diff --git a/cranelift/codegen/meta/src/gen_inst.rs b/cranelift/codegen/meta/src/gen_inst.rs
new file mode 100644
index 0000000000..c975cef961
--- /dev/null
+++ b/cranelift/codegen/meta/src/gen_inst.rs
@@ -0,0 +1,1092 @@
+use crate::cdsl::camel_case;
+use crate::cdsl::formats::{FormatRegistry, InstructionFormat};
+use crate::cdsl::inst::{Instruction, InstructionGroup};
+use crate::cdsl::operands::Operand;
+use crate::cdsl::typevar::{TypeSet, TypeVar};
+use crate::constant_hash;
+use crate::error;
+use crate::srcgen::{Formatter, Match};
+use crate::unique_table::{UniqueSeqTable, UniqueTable};
+
+use std::fmt;
+
+// TypeSet indexes are encoded in 8 bits, with `0xff` reserved.
+const TYPESET_LIMIT: usize = 0xff;
+
+/// Generate an instruction format enumeration.
+fn gen_formats(registry: &FormatRegistry, fmt: &mut Formatter) {
+    fmt.doc_comment(
+        r#"
+        An instruction format
+
+        Every opcode has a corresponding instruction format
+        which is represented by both the `InstructionFormat`
+        and the `InstructionData` enums.
+    "#,
+    );
+    fmt.line("#[derive(Copy, Clone, PartialEq, Eq, Debug)]");
+    fmt.line("pub enum InstructionFormat {");
+    fmt.indent(|fmt| {
+        for format in registry.iter() {
+            fmt.doc_comment(format.to_string());
+            fmtln!(fmt, "{},", format.name);
+        }
+    });
+    fmt.line("}");
+    fmt.empty_line();
+
+    // Emit a From<InstructionData> which also serves to verify that
+    // InstructionFormat and InstructionData are in sync.
+    fmt.line("impl<'a> From<&'a InstructionData> for InstructionFormat {");
+    fmt.indent(|fmt| {
+        fmt.line("fn from(inst: &'a InstructionData) -> Self {");
+        fmt.indent(|fmt| {
+            let mut m = Match::new("*inst");
+            for format in registry.iter() {
+                m.arm(
+                    format!("InstructionData::{}", format.name),
+                    vec![".."],
+                    format!("InstructionFormat::{}", format.name),
+                );
+            }
+            fmt.add_match(m);
+        });
+        fmt.line("}");
+    });
+    fmt.line("}");
+    fmt.empty_line();
+}
+
+/// Generate the InstructionData enum.
+///
+/// Every variant must contain an `opcode` field. The size of `InstructionData` should be kept at
+/// 16 bytes on 64-bit architectures. If more space is needed to represent an instruction, use a
+/// `ValueList` to store the additional information out of line.
+fn gen_instruction_data(registry: &FormatRegistry, fmt: &mut Formatter) {
+    fmt.line("#[derive(Clone, Debug)]");
+    fmt.line("#[allow(missing_docs)]");
+    fmt.line("pub enum InstructionData {");
+    fmt.indent(|fmt| {
+        for format in registry.iter() {
+            fmtln!(fmt, "{} {{", format.name);
+            fmt.indent(|fmt| {
+                fmt.line("opcode: Opcode,");
+                if format.typevar_operand.is_some() {
+                    if format.has_value_list {
+                        fmt.line("args: ValueList,");
+                    } else if format.num_value_operands == 1 {
+                        fmt.line("arg: Value,");
+                    } else {
+                        fmtln!(fmt, "args: [Value; {}],", format.num_value_operands);
+                    }
+                }
+                for field in &format.imm_fields {
+                    fmtln!(fmt, "{}: {},", field.member, field.kind.rust_type);
+                }
+            });
+            fmtln!(fmt, "},");
+        }
+    });
+    fmt.line("}");
+}
+
+fn gen_arguments_method(registry: &FormatRegistry, fmt: &mut Formatter, is_mut: bool) {
+    let (method, mut_, rslice, as_slice) = if is_mut {
+        ("arguments_mut", "mut ", "ref_slice_mut", "as_mut_slice")
+    } else {
+        ("arguments", "", "ref_slice", "as_slice")
+    };
+
+    fmtln!(
+        fmt,
+        "pub fn {}<'a>(&'a {}self, pool: &'a {}ir::ValueListPool) -> &{}[Value] {{",
+        method,
+        mut_,
+        mut_,
+        mut_
+    );
+    fmt.indent(|fmt| {
+        let mut m = Match::new("*self");
+        for format in registry.iter() {
+            let name = format!("InstructionData::{}", format.name);
+
+            // Formats with a value list put all of their arguments in the list. We don't split
+            // them up, just return it all as variable arguments. (I expect the distinction to go
+            // away).
+            if format.has_value_list {
+                m.arm(
+                    name,
+                    vec![format!("ref {}args", mut_), "..".to_string()],
+                    format!("args.{}(pool)", as_slice),
+                );
+                continue;
+            }
+
+            // Fixed args.
