[llvm] [GlobalOpt] Bail out for ConstantPtrAuth in isSimpleEnoughtToCommit. (PR #143400)

[Florian Hahn via llvm-commits]

https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/143400

>From 311d8fe207862b965e3fd5dd4384c1563313e7a5 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Mon, 9 Jun 2025 16:29:19 +0100
Subject: [PATCH 1/2] [GlobalOpt] Bail out for ConstantPtrAuth in
 isSimpleEnoughtToCommit.

Bail out for ConstantPtrAuth constants in isSimpleEnoughValueToCommitHelper
to prevent crash in cast<ConstantExpr> below.
---
 llvm/lib/Transforms/Utils/Evaluator.cpp       |  3 +++
 .../global-constructor-ptrauth-constant.ll    | 27 +++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll

diff --git a/llvm/lib/Transforms/Utils/Evaluator.cpp b/llvm/lib/Transforms/Utils/Evaluator.cpp
index 2af447aadce22..ecdcdf55d5089 100644
--- a/llvm/lib/Transforms/Utils/Evaluator.cpp
+++ b/llvm/lib/Transforms/Utils/Evaluator.cpp
@@ -74,6 +74,9 @@ isSimpleEnoughValueToCommitHelper(Constant *C,
     return true;
   }
 
+  if (isa<ConstantPtrAuth>(C))
+    return false;
+
   // We don't know exactly what relocations are allowed in constant expressions,
   // so we allow &global+constantoffset, which is safe and uniformly supported
   // across targets.
diff --git a/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll b/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
new file mode 100644
index 0000000000000..ef64b3eb1147c
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/global-constructor-ptrauth-constant.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
+; RUN: opt -p globalopt -S %s | FileCheck %s
+
+ at llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
+
+ at foo = internal global ptr null
+
+declare void @user(ptr)
+
+;.
+; CHECK: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @ctor, ptr null }]
+; CHECK: @foo = internal global ptr null
+;.
+define void @ctor() {
+; CHECK-LABEL: define void @ctor() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[DST:%.*]] = alloca ptr, align 8
+; CHECK-NEXT:    store ptr ptrauth (ptr @foo, i32 0), ptr [[DST]], align 8
+; CHECK-NEXT:    call void @user(ptr [[DST]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %dst = alloca ptr, align 8
+  store ptr ptrauth (ptr @foo, i32 0), ptr %dst, align 8
+  call void @user(ptr %dst)
+  ret void
+}

>From fd2042722f7b26c9023d275132a3e22f22e952d5 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Tue, 10 Jun 2025 09:11:02 +0100
Subject: [PATCH 2/2] !fixup use dyn_cast

---
 llvm/lib/Transforms/Utils/Evaluator.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Transforms/Utils/Evaluator.cpp b/llvm/lib/Transforms/Utils/Evaluator.cpp
index ecdcdf55d5089..d1db2ee29f3a2 100644
--- a/llvm/lib/Transforms/Utils/Evaluator.cpp
+++ b/llvm/lib/Transforms/Utils/Evaluator.cpp
@@ -74,13 +74,12 @@ isSimpleEnoughValueToCommitHelper(Constant *C,
     return true;
   }
 
-  if (isa<ConstantPtrAuth>(C))
-    return false;
-
   // We don't know exactly what relocations are allowed in constant expressions,
   // so we allow &global+constantoffset, which is safe and uniformly supported
   // across targets.
-  ConstantExpr *CE = cast<ConstantExpr>(C);
+  ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+  if (!CE)
+    return false;
   switch (CE->getOpcode()) {
   case Instruction::BitCast:
     // Bitcast is fine if the casted value is fine.