[LoopLoadElim] Pass ScalarEvolution in old pass manager. PR49141

Loop canonicalization may end up deleting blocks from CFG. And
Scalar Evolution may still keep cached referenced to those blocks
unless updated properly.

diff --git a/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp b/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp
index 0586121..e7b5a26 100644 (file)
--- a/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp
@@ -664,10 +664,11 @@ public:
     auto *BFI = (PSI && PSI->hasProfileSummary()) ?
                 &getAnalysis<LazyBlockFrequencyInfoPass>().getBFI() :
                 nullptr;
+    auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
 
     // Process each loop nest in the function.
     return eliminateLoadsAcrossLoops(
-        F, LI, DT, BFI, PSI, /*SE*/ nullptr, /*AC*/ nullptr,
+        F, LI, DT, BFI, PSI, SE, /*AC*/ nullptr,
         [&LAA](Loop &L) -> const LoopAccessInfo & { return LAA.getInfo(&L); });
   }
 

diff --git a/llvm/test/Transforms/LoopLoadElim/pr-49141.ll b/llvm/test/Transforms/LoopLoadElim/pr-49141.ll
new file mode 100644 (file)
index 0000000..df7a975
--- /dev/null
+++ b/llvm/test/Transforms/LoopLoadElim/pr-49141.ll
@@ -0,0 +1,35 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -indvars -loop-load-elim < %s 2>&1 | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128-ni:1-p2:32:8:8:32-ni:2"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @test() {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[A_01:%.*]] = phi i16 [ undef, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT:    [[INC]] = add nsw i16 [[A_01]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i16 [[INC]], 2
+; CHECK-NEXT:    [[OR_COND:%.*]] = and i1 false, [[CMP]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[FOR_BODY]], label [[FOR_END:%.*]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.cond:                                         ; preds = %for.body
+  %a.0 = phi i16 [ %inc, %for.body ]
+  %cmp = icmp sle i16 %a.0, 2
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond, %entry
+  %a.01 = phi i16 [ undef, %entry ], [ %a.0, %for.cond ]
+  %inc = add nsw i16 %a.01, 1
+  br i1 false, label %for.cond, label %for.end
+
+for.end:                                          ; preds = %for.body, %for.cond
+  ret void
+}