feat: Add initial float extension

Note that this is only a skeleton, with not even a single op lowering
implemented. It does add support for f64 types and constants though.

src/custom.rs

@@ -21,9 +21,9 @@ use crate::{
 
 use super::emit::EmitOp;
 
+pub mod float;
 pub mod int;
 pub mod prelude;
-// pub mod float_ops;
 // pub mod logic_ops;
 
 /// The extension point for lowering HUGR Extensions to LLVM.

src/custom/float.rs

@@ -0,0 +1,151 @@
+use std::{any::TypeId, collections::HashSet};
+
+use anyhow::{anyhow, Result};
+use hugr::{
+    ops::{constant::CustomConst, CustomOp},
+    std_extensions::arithmetic::{
+        float_ops,
+        float_types::{self, ConstF64, FLOAT64_CUSTOM_TYPE},
+    },
+    HugrView,
+};
+use inkwell::{
+    types::{BasicType, FloatType},
+    values::{BasicValue, BasicValueEnum},
+};
+
+use crate::emit::{func::EmitFuncContext, EmitOp, EmitOpArgs, NullEmitLlvm};
+
+use super::{CodegenExtension, CodegenExtsMap};
+
+struct FloatTypesCodegenExtension;
+
+impl<'c, H: HugrView> CodegenExtension<'c, H> for FloatTypesCodegenExtension {
+    fn extension(&self) -> hugr::extension::ExtensionId {
+        return float_types::EXTENSION_ID;
+    }
+
+    fn llvm_type(
+        &self,
+        context: &crate::types::TypingSession<'c, H>,
+        hugr_type: &hugr::types::CustomType,
+    ) -> anyhow::Result<inkwell::types::BasicTypeEnum<'c>> {
+        if hugr_type == &FLOAT64_CUSTOM_TYPE {
+            Ok(context.iw_context().f64_type().as_basic_type_enum())
+        } else {
+            Err(anyhow!(
+                "FloatCodegenExtension: Unsupported type: {}",
+                hugr_type
+            ))
+        }
+    }
+
+    fn emitter<'a>(
+        &self,
+        _context: &'a mut crate::emit::func::EmitFuncContext<'c, H>,
+    ) -> Box<dyn crate::emit::EmitOp<'c, hugr::ops::CustomOp, H> + 'a> {
+        Box::new(NullEmitLlvm)
+    }
+
+    fn supported_consts(&self) -> HashSet<TypeId> {
+        [TypeId::of::<ConstF64>()].into_iter().collect()
+    }
+
+    fn load_constant(
+        &self,
+        context: &mut EmitFuncContext<'c, H>,
+        konst: &dyn hugr::ops::constant::CustomConst,
+    ) -> Result<Option<BasicValueEnum<'c>>> {
+        let Some(k) = konst.downcast_ref::<ConstF64>() else {
+            return Ok(None);
+        };
+        let ty: FloatType<'c> = context
+            .llvm_type(&k.get_type())?
+            .try_into()
+            .map_err(|_| anyhow!("Failed to get type of ConstF64 as FloatType"))?;
+        Ok(Some(ty.const_float(k.value()).as_basic_value_enum()))
+    }
+}
+
+struct FloatOpsCodegenExtension;
+
+impl<'c, H: HugrView> CodegenExtension<'c, H> for FloatOpsCodegenExtension {
+    fn extension(&self) -> hugr::extension::ExtensionId {
+        return float_ops::EXTENSION_ID;
+    }
+
+    fn llvm_type(
+        &self,
+        _context: &crate::types::TypingSession<'c, H>,
+        hugr_type: &hugr::types::CustomType,
+    ) -> anyhow::Result<inkwell::types::BasicTypeEnum<'c>> {
+        Err(anyhow!(
+            "FloatOpsCodegenExtension: unsupported type: {hugr_type}"
+        ))
+    }
+
+    fn emitter<'a>(
+        &self,
+        context: &'a mut crate::emit::func::EmitFuncContext<'c, H>,
+    ) -> Box<dyn crate::emit::EmitOp<'c, hugr::ops::CustomOp, H> + 'a> {
+        Box::new(FloatOpEmitter(context))
+    }
+}
+
+// we allow dead code for now, but once we implement the emitter, we should
+// remove this
+#[allow(dead_code)]
+struct FloatOpEmitter<'c, 'd, H: HugrView>(&'d mut EmitFuncContext<'c, H>);
+
+impl<'c, H: HugrView> EmitOp<'c, CustomOp, H> for FloatOpEmitter<'c, '_, H> {
+    fn emit(&mut self, args: EmitOpArgs<'c, CustomOp, H>) -> Result<()> {
+        use hugr::ops::NamedOp;
+        let name = args.node().name();
+        match name.as_str() {
+            n => Err(anyhow!("FloatOpEmitter: unknown op: {}", n)),
+        }
+    }
+}
+
+pub fn add_float_extensions<H: HugrView>(cem: CodegenExtsMap<'_, H>) -> CodegenExtsMap<'_, H> {
+    cem.add_cge(FloatTypesCodegenExtension)
+        .add_cge(FloatOpsCodegenExtension)
+}
+
+impl<H: HugrView> CodegenExtsMap<'_, H> {
+    pub fn add_float_extensions(self) -> Self {
+        add_float_extensions(self)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use hugr::{
+        builder::{Dataflow, DataflowSubContainer},
+        std_extensions::arithmetic::{
+            float_ops::FLOAT_OPS_REGISTRY,
+            float_types::{ConstF64, FLOAT64_TYPE},
+        },
+    };
+    use rstest::rstest;
+
+    use super::add_float_extensions;
+    use crate::{
+        check_emission,
+        emit::test::SimpleHugrConfig,
+        test::{llvm_ctx, TestContext},
+    };
+
+    #[rstest]
+    fn const_float(mut llvm_ctx: TestContext) {
+        llvm_ctx.add_extensions(add_float_extensions);
+        let hugr = SimpleHugrConfig::new()
+            .with_outs(FLOAT64_TYPE)
+            .with_extensions(FLOAT_OPS_REGISTRY.to_owned())
+            .finish(|mut builder| {
+                let c = builder.add_load_value(ConstF64::new(3.14));
+                builder.finish_with_outputs([c]).unwrap()
+            });
+        check_emission!(hugr, llvm_ctx);
+    }
+}

src/custom/snapshots/hugr_llvm__custom__float__test__const_float@llvm14.snap

@@ -0,0 +1,14 @@
+---
+source: src/custom/float.rs
+expression: module.to_string()
+---
+; ModuleID = 'test_context'
+source_filename = "test_context"
+
+define double @_hl.main.1() {
+alloca_block:
+  br label %entry_block
+
+entry_block:                                      ; preds = %alloca_block
+  ret double 3.140000e+00
+}

src/custom/snapshots/hugr_llvm__custom__float__test__const_float@pre-mem2reg@llvm14.snap

@@ -0,0 +1,20 @@
+---
+source: src/custom/float.rs
+expression: module.to_string()
+---
+; ModuleID = 'test_context'
+source_filename = "test_context"
+
+define double @_hl.main.1() {
+alloca_block:
+  %"0" = alloca double, align 8
+  %"5_0" = alloca double, align 8
+  br label %entry_block
+
+entry_block:                                      ; preds = %alloca_block
+  store double 3.140000e+00, double* %"5_0", align 8
+  %"5_01" = load double, double* %"5_0", align 8
+  store double %"5_01", double* %"0", align 8
+  %"02" = load double, double* %"0", align 8
+  ret double %"02"
+}