Rename as_bool to as_truthy, and fix TypeSet::as_bool

cranelift/codegen/meta/src/cdsl/typevar.rs

@@ -228,7 +228,7 @@ impl TypeVar {
                     "The `wider` constraint only applies to scalar ints or floats"
                 );
             }
-            DerivedFunc::LaneOf | DerivedFunc::AsBool | DerivedFunc::DynamicToVector => {
+            DerivedFunc::LaneOf | DerivedFunc::AsTruthy | DerivedFunc::DynamicToVector => {
                 /* no particular assertions */
             }
         }
@@ -249,8 +249,8 @@ impl TypeVar {
     pub fn lane_of(&self) -> TypeVar {
         self.derived(DerivedFunc::LaneOf)
     }
-    pub fn as_bool(&self) -> TypeVar {
-        self.derived(DerivedFunc::AsBool)
+    pub fn as_truthy(&self) -> TypeVar {
+        self.derived(DerivedFunc::AsTruthy)
     }
     pub fn half_width(&self) -> TypeVar {
         self.derived(DerivedFunc::HalfWidth)
@@ -332,7 +332,7 @@ impl ops::Deref for TypeVar {
 #[derive(Clone, Copy, Debug, Hash, PartialEq)]
 pub(crate) enum DerivedFunc {
     LaneOf,
-    AsBool,
+    AsTruthy,
     HalfWidth,
     DoubleWidth,
     SplitLanes,
@@ -346,7 +346,7 @@ impl DerivedFunc {
     pub fn name(self) -> &'static str {
         match self {
             DerivedFunc::LaneOf => "lane_of",
-            DerivedFunc::AsBool => "as_bool",
+            DerivedFunc::AsTruthy => "as_truthy",
             DerivedFunc::HalfWidth => "half_width",
             DerivedFunc::DoubleWidth => "double_width",
             DerivedFunc::SplitLanes => "split_lanes",
@@ -425,7 +425,7 @@ impl TypeSet {
     fn image(&self, derived_func: DerivedFunc) -> TypeSet {
         match derived_func {
             DerivedFunc::LaneOf => self.lane_of(),
-            DerivedFunc::AsBool => self.as_bool(),
+            DerivedFunc::AsTruthy => self.as_truthy(),
             DerivedFunc::HalfWidth => self.half_width(),
             DerivedFunc::DoubleWidth => self.double_width(),
             DerivedFunc::SplitLanes => self.half_width().double_vector(),
@@ -443,10 +443,19 @@ impl TypeSet {
         copy
     }
 
-    /// Return a TypeSet describing the image of self across as_bool.
-    fn as_bool(&self) -> TypeSet {
+    /// Return a TypeSet describing the image of self across as_truthy.
+    fn as_truthy(&self) -> TypeSet {
         let mut copy = self.clone();
-        copy.ints = NumSet::new();
+
+        // If this type set represents a scalar, `as_truthy` produces an I8, otherwise it returns a
+        // vector of the same number of lanes, whose elements are integers of the same width. For
+        // example, F32X4 gets turned into I32X4, while I32 gets turned into I8.
+        if self.lanes.len() == 1 && self.lanes.contains(&1) {
+            copy.ints = NumSet::from([8]);
+        } else {
+            copy.ints.extend(&self.floats)
+        }
+
         copy.floats = NumSet::new();
         copy.refs = NumSet::new();
         copy
@@ -814,7 +823,7 @@ fn test_typevar_builder_inverted_bounds_panic() {
 }
 
 #[test]
-fn test_as_bool() {
+fn test_as_truthy() {
     let a = TypeSetBuilder::new()
         .simd_lanes(2..8)
         .ints(8..8)
@@ -824,6 +833,14 @@ fn test_as_bool() {
         a.lane_of(),
         TypeSetBuilder::new().ints(8..8).floats(32..32).build()
     );
+
+    let mut a_as_truthy = TypeSetBuilder::new().simd_lanes(2..8).build();
+    a_as_truthy.ints = num_set![8, 32];
+    assert_eq!(a.as_truthy(), a_as_truthy);
+
+    let a = TypeSetBuilder::new().ints(8..32).floats(32..64).build();
+    let a_as_truthy = TypeSetBuilder::new().ints(8..8).build();
+    assert_eq!(a.as_truthy(), a_as_truthy);
 }
 
 #[test]

cranelift/codegen/meta/src/gen_inst.rs

@@ -669,7 +669,7 @@ fn gen_opcodes(all_inst: &AllInstructions, fmt: &mut Formatter) {
 /// 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.
+/// - `Same`, `Lane`, `AsTruthy` for controlling typevar-derived constraints.
 fn get_constraint<'entries, 'table>(
     operand: &'entries Operand,
     ctrl_typevar: Option<&TypeVar>,
@@ -778,7 +778,7 @@ fn gen_type_constraints(all_inst: &AllInstructions, fmt: &mut Formatter) {
     // 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.
+    // - `Same`, `Lane`, `AsTruthy` for controlling typevar-derived constraints.
     let mut operand_seqs = UniqueSeqTable::new();
 
