From ffe01de6a9831e23d03672dc2f42c2621415aa7e Mon Sep 17 00:00:00 2001
From: Karthika Devi C <quic_kartc@quicinc.com>
Date: Fri, 6 Dec 2024 04:02:33 -0800
Subject: [PATCH] [polly] Skip instructions of different function in
 isHoistableLoad.

After patch 5ce47a5, some assert crashes occur in Polly. This
issue arises because an instruction from one function queries the
Dominator Tree (DT) of another function. To fix this, the
`isHoistableLoad` function now skips instructions that belong to
different function while iterating.
---
 polly/lib/Support/ScopHelper.cpp        |  3 ++-
 polly/test/ScopDetect/dom-tree-crash.ll | 31 +++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 polly/test/ScopDetect/dom-tree-crash.ll

diff --git a/polly/lib/Support/ScopHelper.cpp b/polly/lib/Support/ScopHelper.cpp
index 754bf50e2911f..e57d7aab17f22 100644
--- a/polly/lib/Support/ScopHelper.cpp
+++ b/polly/lib/Support/ScopHelper.cpp
@@ -604,7 +604,8 @@ bool polly::isHoistableLoad(LoadInst *LInst, Region &R, LoopInfo &LI,
 
   for (auto *User : Ptr->users()) {
     auto *UserI = dyn_cast<Instruction>(User);
-    if (!UserI || !R.contains(UserI))
+    if (!UserI || UserI->getFunction() != LInst->getFunction() ||
+        !R.contains(UserI))
       continue;
     if (!UserI->mayWriteToMemory())
       continue;
diff --git a/polly/test/ScopDetect/dom-tree-crash.ll b/polly/test/ScopDetect/dom-tree-crash.ll
new file mode 100644
index 0000000000000..efc732c50e177
--- /dev/null
+++ b/polly/test/ScopDetect/dom-tree-crash.ll
@@ -0,0 +1,31 @@
+; RUN: opt %loadNPMPolly '-passes=print<polly-detect>' -disable-output < %s 2>&1 | FileCheck %s
+
+; CHECK: Detected Scops in Function foo
+
+; This unit test case is to check if the following IR does not crash in isHoistableLoad function during Scop Detection.
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"
+target triple = "aarch64-unknown-linux-gnueabi"
+
+define void @foo(ptr %block) {
+entry:
+  br label %for.body
+
+for.cond1.preheader:                              ; preds = %for.body
+  %0 = load ptr, ptr null, align 8
+  %1 = load i16, ptr %block, align 2
+  %2 = load i16, ptr %0, align 2
+  br label %foo.exit
+
+for.body:                                         ; preds = %for.body, %entry
+  br i1 false, label %for.cond1.preheader, label %for.body
+
+foo.exit:                                     ; preds = %for.cond1.preheader
+  ret void
+}
+
+define void @init_foo() {
+entry:
+  store ptr null, ptr null, align 8
+  ret void
+}