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[SystemZ] [z/OS] Add support for generating huge (1 MiB) stack frames in XPLINK64 

This patch extends support for generating huge stack frames on 64-bit XPLINK by implementing the ABI-mandated call to the stack extension routine.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D120450
This commit is contained in:
Neumann Hon 2022-02-25 02:37:05 -05:00
parent b3ebcd7226
commit eb3e09c9bf
10 changed files with 119 additions and 11 deletions
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7
llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
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@ -262,6 +262,13 @@ void SystemZAsmPrinter::emitInstruction(const MachineInstr *MI) {
emitCallInformation(CallType::BASR76);
return;
case SystemZ::CallBASR_STACKEXT:
EmitToStreamer(*OutStreamer, MCInstBuilder(SystemZ::BASR)
.addReg(SystemZ::R3D)
.addReg(MI->getOperand(0).getReg()));
emitCallInformation(CallType::BASR33);
return;
case SystemZ::CallBRASL:
LoweredMI = MCInstBuilder(SystemZ::BRASL)
.addReg(SystemZ::R14D)

86
llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
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@ -1153,12 +1153,6 @@ void SystemZXPLINKFrameLowering::emitPrologue(MachineFunction &MF,
MFFrame.setStackSize(MFFrame.getStackSize() + Regs.getCallFrameSize());
uint64_t StackSize = MFFrame.getStackSize();
// FIXME: Implement support for large stack sizes, when the stack extension
// routine needs to be called.
if (StackSize > 1024 * 1024) {
llvm_unreachable("Huge Stack Frame not yet supported on z/OS");
}
if (ZFI->getSpillGPRRegs().LowGPR) {
// Skip over the GPR saves.
if ((MBBI != MBB.end()) && ((MBBI->getOpcode() == SystemZ::STMG))) {
@ -1201,6 +1195,18 @@ void SystemZXPLINKFrameLowering::emitPrologue(MachineFunction &MF,
emitIncrement(MBB, InsertPt, DL, Regs.getStackPointerRegister(), Delta,
ZII);
// If the requested stack size is larger than the guard page, then we need
// to check if we need to call the stack extender. This requires adding a
// conditional branch, but splitting the prologue block is not possible at
// this point since it would invalidate the SaveBlocks / RestoreBlocks sets
// of PEI in the single block function case. Build a pseudo to be handled
// later by inlineStackProbe().
const uint64_t GuardPageSize = 1024 * 1024;
if (StackSize > GuardPageSize) {
assert(StoreInstr && "Wrong insertion point");
BuildMI(MBB, InsertPt, DL, ZII->get(SystemZ::XPLINK_STACKALLOC));
}
}
if (HasFP) {
@ -1239,6 +1245,74 @@ void SystemZXPLINKFrameLowering::emitEpilogue(MachineFunction &MF,
}
}
// Emit a compare of the stack pointer against the stack floor, and a call to
// the LE stack extender if needed.
void SystemZXPLINKFrameLowering::inlineStackProbe(
MachineFunction &MF, MachineBasicBlock &PrologMBB) const {
auto *ZII =
static_cast<const SystemZInstrInfo *>(MF.getSubtarget().getInstrInfo());
MachineInstr *StackAllocMI = nullptr;
for (MachineInstr &MI : PrologMBB)
if (MI.getOpcode() == SystemZ::XPLINK_STACKALLOC) {
StackAllocMI = &MI;
break;
}
if (StackAllocMI == nullptr)
return;
MachineBasicBlock &MBB = PrologMBB;
const DebugLoc DL = StackAllocMI->getDebugLoc();
// The 2nd half of block MBB after split.
MachineBasicBlock *NextMBB;
// Add new basic block for the call to the stack overflow function.
MachineBasicBlock *StackExtMBB =
MF.CreateMachineBasicBlock(MBB.getBasicBlock());
MF.push_back(StackExtMBB);
// LG r3,72(,r3)
BuildMI(StackExtMBB, DL, ZII->get(SystemZ::LG), SystemZ::R3D)
.addReg(SystemZ::R3D)
.addImm(72)
.addReg(0);
// BASR r3,r3
BuildMI(StackExtMBB, DL, ZII->get(SystemZ::CallBASR_STACKEXT))
.addReg(SystemZ::R3D);
// LLGT r3,1208
BuildMI(MBB, StackAllocMI, DL, ZII->get(SystemZ::LLGT), SystemZ::R3D)
.addReg(0)
.addImm(1208)
.addReg(0);
// CG r4,64(,r3)
BuildMI(MBB, StackAllocMI, DL, ZII->get(SystemZ::CG))
.addReg(SystemZ::R4D)
.addReg(SystemZ::R3D)
.addImm(64)
.addReg(0);
// JLL b'0100',F'37'
BuildMI(MBB, StackAllocMI, DL, ZII->get(SystemZ::BRC))
.addImm(SystemZ::CCMASK_ICMP)
.addImm(SystemZ::CCMASK_CMP_LT)
.addMBB(StackExtMBB);
NextMBB = SystemZ::splitBlockBefore(StackAllocMI, &MBB);
MBB.addSuccessor(NextMBB);
MBB.addSuccessor(StackExtMBB);
// Add jump back from stack extension BB.
BuildMI(StackExtMBB, DL, ZII->get(SystemZ::J)).addMBB(NextMBB);
StackExtMBB->addSuccessor(NextMBB);
StackAllocMI->eraseFromParent();
// Compute the live-in lists for the new blocks.
recomputeLiveIns(*NextMBB);
recomputeLiveIns(*StackExtMBB);
}
bool SystemZXPLINKFrameLowering::hasFP(const MachineFunction &MF) const {
return (MF.getFrameInfo().hasVarSizedObjects());
}

