[llvm] fix CodeGenPrepare crash with null PSI (issue #173360) (PR #173385)

[via llvm-commits]

https://github.com/nataliakokoromyti updated https://github.com/llvm/llvm-project/pull/173385

>From b2565139f7e5413488a60c147d84acd1b98311d3 Mon Sep 17 00:00:00 2001
From: Natalia <nataliakokoromyti at gmail.com>
Date: Tue, 23 Dec 2025 06:18:42 -0800
Subject: [PATCH 1/3] add test for issue #173360

---
 .../CodeGenPrepare/pr173360-null-psi.ll       | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 llvm/test/Transforms/CodeGenPrepare/pr173360-null-psi.ll

diff --git a/llvm/test/Transforms/CodeGenPrepare/pr173360-null-psi.ll b/llvm/test/Transforms/CodeGenPrepare/pr173360-null-psi.ll
new file mode 100644
index 0000000000000..53500c0bcb481
--- /dev/null
+++ b/llvm/test/Transforms/CodeGenPrepare/pr173360-null-psi.ll
@@ -0,0 +1,21 @@
+; NOTE: This test verifies that CodeGenPrepare doesn't crash when PSI is null
+; RUN: opt -passes=codegenprepare < %s -S | FileCheck %s
+;
+; This test case triggered a null pointer dereference in CodeGenPrepare::_run()
+; when ProfileSummaryInfo (PSI) was not available. The pass attempted to call
+; PSI->hasHugeWorkingSetSize() without checking if PSI was null.
+;
+; The fix adds null checks before dereferencing PSI.
+; See: https://github.com/llvm/llvm-project/issues/173360
+
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: @f(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %iv.next.reg2mem = alloca i32, align 4
+; CHECK-NEXT:    ret void
+define void @f(ptr %A, i32 %n) {
+entry:
+  %iv.next.reg2mem = alloca i32, align 4
+  ret void
+}

>From 5cf237b47552ad247b3f9cacca9798e7b189773c Mon Sep 17 00:00:00 2001
From: Natalia <nataliakokoromyti at gmail.com>
Date: Tue, 23 Dec 2025 06:49:56 -0800
Subject: [PATCH 2/3] trigger CI


>From 3f6f3ed5e06dad9356835569b7fd1534a4f838d1 Mon Sep 17 00:00:00 2001
From: Natalia <nataliakokoromyti at gmail.com>
Date: Tue, 23 Dec 2025 06:53:01 -0800
Subject: [PATCH 3/3] trigger CI