[dev.regabi] cmd/compile: swap inlining order of if then vs else blocks

The upcoming general iterators will process nodes in
source code order, meaning that the "then" block comes
before the "else" block. But for an if node, "then" is Body
while "else" is Rlist, and the inliner processes Rlist first.

The order of processing changes the order of inlining decisions,
which can affect which functions are inlined, but in general
won't affect much. (It's not like we know that we should prefer
to inline functions in else bodies over then bodies.)

Swapping these is not safe for toolstash -cmp.
Doing it in a separate CL lets the upcoming CLs all be toolstash-safe.

Change-Id: Id16172849239b0564930d2bbff1260ad6d03d5ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/275308
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

diff --git a/src/cmd/compile/internal/gc/inl.go b/src/cmd/compile/internal/gc/inl.go
index 64f1b062be57d7174faaead68db39a9ce3aff1a1..980ba7429ae91adadae6b700dc6c59fa241a904a 100644 (file)
--- a/src/cmd/compile/internal/gc/inl.go
+++ b/src/cmd/compile/internal/gc/inl.go
@@ -638,6 +638,14 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool) ir.Node {
                }
        }
 
+       inlnodelist(n.Body(), maxCost, inlMap)
+       s = n.Body().Slice()
+       for i, n1 := range s {
+               if n1.Op() == ir.OINLCALL {
+                       s[i] = inlconv2stmt(n1)
+               }
+       }
+
        inlnodelist(n.Rlist(), maxCost, inlMap)
 
        if n.Op() == ir.OAS2FUNC && n.Rlist().First().Op() == ir.OINLCALL {
@@ -658,14 +666,6 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool) ir.Node {
                }
        }
 
-       inlnodelist(n.Body(), maxCost, inlMap)
-       s = n.Body().Slice()
-       for i, n1 := range s {
-               if n1.Op() == ir.OINLCALL {
-                       s[i] = inlconv2stmt(n1)
-               }
-       }
-
        // with all the branches out of the way, it is now time to
        // transmogrify this node itself unless inhibited by the
        // switch at the top of this function.