Skip to content

[DA] Replace delinearization for fixed size array #161822

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kasuga-fj merged 9 commits into from
Nov 19, 2025
Merged

[DA] Replace delinearization for fixed size array #161822

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
9 commits
Select commit Hold shift + click to select a range
aa3e203
[DA] Replace delinearization for fixed size array
kasuga-fj Oct 3, 2025
66cfa34
Merge branch 'main' into da-replace-delinearize
kasuga-fj Oct 14, 2025
e89cb44
update tests
kasuga-fj Oct 14, 2025
c7dc3af
remove remarks outputs
kasuga-fj Oct 14, 2025
795f2f8
address review comments
kasuga-fj Oct 15, 2025
968da89
Merge branch 'main' into tmp
kasuga-fj Nov 18, 2025
ffd0bad
update comment
kasuga-fj Nov 18, 2025
ca093f0
update test
kasuga-fj Nov 18, 2025
6badd83
Merge branch 'main' into da-replace-delinearize
kasuga-fj Nov 19, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 16 additions & 18 deletions llvm/lib/Analysis/DependenceAnalysis.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3911,12 +3911,13 @@ bool DependenceInfo::tryDelinearizeFixedSize(
"expected src and dst scev unknowns to be equal");
});

SmallVector<int, 4> SrcSizes;
SmallVector<int, 4> DstSizes;
if (!tryDelinearizeFixedSizeImpl(SE, Src, SrcAccessFn, SrcSubscripts,
SrcSizes) ||
!tryDelinearizeFixedSizeImpl(SE, Dst, DstAccessFn, DstSubscripts,
DstSizes))
const SCEV *ElemSize = SE->getElementSize(Src);
assert(ElemSize == SE->getElementSize(Dst) && "Different element sizes");
SmallVector<const SCEV *, 4> SrcSizes, DstSizes;
if (!delinearizeFixedSizeArray(*SE, SE->removePointerBase(SrcAccessFn),
SrcSubscripts, SrcSizes, ElemSize) ||
!delinearizeFixedSizeArray(*SE, SE->removePointerBase(DstAccessFn),
DstSubscripts, DstSizes, ElemSize))
return false;

// Check that the two size arrays are non-empty and equal in length and
Expand All @@ -3942,7 +3943,7 @@ bool DependenceInfo::tryDelinearizeFixedSize(
// iff the subscripts are positive and are less than the range of the
// dimension.
if (!DisableDelinearizationChecks) {
auto AllIndicesInRange = [&](SmallVector<int, 4> &DimensionSizes,
auto AllIndicesInRange = [&](ArrayRef<const SCEV *> DimensionSizes,
SmallVectorImpl<const SCEV *> &Subscripts,
Value *Ptr) {
size_t SSize = Subscripts.size();
Expand All @@ -3955,17 +3956,14 @@ bool DependenceInfo::tryDelinearizeFixedSize(
});
return false;
}
if (auto *SType = dyn_cast<IntegerType>(S->getType())) {
const SCEV *Range = SE->getConstant(
ConstantInt::get(SType, DimensionSizes[I - 1], false));
if (!isKnownLessThan(S, Range)) {
LLVM_DEBUG({
dbgs() << "Check failed: !isKnownLessThan(S, Range)\n";
dbgs() << " S: " << *S << "\n"
<< " Range: " << *Range << "\n";
});
return false;
}
const SCEV *Range = DimensionSizes[I - 1];
if (!isKnownLessThan(S, Range)) {
LLVM_DEBUG({
dbgs() << "Check failed: !isKnownLessThan(S, Range)\n";
dbgs() << " S: " << *S << "\n"
<< " Range: " << *Range << "\n";
});
return false;
}
}
return true;
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Analysis/DependenceAnalysis/Banerjee.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -660,7 +660,7 @@ define void @banerjee7(ptr %A, ptr %B, i64 %m, i64 %n) nounwind uwtable ssp {
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: store i64 0, ptr %arrayidx, align 8
; DELIN-NEXT: da analyze - none!
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: %0 = load i64, ptr %arrayidx7, align 8
; DELIN-NEXT: da analyze - flow [> <=]!
; DELIN-NEXT: da analyze - consistent flow [-1 0]!
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: store i64 %0, ptr %B.addr.11, align 8
; DELIN-NEXT: da analyze - confused!
; DELIN-NEXT: Src: %0 = load i64, ptr %arrayidx7, align 8 --> Dst: %0 = load i64, ptr %arrayidx7, align 8
Expand Down Expand Up @@ -916,7 +916,7 @@ define void @banerjee10(ptr %A, ptr %B, i64 %m, i64 %n) nounwind uwtable ssp {
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: store i64 0, ptr %arrayidx, align 8
; DELIN-NEXT: da analyze - none!
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: %1 = load i64, ptr %arrayidx6, align 8
; DELIN-NEXT: da analyze - flow [<> 0]!
; DELIN-NEXT: da analyze - flow [-11 0]!
; DELIN-NEXT: Src: store i64 0, ptr %arrayidx, align 8 --> Dst: store i64 %1, ptr %B.addr.11, align 8
; DELIN-NEXT: da analyze - confused!
; DELIN-NEXT: Src: %1 = load i64, ptr %arrayidx6, align 8 --> Dst: %1 = load i64, ptr %arrayidx6, align 8
Expand Down
6 changes: 2 additions & 4 deletions llvm/test/Analysis/DependenceAnalysis/Coupled.ll
View file
Open in desktop
Copy link
Contributor Author

