Expose ssa verification as a regalloc2 option (#102)

Adds the validate_ssa flag to the RegallocOptions struct, enabling ssa validation of inputs before register allocation takes place.

Author: elliottt

fuzz/fuzz_targets/ion.rs

@@ -11,5 +11,6 @@ fuzz_target!(|func: Func| {
     let _ = env_logger::try_init();
     log::trace!("func:\n{:?}", func);
     let env = regalloc2::fuzzing::func::machine_env();
-    let _out = regalloc2::fuzzing::ion::run(&func, &env, false).expect("regalloc did not succeed");
+    let _out =
+        regalloc2::fuzzing::ion::run(&func, &env, false, false).expect("regalloc did not succeed");
 });

fuzz/fuzz_targets/ion_checker.rs

@@ -40,7 +40,8 @@ fuzz_target!(|testcase: TestCase| {
     let _ = env_logger::try_init();
     log::trace!("func:\n{:?}", func);
     let env = regalloc2::fuzzing::func::machine_env();
-    let out = regalloc2::fuzzing::ion::run(&func, &env, true).expect("regalloc did not succeed");
+    let out =
+        regalloc2::fuzzing::ion::run(&func, &env, true, false).expect("regalloc did not succeed");
 
     let mut checker = Checker::new(&func, &env);
     checker.prepare(&out);

fuzz/fuzz_targets/ssagen.rs

@@ -8,7 +8,7 @@ use regalloc2::fuzzing::arbitrary::{Arbitrary, Result, Unstructured};
 use regalloc2::fuzzing::cfg::CFGInfo;
 use regalloc2::fuzzing::func::{Func, Options};
 use regalloc2::fuzzing::fuzz_target;
-use regalloc2::fuzzing::ssa::validate_ssa;
+use regalloc2::ssa::validate_ssa;
 
 #[derive(Debug)]
 struct TestCase {

src/fuzzing/mod.rs

@@ -6,7 +6,6 @@
 //! Utilities for fuzzing.
 
 pub mod func;
-pub mod ssa;
 
 // Re-exports for fuzz targets.
 

src/ion/mod.rs

@@ -14,6 +14,7 @@
 //! its design.
 
 use crate::cfg::CFGInfo;
+use crate::ssa::validate_ssa;
 use crate::{Function, MachineEnv, Output, PReg, ProgPoint, RegAllocError, RegClass};
 use std::collections::HashMap;
 
@@ -120,9 +121,14 @@ pub fn run<F: Function>(
     func: &F,
     mach_env: &MachineEnv,
     enable_annotations: bool,
+    enable_ssa_checker: bool,
 ) -> Result<Output, RegAllocError> {
     let cfginfo = CFGInfo::new(func)?;
 
+    if enable_ssa_checker {
+        validate_ssa(func, &cfginfo)?;
+    }
+
     let mut env = Env::new(func, mach_env, cfginfo, enable_annotations);
     env.init()?;
 

src/lib.rs

@@ -34,6 +34,7 @@ pub mod indexset;
 pub(crate) mod ion;
 pub(crate) mod moves;
 pub(crate) mod postorder;
+pub mod ssa;
 
 #[macro_use]
 mod index;
@@ -1477,12 +1478,15 @@ pub fn run<F: Function>(
     env: &MachineEnv,
     options: &RegallocOptions,
 ) -> Result<Output, RegAllocError> {
-    ion::run(func, env, options.verbose_log)
+    ion::run(func, env, options.verbose_log, options.validate_ssa)
 }
 
 /// Options for allocation.
 #[derive(Clone, Copy, Debug, Default)]
 pub struct RegallocOptions {
     /// Add extra verbosity to debug logs.
     pub verbose_log: bool,
+
+    /// Run the SSA validator before allocating registers.
+    pub validate_ssa: bool,
 }