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Differential D150424

[ValueTracking] Add tests for deducing `X * Y != 0` if `LSB(X) * LSB(Y) != 0`; NFC
ClosedPublic

Authored by goldstein.w.n on May 11 2023, 10:04 PM.

Details

Reviewers
nikic
spatel
StephenFan
holland11
Commits
rG7f82f108c2ec: [ValueTracking] Add tests for deducing `X * Y != 0` if `LSB(X) * LSB(Y) != 0`…

Diff Detail

Event Timeline

goldstein.w.n created this revision.May 11 2023, 10:04 PM
Herald added a project: Restricted Project. · View Herald TranscriptMay 11 2023, 10:04 PM
goldstein.w.n requested review of this revision.May 11 2023, 10:04 PM
Herald added a project: Restricted Project. · View Herald TranscriptMay 11 2023, 10:04 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
goldstein.w.n added a child revision: D150425: [ValueTracking] deduce `X * Y != 0` if `LowestKnownBit(X) * LowestKnownBit(Y) != 0`.May 11 2023, 10:05 PM
Harbormaster completed remote builds in B231527: Diff 521553.May 11 2023, 10:37 PM
holland11 added inline comments.May 12 2023, 12:26 PM
llvm/test/Analysis/ValueTracking/known-non-zero.ll
1109

Did you mean to have this be

  %yy = or i8 %y, 8
`

(replaced the x with y)?

1124

Same as above.

goldstein.w.n marked 2 inline comments as done.May 12 2023, 3:07 PM
goldstein.w.n updated this revision to Diff 521812.May 12 2023, 3:07 PM

Use proper variables

Harbormaster completed remote builds in B231720: Diff 521812.May 12 2023, 3:58 PM
goldstein.w.n updated this revision to Diff 521944.May 13 2023, 12:42 PM

Rebase

Harbormaster completed remote builds in B231817: Diff 521944.May 13 2023, 1:57 PM
goldstein.w.n updated this revision to Diff 522376.May 15 2023, 4:11 PM

Rebase

Harbormaster completed remote builds in B232149: Diff 522376.May 15 2023, 6:13 PM
nikic accepted this revision.May 16 2023, 1:14 AM

LGTM

This revision is now accepted and ready to land.May 16 2023, 1:14 AM
Closed by commit rG7f82f108c2ec: [ValueTracking] Add tests for deducing `X * Y != 0` if `LSB(X) * LSB(Y) != 0`… (authored by goldstein.w.n). · Explain WhyMay 16 2023, 4:58 PM
This revision was automatically updated to reflect the committed changes.
goldstein.w.n added a commit: rG7f82f108c2ec: [ValueTracking] Add tests for deducing `X * Y != 0` if `LSB(X) * LSB(Y) != 0`….

Revision Contents

PathSize
llvm/
test/
Analysis/
ValueTracking/
30 lines

Diff 522838

llvm/test/Analysis/ValueTracking/known-non-zero.ll

Show First 20 Lines • Show All 1,090 Lines • ▼ Show 20 Lines
; ;
%y_pos = icmp sge i8 %yy, 0 %y_pos = icmp sge i8 %yy, 0
call void @llvm.assume(i1 %y_pos) call void @llvm.assume(i1 %y_pos)
%x = call i8 @llvm.smax.i8(i8 %xx, i8 %yy) %x = call i8 @llvm.smax.i8(i8 %xx, i8 %yy)
%z = or i8 %x, %ind %z = or i8 %x, %ind
%r = icmp eq i8 %z, 0 %r = icmp eq i8 %z, 0
ret i1 %r ret i1 %r
} }
define i1 @mul_nonzero_contains_nonzero_mul(i8 %x, i8 %y) {
; CHECK-LABEL: @mul_nonzero_contains_nonzero_mul(
; CHECK-NEXT: [[XX:%.*]] = or i8 [[X:%.*]], 16
; CHECK-NEXT: [[YY:%.*]] = or i8 [[Y:%.*]], 8
; CHECK-NEXT: [[XY:%.*]] = mul i8 [[XX]], [[YY]]
; CHECK-NEXT: [[NZ:%.*]] = icmp ne i8 [[XY]], 0
; CHECK-NEXT: ret i1 [[NZ]]
;
%xx = or i8 %x, 16
%yy = or i8 %y, 8
holland11Unsubmitted
Done
ReplyInline Actions
%xx = or i8 %x, 16
- %yy = or i8 %x, 8
+ %yy = or i8 %y, 8
%xy = mul i8 %xx, %yy

Did you mean to have this be

  %yy = or i8 %y, 8
`

(replaced the x with y)?

holland11: Did you mean to have this be ``` %yy = or i8 %y, 8 ```` (replaced the `x` with `y`)?
%xy = mul i8 %xx, %yy
%nz = icmp ne i8 %xy, 0
ret i1 %nz
}
define i1 @src_mul_maybe_zero_no_nonzero_mul(i8 %x, i8 %y) {
; CHECK-LABEL: @src_mul_maybe_zero_no_nonzero_mul(
; CHECK-NEXT: [[XX:%.*]] = or i8 [[X:%.*]], 96
; CHECK-NEXT: [[YY:%.*]] = or i8 [[Y:%.*]], 8
; CHECK-NEXT: [[XY:%.*]] = mul i8 [[XX]], [[YY]]
; CHECK-NEXT: [[NZ:%.*]] = icmp ne i8 [[XY]], 0
; CHECK-NEXT: ret i1 [[NZ]]
;
%xx = or i8 %x, 96
%yy = or i8 %y, 8
holland11Unsubmitted
Done
ReplyInline Actions

Same as above.

holland11: Same as above.
%xy = mul i8 %xx, %yy
%nz = icmp ne i8 %xy, 0
ret i1 %nz
}