a

src/back/glsl/keywords.rs

@@ -480,4 +480,6 @@ pub const RESERVED_KEYWORDS: &[&str] = &[
     // Naga utilities:
     super::MODF_FUNCTION,
     super::MODF_STRUCT,
+    super::FREXP_FUNCTION,
+    super::FREXP_STRUCT,
 ];

src/back/glsl/mod.rs

@@ -72,6 +72,8 @@ pub const SUPPORTED_ES_VERSIONS: &[u16] = &[300, 310, 320];
 /// of detail for bounds checking in `ImageLoad`
 const CLAMPED_LOD_SUFFIX: &str = "_clamped_lod";
 
+pub(crate) const FREXP_FUNCTION: &str = "naga_frexp";
+pub(crate) const FREXP_STRUCT: &str = "naga_frexp_struct";
 pub(crate) const MODF_FUNCTION: &str = "naga_modf";
 pub(crate) const MODF_STRUCT: &str = "naga_modf_struct";
 
@@ -623,6 +625,22 @@ impl<'a, W: Write> Writer<'a, W> {
             )?;
         }
 
+        if self.module.special_types.frexp_result.is_some() {
+            writeln!(
+                self.out,
+                "struct {FREXP_STRUCT} {{
+    float fract;
+    float exp;
+}};
+
+{FREXP_STRUCT} {FREXP_FUNCTION}(float arg) {{
+    float exp;
+    float fract = modf(arg, exp);
+    return {MODF_STRUCT}(fract, exp);
+}}"
+            )?;
+        }
+
         // Write struct types.
         //
         // This are always ordered because the IR is structured in a way that
@@ -879,7 +897,8 @@ impl<'a, W: Write> Writer<'a, W> {
             | TypeInner::Sampler { .. }
             | TypeInner::AccelerationStructure
             | TypeInner::RayQuery
-            | TypeInner::ModfResultF32
+            | TypeInner::ModfResult
+            | TypeInner::FrexpResult
             | TypeInner::BindingArray { .. } => {
                 return Err(Error::Custom(format!("Unable to write type {inner:?}")))
             }
@@ -905,7 +924,11 @@ impl<'a, W: Write> Writer<'a, W> {
             }
             // glsl array has the size separated from the base type
             TypeInner::Array { base, .. } => self.write_type(base),
-            TypeInner::ModfResultF32 => {
+            TypeInner::FrexpResult => {
+                write!(self.out, "{FREXP_STRUCT}")?;
+                Ok(())
+            }
+            TypeInner::ModfResult => {
                 write!(self.out, "{MODF_STRUCT}")?;
                 Ok(())
             }
@@ -2349,7 +2372,10 @@ impl<'a, W: Write> Writer<'a, W> {
                             &self.names[&NameKey::StructMember(ty, index)]
                         )?
                     }
-                    TypeInner::ModfResultF32 => {
+                    TypeInner::FrexpResult => {
+                        write!(self.out, ".{}", if index == 0 { "fract" } else { "exp " })?
+                    }
+                    TypeInner::ModfResult => {
                         write!(self.out, ".{}", if index == 0 { "fract" } else { "whole " })?
                     }
                     ref other => return Err(Error::Custom(format!("Cannot index {other:?}"))),

src/back/hlsl/help.rs

@@ -782,6 +782,28 @@ impl<'a, W: Write> super::Writer<'a, W> {
     }
 
     pub(super) fn write_special_functions(&mut self, module: &crate::Module) -> BackendResult {
+        if module.special_types.frexp_result.is_some() {
+            let function_name = super::writer::FREXP_FUNCTION;
+            let struct_name = super::writer::FREXP_STRUCT;
+            writeln!(
+                self.out,
+                "struct {struct_name} {{
+    float fract;
+    float exp;
+}};
+
+{struct_name} {function_name}(in float arg) {{
+    float exp;
+    float fract = modf(arg, exp);
+    {struct_name} result;
+    result.exp = exp;
+    result.fract = fract;
+    return result;
+}}"
+            )?;
+            // Write extra new line
+            writeln!(self.out)?;
+        }
         if module.special_types.modf_result.is_some() {
             let function_name = super::writer::MODF_FUNCTION;
             let struct_name = super::writer::MODF_STRUCT;

