cybercyst/go
1
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-05-05 23:53:05 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

cmd/compile/internal/ssa: small cleanups

Browse Source 
Change-Id: I0420fb3956577c56fa24a31929331d526d480556
GitHub-Last-Rev: d74b0d4d75d4e432aaf84d02964da4a2e12d0e1b
GitHub-Pull-Request: golang/go#73339
Reviewed-on: https://go-review.googlesource.com/c/go/+/664975
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org>
This commit is contained in:
Marcel Meyer 2025-04-11 20:14:04 +00:00 committed by Gopher Robot
parent f967078712
commit 56fad21c22
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/cmd/compile/internal/ssa/prove.go
View File

@ -664,7 +664,7 @@ func (ft *factsTable) newLimit(v *Value, newLim limit) bool {
d |= unsigned d |= unsigned
} }
if !isTrue { if !isTrue {
r ^= (lt | gt | eq) r ^= lt | gt | eq
} }
// TODO: v.Block is wrong? // TODO: v.Block is wrong?
addRestrictions(v.Block, ft, d, v.Args[0], v.Args[1], r) addRestrictions(v.Block, ft, d, v.Args[0], v.Args[1], r)
@ -697,7 +697,7 @@ func (ft *factsTable) newLimit(v *Value, newLim limit) bool {
// But in the signed domain, we can't express the || // But in the signed domain, we can't express the ||
// condition, so check if a0 is non-negative instead, // condition, so check if a0 is non-negative instead,
// to be able to learn something. // to be able to learn something.
r ^= (lt | gt | eq) // >= (index) or > (slice) r ^= lt | gt | eq // >= (index) or > (slice)
if ft.isNonNegative(v.Args[0]) { if ft.isNonNegative(v.Args[0]) {
ft.update(v.Block, v.Args[0], v.Args[1], signed, r) ft.update(v.Block, v.Args[0], v.Args[1], signed, r)
} }
@ -1299,8 +1299,8 @@ func prove(f *Func) {
} }
// try to rewrite to a downward counting loop checking against start if the // try to rewrite to a downward counting loop checking against start if the
// loop body does not depends on ind or nxt and end is known before the loop. // loop body does not depend on ind or nxt and end is known before the loop.
// This reduce pressure on the register allocator because this do not need // This reduces pressure on the register allocator because this does not need
// to use end on each iteration anymore. We compare against the start constant instead. // to use end on each iteration anymore. We compare against the start constant instead.
// That means this code: // That means this code:
// //
@ -1332,7 +1332,7 @@ func prove(f *Func) {
// //
// exit_loop: // exit_loop:
// //
// this is better because it only require to keep ind then nxt alive while looping, // this is better because it only requires to keep ind then nxt alive while looping,
// while the original form keeps ind then nxt and end alive // while the original form keeps ind then nxt and end alive
start, end := v.min, v.max start, end := v.min, v.max
if v.flags&indVarCountDown != 0 { if v.flags&indVarCountDown != 0 {
@ -1355,7 +1355,7 @@ func prove(f *Func) {
if end.Block == ind.Block { if end.Block == ind.Block {
// we can't rewrite loops where the condition depends on the loop body // we can't rewrite loops where the condition depends on the loop body
// this simple check is forced to work because if this is true a Phi in ind.Block must exists // this simple check is forced to work because if this is true a Phi in ind.Block must exist
continue continue
} }