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Reimplement the bittest intrinsic family as builtins with inline asm
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We need to implement _interlockedbittestandset as a builtin for
windows.h, so we might as well do the whole family. It reduces code
duplication anyway.

Fixes PR33188, a long standing bug in our bittest implementation
encountered by Chakra.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@333978 91177308-0d34-0410-b5e6-96231b3b80d8
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@rnk
rnk committed Jun 5, 2018
1 parent db0407e commit ce9d274
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Showing 6 changed files with 103 additions and 123 deletions.
13 changes: 12 additions & 1 deletion include/clang/Basic/Builtins.def
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Original file line number Diff line number Diff line change
Expand Up @@ -744,6 +744,14 @@ BUILTIN(__builtin_rindex, "c*cC*i", "Fn")
LANGBUILTIN(_alloca, "v*z", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(__annotation, "wC*.","n", ALL_MS_LANGUAGES)
LANGBUILTIN(__assume, "vb", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittest, "UcNiC*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandcomplement, "UcNi*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandreset, "UcNi*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandset, "UcNi*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittest64, "UcWiC*Wi", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandcomplement64, "UcWi*Wi", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandreset64, "UcWi*Wi", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_bittestandset64, "UcWi*Wi", "n", ALL_MS_LANGUAGES)
LIBBUILTIN(_byteswap_ushort, "UsUs", "fnc", "stdlib.h", ALL_MS_LANGUAGES)
LIBBUILTIN(_byteswap_ulong, "UNiUNi", "fnc", "stdlib.h", ALL_MS_LANGUAGES)
LIBBUILTIN(_byteswap_uint64, "ULLiULLi", "fnc", "stdlib.h", ALL_MS_LANGUAGES)
Expand Down Expand Up @@ -783,7 +791,10 @@ LANGBUILTIN(_InterlockedOr, "NiNiD*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_InterlockedXor8, "ccD*c", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_InterlockedXor16, "ssD*s", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_InterlockedXor, "NiNiD*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_interlockedbittestandset, "UcNiD*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_interlockedbittestandreset, "UcNiD*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_interlockedbittestandreset64, "UcWiD*Wi", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_interlockedbittestandset, "UcNiD*Ni", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(_interlockedbittestandset64, "UcWiD*Wi", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(__noop, "i.", "n", ALL_MS_LANGUAGES)
LANGBUILTIN(__popcnt16, "UsUs", "nc", ALL_MS_LANGUAGES)
LANGBUILTIN(__popcnt, "UiUi", "nc", ALL_MS_LANGUAGES)
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75 changes: 56 additions & 19 deletions lib/CodeGen/CGBuiltin.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -484,6 +484,37 @@ CodeGenFunction::emitBuiltinObjectSize(const Expr *E, unsigned Type,
return Builder.CreateCall(F, {Ptr, Min, NullIsUnknown});
}

static RValue EmitBitTestIntrinsic(CodeGenFunction &CGF, const CallExpr *E,
char TestAnd, char Size,
bool Locked = false) {
Value *BitBase = CGF.EmitScalarExpr(E->getArg(0));
Value *BitPos = CGF.EmitScalarExpr(E->getArg(1));

// Build the assembly.
SmallString<64> Asm;
raw_svector_ostream AsmOS(Asm);
if (Locked)
AsmOS << "lock ";
AsmOS << "bt";
if (TestAnd)
AsmOS << TestAnd;
AsmOS << Size << " $2, ($1)\n\tsetc ${0:b}";

// Build the constraints. FIXME: We should support immediates when possible.
std::string Constraints = "=r,r,r,~{cc},~{flags},~{memory},~{fpsr}";
llvm::IntegerType *IntType = llvm::IntegerType::get(
CGF.getLLVMContext(),
CGF.getContext().getTypeSize(E->getArg(1)->getType()));
llvm::Type *IntPtrType = IntType->getPointerTo();
llvm::FunctionType *FTy =
llvm::FunctionType::get(CGF.Int8Ty, {IntPtrType, IntType}, false);

llvm::InlineAsm *IA =
llvm::InlineAsm::get(FTy, Asm, Constraints, /*SideEffects=*/true);
CallSite CS = CGF.Builder.CreateCall(IA, {BitBase, BitPos});
return RValue::get(CS.getInstruction());
}

