Merge pull request #3431 from bjorn3/remove_sarg_t

Remove the sarg_t type and dummy_sarg_t instruction

cranelift/codegen/meta/src/cdsl/types.rs

@@ -393,8 +393,6 @@ impl fmt::Debug for VectorType {
 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
 pub(crate) enum SpecialType {
     Flag(shared_types::Flag),
-    // FIXME remove once the old style backends are removed.
-    StructArgument,
 }
 
 impl SpecialType {
@@ -409,9 +407,6 @@ impl SpecialType {
                 "CPU flags representing the result of a floating point comparison. These
                 flags can be tested with a :type:`floatcc` condition code.",
             ),
-            SpecialType::StructArgument => {
-                String::from("After legalization sarg_t arguments will get this type.")
-            }
         }
     }
 
@@ -419,7 +414,6 @@ impl SpecialType {
     pub fn lane_bits(self) -> u64 {
         match self {
             SpecialType::Flag(_) => 0,
-            SpecialType::StructArgument => 0,
         }
     }
 
@@ -428,7 +422,6 @@ impl SpecialType {
         match self {
             SpecialType::Flag(shared_types::Flag::IFlags) => 1,
             SpecialType::Flag(shared_types::Flag::FFlags) => 2,
-            SpecialType::StructArgument => 3,
         }
     }
 }
@@ -438,7 +431,6 @@ impl fmt::Display for SpecialType {
         match *self {
             SpecialType::Flag(shared_types::Flag::IFlags) => write!(f, "iflags"),
             SpecialType::Flag(shared_types::Flag::FFlags) => write!(f, "fflags"),
-            SpecialType::StructArgument => write!(f, "sarg_t"),
         }
     }
 }
@@ -450,7 +442,6 @@ impl fmt::Debug for SpecialType {
             "{}",
             match *self {
                 SpecialType::Flag(_) => format!("FlagsType({})", self),
-                SpecialType::StructArgument => format!("StructArgument"),
             }
         )
     }
@@ -464,14 +455,12 @@ impl From<shared_types::Flag> for SpecialType {
 
 pub(crate) struct SpecialTypeIterator {
     flag_iter: shared_types::FlagIterator,
-    done: bool,
 }
 
 impl SpecialTypeIterator {
     fn new() -> Self {
         Self {
             flag_iter: shared_types::FlagIterator::new(),
-            done: false,
         }
     }
 }
@@ -479,16 +468,7 @@ impl SpecialTypeIterator {
 impl Iterator for SpecialTypeIterator {
     type Item = SpecialType;
     fn next(&mut self) -> Option<Self::Item> {
-        if let Some(f) = self.flag_iter.next() {
-            Some(SpecialType::from(f))
-        } else {
-            if !self.done {
-                self.done = true;
-                Some(SpecialType::StructArgument)
-            } else {
-                None
-            }
-        }
+        self.flag_iter.next().map(SpecialType::from)
     }
 }