tree f02337be543b5f76ca3e6badfe7236c9a73357b8
parent 70931c087b7ceb660aa969382b8c273efba63426
author Keith Randall <khr@google.com> 1546984009 -0800
committer Keith Randall <khr@golang.org> 1547505693 +0000

cmd/compile: when merging instructions, prefer line number of faulting insn

Normally this happens when combining a sign extension and a load.  We
want the resulting combo-instruction to get the line number of the
load, not the line number of the sign extension.

For each rule, compute where we should get its line number by finding
a value on the match side that can fault.  Use that line number for
all the new values created on the right-hand side.

Fixes #27201

Change-Id: I19b3c6f468fff1a3c0bfbce2d6581828557064a3
Reviewed-on: https://go-review.googlesource.com/c/156937
Reviewed-by: David Chase <drchase@google.com>