runtime: remove nextSampleNoFP from plan9

Plan 9 can use floating point now.

Change-Id: If721b243daa31853609cb3d2c535d86c106a1ee1
Reviewed-on: https://go-review.googlesource.com/c/go/+/655879
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 85f22bd28e3db74d9d7a0d6bee3dfd7e3571b388..bb5f6b3c93bd2222373ee62300985463a84c5313 100644 (file)
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -1815,13 +1815,6 @@ func nextSample() int64 {
                // Sample immediately.
                return 0
        }
-       if GOOS == "plan9" {
-               // Plan 9 doesn't support floating point in note handler.
-               if gp := getg(); gp == gp.m.gsignal {
-                       return nextSampleNoFP()
-               }
-       }
-
        return int64(fastexprand(MemProfileRate))
 }
 
@@ -1855,20 +1848,6 @@ func fastexprand(mean int) int32 {
        return int32(qlog*(minusLog2*float64(mean))) + 1
 }
 
-// nextSampleNoFP is similar to nextSample, but uses older,
-// simpler code to avoid floating point.
-func nextSampleNoFP() int64 {
-       // Set first allocation sample size.
-       rate := MemProfileRate
-       if rate > 0x3fffffff { // make 2*rate not overflow
-               rate = 0x3fffffff
-       }
-       if rate != 0 {
-               return int64(cheaprandn(uint32(2 * rate)))
-       }
-       return 0
-}
-
 type persistentAlloc struct {
        base *notInHeap
        off  uintptr