From 7526cdc65e4f511f3835452b611b2ccd34d08d58 Mon Sep 17 00:00:00 2001
From: Afonso Bordado <afonsobordado@az8.co>
Date: Thu, 8 Jul 2021 10:15:01 +0100
Subject: [PATCH] cranelift: Use ValueConversionKind in branches

---
 cranelift/interpreter/src/step.rs  | 20 ++++++++++----------
 cranelift/interpreter/src/value.rs |  8 ++++++++
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/cranelift/interpreter/src/step.rs b/cranelift/interpreter/src/step.rs
index a29590e6a7..2030d15a40 100644
--- a/cranelift/interpreter/src/step.rs
+++ b/cranelift/interpreter/src/step.rs
@@ -142,16 +142,16 @@ where
     // Interpret a Cranelift instruction.
     Ok(match inst.opcode() {
         Opcode::Jump | Opcode::Fallthrough => ControlFlow::ContinueAt(branch(), args()?),
-        Opcode::Brz => branch_when(match arg(0)?.ty() {
-            ty if ty.is_bool() => !arg(0)?.into_bool()?,
-            ty if ty.is_int() => arg(0)?.into_int()? == 0,
-            _ => return Err(StepError::ValueError(ValueError::InvalidValue(types::B1))),
-        })?,
-        Opcode::Brnz => branch_when(match arg(0)?.ty() {
-            ty if ty.is_bool() => arg(0)?.into_bool()?,
-            ty if ty.is_int() => arg(0)?.into_int()? != 0,
-            _ => return Err(StepError::ValueError(ValueError::InvalidValue(types::B1))),
-        })?,
+        Opcode::Brz => branch_when(
+            !arg(0)?
+                .convert(ValueConversionKind::ToBoolean)?
+                .into_bool()?,
+        )?,
+        Opcode::Brnz => branch_when(
+            arg(0)?
+                .convert(ValueConversionKind::ToBoolean)?
+                .into_bool()?,
+        )?,
         Opcode::BrIcmp => branch_when(icmp(inst.cond_code().unwrap(), &arg(0)?, &arg(1)?)?)?,
         Opcode::Brif => branch_when(state.has_iflag(inst.cond_code().unwrap()))?,
         Opcode::Brff => branch_when(state.has_fflag(inst.fp_cond_code().unwrap()))?,
diff --git a/cranelift/interpreter/src/value.rs b/cranelift/interpreter/src/value.rs
index 991e83bad3..54bff022a2 100644
--- a/cranelift/interpreter/src/value.rs
+++ b/cranelift/interpreter/src/value.rs
@@ -108,6 +108,9 @@ pub enum ValueConversionKind {
     /// Convert a floating point number by rounding to the nearest possible value with ties to even.
     /// See `fdemote`, e.g.
     RoundNearestEven(Type),
+    /// Converts an integer into a boolean, zero integers are converted into a
+    /// `false`, while other integers are converted into `true`. Booleans are passed through.
+    ToBoolean,
 }
 
 /// Helper for creating match expressions over [DataValue].
@@ -263,6 +266,11 @@ impl Value for DataValue {
                 (types::F64, types::F32) => unimplemented!(),
                 _ => unimplemented!("conversion: {} -> {:?}", self.ty(), kind),
             },
+            ValueConversionKind::ToBoolean => match self.ty() {
+                ty if ty.is_bool() => DataValue::B(self.into_bool()?),
+                ty if ty.is_int() => DataValue::B(self.into_int()? != 0),
+                ty => unimplemented!("conversion: {} -> {:?}", ty, kind),
+            },
         })
     }