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: clarify division bounds check optimization

Browse source 
The name of the function should mention division.
Eliminate double negatives from the comment describing it.

Change-Id: Icef1a5139b3a91b86acb930af97938f5160f7342
Reviewed-on: https://go-review.googlesource.com/c/go/+/217001
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
This commit is contained in:
Josh Bleecher Snyder 2020-01-23 22:18:30 -08:00
parent e932f0addc
commit 1b47fde55c
4 changed files with 9 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

8
src/cmd/compile/internal/ssa/prove.go
View file

@ -1243,9 +1243,11 @@ func simplifyBlock(sdom SparseTree, ft *factsTable, b *Block) {
divdLim, divdLimok := ft.limits[divd.ID]
if (divrLimok && (divrLim.max < -1 || divrLim.min > -1)) ||
(divdLimok && divdLim.min > mostNegativeDividend[v.Op]) {
v.AuxInt = 1 // see NeedsFixUp in genericOps - v.AuxInt = 0 means we have not proved
// that the divisor is not -1 and the dividend is not the most negative,
// so we need to add fix-up code.
// See DivisionNeedsFixUp in rewrite.go.
// v.AuxInt = 1 means we have proved both that the divisor is not -1
// and that the dividend is not the most negative integer,
// so we do not need to add fix-up code.
v.AuxInt = 1
if b.Func.pass.debug > 0 {
b.Func.Warnl(v.Pos, "Proved %v does not need fix-up", v.Op)
}