diff options
Diffstat (limited to 'llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-overflow.ll')
| -rw-r--r-- | llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-overflow.ll | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-overflow.ll b/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-overflow.ll new file mode 100644 index 0000000..ba57c7b --- /dev/null +++ b/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-overflow.ll @@ -0,0 +1,125 @@ +; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 6 +; RUN: opt < %s -disable-output "-passes=print<da>" 2>&1 \ +; RUN: | FileCheck %s --check-prefixes=CHECK,CHECK-ALL +; RUN: opt < %s -disable-output "-passes=print<da>" -da-enable-dependence-test=weak-crossing-siv 2>&1 \ +; RUN: | FileCheck %s --check-prefixes=CHECK,CHECK-WEAK-CROSSING-SIV + +; max_i = INT64_MAX/3 // 3074457345618258602 +; for (long long i = 0; i <= max_i; i++) { +; A[-3*i + INT64_MAX] = 0; +; if (i) +; A[3*i - 2] = 1; +; } +; +; FIXME: DependenceAnalysis currently detects no dependency between +; `A[-3*i + INT64_MAX]` and `A[3*i - 2]`, but it does exist. For example, +; +; memory access | i == 1 | i == max_i +; ---------------------|------------------|------------------ +; A[-3*i + INT64_MAX] | A[INT64_MAX - 3] | A[1] +; A[3*i - 2] | A[1] | A[INT64_MAX - 3] +; +; The root cause is that the calculation of the differenct between the two +; constants (INT64_MAX and -2) triggers an overflow. + +define void @weakcorssing_delta_ovfl(ptr %A) { +; CHECK-ALL-LABEL: 'weakcorssing_delta_ovfl' +; CHECK-ALL-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; CHECK-ALL-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; CHECK-ALL-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; +; CHECK-WEAK-CROSSING-SIV-LABEL: 'weakcorssing_delta_ovfl' +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - consistent output [*]! +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - none! +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - consistent output [*]! +; +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, -3 + %subscript.1.next = add nsw i64 %subscript.1, 3 + %ec = icmp sgt i64 %i.inc, 3074457345618258602 + br i1 %ec, label %exit, label %loop.header + +exit: + ret void +} + +; max_i = INT64_MAX/3 // 3074457345618258602 +; for (long long i = 0; i <= max_i; i++) { +; A[-3*i + INT64_MAX] = 0; +; A[3*i + 1] = 1; +; } +; +; FIXME: DependenceAnalysis currently detects no dependency between +; `A[-3*i + INT64_MAX]` and `A[3*i - 2]`, but it does exist. For example, +; +; memory access | i == 0 | i == 1 | i == max_i - 1 | i == max_i +; ---------------------|--------|------------------|----------------|------------------ +; A[-3*i + INT64_MAX] | | A[INT64_MAX - 3] | A[1] | +; A[3*i + 1] | A[1] | | | A[INT64_MAX - 3] +; +; The root cause is that the product of the BTC, the coefficient, and 2 +; triggers an overflow. +; +define void @weakcorssing_prod_ovfl(ptr %A) { +; CHECK-ALL-LABEL: 'weakcorssing_prod_ovfl' +; CHECK-ALL-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; CHECK-ALL-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; CHECK-ALL-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-ALL-NEXT: da analyze - none! +; +; CHECK-WEAK-CROSSING-SIV-LABEL: 'weakcorssing_prod_ovfl' +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - consistent output [*]! +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - none! +; CHECK-WEAK-CROSSING-SIV-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 +; CHECK-WEAK-CROSSING-SIV-NEXT: da analyze - consistent output [*]! +; +entry: + br label %loop + +loop: + %i = phi i64 [ 0, %entry ], [ %i.inc, %loop ] + %subscript.0 = phi i64 [ 9223372036854775807, %entry ], [ %subscript.0.next, %loop ] + %subscript.1 = phi i64 [ 1, %entry ], [ %subscript.1.next, %loop ] + %idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0 + %idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1 + store i8 0, ptr %idx.0 + store i8 1, ptr %idx.1 + %i.inc = add nuw nsw i64 %i, 1 + %subscript.0.next = add nsw i64 %subscript.0, -3 + %subscript.1.next = add nsw i64 %subscript.1, 3 + %ec = icmp sgt i64 %i.inc, 3074457345618258602 + br i1 %ec, label %exit, label %loop + +exit: + ret void +} +;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line: +; CHECK: {{.*}} |