+            let mut fields = Vec::new();
+            let arg = if format.num_value_operands == 0 {
+                format!("&{}[]", mut_)
+            } else if format.num_value_operands == 1 {
+                fields.push(format!("ref {}arg", mut_));
+                format!("{}(arg)", rslice)
+            } else {
+                let arg = format!("args_arity{}", format.num_value_operands);
+                fields.push(format!("args: ref {}{}", mut_, arg));
+                arg
+            };
+            fields.push("..".into());
+
+            m.arm(name, fields, arg);
+        }
+        fmt.add_match(m);
+    });
+    fmtln!(fmt, "}");
+}
+
+/// Generate the boring parts of the InstructionData implementation.
+///
+/// These methods in `impl InstructionData` can be generated automatically from the instruction
+/// formats:
+///
+/// - `pub fn opcode(&self) -> Opcode`
+/// - `pub fn arguments(&self, &pool) -> &[Value]`
+/// - `pub fn arguments_mut(&mut self, &pool) -> &mut [Value]`
+/// - `pub fn take_value_list(&mut self) -> Option<ir::ValueList>`
+/// - `pub fn put_value_list(&mut self, args: ir::ValueList>`
+/// - `pub fn eq(&self, &other: Self, &pool) -> bool`
+/// - `pub fn hash<H: Hasher>(&self, state: &mut H, &pool)`
+fn gen_instruction_data_impl(registry: &FormatRegistry, fmt: &mut Formatter) {
+    fmt.line("impl InstructionData {");
+    fmt.indent(|fmt| {
+        fmt.doc_comment("Get the opcode of this instruction.");
+        fmt.line("pub fn opcode(&self) -> Opcode {");
+        fmt.indent(|fmt| {
+            let mut m = Match::new("*self");
+            for format in registry.iter() {
+                m.arm(format!("InstructionData::{}", format.name), vec!["opcode", ".."],
+                      "opcode".to_string());
+            }
+            fmt.add_match(m);
+        });
+        fmt.line("}");
+        fmt.empty_line();
+
+        fmt.doc_comment("Get the controlling type variable operand.");
+        fmt.line("pub fn typevar_operand(&self, pool: &ir::ValueListPool) -> Option<Value> {");
+        fmt.indent(|fmt| {
+            let mut m = Match::new("*self");
+            for format in registry.iter() {
+                let name = format!("InstructionData::{}", format.name);
+                if format.typevar_operand.is_none() {
+                    m.arm(name, vec![".."], "None".to_string());
+                } else if format.has_value_list {
+                    // We keep all arguments in a value list.
+                    m.arm(name, vec!["ref args", ".."], format!("args.get({}, pool)", format.typevar_operand.unwrap()));
+                } else if format.num_value_operands == 1 {
+                    m.arm(name, vec!["arg", ".."], "Some(arg)".to_string());
+                } else {
+                    // We have multiple value operands and an array `args`.
+                    // Which `args` index to use?
+                    let args = format!("args_arity{}", format.num_value_operands);
+                    m.arm(name, vec![format!("args: ref {}", args), "..".to_string()],
+                        format!("Some({}[{}])", args, format.typevar_operand.unwrap()));
+                }
+            }
+            fmt.add_match(m);
+        });
+        fmt.line("}");
+        fmt.empty_line();
+
+        fmt.doc_comment("Get the value arguments to this instruction.");
+        gen_arguments_method(registry, fmt, false);
+        fmt.empty_line();
+
+        fmt.doc_comment(r#"Get mutable references to the value arguments to this
+                        instruction."#);
+        gen_arguments_method(registry, fmt, true);
+        fmt.empty_line();
+
+        fmt.doc_comment(r#"
+            Take out the value list with all the value arguments and return
+            it.
+
+            This leaves the value list in the instruction empty. Use
+            `put_value_list` to put the value list back.
+        "#);
+        fmt.line("pub fn take_value_list(&mut self) -> Option<ir::ValueList> {");
+        fmt.indent(|fmt| {
+            let mut m = Match::new("*self");
+
+            for format in registry.iter() {
+                if format.has_value_list {
+                    m.arm(format!("InstructionData::{}", format.name),
+                    vec!["ref mut args", ".."],
+                    "Some(args.take())".to_string());
+                }
+            }
+
+            m.arm_no_fields("_", "None");
+
+            fmt.add_match(m);
+        });
+        fmt.line("}");
+        fmt.empty_line();
+
+        fmt.doc_comment(r#"
+            Put back a value list.
+
+            After removing a value list with `take_value_list()`, use this
+            method to put it back. It is required that this instruction has
+            a format that accepts a value list, and that the existing value
+            list is empty. This avoids leaking list pool memory.
+        "#);
+        fmt.line("pub fn put_value_list(&mut self, vlist: ir::ValueList) {");
+        fmt.indent(|fmt| {
+            fmt.line("let args = match *self {");
+            fmt.indent(|fmt| {
+                for format in registry.iter() {
+                    if format.has_value_list {
+                        fmtln!(fmt, "InstructionData::{} {{ ref mut args, .. }} => args,", format.name);
+                    }
+                }
+                fmt.line("_ => panic!(\"No value list: {:?}\", self),");
+            });
+            fmt.line("};");
+            fmt.line("debug_assert!(args.is_empty(), \"Value list already in use\");");
+            fmt.line("*args = vlist;");
+        });
+        fmt.line("}");
+        fmt.empty_line();
+
+        fmt.doc_comment(r#"
+            Compare two `InstructionData` for equality.