src/back/hlsl/keywords.rs

@@ -815,6 +815,8 @@ pub const RESERVED: &[&str] = &[
     "ConstantBuffer",
     "RayQuery",
     // Naga utilities
+    super::writer::FREXP_FUNCTION,
+    super::writer::FREXP_STRUCT,
     super::writer::MODF_FUNCTION,
     super::writer::MODF_STRUCT,
 ];

src/back/hlsl/writer.rs

@@ -17,6 +17,8 @@ const SPECIAL_BASE_VERTEX: &str = "base_vertex";
 const SPECIAL_BASE_INSTANCE: &str = "base_instance";
 const SPECIAL_OTHER: &str = "other";
 
+pub(crate) const FREXP_FUNCTION: &str = "frexp_modf";
+pub(crate) const FREXP_STRUCT: &str = "frexp_modf_result";
 pub(crate) const MODF_FUNCTION: &str = "naga_modf";
 pub(crate) const MODF_STRUCT: &str = "naga_modf_result";
 
@@ -1063,7 +1065,10 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
             TypeInner::Array { base, size, .. } | TypeInner::BindingArray { base, size } => {
                 self.write_array_size(module, base, size)?;
             }
-            TypeInner::ModfResultF32 => {
+            TypeInner::FrexpResult => {
+                write!(self.out, "struct {FREXP_STRUCT}")?;
+            }
+            TypeInner::ModfResult => {
                 write!(self.out, "struct {MODF_STRUCT}")?;
             }
             _ => return Err(Error::Unimplemented(format!("write_value_type {inner:?}"))),
@@ -2284,7 +2289,10 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
                                     &writer.names[&NameKey::StructMember(ty, index)]
                                 )?
                             }
-                            TypeInner::ModfResultF32 => write!(
+                            TypeInner::FrexpResult => {
+                                write!(writer.out, ".{}", if index == 0 { "fract" } else { "exp" })?
+                            }
+                            TypeInner::ModfResult => write!(
                                 writer.out,
                                 ".{}",
                                 if index == 0 { "fract" } else { "whole" }

src/back/msl/keywords.rs

@@ -214,6 +214,8 @@ pub const RESERVED: &[&str] = &[
     // Naga utilities
     "DefaultConstructible",
     "clamped_lod_e",
+    super::writer::FREXP_FUNCTION,
+    super::writer::FREXP_STRUCT,
     super::writer::MODF_FUNCTION,
     super::writer::MODF_STRUCT,
 ];

src/back/msl/writer.rs

@@ -32,6 +32,8 @@ const RAY_QUERY_FIELD_INTERSECTION: &str = "intersection";
 const RAY_QUERY_FIELD_READY: &str = "ready";
 const RAY_QUERY_FUN_MAP_INTERSECTION: &str = "_map_intersection_type";
 
+pub(crate) const FREXP_FUNCTION: &str = "naga_frexp";
+pub(crate) const FREXP_STRUCT: &str = "naga_frexp_result";
 pub(crate) const MODF_FUNCTION: &str = "naga_modf";
 pub(crate) const MODF_STRUCT: &str = "naga_modf_result";
 
