cmd/compile/internal/gc: eliminate stringsCompare for stackvar sorting
Passes go build -a -toolexec 'toolstash -cmp' std cmd.
Change-Id: I2a87d31da74affdf3d0f358d0efdb3f1c646d917
Reviewed-on: https://go-review.googlesource.com/14759
Reviewed-by: Dave Cheney <dave@cheney.net>
diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index 5081ea0..dd185f1 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -409,9 +409,10 @@
return concat(l, list1(n))
}
-// listsort sorts *l in place according to the 3-way comparison function f.
+// listsort sorts *l in place according to the comparison function lt.
+// The algorithm expects lt(a, b) to be equivalent to a < b.
// The algorithm is mergesort, so it is guaranteed to be O(n log n).
-func listsort(l **NodeList, f func(*Node, *Node) int) {
+func listsort(l **NodeList, lt func(*Node, *Node) bool) {
if *l == nil || (*l).Next == nil {
return
}
@@ -436,10 +437,10 @@
(*l).End = l1
l1 = *l
- listsort(&l1, f)
- listsort(&l2, f)
+ listsort(&l1, lt)
+ listsort(&l2, lt)
- if f(l1.N, l2.N) < 0 {
+ if lt(l1.N, l2.N) {
*l = l1
} else {
*l = l2
@@ -451,7 +452,7 @@
var le *NodeList
for (l1 != nil) && (l2 != nil) {
- for (l1.Next != nil) && f(l1.Next.N, l2.N) < 0 {
+ for (l1.Next != nil) && lt(l1.Next.N, l2.N) {
l1 = l1.Next
}
