nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
Perform expression flattening
author
Danielle Maywood
committer
nandi
date
(Jul 26, 2026, 12:11 PM -0700)
commit
34064946
340649464225813b71dffb222d257e7c0ddce0e7
parent
969373cc
969373ccb8ad65d0ec3352ca311b7a6f9470f8f6
change-id
pkvyskmn
pkvyskmnxmrmppyrovunvumtoyrvtmyr
+166
-130
+88
-9
compiler-core/src/cranelift/mir.rs
+88
-9
compiler-core/src/cranelift/mir.rs
···
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Generic,
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}
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-
#[derive(Debug, PartialEq, Eq)]
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+
#[derive(Debug, PartialEq, Eq, Clone)]
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pub enum Expression {
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Block(Vec<Expression>),
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···
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FunctionParameter { name, type_ }
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}));
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-
let body = BodyTranslator::default().translate(&function.body);
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let body = Self::flatten_expression(BodyTranslator::default().translate(&function.body));
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Function {
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name,
···
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type_::Type::Tuple { elements: _ } => todo!(),
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}
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}
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+
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+
fn flatten_expression(expression: Expression) -> Expression {
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match expression {
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Expression::Block(expressions) => {
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let mut block = vec![];
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+
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for expression in expressions {
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let expression = Self::flatten_expression(expression);
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+
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match expression {
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Expression::Block(mut expressions) => block.append(&mut expressions),
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Expression::Var { .. }
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| Expression::Int { .. }
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| Expression::Equals { .. }
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| Expression::IntAdd { .. }
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| Expression::Set { .. }
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| Expression::If { .. } => block.push(expression),
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};
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}
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+
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match block.as_slice() {
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[single] => single.clone(),
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_ => Expression::Block(block),
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+
}
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}
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Expression::Var { name: _ } => expression,
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Expression::Int { value: _ } => expression,
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Expression::Equals { lhs, rhs } => Expression::Equals {
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lhs: Box::new(Self::flatten_expression(*lhs)),
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rhs: Box::new(Self::flatten_expression(*rhs)),
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},
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Expression::IntAdd { lhs, rhs } => Expression::IntAdd {
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lhs: Box::new(Self::flatten_expression(*lhs)),
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rhs: Box::new(Self::flatten_expression(*rhs)),
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},
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Expression::Set { name, value } => Expression::Set {
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name,
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value: Box::new(Self::flatten_expression(*value)),
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},
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Expression::If { cond, then, else_ } => Expression::If {
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cond: Box::new(Self::flatten_expression(*cond)),
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then: Box::new(Self::flatten_expression(*then)),
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else_: Box::new(Self::flatten_expression(*else_)),
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},
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}
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}
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}
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#[derive(Debug, Default)]
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pub struct BodyTranslator {
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variables: HashSet<EcoString>,
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variable_count: usize,
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}
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+
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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enum DecisionKind {
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Case,
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Let,
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}
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impl BodyTranslator {
···
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return name;
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}));
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block.push(self.translate_decision(&subject_vars, clauses, &compiled_case.tree));
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block.push(self.translate_decision(
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DecisionKind::Case,
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&subject_vars,
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clauses,
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&compiled_case.tree,
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));
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Expression::Block(block)
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}
···
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}
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}
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fn translate_assignment(&mut self, _assignment: &ast::TypedAssignment) -> Expression {
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todo!()
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fn translate_assignment(&mut self, assignment: &ast::TypedAssignment) -> Expression {
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let mut block = vec![];
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let value_var = self.make_tmp_var();
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let value = self.translate_expression(&assignment.value);
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+
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block.push(Expression::Set {
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name: value_var.clone(),
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value: Box::new(value),
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});
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+
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block.push(self.translate_decision(
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DecisionKind::Let,
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&[value_var.clone()],
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&[],
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+
&assignment.compiled_case.tree,
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+
));
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+
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block.push(Expression::Var { name: value_var });
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+
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Expression::Block(block)
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}
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fn make_tmp_var(&mut self) -> EcoString {
···
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fn translate_decision(
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&mut self,
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kind: DecisionKind,
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subjects: &[EcoString],
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clauses: &[ast::TypedClause],
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decision: &exhaustiveness::Decision,
···
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block.push(self.translate_binding(subjects, binding.clone(), value));
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}
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-
block.push(self.translate_expression(&clauses[body.clause_index].then));
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+
if kind == DecisionKind::Case {
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block.push(self.translate_expression(&clauses[body.clause_index].then));
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+
}
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Expression::Block(block)
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}
···
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block
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};
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-
let if_false = self.translate_decision(subjects, clauses, if_false);
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+
let if_false = self.translate_decision(kind, subjects, clauses, if_false);
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block.push(Expression::If {