// Many of MSVC builtins are on both x64 and ARM; to avoid repeating code, we
// handle them here.
enum class CodeGenFunction::MSVCIntrin {
Expand All @@ -497,7 +528,6 @@ enum class CodeGenFunction::MSVCIntrin {
_InterlockedIncrement,
_InterlockedOr,
_InterlockedXor,
_interlockedbittestandset,
__fastfail,
};

Expand Down Expand Up @@ -565,22 +595,6 @@ Value *CodeGenFunction::EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID,
case MSVCIntrin::_InterlockedXor:
return MakeBinaryAtomicValue(*this, AtomicRMWInst::Xor, E);

case MSVCIntrin::_interlockedbittestandset: {
llvm::Value *Addr = EmitScalarExpr(E->getArg(0));
llvm::Value *Bit = EmitScalarExpr(E->getArg(1));
AtomicRMWInst *RMWI = Builder.CreateAtomicRMW(
AtomicRMWInst::Or, Addr,
Builder.CreateShl(ConstantInt::get(Bit->getType(), 1), Bit),
llvm::AtomicOrdering::SequentiallyConsistent);
// Shift the relevant bit to the least significant position, truncate to
// the result type, and test the low bit.
llvm::Value *Shifted = Builder.CreateLShr(RMWI, Bit);
llvm::Value *Truncated =
Builder.CreateTrunc(Shifted, ConvertType(E->getType()));
return Builder.CreateAnd(Truncated,
ConstantInt::get(Truncated->getType(), 1));
}

case MSVCIntrin::_InterlockedDecrement: {
llvm::Type *IntTy = ConvertType(E->getType());
AtomicRMWInst *RMWI = Builder.CreateAtomicRMW(
Expand Down Expand Up @@ -2791,9 +2805,32 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
case Builtin::BI_InterlockedXor16:
case Builtin::BI_InterlockedXor:
return RValue::get(EmitMSVCBuiltinExpr(MSVCIntrin::_InterlockedXor, E));

case Builtin::BI_bittest:
return EmitBitTestIntrinsic(*this, E, '\0', 'l');
case Builtin::BI_bittestandcomplement:
return EmitBitTestIntrinsic(*this, E, 'c', 'l');
case Builtin::BI_bittestandreset:
return EmitBitTestIntrinsic(*this, E, 'r', 'l');
case Builtin::BI_bittestandset:
return EmitBitTestIntrinsic(*this, E, 's', 'l');
case Builtin::BI_interlockedbittestandreset:
return EmitBitTestIntrinsic(*this, E, 'r', 'l', /*Locked=*/true);
case Builtin::BI_interlockedbittestandset:
return RValue::get(
EmitMSVCBuiltinExpr(MSVCIntrin::_interlockedbittestandset, E));
return EmitBitTestIntrinsic(*this, E, 's', 'l', /*Locked=*/true);

case Builtin::BI_bittest64:
return EmitBitTestIntrinsic(*this, E, '\0', 'q');
case Builtin::BI_bittestandcomplement64:
return EmitBitTestIntrinsic(*this, E, 'c', 'q');
case Builtin::BI_bittestandreset64:
return EmitBitTestIntrinsic(*this, E, 'r', 'q');
case Builtin::BI_bittestandset64:
return EmitBitTestIntrinsic(*this, E, 's', 'q');
case Builtin::BI_interlockedbittestandreset64:
return EmitBitTestIntrinsic(*this, E, 'r', 'q', /*Locked=*/true);
case Builtin::BI_interlockedbittestandset64:
return EmitBitTestIntrinsic(*this, E, 's', 'q', /*Locked=*/true);

