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authorPetar Jovanovic <petar.jovanovic@imgtec.com>2016-03-01 14:39:55 +0000
committerPetar Jovanovic <petar.jovanovic@imgtec.com>2016-03-01 14:39:55 +0000
commit8aef99aa86b251bf33a83ac24c13f4df0c189067 (patch)
tree36e91235b4014fb71bfe62b470460175c805e624 /llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
parent2cc9d4795fbc1392fdaf31174376b259524f4a28 (diff)
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calculate builtin_object_size if argument is a removable pointer
This patch fixes calculating correct value for builtin_object_size function when pointer is used only in builtin_object_size function call and never after that. Patch by Strahinja Petrovic. Differential Revision: http://reviews.llvm.org/D17337 llvm-svn: 262337
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstructionCombining.cpp')
-rw-r--r--llvm/lib/Transforms/InstCombine/InstructionCombining.cpp25
1 files changed, 19 insertions, 6 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 1b95e93..de4dfb5 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1942,6 +1942,25 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
SmallVector<WeakVH, 64> Users;
if (isAllocSiteRemovable(&MI, Users, TLI)) {
for (unsigned i = 0, e = Users.size(); i != e; ++i) {
+ // Lowering all @llvm.objectsize calls first because they may
+ // use a bitcast/GEP of the alloca we are removing.
+ Instruction *I = cast_or_null<Instruction>(&*Users[i]);
+ if (!I) continue;
+
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
+ if (II->getIntrinsicID() == Intrinsic::objectsize) {
+ uint64_t Size;
+ if (!getObjectSize(II->getArgOperand(0), Size, DL, TLI)) {
+ ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
+ Size = CI->isZero() ? -1ULL : 0;
+ }
+ replaceInstUsesWith(*I, ConstantInt::get(I->getType(), Size));
+ eraseInstFromFunction(*I);
+ Users[i] = nullptr; // Skip examining in the next loop.
+ }
+ }
+ }
+ for (unsigned i = 0, e = Users.size(); i != e; ++i) {
Instruction *I = cast_or_null<Instruction>(&*Users[i]);
if (!I) continue;
@@ -1951,12 +1970,6 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
C->isFalseWhenEqual()));
} else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) {
replaceInstUsesWith(*I, UndefValue::get(I->getType()));
- } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
- if (II->getIntrinsicID() == Intrinsic::objectsize) {
- ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
- uint64_t DontKnow = CI->isZero() ? -1ULL : 0;
- replaceInstUsesWith(*I, ConstantInt::get(I->getType(), DontKnow));
- }
}
eraseInstFromFunction(*I);
}