@kasuga-fj kasuga-fj Oct 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I believe this test will be removed in #160924.

Original file line number Diff line number Diff line change
Expand Up @@ -503,8 +503,7 @@ define void @couple11(ptr %A, ptr %B, i32 %n) nounwind uwtable ssp {
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: store i32 %conv, ptr %arrayidx2, align 4
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx4, align 4
; CHECK-NEXT: da analyze - flow [0|<] splitable!
; CHECK-NEXT: da analyze - split level = 1, iteration = 9!
; CHECK-NEXT: da analyze - flow [0|<]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
; CHECK-NEXT: da analyze - confused!
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx4, align 4 --> Dst: %0 = load i32, ptr %arrayidx4, align 4
Expand Down Expand Up @@ -548,8 +547,7 @@ define void @couple12(ptr %A, ptr %B, i32 %n) nounwind uwtable ssp {
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: store i32 %conv, ptr %arrayidx2, align 4
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx4, align 4
; CHECK-NEXT: da analyze - flow [<] splitable!
; CHECK-NEXT: da analyze - split level = 1, iteration = 11!
; CHECK-NEXT: da analyze - flow [<]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
; CHECK-NEXT: da analyze - confused!
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx4, align 4 --> Dst: %0 = load i32, ptr %arrayidx4, align 4
Expand Down
3 changes: 1 addition & 2 deletions llvm/test/Analysis/DependenceAnalysis/DifferentOffsets.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -149,11 +149,10 @@ define void @multidim_accesses(ptr %A) {
; CHECK-NEXT: Src: store i32 1, ptr %idx0, align 4 --> Dst: store i32 1, ptr %idx0, align 4
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i32 1, ptr %idx0, align 4 --> Dst: store i32 1, ptr %idx1, align 4
; CHECK-NEXT: da analyze - consistent output [0 0 0|<]!
; CHECK-NEXT: da analyze - output [<= * *|<]!
; CHECK-NEXT: Src: store i32 1, ptr %idx1, align 4 --> Dst: store i32 1, ptr %idx1, align 4
; CHECK-NEXT: da analyze - none!
;
; FIXME: the dependence distance is not constant. Distance vector should be [* * *|<]!
Comment on lines -152 to -156
Copy link
Contributor Author

@kasuga-fj kasuga-fj Oct 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This change means fixing a known issue.

; for (i = 0; i < 256; i++)
; for (j = 0; j < 256; j++)
; for (k = 0; k < 256; k++) {
Expand Down
5 changes: 5 additions & 0 deletions llvm/test/Analysis/DependenceAnalysis/Invariant.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,11 @@
; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 \
; RUN: | FileCheck %s

; XFAIL: *
; Currently fails since delinearization doesn't work as expected, due to the
; inconsistency in the estimated array sizes between `rr[i][j]` and `rr[j][j]`.
; The latter is now regarded as an access to a 1D array.

; Test for a bug, which caused an assert when an invalid
; SCEVAddRecExpr is created in addToCoefficient.

Expand Down
4 changes: 3 additions & 1 deletion llvm/test/Analysis/DependenceAnalysis/NonCanonicalizedSubscript.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,8 @@ for.end:
; }
; }
; Extends the previous example to coupled MIV subscripts.
;
; FIXME: Currently delinearization does not work as expected.


