[SystemZ] Use ROSBG and non-zero form of RISBG for OR nodes

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186405 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Richard Sandiford 2013-07-16 11:55:57 +00:00
parent ab42fc66b1
commit de25544a73
3 changed files with 289 additions and 1 deletions

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@ -222,6 +222,11 @@ class SystemZDAGToDAGISel : public SelectionDAGISel {
Addr, Base, Disp, Index);
}
// Check whether (or Op (and X InsertMask)) is effectively an insertion
// of X into bits InsertMask of some Y != Op. Return true if so and
// set Op to that Y.
bool detectOrAndInsertion(SDValue &Op, uint64_t InsertMask);
// Try to fold some of Ops.Input into other fields of Ops. Return true
// on success.
bool expandRISBG(RISBGOperands &Ops);
@ -236,6 +241,10 @@ class SystemZDAGToDAGISel : public SelectionDAGISel {
// Return the selected node on success, otherwise return null.
SDNode *tryRISBGZero(SDNode *N);
// Try to use RISBG or ROSBG to implement OR node N. Return the selected
// node on success, otherwise return null.
SDNode *tryRISBGOrROSBG(SDNode *N);
// If Op0 is null, then Node is a constant that can be loaded using:
//
// (Opcode UpperVal LowerVal)
@ -557,6 +566,38 @@ bool SystemZDAGToDAGISel::selectBDXAddr(SystemZAddressingMode::AddrForm Form,
return true;
}
bool SystemZDAGToDAGISel::detectOrAndInsertion(SDValue &Op,
uint64_t InsertMask) {
// We're only interested in cases where the insertion is into some operand
// of Op, rather than into Op itself. The only useful case is an AND.
if (Op.getOpcode() != ISD::AND)
return false;
// We need a constant mask.
ConstantSDNode *MaskNode =
dyn_cast<ConstantSDNode>(Op.getOperand(1).getNode());
if (!MaskNode)
return false;
// It's not an insertion of Op.getOperand(0) if the two masks overlap.
uint64_t AndMask = MaskNode->getZExtValue();
if (InsertMask & AndMask)
return false;
// It's only an insertion if all bits are covered or are known to be zero.
// The inner check covers all cases but is more expensive.
uint64_t Used = allOnes(Op.getValueType().getSizeInBits());
if (Used != (AndMask | InsertMask)) {
APInt KnownZero, KnownOne;
CurDAG->ComputeMaskedBits(Op.getOperand(0), KnownZero, KnownOne);
if (Used != (AndMask | InsertMask | KnownZero.getZExtValue()))
return false;
}
Op = Op.getOperand(0);
return true;
}
// Return true if Mask matches the regexp 0*1+0*, given that zero masks
// have already been filtered out. Store the first set bit in LSB and
// the number of set bits in Length if so.
@ -761,6 +802,47 @@ SDNode *SystemZDAGToDAGISel::tryRISBGZero(SDNode *N) {
return convertTo(SDLoc(N), VT, SDValue(N, 0)).getNode();
}
SDNode *SystemZDAGToDAGISel::tryRISBGOrROSBG(SDNode *N) {
// Try treating each operand of N as the second operand of RISBG or ROSBG
// and see which goes deepest.
RISBGOperands RISBG[] = { N->getOperand(0), N->getOperand(1) };
unsigned Count[] = { 0, 0 };
for (unsigned I = 0; I < 2; ++I)
while (expandRISBG(RISBG[I]))
Count[I] += 1;
// Do nothing if neither operand is suitable.
if (Count[0] == 0 && Count[1] == 0)
return 0;
// Pick the deepest second operand.
unsigned I = Count[0] > Count[1] ? 0 : 1;
SDValue Op0 = N->getOperand(I ^ 1);
// Prefer IC for character insertions from memory.
if ((RISBG[I].Mask & 0xff) == 0)
if (LoadSDNode *Load = dyn_cast<LoadSDNode>(Op0.getNode()))
if (Load->getMemoryVT() == MVT::i8)
return 0;
// See whether we can avoid an AND in the first operand by converting
// ROSBG to RISBG.