+
+            This operation requires a reference to a `ValueListPool` to
+            determine if the contents of any `ValueLists` are equal.
+        "#);
+        fmt.line("pub fn eq(&self, other: &Self, pool: &ir::ValueListPool) -> bool {");
+        fmt.indent(|fmt| {
+            fmt.line("if ::core::mem::discriminant(self) != ::core::mem::discriminant(other) {");
+            fmt.indent(|fmt| {
+                fmt.line("return false;");
+            });
+            fmt.line("}");
+
+            fmt.line("match (self, other) {");
+            fmt.indent(|fmt| {
+                for format in registry.iter() {
+                    let name = format!("&InstructionData::{}", format.name);
+                    let mut members = vec!["opcode"];
+
+                    let args_eq = if format.typevar_operand.is_none() {
+                        None
+                    } else if format.has_value_list {
+                        members.push("args");
+                        Some("args1.as_slice(pool) == args2.as_slice(pool)")
+                    } else if format.num_value_operands == 1 {
+                        members.push("arg");
+                        Some("arg1 == arg2")
+                    } else {
+                        members.push("args");
+                        Some("args1 == args2")
+                    };
+
+                    for field in &format.imm_fields {
+                        members.push(field.member);
+                    }
+
+                    let pat1 = members.iter().map(|x| format!("{}: ref {}1", x, x)).collect::<Vec<_>>().join(", ");
+                    let pat2 = members.iter().map(|x| format!("{}: ref {}2", x, x)).collect::<Vec<_>>().join(", ");
+                    fmtln!(fmt, "({} {{ {} }}, {} {{ {} }}) => {{", name, pat1, name, pat2);
+                    fmt.indent(|fmt| {
+                        fmt.line("opcode1 == opcode2");
+                        for field in &format.imm_fields {
+                            fmtln!(fmt, "&& {}1 == {}2", field.member, field.member);
+                        }
+                        if let Some(args_eq) = args_eq {
+                            fmtln!(fmt, "&& {}", args_eq);
+                        }
+                    });
+                    fmtln!(fmt, "}");
+                }
+                fmt.line("_ => unreachable!()");
+            });
+            fmt.line("}");
+        });
+        fmt.line("}");
+        fmt.empty_line();
+
+        fmt.doc_comment(r#"
+            Hash an `InstructionData`.
+
+            This operation requires a reference to a `ValueListPool` to
+            hash the contents of any `ValueLists`.
+        "#);
+        fmt.line("pub fn hash<H: ::core::hash::Hasher>(&self, state: &mut H, pool: &ir::ValueListPool) {");
+        fmt.indent(|fmt| {
+            fmt.line("match *self {");
+            fmt.indent(|fmt| {
+                for format in registry.iter() {
+                    let name = format!("InstructionData::{}", format.name);
+                    let mut members = vec!["opcode"];
+
+                    let args = if format.typevar_operand.is_none() {
+                        "&()"
+                    } else if format.has_value_list {
+                        members.push("ref args");
+                        "args.as_slice(pool)"
+                    } else if format.num_value_operands == 1 {
+                        members.push("ref arg");
+                        "arg"
+                    } else {
+                        members.push("ref args");
+                        "args"
+                    };
+
+                    for field in &format.imm_fields {
+                        members.push(field.member);
+                    }
+                    let members = members.join(", ");
+
+                    fmtln!(fmt, "{}{{{}}} => {{", name, members ); // beware the moustaches
+                    fmt.indent(|fmt| {
+                        fmt.line("::core::hash::Hash::hash( &::core::mem::discriminant(self), state);");
+                        fmt.line("::core::hash::Hash::hash(&opcode, state);");
+                        for field in &format.imm_fields {
+                            fmtln!(fmt, "::core::hash::Hash::hash(&{}, state);", field.member);
+                        }
+                        fmtln!(fmt, "::core::hash::Hash::hash({}, state);", args);
+                    });
+                    fmtln!(fmt, "}");
+                }
+            });
+            fmt.line("}");
+        });
+        fmt.line("}");
+    });
+    fmt.line("}");
+}
+
+fn gen_bool_accessor<T: Fn(&Instruction) -> bool>(
+    instruction_groups: &Vec<&InstructionGroup>,
+    get_attr: T,
+    name: &'static str,
+    doc: &'static str,
+    fmt: &mut Formatter,
+) {
+    fmt.doc_comment(doc);
+    fmtln!(fmt, "pub fn {}(self) -> bool {{", name);
+    fmt.indent(|fmt| {
+        let mut m = Match::new("self");
+        for group in instruction_groups.iter() {
+            for inst in group.iter() {
+                if get_attr(inst) {
+                    m.arm_no_fields(format!("Opcode::{}", inst.camel_name), "true");
+                }
+            }
+        }
+        m.arm_no_fields("_", "false");
+        fmt.add_match(m);
+    });
+    fmtln!(fmt, "}");
+    fmt.empty_line();
+}
+
+fn gen_opcodes<'a>(
+    formats: &FormatRegistry,
+    igroups: &Vec<&'a InstructionGroup>,
+    fmt: &mut Formatter,
+) -> Vec<&'a Instruction> {
+    let mut all_inst = Vec::new();
+    for group in igroups {
+        for inst in group.iter() {
+            all_inst.push(inst);
+        }
+    }
+
+    fmt.doc_comment(
+        r#"
+        An instruction opcode.