@a = global [10004 x [10004 x i32]] zeroinitializer, align 16
Expand All @@ -57,7 +59,7 @@ define void @coupled_miv_type_mismatch(i32 %n) {
; CHECK-NEXT: Src: %2 = load i32, ptr %arrayidx5, align 4 --> Dst: %2 = load i32, ptr %arrayidx5, align 4
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: %2 = load i32, ptr %arrayidx5, align 4 --> Dst: store i32 %add6, ptr %arrayidx10, align 4
; CHECK-NEXT: da analyze - consistent anti [1 -2]!
; CHECK-NEXT: da analyze - anti [< >]!
; CHECK-NEXT: Src: store i32 %add6, ptr %arrayidx10, align 4 --> Dst: store i32 %add6, ptr %arrayidx10, align 4
; CHECK-NEXT: da analyze - none!
;
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/Analysis/DependenceAnalysis/PR51512.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ define void @foo() {
; CHECK-NEXT: Src: store i32 42, ptr %getelementptr, align 1 --> Dst: store i32 42, ptr %getelementptr, align 1
; CHECK-NEXT: da analyze - consistent output [0 S]!
; CHECK-NEXT: Src: store i32 42, ptr %getelementptr, align 1 --> Dst: store i32 0, ptr %getelementptr5, align 1
; CHECK-NEXT: da analyze - output [0 *|<]!
; CHECK-NEXT: da analyze - output [0 <=|<]!
; CHECK-NEXT: Src: store i32 0, ptr %getelementptr5, align 1 --> Dst: store i32 0, ptr %getelementptr5, align 1
; CHECK-NEXT: da analyze - none!
;
Expand Down
3 changes: 2 additions & 1 deletion llvm/test/Analysis/DependenceAnalysis/Propagating.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -437,7 +437,8 @@ define void @prop7(ptr %A, ptr %B, i32 %n) nounwind uwtable ssp {
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx7, align 4 --> Dst: store i32 %conv, ptr %arrayidx7, align 4
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx7, align 4 --> Dst: %0 = load i32, ptr %arrayidx13, align 4
; CHECK-NEXT: da analyze - flow [* <>]!
; CHECK-NEXT: da analyze - flow [* -38] splitable!
; CHECK-NEXT: da analyze - split level = 1, iteration = 4!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx7, align 4 --> Dst: store i32 %0, ptr %B.addr.11, align 4
; CHECK-NEXT: da analyze - confused!
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx13, align 4 --> Dst: %0 = load i32, ptr %arrayidx13, align 4
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/Analysis/DependenceAnalysis/SameSDLoops.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -148,7 +148,7 @@ define void @non_samebd0(ptr %A) nounwind uwtable ssp {
; CHECK-NEXT: Src: store i64 %i.013, ptr %arrayidx12, align 8 --> Dst: store i64 %i.013, ptr %arrayidx12, align 8
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i64 %i.013, ptr %arrayidx12, align 8 --> Dst: store i64 %l17.04, ptr %arrayidx24, align 8
; CHECK-NEXT: da analyze - output [-4 -3]!
Copy link
Contributor Author

@kasuga-fj kasuga-fj Oct 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Seems regression, but less important, I believe.

; CHECK-NEXT: da analyze - output [> *]!
; CHECK-NEXT: Src: store i64 %l17.04, ptr %arrayidx24, align 8 --> Dst: store i64 %l17.04, ptr %arrayidx24, align 8
; CHECK-NEXT: da analyze - none!
;
Expand Down
6 changes: 3 additions & 3 deletions llvm/test/Analysis/DependenceAnalysis/Separability.ll
View file
Open in desktop
Copy link
Contributor Author

@kasuga-fj kasuga-fj Oct 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This also will be removed in #160924.

Original file line number Diff line number Diff line change
Expand Up @@ -182,7 +182,7 @@ define void @sep2(ptr %A, ptr %B, i32 %n) nounwind uwtable ssp {
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx12, align 4 --> Dst: store i32 %conv, ptr %arrayidx12, align 4
; CHECK-NEXT: da analyze - consistent output [0 S 0 0]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx12, align 4 --> Dst: %0 = load i32, ptr %arrayidx19, align 4
; CHECK-NEXT: da analyze - flow [> * * -10]!
; CHECK-NEXT: da analyze - flow [* * * <>]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx12, align 4 --> Dst: store i32 %0, ptr %B.addr.31, align 4
; CHECK-NEXT: da analyze - confused!
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx19, align 4 --> Dst: %0 = load i32, ptr %arrayidx19, align 4
Expand Down Expand Up @@ -262,9 +262,9 @@ for.end28: ; preds = %for.inc26
define void @sep3(ptr %A, ptr %B, i32 %n) nounwind uwtable ssp {
; CHECK-LABEL: 'sep3'
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx13, align 4 --> Dst: store i32 %conv, ptr %arrayidx13, align 4
; CHECK-NEXT: da analyze - consistent output [0 S 0 0]!
; CHECK-NEXT: da analyze - output [0 S 0 0]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx13, align 4 --> Dst: %0 = load i32, ptr %arrayidx20, align 4
; CHECK-NEXT: da analyze - flow [> * * *]!
; CHECK-NEXT: da analyze - flow [* * * *|<]!
; CHECK-NEXT: Src: store i32 %conv, ptr %arrayidx13, align 4 --> Dst: store i32 %0, ptr %B.addr.31, align 4
; CHECK-NEXT: da analyze - confused!
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx20, align 4 --> Dst: %0 = load i32, ptr %arrayidx20, align 4
Expand Down
14 changes: 4 additions & 10 deletions llvm/test/Analysis/DependenceAnalysis/StrongSIV.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -534,17 +534,11 @@ for.end: ; preds = %for.body
;; for (long unsigned j = 0; j < 2147483640; j++)
;; if (i < 3000000000)
;; A[i] = 0;
;
; FIXME: DependenceAnalysis fails to detect the dependency between A[i] and
; itself, and the issue is not caused by the Strong SIV.

