machinst x64: implement float-to-int and int-to-float conversions;

cranelift/codegen/src/isa/x64/inst/args.rs

@@ -332,7 +332,7 @@ pub(crate) enum InstructionSet {
 
 /// Some scalar SSE operations requiring 2 operands r/m and r.
 /// TODO: Below only includes scalar operations. To be seen if packed will be added here.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, Copy, PartialEq)]
 pub enum SseOpcode {
     Addss,
     Addsd,
@@ -797,3 +797,26 @@ impl BranchTarget {
         }
     }
 }
+
+/// An operand's size in bits.
+#[derive(Clone, Copy, PartialEq)]
+pub enum OperandSize {
+    Size32,
+    Size64,
+}
+
+impl OperandSize {
+    pub(crate) fn to_bytes(&self) -> u8 {
+        match self {
+            Self::Size32 => 4,
+            Self::Size64 => 8,
+        }
+    }
+
+    pub(crate) fn to_bits(&self) -> u8 {
+        match self {
+            Self::Size32 => 32,
+            Self::Size64 => 64,
+        }
+    }
+}