Use default lowering of DYNAMIC_STACKALLOC. As far as I can tell, ARM isle is doing the right thing and codegen looks correct for both Thumb and Thumb2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101410 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-04-15 22:20:34 +00:00
parent 31d80103d5
commit 3a1588a2e3
3 changed files with 9 additions and 70 deletions

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@ -121,9 +121,6 @@ private:
SDNode *SelectARMIndexedLoad(SDNode *N);
SDNode *SelectT2IndexedLoad(SDNode *N);
/// SelectDYN_ALLOC - Select dynamic alloc for Thumb.
SDNode *SelectDYN_ALLOC(SDNode *N);
/// SelectVLD - Select NEON load intrinsics. NumVecs should be
/// 1, 2, 3 or 4. The opcode arrays specify the instructions used for
/// loads of D registers and even subregs and odd subregs of Q registers.
@ -939,59 +936,6 @@ SDNode *ARMDAGToDAGISel::SelectT2IndexedLoad(SDNode *N) {
return NULL;
}
SDNode *ARMDAGToDAGISel::SelectDYN_ALLOC(SDNode *N) {
DebugLoc dl = N->getDebugLoc();
EVT VT = N->getValueType(0);
SDValue Chain = N->getOperand(0);
SDValue Size = N->getOperand(1);
SDValue Align = N->getOperand(2);
SDValue SP = CurDAG->getCopyFromReg(Chain, dl, ARM::SP, MVT::i32);
int32_t AlignVal = cast<ConstantSDNode>(Align)->getSExtValue();
if (AlignVal < 0)
// We need to align the stack. Use Thumb1 tAND which is the only thumb
// instruction that can read and write SP. This matches to a pseudo
// instruction that has a chain to ensure the result is written back to
// the stack pointer.
SP = SDValue(CurDAG->getMachineNode(ARM::tANDsp, dl, VT, SP, Align), 0);
bool isC = isa<ConstantSDNode>(Size);
uint32_t C = isC ? cast<ConstantSDNode>(Size)->getZExtValue() : ~0UL;
// Handle the most common case for both Thumb1 and Thumb2:
// tSUBspi - immediate is between 0 ... 508 inclusive.
if (C <= 508 && ((C & 3) == 0))
// FIXME: tSUBspi encode scale 4 implicitly.
return CurDAG->SelectNodeTo(N, ARM::tSUBspi_, VT, MVT::Other, SP,
CurDAG->getTargetConstant(C/4, MVT::i32),
Chain);
if (Subtarget->isThumb1Only()) {
// Use tADDspr since Thumb1 does not have a sub r, sp, r. ARMISelLowering
// should have negated the size operand already. FIXME: We can't insert
// new target independent node at this stage so we are forced to negate
// it earlier. Is there a better solution?
return CurDAG->SelectNodeTo(N, ARM::tADDspr_, VT, MVT::Other, SP, Size,
Chain);
} else if (Subtarget->isThumb2()) {
if (isC && Predicate_t2_so_imm(Size.getNode())) {
// t2SUBrSPi
SDValue Ops[] = { SP, CurDAG->getTargetConstant(C, MVT::i32), Chain };
return CurDAG->SelectNodeTo(N, ARM::t2SUBrSPi_, VT, MVT::Other, Ops, 3);
} else if (isC && Predicate_imm0_4095(Size.getNode())) {
// t2SUBrSPi12
SDValue Ops[] = { SP, CurDAG->getTargetConstant(C, MVT::i32), Chain };
return CurDAG->SelectNodeTo(N, ARM::t2SUBrSPi12_, VT, MVT::Other, Ops, 3);
} else {
// t2SUBrSPs
SDValue Ops[] = { SP, Size,
getI32Imm(ARM_AM::getSORegOpc(ARM_AM::lsl,0)), Chain };
return CurDAG->SelectNodeTo(N, ARM::t2SUBrSPs_, VT, MVT::Other, Ops, 4);
}
}
// FIXME: Add ADD / SUB sp instructions for ARM.
return 0;
}
/// PairDRegs - Insert a pair of double registers into an implicit def to
/// form a quad register.
SDNode *ARMDAGToDAGISel::PairDRegs(EVT VT, SDValue V0, SDValue V1) {
@ -1571,8 +1515,6 @@ SDNode *ARMDAGToDAGISel::Select(SDNode *N) {
return CurDAG->SelectNodeTo(N, Opc, MVT::i32, Ops, 5);
}
}
case ARMISD::DYN_ALLOC:
return SelectDYN_ALLOC(N);
case ISD::SRL:
if (SDNode *I = SelectV6T2BitfieldExtractOp(N,
Subtarget->isThumb() ? ARM::t2UBFX : ARM::UBFX))

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@ -384,10 +384,7 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
// FIXME: Shouldn't need this, since no register is used, but the legalizer
// doesn't yet know how to not do that for SjLj.
setExceptionSelectorRegister(ARM::R0);
if (Subtarget->isThumb())
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
else
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
if (!Subtarget->hasV6Ops() && !Subtarget->isThumb2()) {

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@ -7,15 +7,15 @@
define arm_apcscc void @t() nounwind ssp {
entry:
; CHECK: t:
; CHECK: mvn r0, #7
; CHECK: ands sp, r0
; CHECK: mov r1, sp
; CHECK: mov sp, r1
; CHECK: mov r0, sp
; CHECK: bfc r0, #0, #3
; CHECK: subs r0, #16
; CHECK: mov sp, r0
; Yes, this is stupid codegen, but it's correct.
; CHECK: sub sp, #16
; CHECK: mov r1, sp
; CHECK: mov sp, r1
; CHECK: ands sp, r0
; CHECK: mov r0, sp
; CHECK: bfc r0, #0, #3
; CHECK: subs r0, #16
; CHECK: mov sp, r0
%size = mul i32 8, 2
%vla_a = alloca i8, i32 %size, align 8
%vla_b = alloca i8, i32 %size, align 8