Perlito5::X64::Assembler - add repmovs variants

fglock · Mar 24, 2013 · d2b88ac · d2b88ac
1 parent 54135fa
commit d2b88ac
Showing 1 changed file with 27 additions and 1 deletion.
diff --git a/src5/lib/Perlito5/X64/Assembler.pm b/src5/lib/Perlito5/X64/Assembler.pm
@@ -115,7 +115,11 @@ sub emitl {
 
 sub emit_rex_64 {
     my ($reg, $rm_reg) = @_;
-    if ( is_register($reg) && is_register($rm_reg) ) {
+    if ( !@_ ) {
+        # Emit a REX prefix that only sets REX.W to choose a 64-bit operand size.
+        emit(0x48);
+    }
+    elsif ( is_register($reg) && is_register($rm_reg) ) {
         emit(0x48 | $reg->high_bit() << 2 | $rm_reg->high_bit());
     }
     else {
@@ -211,6 +215,28 @@ sub _movsxlq {
     }
 }
 
+sub repmovsb() {
+    emit(0xF3);
+    emit(0xA4);
+}
+
+sub repmovsw() {
+    emit(0x66);    # Operand size override.
+    emit(0xF3);
+    emit(0xA4);
+}
+
+sub repmovsl() {
+    emit(0xF3);
+    emit(0xA5);
+}
+
+sub repmovsq() {
+    emit(0xF3);
+    emit_rex_64();
+    emit(0xA5);
+}
+
 sub _nop {
     emit(0x90);
 }