+
+        All instructions from all supported ISAs are present.
+    "#,
+    );
+    fmt.line("#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]");
+
+    // We explicitly set the discriminant of the first variant to 1, which allows us to take
+    // advantage of the NonZero optimization, meaning that wrapping enums can use the 0
+    // discriminant instead of increasing the size of the whole type, and so the size of
+    // Option<Opcode> is the same as Opcode's.
+    fmt.line("pub enum Opcode {");
+    fmt.indent(|fmt| {
+        let mut is_first_opcode = true;
+        for inst in &all_inst {
+            // TODO we might need to set an instruction number here. Probably can do in the
+            // InstructionGroup itself when adding instruction (would need to remember last
+            // instruction number in the SharedDefinitions or somewhere else).
+            let format = formats.get(inst.format);
+            fmt.doc_comment(format!("`{}`. ({})", inst, format.name));
+
+            // Document polymorphism.
+            if let Some(poly) = &inst.polymorphic_info {
+                if poly.use_typevar_operand {
+                    let op_num = inst.value_opnums[format.typevar_operand.unwrap()];
+                    fmt.doc_comment(format!(
+                        "Type inferred from `{}`.",
+                        inst.operands_in[op_num].name
+                    ));
+                }
+            }
+
+            // Enum variant itself.
+            if is_first_opcode {
+                fmtln!(fmt, "{} = 1,", inst.camel_name);
+                is_first_opcode = false;
+            } else {
+                fmtln!(fmt, "{},", inst.camel_name)
+            }
+        }
+    });
+    fmt.line("}");
+    fmt.empty_line();
+
+    fmt.line("impl Opcode {");
+    fmt.indent(|fmt| {
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_terminator,
+            "is_terminator",
+            "True for instructions that terminate the EBB",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_branch,
+            "is_branch",
+            "True for all branch or jump instructions.",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_indirect_branch,
+            "is_indirect_branch",
+            "True for all indirect branch or jump instructions.",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_call,
+            "is_call",
+            "Is this a call instruction?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_return,
+            "is_return",
+            "Is this a return instruction?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.is_ghost,
+            "is_ghost",
+            "Is this a ghost instruction?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.can_load,
+            "can_load",
+            "Can this instruction read from memory?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.can_store,
+            "can_store",
+            "Can this instruction write to memory?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.can_trap,
+            "can_trap",
+            "Can this instruction cause a trap?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.other_side_effects,
+            "other_side_effects",
+            "Does this instruction have other side effects besides can_* flags?",
+            fmt,
+        );
+        gen_bool_accessor(
+            igroups,
+            |inst| inst.writes_cpu_flags,
+            "writes_cpu_flags",
+            "Does this instruction write to CPU flags?",
+            fmt,
+        );
+    });
+    fmt.line("}");
+    fmt.empty_line();
+
+    // Generate a private opcode_format table.
+    fmtln!(
+        fmt,
+        "const OPCODE_FORMAT: [InstructionFormat; {}] = [",
+        all_inst.len()
+    );
+    fmt.indent(|fmt| {
+        for inst in &all_inst {
+            let format = formats.get(inst.format);
+            fmtln!(fmt, "InstructionFormat::{}, // {}", format.name, inst.name);
+        }
+    });
+    fmtln!(fmt, "];");
+    fmt.empty_line();
+
+    // Generate a private opcode_name function.
+    fmt.line("fn opcode_name(opc: Opcode) -> &\'static str {");
+    fmt.indent(|fmt| {
+        let mut m = Match::new("opc");
+        for inst in &all_inst {
+            m.arm_no_fields(
+                format!("Opcode::{}", inst.camel_name),
+                format!("\"{}\"", inst.name),
+            );
+        }
+        fmt.add_match(m);
+    });
+    fmt.line("}");
+    fmt.empty_line();
+
+    // Generate an opcode hash table for looking up opcodes by name.
+    let hash_table =
+        constant_hash::generate_table(&all_inst, |inst| constant_hash::simple_hash(inst.name));
+    fmtln!(
+        fmt,
+        "const OPCODE_HASH_TABLE: [Option<Opcode>; {}] = [",
+        hash_table.len()
+    );
+    fmt.indent(|fmt| {
+        for i in hash_table {
+            match i {
+                Some(i) => fmtln!(fmt, "Some(Opcode::{}),", i.camel_name),
+                None => fmtln!(fmt, "None,"),
+            }
+        }
+    });
+    fmtln!(fmt, "];");
+    fmt.empty_line();
+
+    all_inst
+}
+
+/// Get the value type constraint for an SSA value operand, where
+/// `ctrl_typevar` is the controlling type variable.
