cmd/compile: preserve name association when eliding copies in expand_calls

If v is a Copy of x, we will rewrite v to x. If v has a name
associated to it, let the name associate to x.

Under register ABI, this helps associate in-register Arg values
to the parameters' names. (But does not address all cases.)

Change-Id: I47c779e56c9d0823a88890497e32326bc0290f82
Reviewed-on: https://go-review.googlesource.com/c/go/+/309330
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
This commit is contained in:
Cherry Zhang 2021-04-11 12:07:33 -04:00
parent 70ed28e5f7
commit 33d99905da

View file

@ -1449,6 +1449,19 @@ func expandCalls(f *Func) {
}
// Step 6: elide any copies introduced.
// Update named values.
for _, name := range f.Names {
values := f.NamedValues[name]
for i, v := range values {
if v.Op == OpCopy {
a := v.Args[0]
for a.Op == OpCopy {
a = a.Args[0]
}
values[i] = a
}
}
}
for _, b := range f.Blocks {
for _, v := range b.Values {
for i, a := range v.Args {