// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ssa

import "fmt"

// Compile is the main entry point for this package.
// Compile modifies f so that on return:
//   · all Values in f map to 0 or 1 assembly instructions of the target architecture
//   · the order of f.Blocks is the order to emit the Blocks
//   · the order of b.Values is the order to emit the Values in each Block
//   · f has a non-nil regAlloc field
func Compile(f *Func) {
	// TODO: debugging - set flags to control verbosity of compiler,
	// which phases to dump IR before/after, etc.
	fmt.Printf("compiling %s\n", f.Name)

	// hook to print function & phase if panic happens
	phaseName := "init"
	defer func() {
		if phaseName != "" {
			fmt.Printf("panic during %s while compiling %s\n", phaseName, f.Name)
		}
	}()

	// Run all the passes
	printFunc(f)
	checkFunc(f)
	for _, p := range passes {
		phaseName = p.name
		fmt.Printf("  pass %s begin\n", p.name)
		p.fn(f)
		fmt.Printf("  pass %s end\n", p.name)
		printFunc(f)
		checkFunc(f)
	}

	// Squash error printing defer
	phaseName = ""
}

type pass struct {
	name string
	fn   func(*Func)
}

// list of passes for the compiler
var passes = [...]pass{
	{"phielim", phielim},
	{"copyelim", copyelim},
	//{"opt", opt},
	// cse
	{"deadcode", deadcode},
	//{"fuse", fuse},
	//{"lower", lower},
	// cse
	//{"critical", critical}, // remove critical edges
	//{"layout", layout},     // schedule blocks
	//{"schedule", schedule}, // schedule values
	// regalloc
	// stack slot alloc (+size stack frame)
	//{"cgen", cgen},
}