https://github.com/kasuga-fj updated https://github.com/llvm/llvm-project/pull/162281
>From 5eeaf558673b5e5e129bc2899260e5ec659e04e3 Mon Sep 17 00:00:00 2001 From: Ryotaro Kasuga <[email protected]> Date: Tue, 7 Oct 2025 12:56:14 +0000 Subject: [PATCH] [DA] Add tests for nsw doesn't hold on entier iteration --- .../monotonicity-loop-guard.ll | 142 ++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 llvm/test/Analysis/DependenceAnalysis/monotonicity-loop-guard.ll diff --git a/llvm/test/Analysis/DependenceAnalysis/monotonicity-loop-guard.ll b/llvm/test/Analysis/DependenceAnalysis/monotonicity-loop-guard.ll new file mode 100644 index 0000000000000..290cf3a5336ce --- /dev/null +++ b/llvm/test/Analysis/DependenceAnalysis/monotonicity-loop-guard.ll @@ -0,0 +1,142 @@ +; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 6 +; RUN: opt < %s -disable-output -passes="print<da>" -da-dump-monotonicity-report \ +; RUN: -da-enable-monotonicity-check 2>&1 | FileCheck %s + +; for (i = 0; i < 9223372036854775806; i++) +; if (i < 2147483640) +; for (j = 0; j < 2147483640; j++) +; a[i + j * 4294967296] = 0; +; +; FIXME: This is not monotonic. The nsw flag is valid under +; the condition i < 2147483640, not for all i. +define void @nsw_under_loop_guard0(ptr %a) { +; CHECK-LABEL: 'nsw_under_loop_guard0' +; CHECK-NEXT: Monotonicity check: +; CHECK-NEXT: Inst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: Expr: {{\{\{}}0,+,1}<nuw><nsw><%loop.i.header>,+,4294967296}<nuw><nsw><%loop.j> +; CHECK-NEXT: Monotonicity: MultiSignedMonotonic +; CHECK-EMPTY: +; CHECK-NEXT: Src: store i8 0, ptr %idx, align 1 --> Dst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: da analyze - none! +; +entry: + br label %loop.i.header + +loop.i.header: + %i = phi i64 [ 0 , %entry ], [ %i.next, %loop.i.latch ] + br label %loop.j.pr + +loop.j.pr: + %guard.j = icmp slt i64 %i, 2147483640 + br i1 %guard.j, label %loop.j, label %exit + +loop.j: + %j = phi i64 [ 0, %loop.j.pr ], [ %j.next, %loop.j ] + %val = phi i64 [ %i, %loop.j.pr ], [ %val.next, %loop.j ] + %j.next = add nsw i64 %j, 1 + %idx = getelementptr inbounds i8, ptr %a, i64 %val + store i8 0, ptr %idx + %val.next = add nsw i64 %val, 4294967296 + %exitcond.j = icmp eq i64 %j.next, 2147483640 + br i1 %exitcond.j, label %loop.i.latch, label %loop.j + +loop.i.latch: + %i.next = add nsw i64 %i, 1 + %exitcond.i = icmp eq i64 %i.next, 9223372036854775806 + br i1 %exitcond.i, label %exit, label %loop.i.header + +exit: + ret void +} + +; for (i = 0; i < 100; i++) +; if (i < 1000) +; for (j = 0; j < 100; j++) +; a[i + j] = 0; +; +; The loop guard is always true, so the nsw flag is valid for all i. +define void @nsw_under_loop_guard1(ptr %a) { +; CHECK-LABEL: 'nsw_under_loop_guard1' +; CHECK-NEXT: Monotonicity check: +; CHECK-NEXT: Inst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: Expr: {{\{\{}}0,+,1}<nuw><nsw><%loop.i.header>,+,1}<nuw><nsw><%loop.j> +; CHECK-NEXT: Monotonicity: MultiSignedMonotonic +; CHECK-EMPTY: +; CHECK-NEXT: Src: store i8 0, ptr %idx, align 1 --> Dst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: da analyze - output [* *]! +; +entry: + br label %loop.i.header + +loop.i.header: + %i = phi i64 [ 0 , %entry ], [ %i.next, %loop.i.latch ] + br label %loop.j.pr + +loop.j.pr: + %guard.j = icmp slt i64 %i, 1000 + br i1 %guard.j, label %loop.j, label %exit + +loop.j: + %j = phi i64 [ 0, %loop.j.pr ], [ %j.next, %loop.j ] + %val = phi i64 [ %i, %loop.j.pr ], [ %val.next, %loop.j ] + %j.next = add nsw i64 %j, 1 + %idx = getelementptr inbounds i8, ptr %a, i64 %val + store i8 0, ptr %idx + %val.next = add nsw i64 %val, 1 + %exitcond.j = icmp eq i64 %j.next, 100 + br i1 %exitcond.j, label %loop.i.latch, label %loop.j + +loop.i.latch: + %i.next = add nsw i64 %i, 1 + %exitcond.i = icmp eq i64 %i.next, 100 + br i1 %exitcond.i, label %exit, label %loop.i.header + +exit: + ret void +} + +; for (i = 0; i < n; i++) +; if (i < m) +; for (j = 0; j < k; j++) +; a[i + j] = 0; +; +; The nsw flag may valid under the condition i < k. +define void @nsw_under_loop_guard2(ptr %a, i64 %n, i64 %m, i64 %k) { +; CHECK-LABEL: 'nsw_under_loop_guard2' +; CHECK-NEXT: Monotonicity check: +; CHECK-NEXT: Inst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: Expr: {{\{\{}}0,+,1}<nuw><nsw><%loop.i.header>,+,1}<nuw><nsw><%loop.j> +; CHECK-NEXT: Monotonicity: MultiSignedMonotonic +; CHECK-EMPTY: +; CHECK-NEXT: Src: store i8 0, ptr %idx, align 1 --> Dst: store i8 0, ptr %idx, align 1 +; CHECK-NEXT: da analyze - output [* *]! +; +entry: + br label %loop.i.header + +loop.i.header: + %i = phi i64 [ 0 , %entry ], [ %i.next, %loop.i.latch ] + br label %loop.j.pr + +loop.j.pr: + %guard.j = icmp slt i64 %i, %m + br i1 %guard.j, label %loop.j, label %exit + +loop.j: + %j = phi i64 [ 0, %loop.j.pr ], [ %j.next, %loop.j ] + %val = phi i64 [ %i, %loop.j.pr ], [ %val.next, %loop.j ] + %j.next = add nsw i64 %j, 1 + %idx = getelementptr inbounds i8, ptr %a, i64 %val + store i8 0, ptr %idx + %val.next = add nsw i64 %val, 1 + %exitcond.j = icmp eq i64 %j.next, %k + br i1 %exitcond.j, label %loop.i.latch, label %loop.j + +loop.i.latch: + %i.next = add nsw i64 %i, 1 + %exitcond.i = icmp eq i64 %i.next, %n + br i1 %exitcond.i, label %exit, label %loop.i.header + +exit: + ret void +} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
