[llvm] [LLVM] Maintain element type of @llvm.compiler.used/@llvm.used if it already exists (PR #162660)
Juan Manuel Martinez Caamaño via llvm-commits
llvm-commits at lists.llvm.org
Fri Oct 10 01:14:18 PDT 2025
https://github.com/jmmartinez updated https://github.com/llvm/llvm-project/pull/162660
>From c9f9939c06d21a396268eb5b6b0744e4b9ce5ec8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 9 Oct 2025 14:57:56 +0200
Subject: [PATCH 1/5] Pre-Commit test: [LLVM] Maintain element type of
@llvm.compiler.used/@llvm.used if it already exists
This new test fails with:
/home/juamarti/llvm/_llvm/llvm/lib/IR/Constants.cpp:1327:
static Constant *llvm::ConstantArray::getImpl(ArrayType *, ArrayRef<Constant *>):
Assertion `C->getType() == Ty->getElementType()
&& "Wrong type in array element initializer"'
failed.
---
.../Transforms/Utils/ModuleUtilsTest.cpp | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp b/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
index d4094c5307060..0cc408af43bc5 100644
--- a/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
+++ b/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
@@ -69,6 +69,23 @@ TEST(ModuleUtils, AppendToUsedList2) {
EXPECT_EQ(1, getListSize(*M, "llvm.used"));
}
+TEST(ModuleUtils, AppendToUsedList3) {
+ LLVMContext C;
+
+ std::unique_ptr<Module> M = parseIR(C, R"(
+ @x = addrspace(1) global [2 x i32] zeroinitializer, align 4
+ @y = addrspace(2) global [2 x i32] zeroinitializer, align 4
+ @llvm.compiler.used = appending global [1 x ptr addrspace (3)] [ptr addrspace(3) addrspacecast (ptr addrspace (1) @x to ptr addrspace(3))]
+ )");
+ GlobalVariable *X = M->getNamedGlobal("x");
+ GlobalVariable *Y = M->getNamedGlobal("y");
+ EXPECT_EQ(1, getListSize(*M, "llvm.compiler.used"));
+ appendToCompilerUsed(*M, X);
+ EXPECT_EQ(1, getListSize(*M, "llvm.compiler.used"));
+ appendToCompilerUsed(*M, Y);
+ EXPECT_EQ(2, getListSize(*M, "llvm.compiler.used"));
+}
+
using AppendFnType = decltype(&appendToGlobalCtors);
using TransformFnType = decltype(&transformGlobalCtors);
using ParamType = std::tuple<StringRef, AppendFnType, TransformFnType>;
>From 276346d4043d7dce22333610611c053cd207cf7a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 9 Oct 2025 14:34:32 +0200
Subject: [PATCH 2/5] [LLVM] Maintain element type of
@llvm.compiler.used/@llvm.used if it already exists
At the moment, the pointer type stored in the
llvm.compiler.used/llvm.used is not well fixed.
The frontend uses a pointer to the default address space (which may not
be 0; for example, it is 4 for SPIRV).
This patch makes `appendToUsed/appendToCompilerUsed` match the behaviour
in BitcodeWriter.cpp: if the variable already exists, preserve its
element type, otherwise use `ptr addrspace (0)`.
This fixes the following error in the newly added test:
UtilsTests: /home/juamarti/llvm/_llvm/llvm/lib/IR/Constants.cpp:1327:
static Constant *llvm::ConstantArray::getImpl(ArrayType *, ArrayRef<Constant *>):
Assertion `C->getType() == Ty->getElementType() && "Wrong type in array element initializer"' failed.
---
llvm/lib/Transforms/Utils/ModuleUtils.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
index 596849ecab742..d1acb0ff1ad6b 100644
--- a/llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -138,10 +138,11 @@ static void appendToUsedList(Module &M, StringRef Name, ArrayRef<GlobalValue *>
SmallSetVector<Constant *, 16> Init;
collectUsedGlobals(GV, Init);
+ Type *ArrayEltTy = GV ? GV->getValueType()->getArrayElementType()
+ : PointerType::getUnqual(M.getContext());
if (GV)
GV->eraseFromParent();
- Type *ArrayEltTy = llvm::PointerType::getUnqual(M.getContext());
for (auto *V : Values)
Init.insert(ConstantExpr::getPointerBitCastOrAddrSpaceCast(V, ArrayEltTy));
>From 9cb36675ccb80889f87bf025639565d6030103d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 9 Oct 2025 14:34:24 +0200
Subject: [PATCH 3/5] [NFC][BitcodeWriter] Use appendToCompilerUsed instead of
custom implementation
---
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 70 ++++++++++-------------
llvm/lib/Bitcode/Writer/CMakeLists.txt | 1 +
2 files changed, 31 insertions(+), 40 deletions(-)
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 7ed140d392fca..f7afa393f3e00 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -75,6 +75,7 @@
#include "llvm/Support/SHA1.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/Triple.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
@@ -5850,25 +5851,25 @@ static const char *getSectionNameForCommandline(const Triple &T) {
void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
bool EmbedBitcode, bool EmbedCmdline,
const std::vector<uint8_t> &CmdArgs) {
- // Save llvm.compiler.used and remove it.
