Move encoding-related information into an EncInfo struct.

The tables returned by recipe_names() and recipe_constraints() are now
collected into an EncInfo struct that is available from
TargetIsa::encoding_info(). This is equivalent to the register bank
tables available fro TargetIsa::register_info().

This cleans of the TargetIsa interface and makes it easier to add
encoding-related information.

lib/cretonne/src/isa/arm32/enc_tables.rs

@@ -2,7 +2,8 @@
 
 use ir::InstructionData;
 use ir::types;
-use isa::enc_tables::{Level1Entry, Level2Entry};
+use isa::EncInfo;
 use isa::constraints::*;
+use isa::enc_tables::{Level1Entry, Level2Entry};
 
 include!(concat!(env!("OUT_DIR"), "/encoding-arm32.rs"));

lib/cretonne/src/isa/arm32/mod.rs

@@ -9,7 +9,7 @@ use binemit::CodeSink;
 use super::super::settings as shared_settings;
 use isa::enc_tables::{self as shared_enc_tables, lookup_enclist, general_encoding};
 use isa::Builder as IsaBuilder;
-use isa::{TargetIsa, RegInfo, Encoding, Legalize, RecipeConstraints};
+use isa::{TargetIsa, RegInfo, EncInfo, Encoding, Legalize};
 use ir;
 
 #[allow(dead_code)]
@@ -55,6 +55,10 @@ impl TargetIsa for Isa {
         registers::INFO.clone()
     }
 
+    fn encoding_info(&self) -> EncInfo {
+        enc_tables::INFO.clone()
+    }
+
     fn encode(&self,
               dfg: &ir::DataFlowGraph,
               inst: &ir::InstructionData)
@@ -72,14 +76,6 @@ impl TargetIsa for Isa {
                 })
     }
 
-    fn recipe_names(&self) -> &'static [&'static str] {
-        &enc_tables::RECIPE_NAMES[..]
-    }
-
-    fn recipe_constraints(&self) -> &'static [RecipeConstraints] {
-        &enc_tables::RECIPE_CONSTRAINTS
-    }
-
     fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
         binemit::emit_inst(func, inst, sink)
     }

lib/cretonne/src/isa/arm64/enc_tables.rs

@@ -2,7 +2,8 @@
 
 use ir::InstructionData;
 use ir::types;
-use isa::enc_tables::{Level1Entry, Level2Entry};
+use isa::EncInfo;
 use isa::constraints::*;
+use isa::enc_tables::{Level1Entry, Level2Entry};
 
 include!(concat!(env!("OUT_DIR"), "/encoding-arm64.rs"));

lib/cretonne/src/isa/arm64/mod.rs

@@ -9,7 +9,7 @@ use binemit::CodeSink;
 use super::super::settings as shared_settings;
 use isa::enc_tables::{lookup_enclist, general_encoding};
 use isa::Builder as IsaBuilder;
-use isa::{TargetIsa, RegInfo, Encoding, Legalize, RecipeConstraints};
+use isa::{TargetIsa, RegInfo, EncInfo, Encoding, Legalize};
 use ir;
 
 #[allow(dead_code)]
@@ -48,6 +48,10 @@ impl TargetIsa for Isa {
         registers::INFO.clone()
     }
 
+    fn encoding_info(&self) -> EncInfo {
+        enc_tables::INFO.clone()
+    }
+
     fn encode(&self,
               dfg: &ir::DataFlowGraph,
               inst: &ir::InstructionData)
@@ -65,14 +69,6 @@ impl TargetIsa for Isa {
                 })
     }
 
-    fn recipe_names(&self) -> &'static [&'static str] {
-        &enc_tables::RECIPE_NAMES[..]
-    }
-
-    fn recipe_constraints(&self) -> &'static [RecipeConstraints] {
-        &enc_tables::RECIPE_CONSTRAINTS
-    }
-
     fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
         binemit::emit_inst(func, inst, sink)
     }

lib/cretonne/src/isa/encoding.rs

@@ -1,6 +1,7 @@
 //! The `Encoding` struct.
 
