1 files changed, 16 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/arm64/obj7.go b/src/cmd/internal/obj/arm64/obj7.go
index 0baf51973a..3b88543852 100644
--- a/src/cmd/internal/obj/arm64/obj7.go
+++ b/src/cmd/internal/obj/arm64/obj7.go
@@ -35,6 +35,7 @@ import (
 	"cmd/internal/objabi"
 	"cmd/internal/src"
 	"cmd/internal/sys"
+	"log"
 	"math"
 )
 
@@ -970,6 +971,21 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				p = q5
 			}
 		}
+
+		if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.Spadj == 0 {
+			f := c.cursym.Func()
+			if f.FuncFlag&objabi.FuncFlag_SPWRITE == 0 {
+				c.cursym.Func().FuncFlag |= objabi.FuncFlag_SPWRITE
+				if ctxt.Debugvlog || !ctxt.IsAsm {
+					ctxt.Logf("auto-SPWRITE: %s %v\n", c.cursym.Name, p)
+					if !ctxt.IsAsm {
+						ctxt.Diag("invalid auto-SPWRITE in non-assembly")
+						ctxt.DiagFlush()
+						log.Fatalf("bad SPWRITE")
+					}
+				}
+			}
+		}
 	}
 }