[polly] 6461bd3 - [Polly] Fix infinite recursion in `ScopExpander::visitAddRecExpr` (#206063)
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Mon Jul 13 03:40:58 PDT 2026
Author: Le Gia Bao
Date: 2026-07-13T16:10:53+05:30
New Revision: 6461bd3749dc09698b76c3349e7b4befab7f7f9b
URL: https://github.com/llvm/llvm-project/commit/6461bd3749dc09698b76c3349e7b4befab7f7f9b
DIFF: https://github.com/llvm/llvm-project/commit/6461bd3749dc09698b76c3349e7b4befab7f7f9b.diff
LOG: [Polly] Fix infinite recursion in `ScopExpander::visitAddRecExpr` (#206063)
visitUnknown follow VMap, call GenSE.getSCEV() on the mapped value, and
get back the original AddRec, recursing visitAddRecExpr infinitely.
Insert the result into SCEVCache before calling visit() to cut
recursion.
Fixes #205137.
Added:
polly/test/CodeGen/issue205137.ll
Modified:
polly/lib/Support/ScopHelper.cpp
Removed:
################################################################################
diff --git a/polly/lib/Support/ScopHelper.cpp b/polly/lib/Support/ScopHelper.cpp
index 6408ec6bbde40..e1e7befdfad96 100644
--- a/polly/lib/Support/ScopHelper.cpp
+++ b/polly/lib/Support/ScopHelper.cpp
@@ -445,6 +445,10 @@ struct ScopExpander final : SCEVVisitor<ScopExpander, const SCEV *> {
// FIXME: This emits a SCEV for GenSE (since GenLRepl will refer to the
// induction variable of a generated loop), so we should not use SCEVVisitor
// with it. However, it still contains references to the SCoP region.
+ //
+ // Insert in the cache to cut recursive cycles:
+ // visitUnknown follow VMap and GenSE.getSCEV() back to E.
+ SCEVCache[E] = Evaluated;
return visit(Evaluated);
}
///}
diff --git a/polly/test/CodeGen/issue205137.ll b/polly/test/CodeGen/issue205137.ll
new file mode 100644
index 0000000000000..1193e45cf99c6
--- /dev/null
+++ b/polly/test/CodeGen/issue205137.ll
@@ -0,0 +1,161 @@
+; RUN: opt %loadNPMPolly '-passes=polly<no-default-opts>' -S %s | FileCheck %s
+;
+; https://github.com/llvm/llvm-project/issues/205137
+; visitAddRecExpr cause infinite recursion when visitUnknown follow VMa
+; and GenSE.getSCEV() back to AddRec.
+;
+; CHECK: polly.split_new_and_old
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a = dso_local local_unnamed_addr global i64 0, align 8
+ at b = dso_local local_unnamed_addr global i16 0, align 2
+
+define dso_local void @_Z1cisPiPA5_A5_xPS0_Pc(i32 noundef %d, i16 noundef signext %e, ptr nofree noundef readonly captures(none) %f, ptr nofree noundef readonly captures(none) %g, ptr nofree noundef readonly captures(none) %h, ptr nofree noundef readnone captures(none) %i) local_unnamed_addr {
+entry:
+ %a.promoted39 = load i64, ptr @a, align 8
+ %tobool38.not = icmp eq i16 %e, 0
+ br label %for.cond1.preheader
+
+for.cond1.preheader:
+ %conv45 = phi i64 [ 0, %entry ], [ %sext, %for.cond56.preheader.1 ]
+ %a.promoted4042 = phi i64 [ %a.promoted39, %entry ], [ %.sroa.speculated.14.1, %for.cond56.preheader.1 ]
+ %invariant.gep = getelementptr [8 x i8], ptr %h, i64 %conv45
+ %arrayidx25 = getelementptr inbounds nuw [200 x i8], ptr %g, i64 %conv45
+ %arrayidx27 = getelementptr inbounds nuw [40 x i8], ptr %arrayidx25, i64 %conv45
+ %arrayidx29 = getelementptr inbounds nuw [8 x i8], ptr %arrayidx27, i64 %conv45
+ br label %for.cond19.preheader
+
+for.cond.cleanup:
+ store i16 %conv47.1, ptr @b, align 2, !tbaa !8
+ ret void
+
+for.cond19.preheader:
+ %conv1532 = phi i64 [ 0, %for.cond1.preheader ], [ %sext17, %for.cond19.preheader ]
+ %a.promoted3031 = phi i64 [ %a.promoted4042, %for.cond1.preheader ], [ %.sroa.speculated.14, %for.cond19.preheader ]
+ %0 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated = tail call i64 @llvm.umax.i64(i64 %a.promoted3031, i64 %0)
+ store i64 %.sroa.speculated, ptr @a, align 8, !tbaa !10
+ %1 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated, i64 %1)
+ store i64 %.sroa.speculated.1, ptr @a, align 8, !tbaa !10
+ %2 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.2 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.1, i64 %2)
+ store i64 %.sroa.speculated.2, ptr @a, align 8, !tbaa !10
+ %3 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.3 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.2, i64 %3)
+ store i64 %.sroa.speculated.3, ptr @a, align 8, !tbaa !10
+ %4 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.4 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.3, i64 %4)
+ store i64 %.sroa.speculated.4, ptr @a, align 8, !tbaa !10
+ %5 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.5 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.4, i64 %5)
+ store i64 %.sroa.speculated.5, ptr @a, align 8, !tbaa !10
+ %6 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.6 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.5, i64 %6)
+ store i64 %.sroa.speculated.6, ptr @a, align 8, !tbaa !10
+ %7 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.7 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.6, i64 %7)
+ store i64 %.sroa.speculated.7, ptr @a, align 8, !tbaa !10
+ %8 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.8 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.7, i64 %8)
+ store i64 %.sroa.speculated.8, ptr @a, align 8, !tbaa !10
+ %9 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.9 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.8, i64 %9)
+ store i64 %.sroa.speculated.9, ptr @a, align 8, !tbaa !10
