Coalesce some formats into MultiAry.

Allow some flexibility in the signature matching for instruction
formats. In particular, look for a value list format as a second chance
option.

The Return, ReturnReg, and TernaryOverflow formats all fit the single
MultiAry catch-all format for instructions without immediate operands.

lib/cretonne/src/ir/builder.rs

@@ -3,7 +3,7 @@
 //! A `Builder` provides a convenient interface for inserting instructions into a Cretonne
 //! function. Many of its methods are generated from the meta language instruction definitions.
 
-use ir::{types, instructions};
+use ir::types;
 use ir::{InstructionData, DataFlowGraph, Cursor};
 use ir::{Opcode, Type, Inst, Value, Ebb, JumpTable, SigRef, FuncRef, ValueList};
 use ir::immediates::{Imm64, Uimm8, Ieee32, Ieee64};

lib/cretonne/src/ir/instructions.rs

@@ -151,11 +151,11 @@ pub enum InstructionData {
         ty: Type,
         args: [Value; 3],
     },
-    TernaryOverflow {
+    MultiAry {
         opcode: Opcode,
         ty: Type,
         second_result: PackedOption<Value>,
-        data: Box<TernaryOverflowData>,
+        args: ValueList,
     },
     InsertLane {
         opcode: Opcode,
@@ -213,16 +213,6 @@ pub enum InstructionData {
         sig_ref: SigRef,
         args: ValueList,
     },
-    Return {
-        opcode: Opcode,
-        ty: Type,
-        args: ValueList,
-    },
-    ReturnReg {
-        opcode: Opcode,
-        ty: Type,
-        args: ValueList,
-    },
 }
 
 /// A variable list of `Value` operands used for function call arguments and passing arguments to
@@ -289,19 +279,6 @@ impl Default for VariableArgs {
     }
 }
 
-/// Payload data for ternary instructions with multiple results, such as `iadd_carry`.
-#[derive(Clone, Debug)]
-pub struct TernaryOverflowData {
-    /// Value arguments.
-    pub args: [Value; 3],
-}
-
-impl Display for TernaryOverflowData {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{}, {}, {}", self.args[0], self.args[1], self.args[2])
-    }
-}
-
 /// Analyzing an instruction.
 ///
 /// Avoid large matches on instruction formats by using the methods defined here to examine