+///
+/// Each operand constraint is represented as a string, one of:
+/// - `Concrete(vt)`, where `vt` is a value type name.
+/// - `Free(idx)` where `idx` is an index into `type_sets`.
+/// - `Same`, `Lane`, `AsBool` for controlling typevar-derived constraints.
+fn get_constraint<'entries, 'table>(
+    operand: &'entries Operand,
+    ctrl_typevar: Option<&TypeVar>,
+    type_sets: &'table mut UniqueTable<'entries, TypeSet>,
+) -> String {
+    assert!(operand.is_value());
+    let type_var = operand.type_var().unwrap();
+
+    if let Some(typ) = type_var.singleton_type() {
+        return format!("Concrete({})", typ.rust_name());
+    }
+
+    if let Some(free_typevar) = type_var.free_typevar() {
+        if ctrl_typevar.is_some() && free_typevar != *ctrl_typevar.unwrap() {
+            assert!(type_var.base.is_none());
+            return format!("Free({})", type_sets.add(&type_var.get_raw_typeset()));
+        }
+    }
+
+    if let Some(base) = &type_var.base {
+        assert!(base.type_var == *ctrl_typevar.unwrap());
+        return camel_case(base.derived_func.name());
+    }
+
+    assert!(type_var == ctrl_typevar.unwrap());
+    return "Same".into();
+}
+
+fn gen_bitset<'a, T: IntoIterator<Item = &'a u16>>(
+    iterable: T,
+    name: &'static str,
+    field_size: u8,
+    fmt: &mut Formatter,
+) {
+    let bits = iterable.into_iter().fold(0, |acc, x| {
+        assert!(x.is_power_of_two());
+        assert!(u32::from(*x) < (1 << u32::from(field_size)));
+        acc | x
+    });
+    fmtln!(fmt, "{}: BitSet::<u{}>({}),", name, field_size, bits);
+}
+
+fn iterable_to_string<I: fmt::Display, T: IntoIterator<Item = I>>(iterable: T) -> String {
+    let elems = iterable
+        .into_iter()
+        .map(|x| x.to_string())
+        .collect::<Vec<_>>()
+        .join(", ");
+    format!("{{{}}}", elems)
+}
+
+fn typeset_to_string(ts: &TypeSet) -> String {
+    let mut result = format!("TypeSet(lanes={}", iterable_to_string(&ts.lanes));
+    if ts.ints.len() > 0 {
+        result += &format!(", ints={}", iterable_to_string(&ts.ints));
+    }
+    if ts.floats.len() > 0 {
+        result += &format!(", floats={}", iterable_to_string(&ts.floats));
+    }
+    if ts.bools.len() > 0 {
+        result += &format!(", bools={}", iterable_to_string(&ts.bools));
+    }
+    if ts.bitvecs.len() > 0 {
+        result += &format!(", bitvecs={}", iterable_to_string(&ts.bitvecs));
+    }
+    if ts.specials.len() > 0 {
+        result += &format!(", specials=[{}]", iterable_to_string(&ts.specials));
+    }
+    result += ")";
+    result
+}
+
+/// Generate the table of ValueTypeSets described by type_sets.
+fn gen_typesets_table(type_sets: &UniqueTable<TypeSet>, fmt: &mut Formatter) {
+    if type_sets.len() == 0 {
+        return;
+    }
+
+    fmt.comment("Table of value type sets.");
+    assert!(type_sets.len() <= TYPESET_LIMIT, "Too many type sets!");
+    fmtln!(
+        fmt,
+        "const TYPE_SETS: [ir::instructions::ValueTypeSet; {}] = [",
+        type_sets.len()
+    );
+    fmt.indent(|fmt| {
+        for ts in type_sets.iter() {
+            fmt.line("ir::instructions::ValueTypeSet {");
+            fmt.indent(|fmt| {
+                assert!(ts.bitvecs.len() == 0, "Bitvector types are not emittable.");
+                fmt.comment(typeset_to_string(ts));
+                gen_bitset(&ts.lanes, "lanes", 16, fmt);
+                gen_bitset(&ts.ints, "ints", 8, fmt);
+                gen_bitset(&ts.floats, "floats", 8, fmt);
+                gen_bitset(&ts.bools, "bools", 8, fmt);
+            });
+            fmt.line("},");
+        }
+    });
+    fmtln!(fmt, "];");
+}
+
+/// Generate value type constraints for all instructions.
+/// - Emit a compact constant table of ValueTypeSet objects.
+/// - Emit a compact constant table of OperandConstraint objects.
+/// - Emit an opcode-indexed table of instruction constraints.
+fn gen_type_constraints(all_inst: &Vec<&Instruction>, fmt: &mut Formatter) {
+    // Table of TypeSet instances.
+    let mut type_sets = UniqueTable::new();
+
+    // Table of operand constraint sequences (as tuples). Each operand
+    // constraint is represented as a string, one of:
+    // - `Concrete(vt)`, where `vt` is a value type name.
+    // - `Free(idx)` where `idx` is an index into `type_sets`.
