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.

cranelift/src/filetest/binemit.rs

@@ -12,7 +12,7 @@ use cretonne::ir::entities::AnyEntity;
 use cretonne::isa::TargetIsa;
 use cton_reader::TestCommand;
 use filetest::subtest::{SubTest, Context, Result};
-use utils::match_directive;
+use utils::{match_directive, pretty_error};
 
 struct TestBinEmit;
 
@@ -117,7 +117,8 @@ impl SubTest for TestBinEmit {
         }
 
         // Relax branches and compute EBB offsets based on the encodings.
-        binemit::relax_branches(&mut func, isa);
+        let code_size = binemit::relax_branches(&mut func, isa)
+            .map_err(|e| pretty_error(&func, context.isa, e))?;
 
         // Collect all of the 'bin:' directives on instructions.
         let mut bins = HashMap::new();
@@ -188,6 +189,10 @@ impl SubTest for TestBinEmit {
             }
         }
 
+        if sink.offset != code_size {
+            return Err(format!("Expected code size {}, got {}", code_size, sink.offset));
+        }
+
         Ok(())
     }
 }

cranelift/src/filetest/compile.rs

@@ -0,0 +1,98 @@
+//! Test command for testing the code generator pipeline
+//!
+//! The `compile` test command runs each function through the full code generator pipeline
+
+use cretonne::binemit;
+use cretonne::ir;
+use cretonne;
+use cton_reader::TestCommand;
+use filetest::subtest::{SubTest, Context, Result};
+use std::borrow::Cow;
+use utils::pretty_error;
+
+struct TestCompile;
+
+pub fn subtest(parsed: &TestCommand) -> Result<Box<SubTest>> {
+    assert_eq!(parsed.command, "compile");
+    if !parsed.options.is_empty() {
+        Err(format!("No options allowed on {}", parsed))
+    } else {
+        Ok(Box::new(TestCompile))
+    }
+}
+
+impl SubTest for TestCompile {
+    fn name(&self) -> Cow<str> {
+        Cow::from("compile")
+    }
+
+    fn is_mutating(&self) -> bool {
+        true
+    }
+
+    fn needs_isa(&self) -> bool {
+        true
+    }
+
+    fn run(&self, func: Cow<ir::Function>, context: &Context) -> Result<()> {
+        let isa = context.isa.expect("compile needs an ISA");
+
+        // Create a compilation context, and drop in the function.
+        let mut comp_ctx = cretonne::Context::new();
+        comp_ctx.func = func.into_owned();
+
+        let code_size = comp_ctx
+            .compile(isa)
+            .map_err(|e| pretty_error(&comp_ctx.func, context.isa, e))?;
+
+        dbg!("Generated {} bytes of code:\n{}",
+             code_size,
+             comp_ctx.func.display(isa));
+
+        // Finally verify that the returned code size matches the emitted bytes.
+        let mut sink = SizeSink { offset: 0 };
+        for ebb in comp_ctx.func.layout.ebbs() {
+            assert_eq!(sink.offset, comp_ctx.func.offsets[ebb]);
+            for inst in comp_ctx.func.layout.ebb_insts(ebb) {
+                isa.emit_inst(&comp_ctx.func, inst, &mut sink);
+            }
+        }
+
+        if sink.offset != code_size {
+            return Err(format!("Expected code size {}, got {}", code_size, sink.offset));
+        }
+
+        Ok(())
+    }
+}
+
+// Code sink that simply counts bytes.
+struct SizeSink {
+    offset: binemit::CodeOffset,
+}
+
+impl binemit::CodeSink for SizeSink {
+    fn offset(&self) -> binemit::CodeOffset {
+        self.offset
+    }
+
+    fn put1(&mut self, _: u8) {
+        self.offset += 1;
+    }
+
+    fn put2(&mut self, _: u16) {
+        self.offset += 2;
+    }
+
+    fn put4(&mut self, _: u32) {
+        self.offset += 4;
+    }
+
+    fn put8(&mut self, _: u64) {
+        self.offset += 8;
+    }
+
+    fn reloc_ebb(&mut self, _reloc: binemit::Reloc, _ebb: ir::Ebb) {}
+    fn reloc_func(&mut self, _reloc: binemit::Reloc, _fref: ir::FuncRef) {}
+    fn reloc_jt(&mut self, _reloc: binemit::Reloc, _jt: ir::JumpTable) {}
+}

cranelift/src/filetest/mod.rs

@@ -14,6 +14,7 @@ use filetest::runner::TestRunner;
 pub mod subtest;
 
 mod binemit;
+mod compile;
 mod concurrent;
 mod domtree;
 mod legalizer;
@@ -57,15 +58,16 @@ pub fn run(verbose: bool, files: Vec<String>) -> CommandResult {
 /// a `.cton` test file.
 fn new_subtest(parsed: &TestCommand) -> subtest::Result<Box<subtest::SubTest>> {
     match parsed.command {
+        "binemit" => binemit::subtest(parsed),
         "cat" => cat::subtest(parsed),
-        "print-cfg" => print_cfg::subtest(parsed),
+        "compile" => compile::subtest(parsed),
         "domtree" => domtree::subtest(parsed),
-        "verifier" => verifier::subtest(parsed),
         "legalizer" => legalizer::subtest(parsed),
         "licm" => licm::subtest(parsed),
+        "print-cfg" => print_cfg::subtest(parsed),
         "regalloc" => regalloc::subtest(parsed),
-        "binemit" => binemit::subtest(parsed),
         "simple-gvn" => simple_gvn::subtest(parsed),
+        "verifier" => verifier::subtest(parsed),
         _ => Err(format!("unknown test command '{}'", parsed.command)),
     }
 }

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)
+    }
 }