unsigned Opcode = SystemZ::ROSBG;
if (detectOrAndInsertion(Op0, RISBG[I].Mask))
Opcode = SystemZ::RISBG;
EVT VT = N->getValueType(0);
SDValue Ops[5] = {
convertTo(SDLoc(N), MVT::i64, Op0),
convertTo(SDLoc(N), MVT::i64, RISBG[I].Input),
CurDAG->getTargetConstant(RISBG[I].Start, MVT::i32),
CurDAG->getTargetConstant(RISBG[I].End, MVT::i32),
CurDAG->getTargetConstant(RISBG[I].Rotate, MVT::i32)
};
N = CurDAG->getMachineNode(Opcode, SDLoc(N), MVT::i64, Ops);
return convertTo(SDLoc(N), VT, SDValue(N, 0)).getNode();
}
SDNode *SystemZDAGToDAGISel::splitLargeImmediate(unsigned Opcode, SDNode *Node,
SDValue Op0, uint64_t UpperVal,
uint64_t LowerVal) {
@ -833,10 +915,13 @@ SDNode *SystemZDAGToDAGISel::Select(SDNode *Node) {
SDNode *ResNode = 0;
switch (Opcode) {
case ISD::OR:
if (Node->getOperand(1).getOpcode() != ISD::Constant)
ResNode = tryRISBGOrROSBG(Node);
// Fall through.
case ISD::XOR:
// If this is a 64-bit operation in which both 32-bit halves are nonzero,
// split the operation into two.
if (Node->getValueType(0) == MVT::i64)
if (!ResNode && Node->getValueType(0) == MVT::i64)
if (ConstantSDNode *Op1 = dyn_cast<ConstantSDNode>(Node->getOperand(1))) {
uint64_t Val = Op1->getZExtValue();
if (!SystemZ::isImmLF(Val) && !SystemZ::isImmHF(Val))

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@ -0,0 +1,93 @@
; Test sequences that can use RISBG with a normal first operand.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
; Test a case with two ANDs.
define i32 @f1(i32 %a, i32 %b) {
; CHECK-LABEL: f1:
; CHECK: risbg %r2, %r3, 60, 62, 0
; CHECK: br %r14
%anda = and i32 %a, -15
%andb = and i32 %b, 14
%or = or i32 %anda, %andb
ret i32 %or
}
; ...and again with i64.
define i64 @f2(i64 %a, i64 %b) {
; CHECK-LABEL: f2:
; CHECK: risbg %r2, %r3, 60, 62, 0
; CHECK: br %r14
%anda = and i64 %a, -15
%andb = and i64 %b, 14
%or = or i64 %anda, %andb
ret i64 %or
}
; Test a case with two ANDs and a shift.
define i32 @f3(i32 %a, i32 %b) {
; CHECK-LABEL: f3:
; CHECK: risbg %r2, %r3, 60, 63, 56
; CHECK: br %r14
%anda = and i32 %a, -16
%shr = lshr i32 %b, 8
%andb = and i32 %shr, 15
%or = or i32 %anda, %andb
ret i32 %or
}
; ...and again with i64.
define i64 @f4(i64 %a, i64 %b) {
; CHECK-LABEL: f4:
; CHECK: risbg %r2, %r3, 60, 63, 56
; CHECK: br %r14
%anda = and i64 %a, -16
%shr = lshr i64 %b, 8
%andb = and i64 %shr, 15
%or = or i64 %anda, %andb
ret i64 %or
}
; Test a case with a single AND and a left shift.
define i32 @f5(i32 %a, i32 %b) {
; CHECK-LABEL: f5:
; CHECK: risbg %r2, %r3, 32, 53, 10
; CHECK: br %r14
%anda = and i32 %a, 1023
%shlb = shl i32 %b, 10
%or = or i32 %anda, %shlb
ret i32 %or
}
; ...and again with i64.
define i64 @f6(i64 %a, i64 %b) {
; CHECK-LABEL: f6:
; CHECK: risbg %r2, %r3, 0, 53, 10
; CHECK: br %r14
%anda = and i64 %a, 1023
%shlb = shl i64 %b, 10
%or = or i64 %anda, %shlb
ret i64 %or
}
; Test a case with a single AND and a right shift.