@@ -146,7 +148,10 @@ impl<'a> Display for TypeContext<'a> {
             crate::TypeInner::Struct { .. } => {
                 unreachable!()
             }
-            crate::TypeInner::ModfResultF32 { .. } => {
+            crate::TypeInner::FrexpResult { .. } => {
+                write!(out, "{}", FREXP_STRUCT)
+            }
+            crate::TypeInner::ModfResult { .. } => {
                 write!(out, "{}", MODF_STRUCT)
             }
             crate::TypeInner::Image {
@@ -460,7 +465,8 @@ impl crate::Type {
             | Ti::Sampler { .. }
             | Ti::AccelerationStructure
             | Ti::RayQuery
-            | Ti::ModfResultF32
+            | Ti::FrexpResult
+            | Ti::ModfResult
             | Ti::BindingArray { .. } => false,
         }
     }
@@ -1644,6 +1650,15 @@ impl<W: Write> Writer<W> {
                 write!(self.out, "{NAMESPACE}::{op}")?;
                 self.put_call_parameters(iter::once(argument), context)?;
             }
+            crate::Expression::Math {
+                fun: crate::MathFunction::Frexp,
+                arg,
+                ..
+            } => {
+                write!(self.out, "{FREXP_FUNCTION}(")?;
+                self.put_expression(arg, context, false)?;
+                write!(self.out, ")")?;
+            }
             crate::Expression::Math {
                 fun: crate::MathFunction::Modf,
                 arg,
@@ -2037,7 +2052,8 @@ impl<W: Write> Writer<W> {
                     }
                     match *base_inner {
                         crate::TypeInner::Struct { .. }
-                        | crate::TypeInner::ModfResultF32 { .. } => (base, None),
+                        | crate::TypeInner::FrexpResult
+                        | crate::TypeInner::ModfResult { .. } => (base, None),
                         _ => (base, Some(index::GuardedIndex::Known(index))),
                     }
                 }
@@ -2152,7 +2168,7 @@ impl<W: Write> Writer<W> {
                             write!(self.out, ".{}", back::COMPONENTS[index as usize])?;
                         }
                     }
-                    crate::TypeInner::ModfResultF32 => {
+                    crate::TypeInner::ModfResult => {
                         self.put_access_chain(base, policy, context)?;
                         write!(self.out, ".{}", if index == 0 { "fract" } else { "whole" })?;
                     }

src/back/spv/block.rs

@@ -396,7 +396,7 @@ impl<'w> BlockContext<'w> {
 
                         load_id
                     }
-                    crate::TypeInner::ModfResultF32 => {
+                    crate::TypeInner::ModfResult => {
                         let id = self.gen_id();
                         let base_id = self.cached[base];
                         block.body.push(Instruction::composite_extract(

src/back/spv/mod.rs

@@ -403,7 +403,8 @@ fn make_local(inner: &crate::TypeInner) -> Option<LocalType> {
         crate::TypeInner::RayQuery => LocalType::RayQuery,
         crate::TypeInner::Array { .. }
         | crate::TypeInner::Struct { .. }
-        | crate::TypeInner::ModfResultF32
+        | crate::TypeInner::FrexpResult
+        | crate::TypeInner::ModfResult
         | crate::TypeInner::BindingArray { .. } => return None,
     })
 }

src/back/spv/writer.rs

@@ -1024,7 +1024,7 @@ impl Writer {
                     }
                     Instruction::type_struct(id, member_ids.as_slice())
                 }
-                crate::TypeInner::ModfResultF32 => {
+                crate::TypeInner::FrexpResult | crate::TypeInner::ModfResult => {
                     let float_ty = arena
                         .get(&crate::Type {
                             name: None,
@@ -1035,7 +1035,18 @@ impl Writer {
                         })
                         .unwrap(); // TODO: unwrap
                     self.decorate_struct_member_special(id, 0, 0, Some("fract"), float_ty, arena)?;
-                    self.decorate_struct_member_special(id, 1, 4, Some("whole"), float_ty, arena)?;
+                    self.decorate_struct_member_special(
+                        id,
+                        1,
+                        4,
+                        Some(if ty.inner == crate::TypeInner::FrexpResult {
+                            "exp"
+                        } else {
+                            "whole"
+                        }),
+                        float_ty,
+                        arena,
+                    )?;
 
                     let float_id = self.get_float_type_id();
                     let member_ids = [float_id; 2];

src/back/wgsl/writer.rs

@@ -1223,7 +1223,10 @@ impl<W: Write> Writer<W> {
                             &self.names[&NameKey::StructMember(ty, index)]
                         )?
                     }
-                    TypeInner::ModfResultF32 => {
+                    TypeInner::FrexpResult => {
+                        write!(self.out, ".{}", if index == 0 { "fract" } else { "exp" })?
+                    }
+                    TypeInner::ModfResult => {
                         write!(self.out, ".{}", if index == 0 { "fract" } else { "whole" })?
                     }
                     ref other => return Err(Error::Custom(format!("Cannot index {other:?}"))),

