mirror
/
go
mirror of https://github.com/golang/go.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

strconv: cleanup old compiler bits.TrailingZeros workaround 

Since CL 599096 the compiler knows bits.TrailingZeros's maximum value
based on the input type size.

Since CL 603996 it knows it based on input's maximum value.

Change-Id: Ib0d6b15a3ba6894d3e7e12b79b387ddbffabe370
Reviewed-on: https://go-review.googlesource.com/c/go/+/618715
Auto-Submit: Robert Griesemer <gri@google.com>
Commit-Queue: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Jorropo 2024-10-09 01:00:36 +02:00 committed by Gopher Robot
parent a763084ed2
commit 672a53def7
1 changed files with 1 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/strconv/itoa.go
View File

@ -152,13 +152,7 @@ func formatBits(dst []byte, u uint64, base int, neg, append_ bool) (d []byte, s
} else if isPowerOfTwo(base) {
// Use shifts and masks instead of / and %.
// Base is a power of 2 and 2 <= base <= len(digits) where len(digits) is 36.
// The largest power of 2 below or equal to 36 is 32, which is 1 << 5;
// i.e., the largest possible shift count is 5. By &-ind that value with
// the constant 7 we tell the compiler that the shift count is always
// less than 8 which is smaller than any register width. This allows
// the compiler to generate better code for the shift operation.
shift := uint(bits.TrailingZeros(uint(base))) & 7
shift := uint(bits.TrailingZeros(uint(base)))
b := uint64(base)
m := uint(base) - 1 // == 1<<shift - 1
for u >= b {