1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 4 2; RUN: opt -passes='print<access-info>' -disable-output < %s 2>&1 | FileCheck %s 3 4; Check that loop-independent forward dependences are discovered properly. 5; 6; FIXME: This does not actually always work which is pretty confusing. Right 7; now there is hack in LAA that tries to figure out loop-independent forward 8; dependeces *outside* of the MemoryDepChecker logic (i.e. proper dependence 9; analysis). 10; 11; Therefore if there is only loop-independent dependences for an array 12; (i.e. the same index is used), we don't discover the forward dependence. 13; So, at ***, we add another non-I-based access of A to trigger 14; MemoryDepChecker analysis for accesses of A. 15; 16; for (unsigned i = 0; i < 100; i++) { 17; A[i + 1] = B[i] + 1; // *** 18; A[i] = B[i] + 2; 19; C[i] = A[i] * 2; 20; } 21 22target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 23 24define void @f(ptr noalias %A, ptr noalias %B, ptr noalias %C, i64 %N) { 25; CHECK-LABEL: 'f' 26; CHECK-NEXT: for.body: 27; CHECK-NEXT: Report: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop 28; CHECK-NEXT: Forward loop carried data dependence that prevents store-to-load forwarding. 29; CHECK-NEXT: Dependences: 30; CHECK-NEXT: Forward: 31; CHECK-NEXT: store i32 %b_p1, ptr %Aidx, align 4 -> 32; CHECK-NEXT: %a = load i32, ptr %Aidx, align 4 33; CHECK-EMPTY: 34; CHECK-NEXT: ForwardButPreventsForwarding: 35; CHECK-NEXT: store i32 %b_p2, ptr %Aidx_next, align 4 -> 36; CHECK-NEXT: %a = load i32, ptr %Aidx, align 4 37; CHECK-EMPTY: 38; CHECK-NEXT: Forward: 39; CHECK-NEXT: store i32 %b_p2, ptr %Aidx_next, align 4 -> 40; CHECK-NEXT: store i32 %b_p1, ptr %Aidx, align 4 41; CHECK-EMPTY: 42; CHECK-NEXT: Run-time memory checks: 43; CHECK-NEXT: Grouped accesses: 44; CHECK-EMPTY: 45; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop. 46; CHECK-NEXT: SCEV assumptions: 47; CHECK-EMPTY: 48; CHECK-NEXT: Expressions re-written: 49; 50 51entry: 52 br label %for.body 53 54for.body: ; preds = %for.body, %entry 55 %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] 56 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 57 58 %Bidx = getelementptr inbounds i32, ptr %B, i64 %indvars.iv 59 %Cidx = getelementptr inbounds i32, ptr %C, i64 %indvars.iv 60 %Aidx_next = getelementptr inbounds i32, ptr %A, i64 %indvars.iv.next 61 %Aidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv 62 63 %b = load i32, ptr %Bidx, align 4 64 %b_p2 = add i32 %b, 1 65 store i32 %b_p2, ptr %Aidx_next, align 4 66 67 %b_p1 = add i32 %b, 2 68 store i32 %b_p1, ptr %Aidx, align 4 69 70 %a = load i32, ptr %Aidx, align 4 71 %c = mul i32 %a, 2 72 store i32 %c, ptr %Cidx, align 4 73 74 %exitcond = icmp eq i64 %indvars.iv.next, %N 75 br i1 %exitcond, label %for.end, label %for.body 76 77for.end: ; preds = %for.body 78 ret void 79} 80