case Builtin::BI__exception_code:
case Builtin::BI_exception_code:
Expand Down
81 changes: 0 additions & 81 deletions lib/Headers/intrin.h
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Original file line number Diff line number Diff line change
Expand Up @@ -161,13 +161,9 @@ static __inline__
unsigned char _BitScanForward(unsigned long *_Index, unsigned long _Mask);
static __inline__
unsigned char _BitScanReverse(unsigned long *_Index, unsigned long _Mask);
static __inline__
unsigned char _bittest(long const *, long);
static __inline__
unsigned char _bittestandcomplement(long *, long);
static __inline__
unsigned char _bittestandreset(long *, long);
static __inline__
unsigned char _bittestandset(long *, long);
void __cdecl _disable(void);
void __cdecl _enable(void);
Expand Down Expand Up @@ -260,20 +256,15 @@ static __inline__
unsigned char _BitScanForward64(unsigned long *_Index, unsigned __int64 _Mask);
static __inline__
unsigned char _BitScanReverse64(unsigned long *_Index, unsigned __int64 _Mask);
static __inline__
unsigned char _bittest64(__int64 const *, __int64);
static __inline__
unsigned char _bittestandcomplement64(__int64 *, __int64);
static __inline__
unsigned char _bittestandreset64(__int64 *, __int64);
static __inline__
unsigned char _bittestandset64(__int64 *, __int64);
long _InterlockedAnd_np(long volatile *_Value, long _Mask);
short _InterlockedAnd16_np(short volatile *_Value, short _Mask);
__int64 _InterlockedAnd64_np(__int64 volatile *_Value, __int64 _Mask);
char _InterlockedAnd8_np(char volatile *_Value, char _Mask);
unsigned char _interlockedbittestandreset64(__int64 volatile *, __int64);
static __inline__
unsigned char _interlockedbittestandset64(__int64 volatile *, __int64);
long _InterlockedCompareExchange_np(long volatile *_Destination, long _Exchange,
long _Comparand);
Expand Down Expand Up @@ -341,78 +332,6 @@ __int64 _InterlockedAnd64(__int64 volatile *_Value, __int64 _Mask);

#endif

/*----------------------------------------------------------------------------*\
|* Bit Counting and Testing
\*----------------------------------------------------------------------------*/
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittest(long const *_BitBase, long _BitPos) {
return (*_BitBase >> _BitPos) & 1;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandcomplement(long *_BitBase, long _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase ^ (1 << _BitPos);
return _Res;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandreset(long *_BitBase, long _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase & ~(1 << _BitPos);
return _Res;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandset(long *_BitBase, long _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase | (1 << _BitPos);
return _Res;
}
#if defined(__arm__) || defined(__aarch64__)
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_interlockedbittestandset_acq(long volatile *_BitBase, long _BitPos) {
long _PrevVal = __atomic_fetch_or(_BitBase, 1l << _BitPos, __ATOMIC_ACQUIRE);
return (_PrevVal >> _BitPos) & 1;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_interlockedbittestandset_nf(long volatile *_BitBase, long _BitPos) {
long _PrevVal = __atomic_fetch_or(_BitBase, 1l << _BitPos, __ATOMIC_RELAXED);
return (_PrevVal >> _BitPos) & 1;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_interlockedbittestandset_rel(long volatile *_BitBase, long _BitPos) {
long _PrevVal = __atomic_fetch_or(_BitBase, 1l << _BitPos, __ATOMIC_RELEASE);
return (_PrevVal >> _BitPos) & 1;
}
#endif
#ifdef __x86_64__
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittest64(__int64 const *_BitBase, __int64 _BitPos) {
return (*_BitBase >> _BitPos) & 1;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandcomplement64(__int64 *_BitBase, __int64 _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase ^ (1ll << _BitPos);
return _Res;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandreset64(__int64 *_BitBase, __int64 _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase & ~(1ll << _BitPos);
return _Res;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_bittestandset64(__int64 *_BitBase, __int64 _BitPos) {
unsigned char _Res = (*_BitBase >> _BitPos) & 1;
*_BitBase = *_BitBase | (1ll << _BitPos);
return _Res;
}
static __inline__ unsigned char __DEFAULT_FN_ATTRS
_interlockedbittestandset64(__int64 volatile *_BitBase, __int64 _BitPos) {
long long _PrevVal =
__atomic_fetch_or(_BitBase, 1ll << _BitPos, __ATOMIC_SEQ_CST);
return (_PrevVal >> _BitPos) & 1;
}
#endif
/*----------------------------------------------------------------------------*\
|* Interlocked Exchange Add
\*----------------------------------------------------------------------------*/
Expand Down
35 changes: 35 additions & 0 deletions test/CodeGen/bittest-intrin.c
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Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
// RUN: %clang_cc1 -fms-extensions -triple x86_64-windows-msvc %s -emit-llvm -o - | FileCheck %s

