[llvm] [BOLT][AArch64] Fix PLT optimization (PR #124192)
Maksim Panchenko via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 24 14:16:13 PST 2025
https://github.com/maksfb updated https://github.com/llvm/llvm-project/pull/124192
>From 5a51bff56474f6277145a7336084a4df81392f8a Mon Sep 17 00:00:00 2001
From: Maksim Panchenko <maks at fb.com>
Date: Wed, 22 Jan 2025 17:21:02 -0800
Subject: [PATCH 1/2] [BOLT][AArch64] Fix PLT optimization
Preserve C++ exception metadata while running PLT optimization on
AArch64.
---
bolt/include/bolt/Core/MCPlusBuilder.h | 7 ++++---
bolt/lib/Passes/PLTCall.cpp | 4 ++--
.../Target/AArch64/AArch64MCPlusBuilder.cpp | 5 ++---
bolt/lib/Target/X86/X86MCPlusBuilder.cpp | 2 +-
bolt/test/AArch64/exceptions-plt.cpp | 21 +++++++++++++++++++
bolt/test/runtime/exceptions-plt.cpp | 16 ++++++++++++++
6 files changed, 46 insertions(+), 9 deletions(-)
create mode 100644 bolt/test/AArch64/exceptions-plt.cpp
create mode 100644 bolt/test/runtime/exceptions-plt.cpp
diff --git a/bolt/include/bolt/Core/MCPlusBuilder.h b/bolt/include/bolt/Core/MCPlusBuilder.h
index 5d77e6faff2fc6..c1460b2aac8a69 100644
--- a/bolt/include/bolt/Core/MCPlusBuilder.h
+++ b/bolt/include/bolt/Core/MCPlusBuilder.h
@@ -1426,11 +1426,12 @@ class MCPlusBuilder {
}
/// Creates an indirect call to the function within the \p DirectCall PLT
- /// stub. The function's memory location is pointed by the \p TargetLocation
+ /// stub. The function's address location is pointed by the \p TargetLocation
/// symbol.
+ /// Move instruction annotations from \p DirectCall to the indirect call.
virtual InstructionListType
- createIndirectPltCall(const MCInst &DirectCall,
- const MCSymbol *TargetLocation, MCContext *Ctx) {
+ createIndirectPLTCall(MCInst &&DirectCall, const MCSymbol *TargetLocation,
+ MCContext *Ctx) {
llvm_unreachable("not implemented");
return {};
}
diff --git a/bolt/lib/Passes/PLTCall.cpp b/bolt/lib/Passes/PLTCall.cpp
index 2ed996fadbb99e..31c2d92ebc2041 100644
--- a/bolt/lib/Passes/PLTCall.cpp
+++ b/bolt/lib/Passes/PLTCall.cpp
@@ -70,8 +70,8 @@ Error PLTCall::runOnFunctions(BinaryContext &BC) {
const BinaryFunction *CalleeBF = BC.getFunctionForSymbol(CallSymbol);
if (!CalleeBF || !CalleeBF->isPLTFunction())
continue;
- const InstructionListType NewCode = BC.MIB->createIndirectPltCall(
- *II, CalleeBF->getPLTSymbol(), BC.Ctx.get());
+ const InstructionListType NewCode = BC.MIB->createIndirectPLTCall(
+ std::move(*II), CalleeBF->getPLTSymbol(), BC.Ctx.get());
II = BB.replaceInstruction(II, NewCode);
assert(!NewCode.empty() && "PLT Call replacement must be non-empty");
std::advance(II, NewCode.size() - 1);
diff --git a/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp b/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
index 0b6f21527f0acf..ac709c5dd063ac 100644
--- a/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
+++ b/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
@@ -1263,7 +1263,7 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
return true;
}
- InstructionListType createIndirectPltCall(const MCInst &DirectCall,
+ InstructionListType createIndirectPLTCall(MCInst &&DirectCall,
const MCSymbol *TargetLocation,
MCContext *Ctx) override {
const bool IsTailCall = isTailCall(DirectCall);
@@ -1297,8 +1297,7 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
MCInst InstCall;
InstCall.setOpcode(IsTailCall ? AArch64::BR : AArch64::BLR);
InstCall.addOperand(MCOperand::createReg(AArch64::X17));
- if (IsTailCall)
- setTailCall(InstCall);
+ moveAnnotations(std::move(DirectCall), InstCall);
Code.emplace_back(InstCall);
return Code;
diff --git a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
index 63086c06d74fd9..465533ee71f2b0 100644
--- a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
+++ b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
@@ -1605,7 +1605,7 @@ class X86MCPlusBuilder : public MCPlusBuilder {
return true;
}
- InstructionListType createIndirectPltCall(const MCInst &DirectCall,
+ InstructionListType createIndirectPLTCall(MCInst &&DirectCall,
const MCSymbol *TargetLocation,
MCContext *Ctx) override {
assert((DirectCall.getOpcode() == X86::CALL64pcrel32 ||
diff --git a/bolt/test/AArch64/exceptions-plt.cpp b/bolt/test/AArch64/exceptions-plt.cpp
new file mode 100644
index 00000000000000..056f2dcb48b9c2
--- /dev/null
+++ b/bolt/test/AArch64/exceptions-plt.cpp
@@ -0,0 +1,21 @@
+// Verify that PLT optimization in BOLT preserves exception-handling info.
