cmd/compile: sort regalloc switch by architecture

Also tweak comment for the arm64 case.

Change-Id: I073405bd2acf901dcaaf33a034a84b6a09dd4a83
Reviewed-on: https://go-review.googlesource.com/c/go/+/334869
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Meng Zhuo <mzh@golangcn.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go
index 3d978e7ac83d8efef9d68a5b0ddcbb5d45d96e62..28fac6ccd0422bfdeeb9fcd34d21008835b2e20c 100644 (file)
--- a/src/cmd/compile/internal/ssa/regalloc.go
+++ b/src/cmd/compile/internal/ssa/regalloc.go
@@ -620,20 +620,20 @@ func (s *regAllocState) init(f *Func) {
        }
        if s.f.Config.ctxt.Flag_dynlink {
                switch s.f.Config.arch {
-               case "amd64":
-                       s.allocatable &^= 1 << 15 // R15
-               case "arm":
-                       s.allocatable &^= 1 << 9 // R9
-               case "ppc64le": // R2 already reserved.
-                       // nothing to do
-               case "arm64":
-                       // nothing to do?
                case "386":
                        // nothing to do.
                        // Note that for Flag_shared (position independent code)
                        // we do need to be careful, but that carefulness is hidden
                        // in the rewrite rules so we always have a free register
                        // available for global load/stores. See gen/386.rules (search for Flag_shared).
+               case "amd64":
+                       s.allocatable &^= 1 << 15 // R15
+               case "arm":
+                       s.allocatable &^= 1 << 9 // R9
+               case "arm64":
+                       // nothing to do
+               case "ppc64le": // R2 already reserved.
+                       // nothing to do
                case "s390x":
                        s.allocatable &^= 1 << 11 // R11
                default: