[llvm] f91a6e6 - [SCEV] Reject comparision of pointers to different address spaces in SCEVWrapPredicate::implies (#137935)

[via llvm-commits]

Author: Vikram Hegde
Date: 2025-04-30T21:03:31+05:30
New Revision: f91a6e6dab44a7eacee2312f955b6e28cb227900

URL: https://github.com/llvm/llvm-project/commit/f91a6e6dab44a7eacee2312f955b6e28cb227900
DIFF: https://github.com/llvm/llvm-project/commit/f91a6e6dab44a7eacee2312f955b6e28cb227900.diff

LOG: [SCEV] Reject comparision of pointers to different address spaces in SCEVWrapPredicate::implies (#137935)

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp
    llvm/test/Analysis/LoopAccessAnalysis/nusw-predicates.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 6055c3d791cb2..43d200f1153d0 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -14967,6 +14967,10 @@ bool SCEVWrapPredicate::implies(const SCEVPredicate *N,
   if (Start->getType()->isPointerTy() != OpStart->getType()->isPointerTy())
     return false;
 
+  // Reject pointers to 
diff erent address spaces.
+  if (Start->getType()->isPointerTy() && Start->getType() != OpStart->getType())
+    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<access-info>' -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_
diff erent_aspace_predicates(ptr %v, ptr addrspace(3) %w, i32 %N) {
+; CHECK-LABEL: 'pointers_to_
diff erent_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: <nusw>
+; CHECK-NEXT:      {%v,+,4}<%loop> Added Flags: <nusw>
+; CHECK-NEXT:      {%w,+,4}<%loop> Added Flags: <nusw>
+; 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
+ }