Add a Context::compile() function which runs all compiler passes.

This is the main entry point to the code generator. It returns the
computed size of the functions code.

Also add a 'test compile' command which runs the whole code generation
pipeline.

lib/cretonne/src/binemit/relaxation.rs

@@ -31,11 +31,12 @@ use binemit::CodeOffset;
 use ir::{Function, DataFlowGraph, Cursor, InstructionData, Opcode, InstEncodings};
 use isa::{TargetIsa, EncInfo};
 use iterators::IteratorExtras;
+use result::CtonError;
 
 /// Relax branches and compute the final layout of EBB headers in `func`.
 ///
 /// Fill in the `func.offsets` table so the function is ready for binary emission.
-pub fn relax_branches(func: &mut Function, isa: &TargetIsa) {
+pub fn relax_branches(func: &mut Function, isa: &TargetIsa) -> Result<CodeOffset, CtonError> {
     let encinfo = isa.encoding_info();
 
     // Clear all offsets so we can recognize EBBs that haven't been visited yet.
@@ -45,13 +46,15 @@ pub fn relax_branches(func: &mut Function, isa: &TargetIsa) {
     // Start by inserting fall through instructions.
     fallthroughs(func);
 
+    let mut offset = 0;
+
     // The relaxation algorithm iterates to convergence.
     let mut go_again = true;
     while go_again {
         go_again = false;
+        offset = 0;
 
         // Visit all instructions in layout order
-        let mut offset = 0;
         let mut pos = Cursor::new(&mut func.layout);
         while let Some(ebb) = pos.next_ebb() {
             // Record the offset for `ebb` and make sure we iterate until offsets are stable.
@@ -90,6 +93,8 @@ pub fn relax_branches(func: &mut Function, isa: &TargetIsa) {
             }
         }
     }
+
+    Ok(offset)
 }
 
 /// Convert `jump` instructions to `fallthrough` instructions where possible and verify that any

lib/cretonne/src/context.rs

@@ -9,6 +9,7 @@
 //! contexts concurrently. Typically, you would have one context per compilation thread and only a
 //! single ISA instance.
 
+use binemit::{CodeOffset, relax_branches};
 use dominator_tree::DominatorTree;
 use flowgraph::ControlFlowGraph;
 use ir::Function;
@@ -16,7 +17,7 @@ use loop_analysis::LoopAnalysis;
 use isa::TargetIsa;
 use legalize_function;
 use regalloc;
-use result::CtonResult;
+use result::{CtonError, CtonResult};
 use verifier;
 use simple_gvn::do_simple_gvn;
 use licm::do_licm;
@@ -54,6 +55,22 @@ impl Context {
         }
     }
 
+    /// Compile the function.
+    ///
+    /// Run the function through all the passes necessary to generate code for the target ISA
+    /// represented by `isa`. This does not include the final step of emitting machine code into a
+    /// code sink.
+    ///
+    /// Returns the size of the function's code.
+    pub fn compile(&mut self, isa: &TargetIsa) -> Result<CodeOffset, CtonError> {
+        self.flowgraph();
+        self.verify_if(isa)?;
+
+        self.legalize(isa)?;
+        self.regalloc(isa)?;
+        self.relax_branches(isa)
+    }
+
     /// Run the verifier on the function.
     ///
     /// Also check that the dominator tree and control flow graph are consistent with the function.
@@ -107,4 +124,12 @@ impl Context {
         self.regalloc
             .run(isa, &mut self.func, &self.cfg, &self.domtree)
     }
+
+    /// Run the branch relaxation pass and return the final code size.
+    pub fn relax_branches(&mut self, isa: &TargetIsa) -> Result<CodeOffset, CtonError> {
+        let code_size = relax_branches(&mut self.func, isa)?;
+        self.verify_if(isa)?;
+
+        Ok(code_size)
+    }
 }