tree c25cfd213feaa83710975ae609166916ccca47f2
parent 46587483e30188ce485097cdeb48a4d1e0c8a445
author Keith Randall <khr@golang.org> 1710273363 -0700
committer Than McIntosh <thanm@google.com> 1711565389 +0000

[release-branch.go1.22] cmd/compile: don't assume args are always zero-extended

On amd64, we always zero-extend when loading arguments from the stack.
On arm64, we extend based on the type. This causes problems with
zeroUpper*Bits, which reports the top bits are zero when they aren't.

Fix it to use the type to decide if the top bits are really zero.

For tests, only f32 currently fails on arm64. Added other tests
just for future-proofing.

Fixes #66076

Change-Id: I2f13fb47198e139ef13c9a34eb1edc932eea3ee3
Reviewed-on: https://go-review.googlesource.com/c/go/+/571135
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
(cherry picked from commit 6bf8b76b95b22e3a7fbcd7cb95bfdb3f42bba60a)
Reviewed-on: https://go-review.googlesource.com/c/go/+/573395
Reviewed-by: Cherry Mui <cherryyz@google.com>