- SmallVector<Constant *, 2> UsedArray;
- SmallVector<GlobalValue *, 4> UsedGlobals;
- GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
- Type *UsedElementType = Used ? Used->getValueType()->getArrayElementType()
- : PointerType::getUnqual(M.getContext());
- for (auto *GV : UsedGlobals) {
- if (GV->getName() != "llvm.embedded.module" &&
- GV->getName() != "llvm.cmdline")
- UsedArray.push_back(
- ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
- }
- if (Used)
- Used->eraseFromParent();
// Embed the bitcode for the llvm module.
std::string Data;
ArrayRef<uint8_t> ModuleData;
Triple T(M.getTargetTriple());
+ SmallVector<GlobalValue *, 2> NewGlobals;
+
+ auto IsCmdOrBitcode = [&](Constant *C) {
+ GlobalVariable *GV = dyn_cast<GlobalVariable>(C);
+ StringRef Name = GV ? GV->getName() : "";
+ if (EmbedBitcode && Name == "llvm.embedded.module")
+ return true;
+ if (EmbedCmdline && Name == "llvm.cmdline")
+ return true;
+ return false;
+ };
+
+ if (EmbedBitcode || EmbedCmdline)
+ removeFromUsedLists(M, IsCmdOrBitcode);
if (EmbedBitcode) {
if (Buf.getBufferSize() == 0 ||
@@ -5887,23 +5888,22 @@ void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
}
llvm::Constant *ModuleConstant =
llvm::ConstantDataArray::get(M.getContext(), ModuleData);
- llvm::GlobalVariable *GV = new llvm::GlobalVariable(
+ llvm::GlobalVariable *EmbeddedModule = new llvm::GlobalVariable(
M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
ModuleConstant);
- GV->setSection(getSectionNameForBitcode(T));
+ EmbeddedModule->setSection(getSectionNameForBitcode(T));
// Set alignment to 1 to prevent padding between two contributions from input
// sections after linking.
- GV->setAlignment(Align(1));
- UsedArray.push_back(
- ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
+ EmbeddedModule->setAlignment(Align(1));
+ NewGlobals.push_back(EmbeddedModule);
if (llvm::GlobalVariable *Old =
M.getGlobalVariable("llvm.embedded.module", true)) {
assert(Old->hasZeroLiveUses() &&
"llvm.embedded.module can only be used once in llvm.compiler.used");
- GV->takeName(Old);
+ EmbeddedModule->takeName(Old);
Old->eraseFromParent();
} else {
- GV->setName("llvm.embedded.module");
+ EmbeddedModule->setName("llvm.embedded.module");
}
// Skip if only bitcode needs to be embedded.
@@ -5913,30 +5913,20 @@ void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
CmdArgs.size());
llvm::Constant *CmdConstant =
llvm::ConstantDataArray::get(M.getContext(), CmdData);
- GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
- llvm::GlobalValue::PrivateLinkage,
- CmdConstant);
- GV->setSection(getSectionNameForCommandline(T));
- GV->setAlignment(Align(1));
- UsedArray.push_back(
- ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
+ GlobalVariable *CmdLine = new llvm::GlobalVariable(
+ M, CmdConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
+ CmdConstant);
+ CmdLine->setSection(getSectionNameForCommandline(T));
+ CmdLine->setAlignment(Align(1));
if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
assert(Old->hasZeroLiveUses() &&
"llvm.cmdline can only be used once in llvm.compiler.used");
- GV->takeName(Old);
+ CmdLine->takeName(Old);
Old->eraseFromParent();
} else {
- GV->setName("llvm.cmdline");
+ CmdLine->setName("llvm.cmdline");
}
+ NewGlobals.push_back(CmdLine);
+ appendToCompilerUsed(M, NewGlobals);
}
-
- if (UsedArray.empty())
- return;
-
- // Recreate llvm.compiler.used.
- ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
- auto *NewUsed = new GlobalVariable(
- M, ATy, false, llvm::GlobalValue::AppendingLinkage,
- llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
- NewUsed->setSection("llvm.metadata");
}
diff --git a/llvm/lib/Bitcode/Writer/CMakeLists.txt b/llvm/lib/Bitcode/Writer/CMakeLists.txt
index 2c508ca9fae95..5bbb872a90341 100644
--- a/llvm/lib/Bitcode/Writer/CMakeLists.txt
+++ b/llvm/lib/Bitcode/Writer/CMakeLists.txt
@@ -15,4 +15,5 @@ add_llvm_component_library(LLVMBitWriter
ProfileData
Support
TargetParser
+ TransformUtils
)
>From 22f1c7f6b679dddeeccb5669df87da784f564180 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Fri, 10 Oct 2025 09:52:55 +0200
Subject: [PATCH 4/5] [Review] Remove lambda from embedBitcodeInModule
---
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index f7afa393f3e00..a6519ad7f29ac 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -5848,6 +5848,12 @@ static const char *getSectionNameForCommandline(const Triple &T) {
llvm_unreachable("Unimplemented ObjectFormatType");
}
+static auto globalInUsedHasName(StringRef Name) {
+ return [Name](Constant* C) {
+ return C->getName() == Name;
+ };
+}
+
void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
bool EmbedBitcode, bool EmbedCmdline,
const std::vector<uint8_t> &CmdArgs) {
@@ -5858,19 +5864,6 @@ void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
Triple T(M.getTargetTriple());
SmallVector<GlobalValue *, 2> NewGlobals;
- auto IsCmdOrBitcode = [&](Constant *C) {
- GlobalVariable *GV = dyn_cast<GlobalVariable>(C);
- StringRef Name = GV ? GV->getName() : "";
- if (EmbedBitcode && Name == "llvm.embedded.module")
- return true;
- if (EmbedCmdline && Name == "llvm.cmdline")
- return true;
- return false;
- };
-
- if (EmbedBitcode || EmbedCmdline)
- removeFromUsedLists(M, IsCmdOrBitcode);
-
if (EmbedBitcode) {
if (Buf.getBufferSize() == 0 ||
!isBitcode((const unsigned char *)Buf.getBufferStart(),
@@ -5898,6 +5891,7 @@ void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
NewGlobals.push_back(EmbeddedModule);
if (llvm::GlobalVariable *Old =
M.getGlobalVariable("llvm.embedded.module", true)) {
+ removeFromUsedLists(M, globalInUsedHasName("llvm.embedded.module"));
assert(Old->hasZeroLiveUses() &&
"llvm.embedded.module can only be used once in llvm.compiler.used");
EmbeddedModule->takeName(Old);
@@ -5919,6 +5913,7 @@ void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
CmdLine->setSection(getSectionNameForCommandline(T));
CmdLine->setAlignment(Align(1));
if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
+ removeFromUsedLists(M, globalInUsedHasName("llvm.cmdline"));
assert(Old->hasZeroLiveUses() &&
"llvm.cmdline can only be used once in llvm.compiler.used");
CmdLine->takeName(Old);
>From 7b445e0ca3391af3053e94bc9fbc34ceb9bff5fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Fri, 10 Oct 2025 09:54:55 +0200
Subject: [PATCH 5/5] [Review] 'addrspace (n)' -> 'addrspace(n)'
---
llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp b/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
index 0cc408af43bc5..cbdb4dcbc9a6f 100644
--- a/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
+++ b/llvm/unittests/Transforms/Utils/ModuleUtilsTest.cpp
@@ -75,7 +75,7 @@ TEST(ModuleUtils, AppendToUsedList3) {
std::unique_ptr<Module> M = parseIR(C, R"(
@x = addrspace(1) global [2 x i32] zeroinitializer, align 4
@y = addrspace(2) global [2 x i32] zeroinitializer, align 4
- @llvm.compiler.used = appending global [1 x ptr addrspace (3)] [ptr addrspace(3) addrspacecast (ptr addrspace (1) @x to ptr addrspace(3))]
+ @llvm.compiler.used = appending global [1 x ptr addrspace(3)] [ptr addrspace(3) addrspacecast (ptr addrspace(1) @x to ptr addrspace(3))]
)");
GlobalVariable *X = M->getNamedGlobal("x");
GlobalVariable *Y = M->getNamedGlobal("y");
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