Add full x86 fast-isel support for memcpy and memset.

rdar://9431466



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132864 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman 2011-06-10 23:39:36 +00:00
parent b3e009a165
commit 25255cbe00
2 changed files with 74 additions and 9 deletions

View File

@ -111,6 +111,8 @@ private:
bool X86VisitIntrinsicCall(const IntrinsicInst &I);
bool X86SelectCall(const Instruction *I);
bool DoSelectCall(const Instruction *I, const char *MemIntName);
const X86InstrInfo *getInstrInfo() const {
return getTargetMachine()->getInstrInfo();
}
@ -1333,20 +1335,44 @@ bool X86FastISel::X86VisitIntrinsicCall(const IntrinsicInst &I) {
case Intrinsic::memcpy: {
const MemCpyInst &MCI = cast<MemCpyInst>(I);
// Don't handle volatile or variable length memcpys.
if (MCI.isVolatile() || !isa<ConstantInt>(MCI.getLength()))
if (MCI.isVolatile())
return false;
uint64_t Len = cast<ConstantInt>(MCI.getLength())->getZExtValue();
if (isa<ConstantInt>(MCI.getLength())) {
// Small memcpy's are common enough that we want to do them
// without a call if possible.
uint64_t Len = cast<ConstantInt>(MCI.getLength())->getZExtValue();
if (IsMemcpySmall(Len)) {
X86AddressMode DestAM, SrcAM;
if (!X86SelectAddress(MCI.getRawDest(), DestAM) ||
!X86SelectAddress(MCI.getRawSource(), SrcAM))
return false;
TryEmitSmallMemcpy(DestAM, SrcAM, Len);
return true;
}
}
// Get the address of the dest and source addresses.
X86AddressMode DestAM, SrcAM;
if (!X86SelectAddress(MCI.getRawDest(), DestAM) ||
!X86SelectAddress(MCI.getRawSource(), SrcAM))
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MCI.getLength()->getType()->isIntegerTy(SizeWidth))
return false;
return TryEmitSmallMemcpy(DestAM, SrcAM, Len);
if (MCI.getSourceAddressSpace() > 255 || MCI.getDestAddressSpace() > 255)
return false;
return DoSelectCall(&I, "memcpy");
}
case Intrinsic::memset: {
const MemSetInst &MSI = cast<MemSetInst>(I);
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MSI.getLength()->getType()->isIntegerTy(SizeWidth))
return false;
if (MSI.getDestAddressSpace() > 255)
return false;
return DoSelectCall(&I, "memset");
}
case Intrinsic::stackprotector: {
// Emit code inline code to store the stack guard onto the stack.
EVT PtrTy = TLI.getPointerTy();
@ -1437,6 +1463,14 @@ bool X86FastISel::X86SelectCall(const Instruction *I) {
if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI))
return X86VisitIntrinsicCall(*II);
return DoSelectCall(I, 0);
}
// Select either a call, or an llvm.memcpy/memmove/memset intrinsic
bool X86FastISel::DoSelectCall(const Instruction *I, const char *MemIntName) {
const CallInst *CI = cast<CallInst>(I);
const Value *Callee = CI->getCalledValue();
// Handle only C and fastcc calling conventions for now.
ImmutableCallSite CS(CI);
CallingConv::ID CC = CS.getCallingConv();
@ -1498,6 +1532,10 @@ bool X86FastISel::X86SelectCall(const Instruction *I) {
ArgFlags.reserve(CS.arg_size());
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
// If we're lowering a mem intrinsic instead of a regular call, skip the
// last two arguments, which should not passed to the underlying functions.
if (MemIntName && e-i <= 2)
break;
Value *ArgVal = *i;
ISD::ArgFlagsTy Flags;
unsigned AttrInd = i - CS.arg_begin() + 1;
@ -1744,8 +1782,11 @@ bool X86FastISel::X86SelectCall(const Instruction *I) {
}
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CallOpc))
.addGlobalAddress(GV, 0, OpFlags);
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CallOpc));
if (MemIntName)
MIB.addExternalSymbol(MemIntName);
else
MIB.addGlobalAddress(GV, 0, OpFlags);
}
// Add an implicit use GOT pointer in EBX.

View File

@ -29,3 +29,27 @@ define void @test2(%struct.s* %d) nounwind {
; CHECK: movl 8(%eax)
; CHECK: movl {{.*}}, 8(%esp)
}
declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
define void @test3(i8* %a) {
call void @llvm.memset.p0i8.i32(i8* %a, i8 0, i32 100, i32 1, i1 false)
ret void
; CHECK: test3:
; CHECK: movl {{.*}}, (%esp)
; CHECK: movl $0, 4(%esp)
; CHECK: movl $100, 8(%esp)
; CHECK: calll {{.*}}memset
}
declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
define void @test4(i8* %a, i8* %b) {
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %b, i32 100, i32 1, i1 false)
ret void
; CHECK: test4:
; CHECK: movl {{.*}}, (%esp)
; CHECK: movl {{.*}}, 4(%esp)
; CHECK: movl $100, 8(%esp)
; CHECK: calll {{.*}}memcpy
}