     // Preload table with constraints for typical binops.

cranelift/codegen/meta/src/shared/instructions.rs

@@ -1627,7 +1627,7 @@ pub(crate) fn define(
             Operand::new("x", Int),
             Operand::new("y", Int),
         ])
-        .operands_out(vec![Operand::new("a", &Int.as_bool())]),
+        .operands_out(vec![Operand::new("a", &Int.as_truthy())]),
     );
 
     ig.push(
@@ -2684,7 +2684,7 @@ pub(crate) fn define(
             Operand::new("x", Float),
             Operand::new("y", Float),
         ])
-        .operands_out(vec![Operand::new("a", &Float.as_bool())]),
+        .operands_out(vec![Operand::new("a", &Float.as_truthy())]),
     );
 
     ig.push(

cranelift/codegen/src/ir/instructions.rs

@@ -683,8 +683,8 @@ enum OperandConstraint {
     /// This operand is `ctrlType.lane_of()`.
     LaneOf,
 
-    /// This operand is `ctrlType.as_bool()`.
-    AsBool,
+    /// This operand is `ctrlType.as_truthy()`.
+    AsTruthy,
 
     /// This operand is `ctrlType.half_width()`.
     HalfWidth,
@@ -719,7 +719,7 @@ impl OperandConstraint {
             Free(vts) => ResolvedConstraint::Free(TYPE_SETS[vts as usize]),
             Same => Bound(ctrl_type),
             LaneOf => Bound(ctrl_type.lane_of()),
-            AsBool => Bound(ctrl_type.as_bool()),
+            AsTruthy => Bound(ctrl_type.as_truthy()),
             HalfWidth => Bound(ctrl_type.half_width().expect("invalid type for half_width")),
             DoubleWidth => Bound(
                 ctrl_type

cranelift/codegen/src/ir/types.rs

@@ -133,28 +133,27 @@ impl Type {
     ///
     /// Lane types are treated as vectors with one lane, so they are converted to the multi-bit
     /// boolean types.
-    pub fn as_bool_pedantic(self) -> Self {
+    pub fn as_truthy_pedantic(self) -> Self {
         // Replace the low 4 bits with the boolean version, preserve the high 4 bits.
         self.replace_lanes(match self.lane_type() {
             I8 => I8,
             I16 => I16,
             I32 | F32 => I32,
             I64 | F64 => I64,
-            R32 | R64 => panic!("Reference types should not convert to bool"),
+            R32 | R64 => panic!("Reference types are not truthy"),
             I128 => I128,
             _ => I8,
         })
     }
 
-    /// Get a type with the same number of lanes as this type, but with the lanes replaced by
-    /// booleans of the same size.
-    ///
-    /// Scalar types are all converted to `b1` which is usually what you want.
-    pub fn as_bool(self) -> Self {
+    /// Get the type of a comparison result for the given type. For vectors this will be a vector
+    /// with the same number of lanes and integer elements, and for scalar types this will be `i8`,
+    /// which is the result type of comparisons.
+    pub fn as_truthy(self) -> Self {
         if !self.is_vector() {
             I8
         } else {
-            self.as_bool_pedantic()
+            self.as_truthy_pedantic()
         }
     }
 
@@ -604,11 +603,11 @@ mod tests {
     }
 
     #[test]
-    fn as_bool() {
-        assert_eq!(I32X4.as_bool(), I32X4);
-        assert_eq!(I32.as_bool(), I8);
-        assert_eq!(I32X4.as_bool_pedantic(), I32X4);
-        assert_eq!(I32.as_bool_pedantic(), I32);
+    fn as_truthy() {
+        assert_eq!(I32X4.as_truthy(), I32X4);
+        assert_eq!(I32.as_truthy(), I8);
+        assert_eq!(I32X4.as_truthy_pedantic(), I32X4);
+        assert_eq!(I32.as_truthy_pedantic(), I32);
     }
 
     #[test]

cranelift/interpreter/src/step.rs

@@ -865,7 +865,7 @@ where
                         V::bool(
                             fcmp(inst.fp_cond_code().unwrap(), &x, &y).unwrap(),
                             ctrl_ty.is_vector(),
-                            ctrl_ty.lane_type().as_bool(),
+                            ctrl_ty.lane_type().as_truthy(),
                         )
                     })
                     .collect::<ValueResult<SimdVec<V>>>()?),
@@ -985,7 +985,7 @@ where
         }
         Opcode::Bmask => assign({
             let bool = arg(0)?;
-            let bool_ty = ctrl_ty.as_bool_pedantic();
+            let bool_ty = ctrl_ty.as_truthy_pedantic();
             let lanes = extractlanes(&bool, bool_ty)?
                 .into_iter()
                 .map(|lane| lane.convert(ValueConversionKind::Mask(ctrl_ty.lane_type())))
@@ -1467,7 +1467,7 @@ where
         )?)
     };
 
-    let dst_ty = ctrl_ty.as_bool();
+    let dst_ty = ctrl_ty.as_truthy();
     let left = extractlanes(left, ctrl_ty)?;
     let right = extractlanes(right, ctrl_ty)?;