1 //! Peephole optimizations that can be performed while creating clif ir.
3 use cranelift_codegen::ir::{condcodes::IntCC, InstructionData, Opcode, Value, ValueDef};
4 use cranelift_frontend::FunctionBuilder;
6 /// If the given value was produced by the lowering of `Rvalue::Not` return the input and true,
7 /// otherwise return the given value and false.
8 pub(crate) fn maybe_unwrap_bool_not(bcx: &mut FunctionBuilder<'_>, arg: Value) -> (Value, bool) {
9 if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
10 match bcx.func.dfg[arg_inst] {
11 // This is the lowering of `Rvalue::Not`
12 InstructionData::IntCompareImm {
13 opcode: Opcode::IcmpImm,
17 } if imm.bits() == 0 => (arg, true),
25 /// Returns whether the branch is statically known to be taken or `None` if it isn't statically known.
26 pub(crate) fn maybe_known_branch_taken(
27 bcx: &FunctionBuilder<'_>,
31 let arg_inst = if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
37 match bcx.func.dfg[arg_inst] {
38 InstructionData::UnaryImm { opcode: Opcode::Iconst, imm } => {