[cfe-commits] r139643 - in /cfe/trunk: lib/CodeGen/CGBuiltin.cpp lib/CodeGen/ItaniumCXXABI.cpp test/CodeGen/Atomics.c test/CodeGen/atomic.c test/CodeGenCXX/static-init.cpp
Eli Friedman
eli.friedman at gmail.com
Tue Sep 13 14:31:32 PDT 2011
Author: efriedma
Date: Tue Sep 13 16:31:32 2011
New Revision: 139643
URL: http://llvm.org/viewvc/llvm-project?rev=139643&view=rev
Log:
Make clang use Acquire loads and Release stores where necessary.
Modified:
cfe/trunk/lib/CodeGen/CGBuiltin.cpp
cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
cfe/trunk/test/CodeGen/Atomics.c
cfe/trunk/test/CodeGen/atomic.c
cfe/trunk/test/CodeGenCXX/static-init.cpp
Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=139643&r1=139642&r2=139643&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Tue Sep 13 16:31:32 2011
@@ -900,13 +900,14 @@
case Builtin::BI__sync_lock_release_8:
case Builtin::BI__sync_lock_release_16: {
Value *Ptr = EmitScalarExpr(E->getArg(0));
- llvm::Type *ElTy =
+ llvm::Type *ElLLVMTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
llvm::StoreInst *Store =
- Builder.CreateStore(llvm::Constant::getNullValue(ElTy), Ptr);
- // FIXME: This is completely, utterly wrong; it only even sort-of works
- // on x86.
- Store->setVolatile(true);
+ Builder.CreateStore(llvm::Constant::getNullValue(ElLLVMTy), Ptr);
+ QualType ElTy = E->getArg(0)->getType()->getPointeeType();
+ CharUnits StoreSize = getContext().getTypeSizeInChars(ElTy);
+ Store->setAlignment(StoreSize.getQuantity());
+ Store->setAtomic(llvm::Release);
return RValue::get(0);
}
Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=139643&r1=139642&r2=139643&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Tue Sep 13 16:31:32 2011
@@ -1130,20 +1130,27 @@
} else {
// Load the first byte of the guard variable.
llvm::Type *PtrTy = Builder.getInt8PtrTy();
- llvm::Value *V =
+ llvm::LoadInst *LI =
Builder.CreateLoad(Builder.CreateBitCast(GuardVariable, PtrTy), "tmp");
+ LI->setAlignment(1);
- IsInitialized = Builder.CreateIsNull(V, "guard.uninitialized");
+ // Itanium ABI:
+ // An implementation supporting thread-safety on multiprocessor
+ // systems must also guarantee that references to the initialized
+ // object do not occur before the load of the initialization flag.
+ //
+ // In LLVM, we do this by marking the load Acquire.
+ if (threadsafe)
+ LI->setAtomic(llvm::Acquire);
+
+ IsInitialized = Builder.CreateIsNull(LI, "guard.uninitialized");
}
llvm::BasicBlock *InitCheckBlock = CGF.createBasicBlock("init.check");
llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
- llvm::BasicBlock *NoCheckBlock = EndBlock;
- if (threadsafe) NoCheckBlock = CGF.createBasicBlock("init.barrier");
-
// Check if the first byte of the guard variable is zero.
- Builder.CreateCondBr(IsInitialized, InitCheckBlock, NoCheckBlock);
+ Builder.CreateCondBr(IsInitialized, InitCheckBlock, EndBlock);
CGF.EmitBlock(InitCheckBlock);
@@ -1177,23 +1184,5 @@
Builder.CreateStore(llvm::ConstantInt::get(GuardTy, 1), GuardVariable);
}
- // Emit an acquire memory barrier if using thread-safe statics:
- // Itanium ABI:
- // An implementation supporting thread-safety on multiprocessor
- // systems must also guarantee that references to the initialized
- // object do not occur before the load of the initialization flag.
