Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/compile: rewrite Rsh to RshU if arguments are proved positive

Browse source 
Fixes #76332

Change-Id: I9044025d5dc599531c7f88ed2870bcf3d8b0acbd
Reviewed-on: https://go-review.googlesource.com/c/go/+/721206
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Jorropo <jorropo.pgm@gmail.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 2025-11-18 01:42:37 +01:00 • committed by Gopher Robot
parent 3820f94c1d
commit ec92bc6d63
3 changed files with 43 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

14
test/prove_constant_folding.go
View file

@ -30,10 +30,10 @@ func f0u(x uint) int {
}
if x < 1000 {
return int(x)>>31 // ERROR "Proved.+is constant 0$"
return int(x) >> 31 // ERROR "(Proved.+is constant 0|Proved Rsh[0-9]+x[0-9]+ is unsigned)$"
}
if x := int32(x); x < -1000 {
return int(x>>31) // ERROR "Proved.+is constant -1$"
return int(x >> 31) // ERROR "Proved.+is constant -1$"
}
return int(x) + 1
@ -45,35 +45,35 @@ func sh64(n int64) int64 {
if n < 0 {
return n
}
return n >> 63 // ERROR "Proved .+ is constant 0$"
return n >> 63 // ERROR "(Proved .+ is constant 0|Proved Rsh[0-9]+x[0-9]+ is unsigned)$"
}
func sh32(n int32) int32 {
if n < 0 {
return n
}
return n >> 31 // ERROR "Proved .+ is constant 0$"
return n >> 31 // ERROR "(Proved .+ is constant 0|Proved Rsh[0-9]+x[0-9]+ is unsigned)$"
}
func sh32x64(n int32) int32 {
if n < 0 {
return n
}
return n >> uint64(31) // ERROR "Proved .+ is constant 0$"
return n >> uint64(31) // ERROR "(Proved .+ is constant 0|Proved Rsh[0-9]+x[0-9]+ is unsigned)$"
}
func sh32x64n(n int32) int32 {
if n >= 0 {
return 0
}
return n >> 31// ERROR "Proved .+ is constant -1$"
return n >> 31 // ERROR "Proved .+ is constant -1$"
}
func sh16(n int16) int16 {
if n < 0 {
return n
}
return n >> 15 // ERROR "Proved .+ is constant 0$"
return n >> 15 // ERROR "(Proved .+ is constant 0|Proved Rsh[0-9]+x[0-9]+ is unsigned)$"
}
func sh64noopt(n int64) int64 {