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authorBill Wendling <isanbard@gmail.com>2010-09-15 00:32:05 +0000
committerBill Wendling <isanbard@gmail.com>2010-09-15 00:32:05 +0000
commit68cf62a515043c1795e0ebf4c45f906a297ad2e2 (patch)
tree96d084aad4e57936f0915af71a8871a7966c125a
parent1c8b0a1846a6a4548bd4b1acc5b8d4ef2f2f3424 (diff)
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Approved by Chris:
$ svn merge -c 113911 https://llvm.org/svn/llvm-project/llvm/trunk --- Merging r113911 into '.': U test/Transforms/ConstantMerge/dont-merge.ll U lib/Transforms/IPO/ConstantMerge.cpp llvm-svn: 113912
-rw-r--r--llvm/lib/Transforms/IPO/ConstantMerge.cpp28
-rw-r--r--llvm/test/Transforms/ConstantMerge/dont-merge.ll14
2 files changed, 41 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/IPO/ConstantMerge.cpp b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
index 75282fa..64e8d79 100644
--- a/llvm/lib/Transforms/IPO/ConstantMerge.cpp
+++ b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
@@ -19,10 +19,12 @@
#define DEBUG_TYPE "constmerge"
#include "llvm/Transforms/IPO.h"
+#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
using namespace llvm;
@@ -46,7 +48,27 @@ INITIALIZE_PASS(ConstantMerge, "constmerge",
ModulePass *llvm::createConstantMergePass() { return new ConstantMerge(); }
+
+
+/// Find values that are marked as llvm.used.
+static void FindUsedValues(GlobalVariable *LLVMUsed,
+ SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
+ if (LLVMUsed == 0) return;
+ ConstantArray *Inits = dyn_cast<ConstantArray>(LLVMUsed->getInitializer());
+ if (Inits == 0) return;
+
+ for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
+ if (GlobalValue *GV =
+ dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
+ UsedValues.insert(GV);
+}
+
bool ConstantMerge::runOnModule(Module &M) {
+ // Find all the globals that are marked "used". These cannot be merged.
+ SmallPtrSet<const GlobalValue*, 8> UsedGlobals;
+ FindUsedValues(M.getGlobalVariable("llvm.used"), UsedGlobals);
+ FindUsedValues(M.getGlobalVariable("llvm.compiler.used"), UsedGlobals);
+
// Map unique constant/section pairs to globals. We don't want to merge
// globals in different sections.
DenseMap<Constant*, GlobalVariable*> CMap;
@@ -79,9 +101,13 @@ bool ConstantMerge::runOnModule(Module &M) {
// Only process constants with initializers in the default addres space.
if (!GV->isConstant() ||!GV->hasDefinitiveInitializer() ||
- GV->getType()->getAddressSpace() != 0 || !GV->getSection().empty())
+ GV->getType()->getAddressSpace() != 0 || !GV->getSection().empty() ||
+ // Don't touch values marked with attribute(used).
+ UsedGlobals.count(GV))
continue;
+
+
Constant *Init = GV->getInitializer();
// Check to see if the initializer is already known.
diff --git a/llvm/test/Transforms/ConstantMerge/dont-merge.ll b/llvm/test/Transforms/ConstantMerge/dont-merge.ll
index 877cf8d..e5337df 100644
--- a/llvm/test/Transforms/ConstantMerge/dont-merge.ll
+++ b/llvm/test/Transforms/ConstantMerge/dont-merge.ll
@@ -28,3 +28,17 @@ define void @test2(i32** %P1, i32 addrspace(30)** %P2) {
store i32 addrspace(30)* @T2b, i32 addrspace(30)** %P2
ret void
}
+
+; PR8144 - Don't merge globals marked attribute(used)
+; CHECK: @T3A =
+; CHECK: @T3B =
+
+@T3A = internal constant i32 0
+@T3B = internal constant i32 0
+@llvm.used = appending global [2 x i32*] [i32* @T3A, i32* @T3B], section
+"llvm.metadata"
+
+define void @test3() {
+ call void asm sideeffect "T3A, T3B",""() ; invisible use of T3A and T3B
+ ret void
+}