+    // - `Same`, `Lane`, `AsBool` for controlling typevar-derived constraints.
+    let mut operand_seqs = UniqueSeqTable::new();
+
+    // Preload table with constraints for typical binops.
+    operand_seqs.add(&vec!["Same".to_string(); 3]);
+
+    fmt.comment("Table of opcode constraints.");
+    fmtln!(
+        fmt,
+        "const OPCODE_CONSTRAINTS: [OpcodeConstraints; {}] = [",
+        all_inst.len()
+    );
+    fmt.indent(|fmt| {
+        for inst in all_inst {
+            let (ctrl_typevar, ctrl_typeset) = if let Some(poly) = &inst.polymorphic_info {
+                let index = type_sets.add(&*poly.ctrl_typevar.get_raw_typeset());
+                (Some(&poly.ctrl_typevar), index)
+            } else {
+                (None, TYPESET_LIMIT)
+            };
+
+            // Collect constraints for the value results, not including `variable_args` results
+            // which are always special cased.
+            let mut constraints = Vec::new();
+            for &index in &inst.value_results {
+                constraints.push(get_constraint(&inst.operands_out[index], ctrl_typevar, &mut type_sets));
+            }
+            for &index in &inst.value_opnums {
+                constraints.push(get_constraint(&inst.operands_in[index], ctrl_typevar, &mut type_sets));
+            }
+
+            let constraint_offset = operand_seqs.add(&constraints);
+
+            let fixed_results = inst.value_results.len();
+            let fixed_values = inst.value_opnums.len();
+
+            // Can the controlling type variable be inferred from the designated operand?
+            let use_typevar_operand = if let Some(poly) = &inst.polymorphic_info {
+                poly.use_typevar_operand
+            } else {
+                false
+            };
+
+            // Can the controlling type variable be inferred from the result?
+            let use_result = fixed_results > 0 && inst.operands_out[inst.value_results[0]].type_var() == ctrl_typevar;
+
+            // Are we required to use the designated operand instead of the result?
+            let requires_typevar_operand = use_typevar_operand && !use_result;
+
+            fmt.comment(
+                format!("{}: fixed_results={}, use_typevar_operand={}, requires_typevar_operand={}, fixed_values={}",
+                inst.camel_name,
+                fixed_results,
+                use_typevar_operand,
+                requires_typevar_operand,
+                fixed_values)
+            );
+            fmt.comment(format!("Constraints=[{}]", constraints
+                .iter()
+                .map(|x| format!("'{}'", x))
+                .collect::<Vec<_>>()
+                .join(", ")));
+            if let Some(poly) = &inst.polymorphic_info {
+                fmt.comment(format!("Polymorphic over {}", typeset_to_string(&poly.ctrl_typevar.get_raw_typeset())));
+            }
+
+            // Compute the bit field encoding, c.f. instructions.rs.
+            assert!(fixed_results < 8 && fixed_values < 8, "Bit field encoding too tight");
+            let mut flags = fixed_results; // 3 bits
+            if use_typevar_operand {
+                flags |= 1<<3; // 4th bit
+            }
+            if requires_typevar_operand {
+                flags |= 1<<4; // 5th bit
+            }
+            flags |= fixed_values << 5; // 6th bit and more
+
+            fmt.line("OpcodeConstraints {");
+            fmt.indent(|fmt| {
+                fmtln!(fmt, "flags: {:#04x},", flags);
+                fmtln!(fmt, "typeset_offset: {},", ctrl_typeset);
+                fmtln!(fmt, "constraint_offset: {},", constraint_offset);
+            });
+            fmt.line("},");
+        }
+    });
+    fmtln!(fmt, "];");
+    fmt.empty_line();
+
+    gen_typesets_table(&type_sets, fmt);
+    fmt.empty_line();
+
+    fmt.comment("Table of operand constraint sequences.");
+    fmtln!(
+        fmt,
+        "const OPERAND_CONSTRAINTS: [OperandConstraint; {}] = [",
+        operand_seqs.len()
+    );
+    fmt.indent(|fmt| {
+        for constraint in operand_seqs.iter() {
+            fmtln!(fmt, "OperandConstraint::{},", constraint);
+        }
+    });
+    fmtln!(fmt, "];");
+}
+
+/// Emit member initializers for an instruction format.
+fn gen_member_inits(format: &InstructionFormat, fmt: &mut Formatter) {
+    // Immediate operands.
+    // We have local variables with the same names as the members.
+    for f in &format.imm_fields {
+        fmtln!(fmt, "{},", f.member);
+    }
+
+    // Value operands.
+    if format.has_value_list {
+        fmt.line("args,");
+    } else if format.num_value_operands == 1 {
+        fmt.line("arg: arg0,");
+    } else if format.num_value_operands > 1 {
+        let mut args = Vec::new();
+        for i in 0..format.num_value_operands {
+            args.push(format!("arg{}", i));
+        }
+        fmtln!(fmt, "args: [{}],", args.join(", "));
+    }
+}
+
+/// Emit a method for creating and inserting an instruction format.
+///
+/// All instruction formats take an `opcode` argument and a `ctrl_typevar` argument for deducing
+/// the result types.