 use std::fmt;
+use isa::constraints::RecipeConstraints;
 
 /// Bits needed to encode an instruction as binary machine code.
 ///
@@ -76,3 +77,28 @@ impl fmt::Display for DisplayEncoding {
         }
     }
 }
+
+/// Information about all the encodings in this ISA.
+#[derive(Clone)]
+pub struct EncInfo {
+    /// Constraints on value operands per recipe.
+    pub constraints: &'static [RecipeConstraints],
+
+    /// Names of encoding recipes.
+    pub names: &'static [&'static str],
+}
+
+impl EncInfo {
+    /// Get the value operand constraints for `enc` if it is a legal encoding.
+    pub fn operand_constraints(&self, enc: Encoding) -> Option<&RecipeConstraints> {
+        self.constraints.get(enc.recipe())
+    }
+
+    /// Create an object that can display an ISA-dependent encoding properly.
+    pub fn display(&self, enc: Encoding) -> DisplayEncoding {
+        DisplayEncoding {
+            encoding: enc,
+            recipe_names: self.names,
+        }
+    }
+}

lib/cretonne/src/isa/intel/enc_tables.rs

@@ -2,7 +2,8 @@
 
 use ir::InstructionData;
 use ir::types;
-use isa::enc_tables::{Level1Entry, Level2Entry};
+use isa::EncInfo;
 use isa::constraints::*;
+use isa::enc_tables::{Level1Entry, Level2Entry};
 
 include!(concat!(env!("OUT_DIR"), "/encoding-intel.rs"));

lib/cretonne/src/isa/intel/mod.rs

@@ -9,7 +9,7 @@ use binemit::CodeSink;
 use super::super::settings as shared_settings;
 use isa::enc_tables::{self as shared_enc_tables, lookup_enclist, general_encoding};
 use isa::Builder as IsaBuilder;
-use isa::{TargetIsa, RegInfo, Encoding, Legalize, RecipeConstraints};
+use isa::{TargetIsa, RegInfo, EncInfo, Encoding, Legalize};
 use ir;
 
 #[allow(dead_code)]
@@ -55,6 +55,10 @@ impl TargetIsa for Isa {
         registers::INFO.clone()
     }
 
+    fn encoding_info(&self) -> EncInfo {
+        enc_tables::INFO.clone()
+    }
+
     fn encode(&self,
               dfg: &ir::DataFlowGraph,
               inst: &ir::InstructionData)
@@ -72,14 +76,6 @@ impl TargetIsa for Isa {
                 })
     }
 
-    fn recipe_names(&self) -> &'static [&'static str] {
-        &enc_tables::RECIPE_NAMES[..]
-    }
-
-    fn recipe_constraints(&self) -> &'static [RecipeConstraints] {
-        &enc_tables::RECIPE_CONSTRAINTS
-    }
-
     fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
         binemit::emit_inst(func, inst, sink)
     }

lib/cretonne/src/isa/mod.rs

@@ -40,9 +40,9 @@
 //! The configured target ISA trait object is a `Box<TargetIsa>` which can be used for multiple
 //! concurrent function compilations.
 
-pub use isa::encoding::Encoding;
-pub use isa::registers::{RegInfo, RegUnit, RegClass, RegClassIndex};
 pub use isa::constraints::{RecipeConstraints, OperandConstraint, ConstraintKind};
+pub use isa::encoding::{Encoding, EncInfo};
+pub use isa::registers::{RegInfo, RegUnit, RegClass, RegClassIndex};
 
 use binemit::CodeSink;
 use settings;
@@ -143,25 +143,8 @@ pub trait TargetIsa {
     /// This is also the main entry point for determining if an instruction is legal.
     fn encode(&self, dfg: &DataFlowGraph, inst: &InstructionData) -> Result<Encoding, Legalize>;
 