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cond: Box::new(cond),
···
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fallback,
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fallback_check: _,
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} => {
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-
let fallback = self.translate_decision(subjects, clauses, fallback);
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+
let fallback = self.translate_decision(kind, subjects, clauses, fallback);
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DoubleEndedIterator::rfold(choices.iter(), fallback, |fallback, (check, then)| {
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Expression::If {
···
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name: subjects[var.id].clone(),
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531
},
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)),
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-
then: Box::new(self.translate_decision(subjects, clauses, then)),
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+
then: Box::new(self.translate_decision(kind, subjects, clauses, then)),
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else_: Box::new(fallback),
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}
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})
+30
-46
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples-2.snap
+30
-46
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples-2.snap
···
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],
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body: Block(
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[
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-
Block(
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[
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Set {
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Set {
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name: "_tmp0",
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value: Var {
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name: "n",
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},
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},
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If {
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cond: Equals {
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lhs: Var {
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name: "_tmp0",
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-
value: Var {
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name: "n",
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-
},
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},
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-
If {
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cond: Equals {
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lhs: Var {
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name: "_tmp0",
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-
},
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rhs: Int {
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value: 0,
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-
},
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rhs: Int {
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value: 0,
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},
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},
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then: Int {
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value: 2,
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},
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else_: If {
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cond: Equals {
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lhs: Var {
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name: "_tmp0",
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},
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-
then: Block(
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[
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Int {
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value: 2,
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},
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-
],
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),
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-
else_: If {
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cond: Equals {
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lhs: Var {
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name: "_tmp0",
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},
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rhs: Int {
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value: 1,
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},
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-
},
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then: Block(
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[
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Int {
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value: 4,
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},
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-
],
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),
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-
else_: Block(
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[
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Int {
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value: 6,
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},
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-
],
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-
),
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+
rhs: Int {
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+
value: 1,
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},
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},
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-
],
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-
),
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+
then: Int {
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value: 4,
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+
},
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+
else_: Int {
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+
value: 6,
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+
},
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+
},
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+
},
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],
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),
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57
},
+39
-59
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples-3.snap
+39
-59
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples-3.snap
···
17
17
],
18
18
body: Block(
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[
20
-
Block(
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-
[
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-
Set {
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-
name: "_tmp0",
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-
value: Var {
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-
name: "n",
20
+
Set {
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+
name: "_tmp0",
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+
value: Var {
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+
name: "n",
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+
},
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+
},
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Set {
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+
name: "y",
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+
value: Var {
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+
name: "_tmp0",
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+
},
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+
},
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+
If {
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+
cond: Equals {
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+
lhs: Var {
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+
name: "y",
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+
},
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+
rhs: Int {
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+
value: 0,
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+
},
40
+
},
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+
then: Int {
42
+
value: 2,
43
+
},
44
+
else_: If {
45
+
cond: Equals {
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+
lhs: Var {
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+
name: "_tmp0",
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+
},
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+
rhs: Int {
50
+
value: 1,
26
51
},
27
52
},
28
-
Block(
29
-
[
30
-
Set {
31
-
name: "y",
32
-
value: Var {
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-
name: "_tmp0",
34
-
},
35
-
},
36
-
If {
37
-
cond: Equals {
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-
lhs: Var {
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-
name: "y",
40
-
},
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-
rhs: Int {
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-
value: 0,
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-
},
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-
},
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-
then: Block(
46
-
[
47
-
Int {
48
-
value: 2,
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-
},
50
-
],
51
-
),
52
-
else_: If {
53
-
cond: Equals {
54
-
lhs: Var {
55
-
name: "_tmp0",
56
-
},
57
-
rhs: Int {
58
-
value: 1,
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-
},
60
-
},
61
-
then: Block(
62
-
[
63
-
Int {
64
-
value: 4,
65
-
},
66
-
],
67
-
),
68
-
else_: Block(
69
-
[
70
-
Int {
71
-
value: 6,
72
-
},
73
-
],
74
-
),
75
-
},
76
-
},
77
-
],
78
-
),
79
-
],
80
-
),
53
+
then: Int {
54
+
value: 4,
55
+
},
56
+
else_: Int {
57
+
value: 6,
58
+
},
59
+
},
60
+
},
81
61
],
82
62
),
83
63
},
+8
-12
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples.snap
+8
-12
compiler-core/src/cranelift/snapshots/gleam_core__cranelift__mir__tests__translates_samples.snap
···
21
21
),
22
22
},
23
23
],
24
-
body: Block(
25
-
[
26
-
IntAdd {
27
-
lhs: Var {
28
-
name: "lhs",
29
-
},
30
-
rhs: Var {
31
-
name: "rhs",
32
-
},
33
-
},
34
-
],
35
-
),
24
+
body: IntAdd {
25
+
lhs: Var {
26
+
name: "lhs",
27
+
},
28
+
rhs: Var {
29
+
name: "rhs",
30
+
},
31
+
},
36
32
},
37
33
],
38
34
}