+fn gen_format_constructor(format: &InstructionFormat, fmt: &mut Formatter) {
+    // Construct method arguments.
+    let mut args = vec![
+        "self".to_string(),
+        "opcode: Opcode".into(),
+        "ctrl_typevar: Type".into(),
+    ];
+
+    // Normal operand arguments. Start with the immediate operands.
+    for f in &format.imm_fields {
+        args.push(format!("{}: {}", f.member, f.kind.rust_type));
+    }
+
+    // Then the value operands.
+    if format.has_value_list {
+        // Take all value arguments as a finished value list. The value lists
+        // are created by the individual instruction constructors.
+        args.push("args: ir::ValueList".into());
+    } else {
+        // Take a fixed number of value operands.
+        for i in 0..format.num_value_operands {
+            args.push(format!("arg{}: Value", i));
+        }
+    }
+
+    let proto = format!(
+        "{}({}) -> (Inst, &'f mut ir::DataFlowGraph)",
+        format.name,
+        args.join(", ")
+    );
+
+    fmt.doc_comment(format.to_string());
+    fmt.line("#[allow(non_snake_case)]");
+    fmtln!(fmt, "fn {} {{", proto);
+    fmt.indent(|fmt| {
+        // Generate the instruction data.
+        fmtln!(fmt, "let data = ir::InstructionData::{} {{", format.name);
+        fmt.indent(|fmt| {
+            fmt.line("opcode,");
+            gen_member_inits(format, fmt);
+        });
+        fmtln!(fmt, "};");
+        fmt.line("self.build(data, ctrl_typevar)");
+    });
+    fmtln!(fmt, "}");
+}
+
+/// Emit a method for generating the instruction `inst`.
+///
+/// The method will create and insert an instruction, then return the result values, or the
+/// instruction reference itself for instructions that don't have results.
+fn gen_inst_builder(inst: &Instruction, format: &InstructionFormat, fmt: &mut Formatter) {
+    // Construct method arguments.
+    let mut args = vec![if format.has_value_list {
+        "mut self"
+    } else {
+        "self"
+    }
+    .to_string()];
+
+    // The controlling type variable will be inferred from the input values if
+    // possible. Otherwise, it is the first method argument.
+    if let Some(poly) = &inst.polymorphic_info {
+        if !poly.use_typevar_operand {
+            args.push(format!("{}: crate::ir::Type", poly.ctrl_typevar.name));
+        }
+    }
+
+    let mut tmpl_types = Vec::new();
+    let mut into_args = Vec::new();
+    for op in &inst.operands_in {
+        let t = if op.is_pure_immediate() {
+            let t = format!("T{}{}", tmpl_types.len() + 1, op.kind.name);
+            tmpl_types.push(format!("{}: Into<{}>", t, op.kind.rust_type));
+            into_args.push(op.name);
+            t
+        } else {
+            op.kind.rust_type.clone()
+        };
+        args.push(format!("{}: {}", op.name, t));
+    }
+
+    let rtype = match inst.value_results.len() {
+        0 => "Inst".into(),
+        1 => "Value".into(),
+        _ => format!("({})", vec!["Value"; inst.value_results.len()].join(", ")),
+    };
+
+    let tmpl = if tmpl_types.len() > 0 {
+        format!("<{}>", tmpl_types.join(", "))
+    } else {
+        "".into()
+    };
+
+    let proto = format!(
+        "{}{}({}) -> {}",
+        inst.snake_name(),
+        tmpl,
+        args.join(", "),
+        rtype
+    );
+
+    fmt.doc_comment(format!("`{}`\n\n{}", inst, inst.doc_comment_first_line()));
+    fmt.line("#[allow(non_snake_case)]");
+    fmtln!(fmt, "fn {} {{", proto);
+    fmt.indent(|fmt| {
+        // Convert all of the `Into<>` arguments.
+        for arg in &into_args {
+            fmtln!(fmt, "let {} = {}.into();", arg, arg);
+        }
+
+        // Arguments for instruction constructor.
+        let first_arg = format!("Opcode::{}", inst.camel_name);
+        let mut args = vec![first_arg.as_str()];
+        if let Some(poly) = &inst.polymorphic_info {
+            if poly.use_typevar_operand {
+                // Infer the controlling type variable from the input operands.
+                let op_num = inst.value_opnums[format.typevar_operand.unwrap()];
+                fmtln!(
+                    fmt,
+                    "let ctrl_typevar = self.data_flow_graph().value_type({});",
+                    inst.operands_in[op_num].name
+                );
+
+                // The format constructor will resolve the result types from the type var.
+                args.push("ctrl_typevar");
+            } else {
+                // This was an explicit method argument.
+                args.push(&poly.ctrl_typevar.name);
+            }
+        } else {
+            // No controlling type variable needed.
+            args.push("types::INVALID");
+        }
+
+        // Now add all of the immediate operands to the constructor arguments.
+        for &op_num in &inst.imm_opnums {
+            args.push(inst.operands_in[op_num].name);
+        }
+
+        // Finally, the value operands.
+        if format.has_value_list {
+            // We need to build a value list with all the arguments.
