Skip to content

[DA] Add test where ExactSIV misses dependency due to overflow (NFC) #157085

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
merged 4 commits into from
Sep 16, 2025
Merged

[DA] Add test where ExactSIV misses dependency due to overflow (NFC) #157085

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
fb2bcf2
[DA] Add option to run only SIV routines
kasuga-fj Sep 5, 2025
4e43533
[DA] Add test where ExactSIV misses dependency due to overflow (NFC)
kasuga-fj Sep 5, 2025
6a3a5fc
address review comment
kasuga-fj Sep 16, 2025
028ddb1
Merge branch 'main' into users/kasuga-fj/da-fix-exact-siv-ovfl-2
kasuga-fj Sep 16, 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
120 changes: 120 additions & 0 deletions llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -807,3 +807,123 @@ for.body: ; preds = %entry, %for.body
for.end: ; preds = %for.body
ret void
}

;; max_i = INT64_MAX/6 // 1537228672809129301
;; for (long long i = 0; i <= max_i; i++) {
;; A[-6*i + INT64_MAX] = 0;
;; if (i)
;; A[3*i - 2] = 1;
;; }
;;
;; FIXME: DependencyAnalsysis currently detects no dependency between
;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`, but it does exist. For example,
;;
;; | memory location | -6*i + INT64_MAX | 3*i - 2
;; |------------------------|------------------------|-----------
;; | A[1] | i = max_i | i = 1
;; | A[4611686018427387901] | i = 768614336404564651 | i = max_i
;;
;; Actually,
;; * 1 = -6*max_i + INT64_MAX = 3*1 - 2
;; * 4611686018427387901 = -6*768614336404564651 + INT64_MAX = 3*max_i - 2
;;

define void @exact14(ptr %A) {
; CHECK-LABEL: 'exact14'
; CHECK-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT: da analyze - none!
;
; CHECK-SIV-ONLY-LABEL: 'exact14'
; CHECK-SIV-ONLY-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - none!
; CHECK-SIV-ONLY-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - none!
; CHECK-SIV-ONLY-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - none!
;
entry:
br label %loop.header

loop.header:
%i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
%subscript.0 = phi i64 [ 9223372036854775807, %entry ], [ %subscript.0.next, %loop.latch ]
%subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
%idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
store i8 0, ptr %idx.0
%cond.store = icmp ne i64 %i, 0
br i1 %cond.store, label %if.store, label %loop.latch

if.store:
%idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
store i8 1, ptr %idx.1
br label %loop.latch

loop.latch:
%i.inc = add nuw nsw i64 %i, 1
%subscript.0.next = add nsw i64 %subscript.0, -6
%subscript.1.next = add nsw i64 %subscript.1, 3
%exitcond = icmp sgt i64 %i.inc, 1537228672809129301
br i1 %exitcond, label %exit, label %loop.header

exit:
ret void
}

;; A generalized version of @exact14.
;;
;; for (long long i = 0; i <= n / 6; i++) {
;; A[-6*i + n] = 0;
;; if (i)
;; A[3*i - 2] = 1;
;; }

define void @exact15(ptr %A, i64 %n) {
; CHECK-LABEL: 'exact15'
; CHECK-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-NEXT: da analyze - none!
; CHECK-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT: da analyze - output [*|<]!
; CHECK-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT: da analyze - none!
;
; CHECK-SIV-ONLY-LABEL: 'exact15'
; CHECK-SIV-ONLY-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - none!
; CHECK-SIV-ONLY-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - output [*|<]!
; CHECK-SIV-ONLY-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-SIV-ONLY-NEXT: da analyze - none!
;
entry:
%bound = sdiv i64 %n, 6
%guard = icmp sgt i64 %n, 0
br i1 %guard, label %loop.header, label %exit

loop.header:
%i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
%subscript.0 = phi i64 [ %n, %entry ], [ %subscript.0.next, %loop.latch ]
%subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
%idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
store i8 0, ptr %idx.0
%cond.store = icmp ne i64 %i, 0
br i1 %cond.store, label %if.store, label %loop.latch

if.store:
%idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
store i8 1, ptr %idx.1
br label %loop.latch

loop.latch:
%i.inc = add nuw nsw i64 %i, 1
%subscript.0.next = add nsw i64 %subscript.0, -6
%subscript.1.next = add nsw i64 %subscript.1, 3
%exitcond = icmp sgt i64 %i.inc, %bound
br i1 %exitcond, label %exit, label %loop.header

exit:
ret void
}