- if (threadsafe) {
- Builder.CreateBr(EndBlock);
- CGF.EmitBlock(NoCheckBlock);
-
- llvm::Value *_false = Builder.getFalse();
- llvm::Value *_true = Builder.getTrue();
-
- Builder.CreateCall5(CGM.getIntrinsic(llvm::Intrinsic::memory_barrier),
- /* load-load, load-store */ _true, _true,
- /* store-load, store-store */ _false, _false,
- /* device or I/O */ _false);
- }
-
CGF.EmitBlock(EndBlock);
}
Modified: cfe/trunk/test/CodeGen/Atomics.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/Atomics.c?rev=139643&r1=139642&r2=139643&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/Atomics.c (original)
+++ cfe/trunk/test/CodeGen/Atomics.c Tue Sep 13 16:31:32 2011
@@ -192,13 +192,12 @@
__sync_synchronize (); // CHECK: fence seq_cst
- // FIXME: These are wrong!
- __sync_lock_release (&sc); // CHECK: store volatile
- __sync_lock_release (&uc); // CHECK: store volatile
- __sync_lock_release (&ss); // CHECK: store volatile
- __sync_lock_release (&us); // CHECK: store volatile
- __sync_lock_release (&si); // CHECK: store volatile
- __sync_lock_release (&ui); // CHECK: store volatile
- __sync_lock_release (&sll); // CHECK: store volatile
- __sync_lock_release (&ull); // CHECK: store volatile
+ __sync_lock_release (&sc); // CHECK: store atomic {{.*}} release, align 1
+ __sync_lock_release (&uc); // CHECK: store atomic {{.*}} release, align 1
+ __sync_lock_release (&ss); // CHECK: store atomic {{.*}} release, align 2
+ __sync_lock_release (&us); /// CHECK: store atomic {{.*}} release, align 2
+ __sync_lock_release (&si); // CHECK: store atomic {{.*}} release, align 4
+ __sync_lock_release (&ui); // CHECK: store atomic {{.*}} release, align 4
+ __sync_lock_release (&sll); // CHECK: store atomic {{.*}} release, align 8
+ __sync_lock_release (&ull); // CHECK: store atomic {{.*}} release, align 8
}
Modified: cfe/trunk/test/CodeGen/atomic.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/atomic.c?rev=139643&r1=139642&r2=139643&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/atomic.c (original)
+++ cfe/trunk/test/CodeGen/atomic.c Tue Sep 13 16:31:32 2011
@@ -75,8 +75,7 @@
// CHECK: cmpxchg i32* null, i32 0, i32 0 seq_cst
__sync_lock_release(&val);
- // FIXME: WRONG!
- // CHECK: store volatile i32 0, i32*
+ // CHECK: store atomic {{.*}} release, align 4
__sync_synchronize ();
// CHECK: fence seq_cst
@@ -88,8 +87,7 @@
void release_return(int *lock) {
// Ensure this is actually returning void all the way through.
return __sync_lock_release(lock);
- // FIXME: WRONG!
- // CHECK: store volatile i32 0, i32*
+ // CHECK: store atomic {{.*}} release, align 4
}
Modified: cfe/trunk/test/CodeGenCXX/static-init.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/static-init.cpp?rev=139643&r1=139642&r2=139643&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/static-init.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/static-init.cpp Tue Sep 13 16:31:32 2011
@@ -12,13 +12,11 @@
};
void f() {
+ // CHECK: load atomic i8* bitcast (i64* @_ZGVZ1fvE1a to i8*) acquire, align 1
// CHECK: call i32 @__cxa_guard_acquire
// CHECK: call void @_ZN1AC1Ev
// CHECK: call i32 @__cxa_atexit(void (i8*)* bitcast (void (%struct.A*)* @_ZN1AD1Ev to void (i8*)*), i8* getelementptr inbounds (%struct.A* @_ZZ1fvE1a, i32 0, i32 0), i8* bitcast (i8** @__dso_handle to i8*))
// CHECK: call void @__cxa_guard_release
-
- // rdar://problem/9496726
- // CHECK: call void @llvm.memory.barrier(i1 true, i1 true, i1 false, i1 false, i1 false)
static A a;
}
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