+            fmt.line("let mut vlist = ir::ValueList::default();");
+            args.push("vlist");
+            fmt.line("{");
+            fmt.indent(|fmt| {
+                fmt.line("let pool = &mut self.data_flow_graph_mut().value_lists;");
+                for op in &inst.operands_in {
+                    if op.is_value() {
+                        fmtln!(fmt, "vlist.push({}, pool);", op.name);
+                    } else if op.is_varargs() {
+                        fmtln!(fmt, "vlist.extend({}.iter().cloned(), pool);", op.name);
+                    }
+                }
+            });
+            fmt.line("}");
+        } else {
+            // With no value list, we're guaranteed to just have a set of fixed value operands.
+            for &op_num in &inst.value_opnums {
+                args.push(inst.operands_in[op_num].name);
+            }
+        }
+
+        // Call to the format constructor,
+        let fcall = format!("self.{}({})", format.name, args.join(", "));
+
+        if inst.value_results.len() == 0 {
+            fmtln!(fmt, "{}.0", fcall);
+            return;
+        }
+
+        fmtln!(fmt, "let (inst, dfg) = {};", fcall);
+        if inst.value_results.len() == 1 {
+            fmt.line("dfg.first_result(inst)");
+        } else {
+            fmtln!(
+                fmt,
+                "let results = &dfg.inst_results(inst)[0..{}];",
+                inst.value_results.len()
+            );
+            fmtln!(
+                fmt,
+                "({})",
+                inst.value_results
+                    .iter()
+                    .enumerate()
+                    .map(|(i, _)| format!("results[{}]", i))
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            );
+        }
+    });
+    fmtln!(fmt, "}")
+}
+
+/// Generate a Builder trait with methods for all instructions.
+fn gen_builder(instructions: &Vec<&Instruction>, formats: &FormatRegistry, fmt: &mut Formatter) {
+    fmt.doc_comment(
+        r#"
+        Convenience methods for building instructions.
+
+        The `InstBuilder` trait has one method per instruction opcode for
+        conveniently constructing the instruction with minimum arguments.
+        Polymorphic instructions infer their result types from the input
+        arguments when possible. In some cases, an explicit `ctrl_typevar`
+        argument is required.
+
+        The opcode methods return the new instruction's result values, or
+        the `Inst` itself for instructions that don't have any results.
+
+        There is also a method per instruction format. These methods all
+        return an `Inst`.
+    "#,
+    );
+    fmt.line("pub trait InstBuilder<'f>: InstBuilderBase<'f> {");
+    fmt.indent(|fmt| {
+        for inst in instructions {
+            gen_inst_builder(inst, formats.get(inst.format), fmt);
+        }
+        for format in formats.iter() {
+            gen_format_constructor(format, fmt);
+        }
+    });
+    fmt.line("}");
+}
+
+pub fn generate(
+    all_inst_groups: Vec<&InstructionGroup>,
+    format_registry: &FormatRegistry,
+    opcode_filename: &str,
+    inst_builder_filename: &str,
+    out_dir: &str,
+) -> Result<(), error::Error> {
+    // Opcodes.
+    let mut fmt = Formatter::new();
+    gen_formats(format_registry, &mut fmt);
+    gen_instruction_data(format_registry, &mut fmt);
+    fmt.empty_line();
+    gen_instruction_data_impl(format_registry, &mut fmt);
+    fmt.empty_line();
+    let all_inst = gen_opcodes(format_registry, &all_inst_groups, &mut fmt);
+    gen_type_constraints(&all_inst, &mut fmt);
+    fmt.update_file(opcode_filename, out_dir)?;
+
+    // Instruction builder.
+    let mut fmt = Formatter::new();
+    gen_builder(&all_inst, format_registry, &mut fmt);
+    fmt.update_file(inst_builder_filename, out_dir)?;
+
+    Ok(())
+}
diff --git a/cranelift/codegen/meta/src/lib.rs b/cranelift/codegen/meta/src/lib.rs
index 9b50fe1232..8118922fb0 100644
--- a/cranelift/codegen/meta/src/lib.rs
+++ b/cranelift/codegen/meta/src/lib.rs
@@ -5,6 +5,7 @@ mod srcgen;
 pub mod error;
 pub mod isa;
 
+mod gen_inst;
 mod gen_registers;
 mod gen_settings;
 mod gen_types;
@@ -33,6 +34,17 @@ pub fn generate(isas: &Vec<isa::Isa>, out_dir: &str) -> Result<(), error::Error>
     // Per ISA definitions.
     let isas = isa::define(isas, &mut shared_defs);
 
+    let mut all_inst_groups = vec![&shared_defs.instructions];
+    all_inst_groups.extend(isas.iter().map(|isa| &isa.instructions));
+
+    gen_inst::generate(
+        all_inst_groups,
+        &shared_defs.format_registry,
+        "new_opcodes.rs",
+        "new_inst_builder.rs",
+        &out_dir,
+    )?;
+
     for isa in isas {
         gen_registers::generate(&isa, &format!("registers-{}.rs", isa.name), &out_dir)?;
         gen_settings::generate(