add bnot to peepmatic + transform rule

cranelift/codegen/src/peepmatic.rs

@@ -237,6 +237,7 @@ impl Opcode {
             BandImm,
             Bconst,
             Bint,
+            Bnot,
             Bor,
             BorImm,
             Brnz,
@@ -549,6 +550,11 @@ unsafe impl<'a, 'b> InstructionSet<'b> for &'a dyn TargetIsa {
                 let val = pos.ins().bint(ty, a);
                 pos.func.dfg.value_def(val).unwrap_inst().into()
             }
+            Operator::Bnot => {
+                let a = part_to_value(pos, root, a).unwrap();
+                let val = pos.ins().bnot(a);
+                pos.func.dfg.value_def(val).unwrap_inst().into()
+            }
             Operator::Brnz => {
                 let a = part_to_value(pos, root, a).unwrap();
 

cranelift/codegen/src/preopt.peepmatic

@@ -112,6 +112,7 @@
 
 ;; Replace with negative 1.
 (=> (bor_imm -1 $x) -1)
+(=> (bxor_imm -1 $x) (bnot $x))
 
 ;; Transform `[(x << N) >> N]` into a (un)signed-extending move.
 ;;

cranelift/peepmatic/crates/runtime/src/operator.rs

@@ -45,6 +45,10 @@ pub enum Operator {
     #[peepmatic(params(bNN), result(iNN))]
     Bint,
 
+    /// `bnot`
+    #[peepmatic(params(iNN), result(iNN))]
+    Bnot,
+
     /// `bor`
     #[peepmatic(params(iNN, iNN), result(iNN))]
     Bor,