define void @strong11(ptr %A) nounwind uwtable ssp {
; CHECK-ALL-LABEL: 'strong11'
; CHECK-ALL-NEXT: Src: store i32 0, ptr %arrayidx, align 4 --> Dst: store i32 0, ptr %arrayidx, align 4
; CHECK-ALL-NEXT: da analyze - none!
;
; CHECK-STRONG-SIV-LABEL: 'strong11'
; CHECK-STRONG-SIV-NEXT: Src: store i32 0, ptr %arrayidx, align 4 --> Dst: store i32 0, ptr %arrayidx, align 4
; CHECK-STRONG-SIV-NEXT: da analyze - consistent output [0 S]!
; CHECK-LABEL: 'strong11'
; CHECK-NEXT: Src: store i32 0, ptr %arrayidx, align 4 --> Dst: store i32 0, ptr %arrayidx, align 4
; CHECK-NEXT: da analyze - consistent output [0 S]!
;
entry:
br label %for.cond1.preheader
Expand Down
5 changes: 5 additions & 0 deletions llvm/test/Transforms/LoopFusion/pr164082.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,11 @@
; RUN: opt -passes=loop-fusion -disable-output -stats < %s 2>&1 | FileCheck -check-prefix=STAT %s
; STAT: 1 loop-fusion - Loops fused

; XFAIL: *
; Currently fails since delinearization doesn't work as expected. The estimated
; array size is different for `Array[i][i]` and `Array[i][j]`. The former is
; now regarded as an access to a 1D array.

; C Code
;
;; for (int i = 0; i < 100; ++i)
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Transforms/LoopInterchange/legality-check.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -149,10 +149,10 @@ exit:
;; for (int k = 0; k < 19; k++)
;; b[i][j][k] = b[i][5][k + 1];
;;
;; The direction vector of `b` is [= * <]. We cannot interchange all the loops.
;; The direction vector of `b` is [= * *]. We cannot interchange all the loops.

; CHECK: Dependency matrix before interchange:
; CHECK-NEXT: = * <
; CHECK-NEXT: = * *
Comment on lines +152 to +155
Copy link
Contributor Author

@kasuga-fj kasuga-fj Oct 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I remember I added this test in #139690. It should be sufficient to ensure no interchange occurs for this case.

; CHECK-NEXT: Processing InnerLoopId = 2 and OuterLoopId = 1
; CHECK-NEXT: Failed interchange InnerLoopId = 2 and OuterLoopId = 1 due to dependence
; CHECK-NEXT: Not interchanging loops. Cannot prove legality.
Expand Down
11 changes: 6 additions & 5 deletions llvm/test/Transforms/LoopInterchange/outer-dependency-lte.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,15 +15,16 @@
;;
;; The entry of the direction vector for the outermost loop is `DVEntry::LE`.
;; We need to treat this as `*`, not `<`. See issue #123920 for details.
;; In conclusion, we must not interchange the loops.

; CHECK: --- !Missed
; CHECK-NEXT: Pass: loop-interchange
; CHECK-NEXT: Name: Dependence
; CHECK-NEXT: Function: f
; CHECK: --- !Missed
; CHECK: --- !Missed
; CHECK-NEXT: Pass: loop-interchange
; CHECK-NEXT: Name: Dependence
; CHECK-NEXT: Function: f
; CHECK-NEXT: Args:
; CHECK-NEXT: - String: All loops have dependencies in all directions.
; CHECK-NEXT: ...


@a = dso_local global [16 x [16 x [16 x i32]]] zeroinitializer, align 4

Expand Down
4 changes: 4 additions & 0 deletions llvm/test/Transforms/LoopUnrollAndJam/dependencies_multidims.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,10 @@

target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"

; XFAIL: *
; The transformation seems to have succeeded "accidentally". It should be fixed
; by PR #156578.
Comment on lines +6 to +8
Copy link
Contributor Author

@kasuga-fj kasuga-fj Nov 18, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I was planning to wait for #156578 to be merged, but the author has not responded for a while, I'd prefer to proceed this one first. I believe this test should be fixed by that PR.


; CHECK-LABEL: sub_sub_less
; CHECK: %j = phi
; CHECK-NOT: %j.1 = phi
Expand Down
Loading