From 5323693bfef99c7bd5396eefd743562f51187623 Mon Sep 17 00:00:00 2001 From: vikhegde Date: Wed, 30 Apr 2025 13:21:58 +0530 Subject: [PATCH 1/3] [SCEV] reject comparision of pointers to different address spaces in SCEVWrapPredicate::implies --- llvm/lib/Analysis/ScalarEvolution.cpp | 6 ++++ .../LoopAccessAnalysis/nusw-predicates.ll | 36 ++++++++++++++++++- 2 files changed, 41 insertions(+), 1 deletion(-) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 6055c3d791cb2..b39662ef90c05 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -14967,6 +14967,12 @@ bool SCEVWrapPredicate::implies(const SCEVPredicate *N, if (Start->getType()->isPointerTy() != OpStart->getType()->isPointerTy()) return false; + if (Start->getType()->isPointerTy()) { + if (Start->getType()->getPointerAddressSpace() != + OpStart->getType()->getPointerAddressSpace()) + return false; + } + const SCEV *Step = AR->getStepRecurrence(SE); const SCEV *OpStep = Op->AR->getStepRecurrence(SE); if (!SE.isKnownPositive(Step) || !SE.isKnownPositive(OpStep)) diff --git a/llvm/test/Analysis/LoopAccessAnalysis/nusw-predicates.ll b/llvm/test/Analysis/LoopAccessAnalysis/nusw-predicates.ll index d4f7f82a8cff1..ab40a22a3274d 100644 --- a/llvm/test/Analysis/LoopAccessAnalysis/nusw-predicates.ll +++ b/llvm/test/Analysis/LoopAccessAnalysis/nusw-predicates.ll @@ -1,7 +1,7 @@ ; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5 ; RUN: opt -passes='print' -disable-output %s 2>&1 | FileCheck %s -target datalayout = "p:16:16" +target datalayout = "p:16:16-p3:32:32" define void @int_and_pointer_predicate(ptr %v, i32 %N) { ; CHECK-LABEL: 'int_and_pointer_predicate' @@ -124,3 +124,37 @@ loop: exit: ret void } + +define void @pointers_to_different_aspace_predicates(ptr %v, ptr addrspace(3) %w, i32 %N) { +; CHECK-LABEL: 'pointers_to_different_aspace_predicates' +; CHECK-NEXT: loop: +; CHECK-NEXT: Report: cannot identify array bounds +; CHECK-NEXT: Dependences: +; CHECK-NEXT: Run-time memory checks: +; CHECK-NEXT: Grouped accesses: +; CHECK-EMPTY: +; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop. +; CHECK-NEXT: SCEV assumptions: +; CHECK-NEXT: {0,+,1}<%loop> Added Flags: +; CHECK-NEXT: {%v,+,4}<%loop> Added Flags: +; CHECK-NEXT: {%w,+,4}<%loop> Added Flags: +; CHECK-EMPTY: +; CHECK-NEXT: Expressions re-written: +; +entry: + br label %loop + +loop: + %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ] + %gep.v = getelementptr {i16, i16}, ptr %v, i64 %iv + store i16 0, ptr %gep.v, align 1 + %gep.w = getelementptr i32, ptr addrspace(3) %w, i64 %iv + store i32 0, ptr addrspace(3) %gep.w, align 1 + %iv.next = add i64 %iv, 1 + %iv.i32 = trunc i64 %iv to i32 + %.not = icmp ult i32 %N, %iv.i32 + br i1 %.not, label %exit, label %loop + + exit: + ret void + } From 5127939a5036b32b45220ad6e4485615a16e3296 Mon Sep 17 00:00:00 2001 From: vikhegde Date: Wed, 30 Apr 2025 17:15:02 +0530 Subject: [PATCH 2/3] review comment --- llvm/lib/Analysis/ScalarEvolution.cpp | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index b39662ef90c05..83b5b59fbc4d9 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -14967,11 +14967,8 @@ bool SCEVWrapPredicate::implies(const SCEVPredicate *N, if (Start->getType()->isPointerTy() != OpStart->getType()->isPointerTy()) return false; - if (Start->getType()->isPointerTy()) { - if (Start->getType()->getPointerAddressSpace() != - OpStart->getType()->getPointerAddressSpace()) - return false; - } + if (Start->getType()->isPointerTy() && Start->getType() != OpStart->getType()) + return false; const SCEV *Step = AR->getStepRecurrence(SE); const SCEV *OpStep = Op->AR->getStepRecurrence(SE); From aa5ff25e3f404bcf83a791f728266d10f4836f8a Mon Sep 17 00:00:00 2001 From: vikhegde Date: Wed, 30 Apr 2025 19:11:16 +0530 Subject: [PATCH 3/3] add comment --- llvm/lib/Analysis/ScalarEvolution.cpp | 1 + 1 file changed, 1 insertion(+) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 83b5b59fbc4d9..43d200f1153d0 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -14967,6 +14967,7 @@ bool SCEVWrapPredicate::implies(const SCEVPredicate *N, if (Start->getType()->isPointerTy() != OpStart->getType()->isPointerTy()) return false; + // Reject pointers to different address spaces. if (Start->getType()->isPointerTy() && Start->getType() != OpStart->getType()) return false;