From d32b1f02c3e869b6ddf73d2113477b1fd77d42c8 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 29 Oct 2025 13:37:52 -0400
Subject: runtime: delete timediv

Now that the compiler handles constant 64-bit divisions
without function calls on 32-bit systems, we no longer need
to maintain and test a bad custom implementation of 64-bit division.

Change-Id: If28807ad4f86507267ae69bc8f0b09ec18e98b66
Reviewed-on: https://go-review.googlesource.com/c/go/+/716463
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
---
 src/runtime/runtime_test.go | 76 ---------------------------------------------
 1 file changed, 76 deletions(-)

(limited to 'src/runtime/runtime_test.go')

diff --git a/src/runtime/runtime_test.go b/src/runtime/runtime_test.go
index 6c628f8903..c1c63e3cea 100644
--- a/src/runtime/runtime_test.go
+++ b/src/runtime/runtime_test.go
@@ -6,7 +6,6 @@ package runtime_test
 
 import (
 	"flag"
-	"fmt"
 	"internal/asan"
 	"internal/cpu"
 	"internal/msan"
@@ -498,81 +497,6 @@ func TestVersion(t *testing.T) {
 	}
 }
 
-func TestTimediv(t *testing.T) {
-	for _, tc := range []struct {
-		num int64
-		div int32
-		ret int32
-		rem int32
-	}{
-		{
-			num: 8,
-			div: 2,
-			ret: 4,
-			rem: 0,
-		},
-		{
-			num: 9,
-			div: 2,
-			ret: 4,
-			rem: 1,
-		},
-		{
-			// Used by runtime.check.
-			num: 12345*1000000000 + 54321,
-			div: 1000000000,
-			ret: 12345,
-			rem: 54321,
-		},
-		{
-			num: 1<<32 - 1,
-			div: 2,
-			ret: 1<<31 - 1, // no overflow.
-			rem: 1,
-		},
-		{
-			num: 1 << 32,
-			div: 2,
-			ret: 1<<31 - 1, // overflow.
-			rem: 0,
-		},
-		{
-			num: 1 << 40,
-			div: 2,
-			ret: 1<<31 - 1, // overflow.
-			rem: 0,
-		},
-		{
-			num: 1<<40 + 1,
-			div: 1 << 10,
-			ret: 1 << 30,
-			rem: 1,
-		},
-	} {
-		name := fmt.Sprintf("%d div %d", tc.num, tc.div)
-		t.Run(name, func(t *testing.T) {
-			// Double check that the inputs make sense using
-			// standard 64-bit division.
-			ret64 := tc.num / int64(tc.div)
-			rem64 := tc.num % int64(tc.div)
-			if ret64 != int64(int32(ret64)) {
-				// Simulate timediv overflow value.
-				ret64 = 1<<31 - 1
-				rem64 = 0
-			}
-			if ret64 != int64(tc.ret) {
-				t.Errorf("%d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret64, rem64, tc.ret, tc.rem)
-			}
-
-			var rem int32
-			ret := Timediv(tc.num, tc.div, &rem)
-			if ret != tc.ret || rem != tc.rem {
-				t.Errorf("timediv %d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret, rem, tc.ret, tc.rem)
-			}
-		})
-	}
-}
-
 func BenchmarkProcYield(b *testing.B) {
 	benchN := func(n uint32) func(*testing.B) {
 		return func(b *testing.B) {
-- 
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