+ %10 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.10 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.9, i64 %10)
+ store i64 %.sroa.speculated.10, ptr @a, align 8, !tbaa !10
+ %11 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.11 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.10, i64 %11)
+ store i64 %.sroa.speculated.11, ptr @a, align 8, !tbaa !10
+ %12 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.12 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.11, i64 %12)
+ store i64 %.sroa.speculated.12, ptr @a, align 8, !tbaa !10
+ %13 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.13 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.12, i64 %13)
+ store i64 %.sroa.speculated.13, ptr @a, align 8, !tbaa !10
+ %14 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.14 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.13, i64 %14)
+ store i64 %.sroa.speculated.14, ptr @a, align 8, !tbaa !10
+ %sext17 = add nuw nsw i64 %conv1532, 12884901888
+ %cmp16 = icmp samesign ult i64 %conv1532, 51539607552
+ br i1 %cmp16, label %for.cond19.preheader, label %for.cond14.preheader.1, !llvm.loop !12
+
+for.cond14.preheader.1:
+ %conv.pn.1 = select i1 %tobool38.not, i64 4, i64 %conv45
+ %gep.1 = getelementptr [40 x i8], ptr %invariant.gep, i64 %conv.pn.1
+ br label %for.cond19.preheader.1
+
+for.cond19.preheader.1:
+ %conv1532.1 = phi i64 [ 0, %for.cond14.preheader.1 ], [ %sext17.1, %for.cond19.preheader.1 ]
+ %a.promoted3031.1 = phi i64 [ %.sroa.speculated.14, %for.cond14.preheader.1 ], [ %.sroa.speculated.14.1, %for.cond19.preheader.1 ]
+ %15 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.147 = tail call i64 @llvm.umax.i64(i64 %a.promoted3031.1, i64 %15)
+ store i64 %.sroa.speculated.147, ptr @a, align 8, !tbaa !10
+ %16 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.1.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.147, i64 %16)
+ store i64 %.sroa.speculated.1.1, ptr @a, align 8, !tbaa !10
+ %17 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.2.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.1.1, i64 %17)
+ store i64 %.sroa.speculated.2.1, ptr @a, align 8, !tbaa !10
+ %18 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.3.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.2.1, i64 %18)
+ store i64 %.sroa.speculated.3.1, ptr @a, align 8, !tbaa !10
+ %19 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.4.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.3.1, i64 %19)
+ store i64 %.sroa.speculated.4.1, ptr @a, align 8, !tbaa !10
+ %20 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.5.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.4.1, i64 %20)
+ store i64 %.sroa.speculated.5.1, ptr @a, align 8, !tbaa !10
+ %21 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.6.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.5.1, i64 %21)
+ store i64 %.sroa.speculated.6.1, ptr @a, align 8, !tbaa !10
+ %22 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.7.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.6.1, i64 %22)
+ store i64 %.sroa.speculated.7.1, ptr @a, align 8, !tbaa !10
+ %23 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.8.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.7.1, i64 %23)
+ store i64 %.sroa.speculated.8.1, ptr @a, align 8, !tbaa !10
+ %24 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.9.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.8.1, i64 %24)
+ store i64 %.sroa.speculated.9.1, ptr @a, align 8, !tbaa !10
+ %25 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.10.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.9.1, i64 %25)
+ store i64 %.sroa.speculated.10.1, ptr @a, align 8, !tbaa !10
+ %26 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.11.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.10.1, i64 %26)
+ store i64 %.sroa.speculated.11.1, ptr @a, align 8, !tbaa !10
+ %27 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.12.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.11.1, i64 %27)
+ store i64 %.sroa.speculated.12.1, ptr @a, align 8, !tbaa !10
+ %28 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.13.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.12.1, i64 %28)
+ store i64 %.sroa.speculated.13.1, ptr @a, align 8, !tbaa !10
+ %29 = load i64, ptr %arrayidx29, align 8, !tbaa !10
+ %.sroa.speculated.14.1 = tail call i64 @llvm.umax.i64(i64 %.sroa.speculated.13.1, i64 %29)
+ store i64 %.sroa.speculated.14.1, ptr @a, align 8, !tbaa !10
+ %sext17.1 = add nuw nsw i64 %conv1532.1, 12884901888
+ %cmp16.1 = icmp samesign ult i64 %conv1532.1, 51539607552
+ br i1 %cmp16.1, label %for.cond19.preheader.1, label %for.cond56.preheader.1, !llvm.loop !12
+
+for.cond56.preheader.1:
+ %cond.1 = load i64, ptr %gep.1, align 8, !tbaa !10
+ %conv47.1 = trunc i64 %cond.1 to i16
+ %sext = add nuw nsw i64 %conv45, 1
+ %exitcond.not = icmp eq i64 %sext, 5
+ br i1 %exitcond.not, label %for.cond.cleanup, label %for.cond1.preheader, !llvm.loop !14
+}
+
+declare i64 @llvm.umax.i64(i64, i64)
+
+!6 = !{!"omnipotent char", !7, i64 0}
+!7 = !{!"Simple C++ TBAA"}
+!8 = !{!9, !9, i64 0}
+!9 = !{!"short", !6, i64 0}
+!10 = !{!11, !11, i64 0}
+!11 = !{!"long long", !6, i64 0}
+!12 = distinct !{!12, !13}
+!13 = !{!"llvm.loop.mustprogress"}
+!14 = distinct !{!14, !13}
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