[meta] Use named predicates for x86 settings in the Rust crate too;

And generate them using the same deterministic order that the Python
code uses.

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

@@ -23,6 +23,15 @@ macro_rules! predicate {
     ($a:ident && $($b:tt)*) => {
         PredicateNode::And(Box::new($a.into()), Box::new(predicate!($($b)*)))
     };
+    (!$a:ident && $($b:tt)*) => {
+        PredicateNode::And(
+            Box::new(PredicateNode::Not(Box::new($a.into()))),
+            Box::new(predicate!($($b)*))
+        )
+    };
+    (!$a:ident) => {
+        PredicateNode::Not(Box::new($a.into()))
+    };
     ($a:ident) => {
         $a.into()
     };

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

@@ -153,7 +153,7 @@ impl SettingGroup {
 /// This is the basic information needed to track the specific parts of a setting when building
 /// them.
 pub enum ProtoSpecificSetting {
-    Bool(bool, u8),
+    Bool(bool),
     Enum(Vec<&'static str>),
     Num(u8),
 }
@@ -169,6 +169,7 @@ struct ProtoSetting {
 pub enum PredicateNode {
     OwnedBool(BoolSettingIndex),
     SharedBool(&'static str, &'static str),
+    Not(Box<PredicateNode>),
     And(Box<PredicateNode>, Box<PredicateNode>),
 }
 
@@ -198,10 +199,16 @@ impl PredicateNode {
             PredicateNode::And(ref lhs, ref rhs) => {
                 format!("{} && {}", lhs.render(group), rhs.render(group))
             }
+            PredicateNode::Not(ref node) => format!("!({})", node.render(group)),
         }
     }
 }
 
+struct ProtoPredicate {
+    pub name: &'static str,
+    node: PredicateNode,
+}
+
 pub struct Predicate {
     pub name: &'static str,
     node: PredicateNode,
@@ -218,8 +225,7 @@ pub struct SettingGroupBuilder {
     name: &'static str,
     settings: Vec<ProtoSetting>,
     presets: Vec<Preset>,
-    predicates: Vec<Predicate>,
-    predicate_number: u8,
+    predicates: Vec<ProtoPredicate>,
 }
 
 impl SettingGroupBuilder {
@@ -229,7 +235,6 @@ impl SettingGroupBuilder {
             settings: Vec::new(),
             presets: Vec::new(),
             predicates: Vec::new(),
-            predicate_number: 0,
         }
     }
 
@@ -256,13 +261,7 @@ impl SettingGroupBuilder {
             self.predicates.len() == 0,
             "predicates must be added after the boolean settings"
         );
-        let predicate_number = self.predicate_number;
-        self.predicate_number += 1;
-        self.add_setting(
-            name,
-            comment,
-            ProtoSpecificSetting::Bool(default, predicate_number),
-        );
+        self.add_setting(name, comment, ProtoSpecificSetting::Bool(default));
         BoolSettingIndex(self.settings.len() - 1)
     }
 
@@ -280,9 +279,7 @@ impl SettingGroupBuilder {
     }
 
     pub fn add_predicate(&mut self, name: &'static str, node: PredicateNode) {
-        let number = self.predicate_number;
-        self.predicate_number += 1;
-        self.predicates.push(Predicate { name, node, number });
+        self.predicates.push(ProtoPredicate { name, node });
     }
 
     pub fn add_preset(&mut self, name: &'static str, args: Vec<PresetType>) -> PresetIndex {
@@ -307,8 +304,8 @@ impl SettingGroupBuilder {
     /// 1. Byte-sized settings like `NumSetting` and `EnumSetting`.
     /// 2. `BoolSetting` settings.
     /// 3. Precomputed named predicates.
-    /// 4. Other numbered predicates, including anonymous predicates and parent
-    ///    predicates that need to be accessible by number.
+    /// 4. Other numbered predicates, including parent predicates that need to be accessible by
+    ///    number.
     ///
     /// Set `self.settings_size` to the length of the byte vector prefix that
     /// contains the settings. All bytes after that are computed, not
@@ -318,9 +315,6 @@ impl SettingGroupBuilder {
     /// 2. in the list above.
     ///
     /// Assign `byte_offset` and `bit_offset` fields in all settings.
-    ///
-    /// After calling this method, no more settings can be added, but
-    /// additional predicates can be made accessible with `number_predicate()`.
     pub fn finish(self) -> SettingGroup {
         let mut group = SettingGroup {
             name: self.name,
@@ -353,12 +347,12 @@ impl SettingGroupBuilder {
 
         group.bool_start_byte_offset = byte_offset;
 
+        let mut predicate_number = 0;
+
         // Then the boolean settings.
         for s in &self.settings {
-            let (default, predicate_number) = match s.specific {
-                ProtoSpecificSetting::Bool(default, predicate_number) => {
-                    (default, predicate_number)
-                }
+            let default = match s.specific {
+                ProtoSpecificSetting::Bool(default) => default,
                 ProtoSpecificSetting::Enum(_) | ProtoSpecificSetting::Num(_) => continue,
             };
             group.settings.push(Setting {
@@ -371,6 +365,7 @@ impl SettingGroupBuilder {
                     predicate_number,
                 }),
             });
+            predicate_number += 1;
         }
 
         assert!(
@@ -379,7 +374,22 @@ impl SettingGroupBuilder {
         );
         group.settings_size = group.byte_size();
 
-        group.predicates.extend(self.predicates);
+        // Sort predicates by name to ensure the same order as the Python code.
+        let mut predicates = self.predicates;
+        predicates.sort_by_key(|predicate| predicate.name);
+
+        group
+            .predicates
+            .extend(predicates.into_iter().map(|predicate| {
+                let number = predicate_number;
+                predicate_number += 1;
+                return Predicate {
+                    name: predicate.name,
+                    node: predicate.node,
+                    number,
+                };
+            }));
+
         group.presets.extend(self.presets);
 
         group

cranelift/codegen/meta/src/isa/x86/mod.rs

@@ -11,7 +11,7 @@ use crate::shared::Definitions as SharedDefinitions;
 mod instructions;
 mod legalize;
 
-fn define_settings(_shared: &SettingGroup) -> SettingGroup {
+fn define_settings(shared: &SettingGroup) -> SettingGroup {
     let mut settings = SettingGroupBuilder::new("x86");
 
     // CPUID.01H:ECX
@@ -47,6 +47,24 @@ fn define_settings(_shared: &SettingGroup) -> SettingGroup {
     settings.add_predicate("use_bmi1", predicate!(has_bmi1));
     settings.add_predicate("use_lznct", predicate!(has_lzcnt));
 
+    // Some shared boolean values are used in x86 instruction predicates, so we need to group them
+    // in the same TargetIsa, for compabitibity with code generated by meta-python.
+    // TODO Once all the meta generation code has been migrated from Python to Rust, we can put it
+    // back in the shared SettingGroup, and use it in x86 instruction predicates.
+
+    let is_pic = shared.get_bool("is_pic");
+    let allones_funcaddrs = shared.get_bool("allones_funcaddrs");
+    settings.add_predicate("is_pic", predicate!(is_pic));
+    settings.add_predicate("not_is_pic", predicate!(!is_pic));
+    settings.add_predicate(
+        "all_ones_funcaddrs_and_not_is_pic",
+        predicate!(allones_funcaddrs && !is_pic),
+    );
+    settings.add_predicate(
+        "not_all_ones_funcaddrs_and_not_is_pic",
+        predicate!(!allones_funcaddrs && !is_pic),
+    );
+
     settings.add_preset("baseline", preset!());
     let nehalem = settings.add_preset(
         "nehalem",