Method transplant_inst

cranelift/codegen/src/ir/function.rs:344–359

Replace the `dst` instruction's data with the `src` instruction's data and then remove `src`. `src` and its result values should not be used at all, as any uses would be left dangling after calling this method. `src` and `dst` must have the same number of resulting values, and `src`'s i^th value must have the same type as `dst`'s i^th value.

(&mut self, dst: Inst, src: Inst)

    /// `src` and `dst` must have the same number of resulting values, and
    /// `src`'s i^th value must have the same type as `dst`'s i^th value.
    pub fn transplant_inst(&mut self, dst: Inst, src: Inst) {
        debug_assert_eq!(
            self.dfg.inst_results(dst).len(),
            self.dfg.inst_results(src).len()
        );
        debug_assert!(
            self.dfg
                .inst_results(dst)
                .iter()
                .zip(self.dfg.inst_results(src))
                .all(|(a, b)| self.dfg.value_type(*a) == self.dfg.value_type(*b))
        );

        self.dfg.insts[dst] = self.dfg.insts[src];
        self.layout.remove_inst(src);
    }

    /// Size occupied by all stack slots associated with this function.
    ///