-    /// Get a static array of names associated with encoding recipes in this ISA. Encoding recipes
-    /// are numbered starting from 0, corresponding to indexes into the name array.
-    ///
-    /// This is just used for printing and parsing encodings in the textual IL format.
-    fn recipe_names(&self) -> &'static [&'static str];
-
-    /// Get a static array of value operand constraints associated with encoding recipes in this
-    /// ISA.
-    ///
-    /// The constraints describe which registers can be used with an encoding recipe.
-    fn recipe_constraints(&self) -> &'static [RecipeConstraints];
-
-    /// Create an object that can display an ISA-dependent encoding properly.
-    fn display_enc(&self, enc: Encoding) -> encoding::DisplayEncoding {
-        encoding::DisplayEncoding {
-            encoding: enc,
-            recipe_names: self.recipe_names(),
-        }
-    }
+    /// Get a data structure describing the instruction encodings in this ISA.
+    fn encoding_info(&self) -> EncInfo;
 
     /// Legalize a function signature.
     ///

lib/cretonne/src/isa/riscv/enc_tables.rs

@@ -1,11 +1,12 @@
 //! Encoding tables for RISC-V.
 
 use ir::condcodes::IntCC;
-use ir::{Opcode, InstructionData};
 use ir::types;
-use predicates;
-use isa::enc_tables::{Level1Entry, Level2Entry};
+use ir::{Opcode, InstructionData};
+use isa::EncInfo;
 use isa::constraints::*;
+use isa::enc_tables::{Level1Entry, Level2Entry};
+use predicates;
 use super::registers::*;
 
 // Include the generated encoding tables:
@@ -13,4 +14,5 @@ use super::registers::*;
 // - `LEVEL1_RV64`
 // - `LEVEL2`
 // - `ENCLIST`
+// - `INFO`
 include!(concat!(env!("OUT_DIR"), "/encoding-riscv.rs"));

lib/cretonne/src/isa/riscv/mod.rs

@@ -10,7 +10,7 @@ use super::super::settings as shared_settings;
 use binemit::CodeSink;
 use isa::enc_tables::{self as shared_enc_tables, lookup_enclist, general_encoding};
 use isa::Builder as IsaBuilder;
-use isa::{TargetIsa, RegInfo, Encoding, Legalize, RecipeConstraints};
+use isa::{TargetIsa, RegInfo, EncInfo, Encoding, Legalize};
 use ir::{Function, Inst, InstructionData, DataFlowGraph, Signature};
 
 #[allow(dead_code)]
@@ -56,6 +56,10 @@ impl TargetIsa for Isa {
         registers::INFO.clone()
     }
 
+    fn encoding_info(&self) -> EncInfo {
+        enc_tables::INFO.clone()
+    }
+
     fn encode(&self, dfg: &DataFlowGraph, inst: &InstructionData) -> Result<Encoding, Legalize> {
         lookup_enclist(inst.ctrl_typevar(dfg),
                        inst.opcode(),
@@ -70,14 +74,6 @@ impl TargetIsa for Isa {
                 })
     }
 
-    fn recipe_names(&self) -> &'static [&'static str] {
-        &enc_tables::RECIPE_NAMES[..]
-    }
-
-    fn recipe_constraints(&self) -> &'static [RecipeConstraints] {
-        &enc_tables::RECIPE_CONSTRAINTS
-    }
-
     fn legalize_signature(&self, sig: &mut Signature) {
         // We can pass in `self.isa_flags` too, if we need it.
         abi::legalize_signature(sig, &self.shared_flags)
@@ -100,7 +96,7 @@ mod tests {
     use ir::{types, immediates};
 
     fn encstr(isa: &isa::TargetIsa, enc: isa::Encoding) -> String {
-        isa.display_enc(enc).to_string()
+        isa.encoding_info().display(enc).to_string()
     }
 
     #[test]