define i32 @f7(i32 %a, i32 %b) {
; CHECK-LABEL: f7:
; CHECK: risbg %r2, %r3, 40, 63, 56
; CHECK: br %r14
%anda = and i32 %a, -16777216
%shrb = lshr i32 %b, 8
%or = or i32 %anda, %shrb
ret i32 %or
}
; ...and again with i64.
define i64 @f8(i64 %a, i64 %b) {
; CHECK-LABEL: f8:
; CHECK: risbg %r2, %r3, 8, 63, 56
; CHECK: br %r14
%anda = and i64 %a, -72057594037927936
%shrb = lshr i64 %b, 8
%or = or i64 %anda, %shrb
ret i64 %or
}

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@ -0,0 +1,110 @@
; Test sequences that can use ROSBG.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
; Test the simple case.
define i32 @f1(i32 %a, i32 %b) {
; CHECK-LABEL: f1:
; CHECK: rosbg %r2, %r3, 59, 59, 0
; CHECK: br %r14
%andb = and i32 %b, 16
%or = or i32 %a, %andb
ret i32 %or
}
; ...and again with i64.
define i64 @f2(i64 %a, i64 %b) {
; CHECK-LABEL: f2:
; CHECK: rosbg %r2, %r3, 59, 59, 0
; CHECK: br %r14
%andb = and i64 %b, 16
%or = or i64 %a, %andb
ret i64 %or
}
; Test a case where wraparound is needed.
define i32 @f3(i32 %a, i32 %b) {
; CHECK-LABEL: f3:
; CHECK: rosbg %r2, %r3, 63, 60, 0
; CHECK: br %r14
%andb = and i32 %b, -7
%or = or i32 %a, %andb
ret i32 %or
}
; ...and again with i64.
define i64 @f4(i64 %a, i64 %b) {
; CHECK-LABEL: f4:
; CHECK: rosbg %r2, %r3, 63, 60, 0
; CHECK: br %r14
%andb = and i64 %b, -7
%or = or i64 %a, %andb
ret i64 %or
}
; Test a case with just a shift.
define i32 @f6(i32 %a, i32 %b) {
; CHECK-LABEL: f6:
; CHECK: rosbg %r2, %r3, 32, 51, 12
; CHECK: br %r14
%shrb = shl i32 %b, 12
%or = or i32 %a, %shrb
ret i32 %or
}
; ...and again with i64.
define i64 @f7(i64 %a, i64 %b) {
; CHECK-LABEL: f7:
; CHECK: rosbg %r2, %r3, 0, 51, 12
; CHECK: br %r14
%shrb = shl i64 %b, 12
%or = or i64 %a, %shrb
ret i64 %or
}
; Test a case with just a rotate. This can't use ROSBG.
define i32 @f8(i32 %a, i32 %b) {
; CHECK-LABEL: f8:
; CHECK: rll {{%r[0-5]}}
; CHECK: or {{%r[0-5]}}
; CHECK: br %r14
%shlb = shl i32 %b, 30
%shrb = lshr i32 %b, 2
%rotlb = or i32 %shlb, %shrb
%or = or i32 %a, %rotlb
ret i32 %or
}
; ...and again with i64, which can.
define i64 @f9(i64 %a, i64 %b) {
; CHECK-LABEL: f9:
; CHECK: rosbg %r2, %r3, 0, 63, 47
; CHECK: br %r14
%shlb = shl i64 %b, 47
%shrb = lshr i64 %b, 17
%rotlb = or i64 %shlb, %shrb
%or = or i64 %a, %rotlb
ret i64 %or
}
; Test a case with a shift and AND.
define i32 @f10(i32 %a, i32 %b) {
; CHECK-LABEL: f10:
; CHECK: rosbg %r2, %r3, 56, 59, 4
; CHECK: br %r14
%shrb = shl i32 %b, 4
%andb = and i32 %shrb, 240
%or = or i32 %a, %andb
ret i32 %or
}
; ...and again with i64.
define i64 @f11(i64 %a, i64 %b) {
; CHECK-LABEL: f11:
; CHECK: rosbg %r2, %r3, 56, 59, 4
; CHECK: br %r14
%shrb = shl i64 %b, 4
%andb = and i64 %shrb, 240
%or = or i64 %a, %andb
ret i64 %or
}