findLoop: mark fdel

cl/_testdefer/loop/out.txt

@@ -1,7 +1,7 @@
-0: always
+ 0: always
-2: loop
+ 1: cond
-4: loop
+ 2: loop
-5: loop
+ 5: loop
-3: cond
+ 4: loop
-6: cond
+ 6: cond
-1: cond
+ 3: cond

cl/blocks/block.go

@@ -26,6 +26,8 @@ type Info struct {
 	Next int
 }
 
+// var debug = false
+
 // -----------------------------------------------------------------------------
 
 type blockState struct {
@@ -62,9 +64,12 @@ func findLoop(states []*blockState, path []int, from, iblk int) []int {
 		if states[succ].fdel {
 			continue
 		}
-		if succ == from {
+		if pos := find(path, succ); pos >= 0 {
+			path = path[pos:]
 			for _, i := range path {
-				states[i].loop = true
+				s := states[i]
+				s.loop = true
+				s.fdel = true
 			}
 			return path
 		}
@@ -153,4 +158,13 @@ func isEnd(blk *ssa.BasicBlock) bool {
 	return len(blk.Succs) == 0 && (len(blk.Preds) > 0 || blk.Index == 0)
 }
 
+func find(path []int, fv int) int {
+	for i, v := range path {
+		if v == fv {
+			return i
+		}
+	}
+	return -1
+}
+
 // -----------------------------------------------------------------------------

cl/blocks/block_test.go

@@ -38,7 +38,7 @@ import (
 
 func TestTestdefer(t *testing.T) {
 	// debug = true
-	fromDir(t, "loop", "../_testdefer")
+	fromDir(t, "print", "../_testdefer")
 }
 
 func fromDir(t *testing.T, sel, relDir string) {