volatile unsigned char sink = 0;
void test32(long *base, long idx) {
sink = _bittest(base, idx);
sink = _bittestandcomplement(base, idx);
sink = _bittestandreset(base, idx);
sink = _bittestandset(base, idx);
sink = _interlockedbittestandreset(base, idx);
sink = _interlockedbittestandset(base, idx);
}
void test64(__int64 *base, __int64 idx) {
sink = _bittest64(base, idx);
sink = _bittestandcomplement64(base, idx);
sink = _bittestandreset64(base, idx);
sink = _bittestandset64(base, idx);
sink = _interlockedbittestandreset64(base, idx);
sink = _interlockedbittestandset64(base, idx);
}

// CHECK-LABEL: define dso_local void @test32(i32* %base, i32 %idx)
// CHECK: call i8 asm sideeffect "btl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
// CHECK: call i8 asm sideeffect "btcl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
// CHECK: call i8 asm sideeffect "btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
// CHECK: call i8 asm sideeffect "btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
// CHECK: call i8 asm sideeffect "lock btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
// CHECK: call i8 asm sideeffect "lock btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})

// CHECK-LABEL: define dso_local void @test64(i64* %base, i64 %idx)
// CHECK: call i8 asm sideeffect "btq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
// CHECK: call i8 asm sideeffect "btcq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
// CHECK: call i8 asm sideeffect "btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
// CHECK: call i8 asm sideeffect "btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
// CHECK: call i8 asm sideeffect "lock btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
// CHECK: call i8 asm sideeffect "lock btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
11 changes: 0 additions & 11 deletions test/CodeGen/ms-intrinsics-other.c
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Original file line number Diff line number Diff line change
Expand Up @@ -148,14 +148,3 @@ LONG test_InterlockedDecrement(LONG volatile *Addend) {
// CHECK: [[RESULT:%[0-9]+]] = add i32 [[TMP]], -1
// CHECK: ret i32 [[RESULT]]
// CHECK: }

unsigned char test_interlockedbittestandset(volatile LONG *ptr, LONG bit) {
return _interlockedbittestandset(ptr, bit);
}
// CHECK-LABEL: define{{.*}} i8 @test_interlockedbittestandset
// CHECK: [[MASKBIT:%[0-9]+]] = shl i32 1, %bit
// CHECK: [[OLD:%[0-9]+]] = atomicrmw or i32* %ptr, i32 [[MASKBIT]] seq_cst
// CHECK: [[SHIFT:%[0-9]+]] = lshr i32 [[OLD]], %bit
// CHECK: [[TRUNC:%[0-9]+]] = trunc i32 [[SHIFT]] to i8
// CHECK: [[AND:%[0-9]+]] = and i8 [[TRUNC]], 1
// CHECK: ret i8 [[AND]]
11 changes: 0 additions & 11 deletions test/CodeGen/ms-intrinsics.c
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Original file line number Diff line number Diff line change
Expand Up @@ -455,17 +455,6 @@ __int64 test_InterlockedDecrement64(__int64 volatile *Addend) {

#endif

unsigned char test_interlockedbittestandset(volatile long *ptr, long bit) {
return _interlockedbittestandset(ptr, bit);
}
// CHECK-LABEL: define{{.*}} i8 @test_interlockedbittestandset
// CHECK: [[MASKBIT:%[0-9]+]] = shl i32 1, %bit
// CHECK: [[OLD:%[0-9]+]] = atomicrmw or i32* %ptr, i32 [[MASKBIT]] seq_cst
// CHECK: [[SHIFT:%[0-9]+]] = lshr i32 [[OLD]], %bit
// CHECK: [[TRUNC:%[0-9]+]] = trunc i32 [[SHIFT]] to i8
// CHECK: [[AND:%[0-9]+]] = and i8 [[TRUNC]], 1
// CHECK: ret i8 [[AND]]

void test__fastfail() {
__fastfail(42);
}
Expand Down

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