Add get_bit_width method for float type (#589)

* feat: add `get_bit_width` method for float type

* test: add `test_float_type`

* fix: change bfloat to only llvm11+

---------

Co-authored-by: Dan Kolsoi <ThaDan64@gmail.com>

Author: my4ng

src/types/float_type.rs

@@ -1,4 +1,4 @@
-use llvm_sys::core::{LLVMConstReal, LLVMConstRealOfStringAndSize};
+use llvm_sys::core::{LLVMConstReal, LLVMConstRealOfStringAndSize, LLVMGetTypeKind};
 use llvm_sys::execution_engine::LLVMCreateGenericValueOfFloat;
 use llvm_sys::prelude::LLVMTypeRef;
 
@@ -254,6 +254,41 @@ impl<'ctx> FloatType<'ctx> {
         self.float_type.ptr_type(address_space)
     }
 
+    /// Gets the bit width of a `FloatType`.
+    ///
+    /// # Example
+    /// ```no_run
+    /// use inkwell::context::Context;
+    ///
+    /// let context = Context::create();
+    /// let f128_type = context.f128_type();
+    ///
+    /// assert_eq!(f128_type.get_bit_width(), 128);
+    /// ```
+    pub fn get_bit_width(self) -> u32 {
+        let type_kind = unsafe { LLVMGetTypeKind(self.as_type_ref()) };
+
+        match type_kind {
+            llvm_sys::LLVMTypeKind::LLVMHalfTypeKind => 16,
+            #[cfg(any(
+                feature = "llvm11-0",
+                feature = "llvm12-0",
+                feature = "llvm13-0",
+                feature = "llvm14-0",
+                feature = "llvm15-0",
+                feature = "llvm16-0",
+                feature = "llvm17-0",
+                feature = "llvm18-1"
+            ))]
+            llvm_sys::LLVMTypeKind::LLVMBFloatTypeKind => 16,
+            llvm_sys::LLVMTypeKind::LLVMFloatTypeKind => 32,
+            llvm_sys::LLVMTypeKind::LLVMDoubleTypeKind => 64,
+            llvm_sys::LLVMTypeKind::LLVMX86_FP80TypeKind => 80,
+            llvm_sys::LLVMTypeKind::LLVMFP128TypeKind | llvm_sys::LLVMTypeKind::LLVMPPC_FP128TypeKind => 128,
+            _ => unreachable!(),
+        }
+    }
+
     /// Print the definition of a `FloatType` to `LLVMString`.
     pub fn print_to_string(self) -> LLVMString {
         self.float_type.print_to_string()

tests/all/test_types.rs

@@ -489,6 +489,25 @@ fn test_const_zero() {
     );
 }
 
+#[test]
+fn test_float_type() {
+    let context = Context::create();
+
+    let f16_type = context.f16_type();
+    let f32_type = context.f32_type();
+    let f64_type = context.f64_type();
+    let f128_type = context.f128_type();
+    let x86_f80_type = context.x86_f80_type();
+    let ppc_f128_type = context.ppc_f128_type();
+
+    assert_eq!(f16_type.get_bit_width(), 16);
+    assert_eq!(f32_type.get_bit_width(), 32);
+    assert_eq!(f64_type.get_bit_width(), 64);
+    assert_eq!(f128_type.get_bit_width(), 128);
+    assert_eq!(x86_f80_type.get_bit_width(), 80);
+    assert_eq!(ppc_f128_type.get_bit_width(), 128);
+}
+
 #[test]
 fn test_vec_type() {
     let context = Context::create();