machinst x64: add support for rotations;

cranelift/codegen/src/isa/x64/inst/args.rs

@@ -509,6 +509,8 @@ pub enum ShiftKind {
     Left,
     RightZ,
     RightS,
+    RotateLeft,
+    RotateRight,
 }
 
 impl fmt::Debug for ShiftKind {
@@ -517,6 +519,8 @@ impl fmt::Debug for ShiftKind {
             ShiftKind::Left => "shl",
             ShiftKind::RightZ => "shr",
             ShiftKind::RightS => "sar",
+            ShiftKind::RotateLeft => "rol",
+            ShiftKind::RotateRight => "ror",
         };
         write!(fmt, "{}", name)
     }

cranelift/codegen/src/isa/x64/inst/emit.rs

@@ -925,6 +925,8 @@ pub(crate) fn emit(
         } => {
             let enc_dst = int_reg_enc(dst.to_reg());
             let subopcode = match kind {
+                ShiftKind::RotateLeft => 0,
+                ShiftKind::RotateRight => 1,
                 ShiftKind::Left => 4,
                 ShiftKind::RightZ => 5,
                 ShiftKind::RightS => 7,

cranelift/codegen/src/isa/x64/inst/emit_tests.rs

@@ -2258,6 +2258,26 @@ fn test_x64_emit() {
         "49C1FD3F",
         "sarq    $63, %r13",
     ));
+    insns.push((
+        Inst::shift_r(true, ShiftKind::RotateLeft, None, w_r8),
+        "49D3C0",
+        "rolq    %cl, %r8",
+    ));
+    insns.push((
+        Inst::shift_r(false, ShiftKind::RotateLeft, Some(3), w_r9),
+        "41C1C103",
+        "roll    $3, %r9d",
+    ));
+    insns.push((
+        Inst::shift_r(false, ShiftKind::RotateRight, None, w_rsi),
+        "D3CE",
+        "rorl    %cl, %esi",
+    ));
+    insns.push((
+        Inst::shift_r(true, ShiftKind::RotateRight, Some(5), w_r15),
+        "49C1CF05",
+        "rorq    $5, %r15",
+    ));
 
     // ========================================================
     // CmpRMIR