaxpeax_x86::real_mode::{InstDecoder, Operand, RegSpec};
-use yaxpeax_x86::MemoryAccessSize;
+use yaxpeax_x86::real_mode::{InstDecoder};
 
 #[test]
 fn test_implied_memory_width() {
@@ -17,4 +16,8 @@ fn test_implied_memory_width() {
     assert_eq!(mem_size_of(&[0x66, 0x58]), Some(2));
     assert_eq!(mem_size_of(&[0xff, 0xf0]), Some(2));
     assert_eq!(mem_size_of(&[0x66, 0xff, 0xf0]), Some(4));
+    // unlike 64-bit mode, operand-size prefixed call and jump do have a different size: they read
+    // four bytes.
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x10]), Some(4));
+    assert_eq!(mem_size_of(&[0x66, 0xff, 0x20]), Some(4));
 }