+
+// REQUIRES: system-linux
+
+// RUN: %clangxx %cflags -O1 -Wl,-q,-znow %s -o %t.exe
+// RUN: llvm-bolt %t.exe -o %t.bolt.exe --plt=all --print-only=.*main.* \
+// RUN: --print-finalized 2>&1 | FileCheck %s
+
+// CHECK-LABEL: Binary Function
+// CHECK: adrp {{.*}}__cxa_throw
+// CHECK-NEXT: ldr {{.*}}__cxa_throw
+// CHECK-NEXT: blr x17 {{.*}} handler: {{.*}} PLTCall:
+
+int main() {
+ try {
+ throw new int;
+ } catch (...) {
+ return 0;
+ }
+ return 1;
+}
diff --git a/bolt/test/runtime/exceptions-plt.cpp b/bolt/test/runtime/exceptions-plt.cpp
new file mode 100644
index 00000000000000..459d7f56cf9a61
--- /dev/null
+++ b/bolt/test/runtime/exceptions-plt.cpp
@@ -0,0 +1,16 @@
+// Verify that PLT optimization in BOLT preserves exception-handling info.
+
+// REQUIRES: system-linux
+
+// RUN: %clangxx -O1 -Wl,-q,-znow %s -o %t.exe
+// RUN: llvm-bolt %t.exe -o %t.bolt.exe --plt=all
+// RUN: %t.bolt.exe
+
+int main() {
+ try {
+ throw new int;
+ } catch (...) {
+ return 0;
+ }
+ return 1;
+}
>From faa880472d9dcae954dd3b5363082b726ed59d95 Mon Sep 17 00:00:00 2001
From: Maksim Panchenko <maks at fb.com>
Date: Fri, 24 Jan 2025 14:16:02 -0800
Subject: [PATCH 2/2] fixup! [BOLT][AArch64] Fix PLT optimization
---
bolt/test/AArch64/exceptions-plt.cpp | 2 +-
bolt/test/runtime/exceptions-plt.cpp | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/bolt/test/AArch64/exceptions-plt.cpp b/bolt/test/AArch64/exceptions-plt.cpp
index 056f2dcb48b9c2..576f0fc91a9d84 100644
--- a/bolt/test/AArch64/exceptions-plt.cpp
+++ b/bolt/test/AArch64/exceptions-plt.cpp
@@ -2,7 +2,7 @@
// REQUIRES: system-linux
-// RUN: %clangxx %cflags -O1 -Wl,-q,-znow %s -o %t.exe
+// RUN: %clangxx %cxxflags -O1 -Wl,-q,-znow %s -o %t.exe
// RUN: llvm-bolt %t.exe -o %t.bolt.exe --plt=all --print-only=.*main.* \
// RUN: --print-finalized 2>&1 | FileCheck %s
diff --git a/bolt/test/runtime/exceptions-plt.cpp b/bolt/test/runtime/exceptions-plt.cpp
index 459d7f56cf9a61..8a75a3cb384b90 100644
--- a/bolt/test/runtime/exceptions-plt.cpp
+++ b/bolt/test/runtime/exceptions-plt.cpp
@@ -2,7 +2,7 @@
// REQUIRES: system-linux
-// RUN: %clangxx -O1 -Wl,-q,-znow %s -o %t.exe
+// RUN: %clangxx %cxxflags -O1 -Wl,-q,-znow %s -o %t.exe
// RUN: llvm-bolt %t.exe -o %t.bolt.exe --plt=all
// RUN: %t.bolt.exe
More information about the llvm-commits
mailing list