src/front/type_gen.rs

@@ -322,11 +322,26 @@ impl crate::Module {
         let handle = self.types.insert(
             crate::Type {
                 name: Some("__naga_modf_result".to_string()),
-                inner: crate::TypeInner::ModfResultF32,
+                inner: crate::TypeInner::ModfResult,
             },
             Span::UNDEFINED,
         );
         self.special_types.modf_result = Some(handle);
         handle
     }
+
+    pub fn generate_frexp_result(&mut self) -> Handle<crate::Type> {
+        if let Some(handle) = self.special_types.frexp_result {
+            return handle;
+        }
+        let handle = self.types.insert(
+            crate::Type {
+                name: Some("__naga_frexp_result".to_string()),
+                inner: crate::TypeInner::FrexpResult,
+            },
+            Span::UNDEFINED,
+        );
+        self.special_types.frexp_result = Some(handle);
+        handle
+    }
 }

src/front/wgsl/lower/mod.rs

@@ -1587,7 +1587,23 @@ impl<'source, 'temp> Lowerer<'source, 'temp> {
                             ),
                         }
                     }
-                    crate::TypeInner::ModfResultF32 => {
+                    crate::TypeInner::FrexpResult => {
+                        let index = if field.name == "fract" {
+                            0
+                        } else if field.name == "exp" {
+                            1
+                        } else {
+                            return Err(Error::BadAccessor(field.span));
+                        };
+                        (
+                            crate::Expression::AccessIndex {
+                                base: handle,
+                                index,
+                            },
+                            is_reference,
+                        )
+                    }
+                    crate::TypeInner::ModfResult => {
                         let index = if field.name == "fract" {
                             0
                         } else if field.name == "whole" {
@@ -1731,9 +1747,13 @@ impl<'source, 'temp> Lowerer<'source, 'temp> {
 
                     // Handle special functions return structures
                     match fun {
-                        crate::MathFunction::Modf => {
+                        crate::MathFunction::Frexp | crate::MathFunction::Modf => {
                             args.finish()?;
-                            let _ = ctx.module.generate_modf_result();
+                            let _ = if fun == crate::MathFunction::Frexp {
+                                ctx.module.generate_frexp_result()
+                            } else {
+                                ctx.module.generate_modf_result()
+                            };
                             crate::Expression::Math {
                                 fun,
                                 arg,
@@ -2122,8 +2142,7 @@ impl<'source, 'temp> Lowerer<'source, 'temp> {
                             return Ok(Some(result));
                         }
                         "rayQueryGetCommittedIntersection" => {
-                            let mut args: ArgumentContext<'_, '_> =
-                                ctx.prepare_args(arguments, 1, span);
+                            let mut args = ctx.prepare_args(arguments, 1, span);
                             let query = self.ray_query_pointer(args.next()?, ctx.reborrow())?;
                             args.finish()?;
 

src/front/wgsl/mod.rs

@@ -185,7 +185,8 @@ impl crate::TypeInner {
             Ti::Sampler { .. } => "sampler".to_string(),
             Ti::AccelerationStructure => "acceleration_structure".to_string(),
             Ti::RayQuery => "ray_query".to_string(),
-            Ti::ModfResultF32 => "__modf_result_f32".to_string(),
+            Ti::FrexpResult => "__frexp_result_f32".to_string(),
+            Ti::ModfResult => "__modf_result_f32".to_string(),
             Ti::BindingArray { base, size, .. } => {
                 let member_type = &gctx.types[base];
                 let base = member_type.name.as_deref().unwrap_or("unknown");

src/front/wgsl/tests.rs

@@ -438,10 +438,11 @@ fn binary_expression_mixed_scalar_and_vector_operands() {
 #[test]
 fn parse_pointers() {
     parse_str(
-        "fn foo() {
+        "fn foo(a: ptr<private, f32>) -> f32 { return *a; }
+    fn bar() {
         var x: f32 = 1.0;
         let px = &x;
-        let py = frexp(0.5, px);
+        let py = foo(px);
     }",
     )
     .unwrap();