From 2493072db68a8f8b545bb2a6faebac0da0f01336 Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Mon, 18 Jul 2022 11:47:19 -0700 Subject: cmd/compile: avoid assignment conversion in append(a, b...) There's no need for a and b to match types. The typechecker already ensured that a and b are both slices with the same base type, or a and b are (possibly named) []byte and string. The optimization to treat append(b, make([], ...)) as a zeroing slice extension doesn't fire when there's a OCONVNOP wrapping the make. Fixes #53888 Change-Id: Ied871ed0bbb8e4a4b35d280c71acbab8103691bc Reviewed-on: https://go-review.googlesource.com/c/go/+/418475 TryBot-Result: Gopher Robot Reviewed-by: Matthew Dempsky Reviewed-by: Cuong Manh Le Reviewed-by: Keith Randall Run-TryBot: Keith Randall --- src/cmd/compile/internal/noder/transform.go | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'src/cmd/compile/internal/noder') diff --git a/src/cmd/compile/internal/noder/transform.go b/src/cmd/compile/internal/noder/transform.go index ddbccf4ff4..50254e694a 100644 --- a/src/cmd/compile/internal/noder/transform.go +++ b/src/cmd/compile/internal/noder/transform.go @@ -730,11 +730,11 @@ func transformAppend(n *ir.CallExpr) ir.Node { assert(t.IsSlice()) if n.IsDDD { - if t.Elem().IsKind(types.TUINT8) && args[1].Type().IsString() { - return n - } - - args[1] = assignconvfn(args[1], t.Underlying()) + // assignconvfn is of args[1] not required here, as the + // types of args[0] and args[1] don't need to match + // (They will both have an underlying type which are + // slices of indentical base types, or be []byte and string.) + // See issue 53888. return n } -- cgit v1.3