From 92e6cf4c0f9bf2e1ecd57f22a430d96020cbdd69 Mon Sep 17 00:00:00 2001
From: David Chase <drchase@google.com>
Date: Wed, 27 Mar 2019 16:15:04 -0400
Subject: [PATCH] cmd/compile: repair ssa/debug_test regression

Code introduced in

[2034fbab5b1d11bc59cb476bc3f49ee1b344839d]
cmd/compile: use existing instructions instead of nops for inline marks

to change a src.Pos's column to 1 accidentally reset
the is_stmt and prologue/epilogue bits, and that
turned out to cause a regression in ssa/debug_test.

Preserving that information fixed the regression.

Change-Id: I7c6859c8b68d9c6f7c0cbc8805c1f41dc5c1d5fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/169739
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
---
 src/cmd/internal/src/pos.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/cmd/internal/src/pos.go b/src/cmd/internal/src/pos.go
index 8344a5a6125..954c00716f8 100644
--- a/src/cmd/internal/src/pos.go
+++ b/src/cmd/internal/src/pos.go
@@ -311,7 +311,9 @@ const (
 	colBits, colMax       = 32 - lineBits - xlogueBits - isStmtBits, 1<<colBits - 1
 
 	isStmtShift = 0
+	isStmtMask  = isStmtMax << isStmtShift
 	xlogueShift = isStmtBits + isStmtShift
+	xlogueMask  = xlogueMax << xlogueShift
 	colShift    = xlogueBits + xlogueShift
 	lineShift   = colBits + colShift
 )
@@ -443,5 +445,5 @@ func (x lico) lineNumberHTML() string {
 }
 
 func (x lico) atColumn1() lico {
-	return makeLico(x.Line(), 1)
+	return makeLico(x.Line(), 1) | (x & (isStmtMask | xlogueMask))
 }