cmd/compile: simplify uninterruptable range check for write barriers

Make the load detection a bit clearer and more precise. In particular,
for architectures which have to materialize the address using a
separate instruction, we were using the address materialization
instruction, not the load itself.

Also apply the marking a bit less. We don't need to mark the load itself,
only the instructions after the load. And we don't need to mark the WBend
itself, only the instructions before it.

Change-Id: Ie367a8023b003d5317b752d873bb385f931bb30e
Reviewed-on: https://go-review.googlesource.com/c/go/+/499395
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

0 files changed, 0 insertions, 0 deletions