llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-analysis Author: Ryotaro Kasuga (kasuga-fj) <details> <summary>Changes</summary> This patch adds test cases where DA fails to detect dependencies due to overflow during analysis. For now, they are added to `ExactSIV.ll`, but `symbolicRDIVtest` and `gcdMIVtest` also exhibit similar issues and will need to be fixed as well. --- Full diff: https://github.com/llvm/llvm-project/pull/157085.diff 1 Files Affected: - (modified) llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll (+113) ``````````diff diff --git a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll index 0fe62991fede9..97b58c06303e6 100644 --- a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll +++ b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll @@ -807,3 +807,116 @@ for.body: ; preds = %entry, %for.body for.end: ; preds = %for.body ret void } + +;; FIXME: There is a loop-carried dependency between +;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`. For example, +;; +;; - 1 = -6*max_i + INT64_MAX = 3*1 - 2 +;; - 4611686018427387901 = -6*768614336404564651 + INT64_MAX = 3*max_i - 2 +;; +;; 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; +;; } + +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 nuw nsw i64 %subscript.0, -6 + %subscript.1.next = add nuw 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 nuw nsw i64 %subscript.0, -6 + %subscript.1.next = add nuw nsw i64 %subscript.1, 3 + %exitcond = icmp sgt i64 %i.inc, %bound + br i1 %exitcond, label %exit, label %loop.header + +exit: + ret void +} `````````` </details> https://github.com/llvm/llvm-project/pull/157085 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
