From 529fa67855e8f44373d90d7e7b5c7a08b9745f56 Mon Sep 17 00:00:00 2001
From: David Mak <chmakac@connect.ust.hk>
Date: Fri, 7 Feb 2025 14:01:10 +0800
Subject: [PATCH] [core] codegen: Add bool_to_int_type to replace
 bool_to_{i1,i8}

Unifies the implementation for both functions.
---
 nac3core/src/codegen/expr.rs      |  2 +-
 nac3core/src/codegen/generator.rs | 20 +++++++++---
 nac3core/src/codegen/mod.rs       | 52 +++++++++++--------------------
 3 files changed, 35 insertions(+), 39 deletions(-)

diff --git a/nac3core/src/codegen/expr.rs b/nac3core/src/codegen/expr.rs
index 20d296e4..f4e03d04 100644
--- a/nac3core/src/codegen/expr.rs
+++ b/nac3core/src/codegen/expr.rs
@@ -2001,7 +2001,7 @@ pub fn gen_cmpop_expr_with_values<'ctx, G: CodeGenerator>(
                 ).into_int_value();
                 let result = call_string_eq(ctx, lhs_ptr, lhs_len, rhs_ptr, rhs_len);
                 if *op == Cmpop::NotEq {
-                    ctx.builder.build_not(result, "").unwrap() 
+                    ctx.builder.build_not(result, "").unwrap()
                 } else {
                     result
                 }
diff --git a/nac3core/src/codegen/generator.rs b/nac3core/src/codegen/generator.rs
index 620ede0e..42c7c71b 100644
--- a/nac3core/src/codegen/generator.rs
+++ b/nac3core/src/codegen/generator.rs
@@ -7,7 +7,7 @@ use inkwell::{
 
 use nac3parser::ast::{Expr, Stmt, StrRef};
 
-use super::{bool_to_i1, bool_to_i8, expr::*, stmt::*, values::ArraySliceValue, CodeGenContext};
+use super::{bool_to_int_type, expr::*, stmt::*, values::ArraySliceValue, CodeGenContext};
 use crate::{
     symbol_resolver::ValueEnum,
     toplevel::{DefinitionId, TopLevelDef},
@@ -248,22 +248,32 @@ pub trait CodeGenerator {
         gen_block(self, ctx, stmts)
     }
 
-    /// See [`bool_to_i1`].
+    /// Converts the value of a boolean-like value `bool_value` into an `i1`.
     fn bool_to_i1<'ctx>(
         &self,
         ctx: &CodeGenContext<'ctx, '_>,
         bool_value: IntValue<'ctx>,
     ) -> IntValue<'ctx> {
-        bool_to_i1(&ctx.builder, bool_value)
+        self.bool_to_int_type(ctx, bool_value, ctx.ctx.bool_type())
     }
 
-    /// See [`bool_to_i8`].
+    /// Converts the value of a boolean-like value `bool_value` into an `i8`.
     fn bool_to_i8<'ctx>(
         &self,
         ctx: &CodeGenContext<'ctx, '_>,
         bool_value: IntValue<'ctx>,
     ) -> IntValue<'ctx> {
-        bool_to_i8(&ctx.builder, ctx.ctx, bool_value)
+        self.bool_to_int_type(ctx, bool_value, ctx.ctx.i8_type())
+    }
+
+    /// See [`bool_to_int_type`].
+    fn bool_to_int_type<'ctx>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        bool_value: IntValue<'ctx>,
+        ty: IntType<'ctx>,
+    ) -> IntValue<'ctx> {
+        bool_to_int_type(&ctx.builder, bool_value, ty)
     }
 }
 
diff --git a/nac3core/src/codegen/mod.rs b/nac3core/src/codegen/mod.rs
index a188d1c3..f1b9cfb9 100644
--- a/nac3core/src/codegen/mod.rs
+++ b/nac3core/src/codegen/mod.rs
@@ -933,7 +933,7 @@ pub fn gen_func_impl<
             let param_val = param.into_int_value();
 
             if expected_ty.get_bit_width() == 8 && param_val.get_type().get_bit_width() == 1 {
-                bool_to_i8(&builder, context, param_val)
+                bool_to_int_type(&builder, param_val, context.i8_type())
             } else {
                 param_val
             }
@@ -1103,43 +1103,29 @@ pub fn gen_func<'ctx, G: CodeGenerator>(
     })
 }
 
-/// Converts the value of a boolean-like value `bool_value` into an `i1`.
-fn bool_to_i1<'ctx>(builder: &Builder<'ctx>, bool_value: IntValue<'ctx>) -> IntValue<'ctx> {
-    if bool_value.get_type().get_bit_width() == 1 {
-        bool_value
-    } else {
-        builder
-            .build_int_compare(
-                IntPredicate::NE,
-                bool_value,
-                bool_value.get_type().const_zero(),
-                "tobool",
-            )
-            .unwrap()
-    }
-}
-
-/// Converts the value of a boolean-like value `bool_value` into an `i8`.
-fn bool_to_i8<'ctx>(
+/// Converts the value of a boolean-like value `value` into an arbitrary [`IntType`].
+///
+/// This has the same semantics as `(ty)(value != 0)` in C.
+///
+/// The returned value is guaranteed to either be `0` or `1`, except for `ty == i1` where only the
+/// least-significant bit would be guaranteed to be `0` or `1`.
+fn bool_to_int_type<'ctx>(
     builder: &Builder<'ctx>,
-    ctx: &'ctx Context,
-    bool_value: IntValue<'ctx>,
+    value: IntValue<'ctx>,
+    ty: IntType<'ctx>,
 ) -> IntValue<'ctx> {
-    let value_bits = bool_value.get_type().get_bit_width();
-    match value_bits {
-        8 => bool_value,
-        1 => builder.build_int_z_extend(bool_value, ctx.i8_type(), "frombool").unwrap(),
-        _ => bool_to_i8(
+    // i1 -> i1    : %value                                     ; no-op
+    // i1 -> i<N>  : zext i1 %value to i<N>                     ; guaranteed to be 0 or 1 - see docs
+    // i<M> -> i<N>: zext i1 (icmp eq i<M> %value, 0) to i<N>   ; same as i<M> -> i1 -> i<N>
+    match (value.get_type().get_bit_width(), ty.get_bit_width()) {
+        (1, 1) => value,
+        (1, _) => builder.build_int_z_extend(value, ty, "frombool").unwrap(),
+        _ => bool_to_int_type(
             builder,
-            ctx,
             builder
-                .build_int_compare(
-                    IntPredicate::NE,
-                    bool_value,
-                    bool_value.get_type().const_zero(),
-                    "",
-                )
+                .build_int_compare(IntPredicate::NE, value, value.get_type().const_zero(), "tobool")
                 .unwrap(),
+            ty,
         ),
     }
 }