3
llvm/lib/Target/SystemZ/SystemZFrameLowering.h
View File

@ -127,6 +127,9 @@ public:
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
void inlineStackProbe(MachineFunction &MF,
MachineBasicBlock &PrologMBB) const override;
bool hasFP(const MachineFunction &MF) const override;
void processFunctionBeforeFrameFinalized(MachineFunction &MF,

8
llvm/lib/Target/SystemZ/SystemZInstrInfo.td
View File

@ -42,6 +42,10 @@ let Defs = [R1D, R15D, CC], Uses = [R15D], hasNoSchedulingInfo = 1,
hasSideEffects = 1 in
def PROBED_STACKALLOC : Pseudo<(outs), (ins i64imm:$stacksize), []>;
let Defs = [R3D, CC], Uses = [R3D, R4D], hasNoSchedulingInfo = 1,
hasSideEffects = 1 in
def XPLINK_STACKALLOC : Pseudo<(outs), (ins), []>;
//===----------------------------------------------------------------------===//
// Branch instructions
//===----------------------------------------------------------------------===//
@ -285,6 +289,10 @@ let Predicates = [IsTargetXPLINK64] in {
def CallBASR_XPLINK64 : Alias<4, (outs), (ins ADDR64:$R2, variable_ops),
[(z_call ADDR64:$R2)]>;
}
let isCall = 1, Defs = [R3D, CC], Uses = [FPC] in {
def CallBASR_STACKEXT : Alias<4, (outs), (ins ADDR64:$R2), []>;
}
}
// Regular calls.

2
llvm/lib/Target/SystemZ/SystemZScheduleZ13.td
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@ -168,7 +168,7 @@ def : InstRW<[WLat1, FXb, LSU, NormalGr], (instregex "CL(G)?T(Asm.*)?$")>;
// Call
def : InstRW<[WLat1, VBU, FXa2, GroupAlone], (instregex "(Call)?BRAS$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BRASL(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64|_STACKEXT)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "TLS_(G|L)DCALL$")>;
// Return

2
llvm/lib/Target/SystemZ/SystemZScheduleZ14.td
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@ -169,7 +169,7 @@ def : InstRW<[WLat1, FXb, LSU, NormalGr], (instregex "CL(G)?T(Asm.*)?$")>;
// Call
def : InstRW<[WLat1, VBU, FXa2, GroupAlone], (instregex "(Call)?BRAS$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BRASL(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64|_STACKEXT)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "TLS_(G|L)DCALL$")>;
// Return

2
llvm/lib/Target/SystemZ/SystemZScheduleZ15.td
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@ -169,7 +169,7 @@ def : InstRW<[WLat1, FXb, LSU, NormalGr], (instregex "CL(G)?T(Asm.*)?$")>;
// Call
def : InstRW<[WLat1, VBU, FXa2, GroupAlone], (instregex "(Call)?BRAS$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BRASL(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64|_STACKEXT)?$")>;
def : InstRW<[WLat1, FXa2, FXb, GroupAlone], (instregex "TLS_(G|L)DCALL$")>;
// Return

2
llvm/lib/Target/SystemZ/SystemZScheduleZ196.td
View File

@ -147,7 +147,7 @@ def : InstRW<[WLat1, FXU, NormalGr], (instregex "CL(F|G)IT(Asm.*)?$")>;
// Call
def : InstRW<[WLat1, LSU, FXU2, GroupAlone], (instregex "(Call)?BRAS$")>;
def : InstRW<[WLat1, LSU, FXU2, GroupAlone], (instregex "(Call)?BRASL(_XPLINK64)?$")>;
def : InstRW<[WLat1, LSU, FXU2, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64)?$")>;
def : InstRW<[WLat1, LSU, FXU2, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64|_STACKEXT)?$")>;
def : InstRW<[WLat1, LSU, FXU2, GroupAlone], (instregex "TLS_(G|L)DCALL$")>;
// Return

2
llvm/lib/Target/SystemZ/SystemZScheduleZEC12.td
View File

@ -152,7 +152,7 @@ def : InstRW<[WLat1, FXU, LSU, NormalGr], (instregex "CL(G)?T(Asm.*)?$")>;
// Call
def : InstRW<[WLat1, FXU2, VBU, GroupAlone], (instregex "(Call)?BRAS$")>;
def : InstRW<[WLat1, FXU2, LSU, GroupAlone], (instregex "(Call)?BRASL(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXU2, LSU, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64)?$")>;
def : InstRW<[WLat1, FXU2, LSU, GroupAlone], (instregex "(Call)?BAS(R)?(_XPLINK64|_STACKEXT)?$")>;
def : InstRW<[WLat1, FXU2, LSU, GroupAlone], (instregex "TLS_(G|L)DCALL$")>;
// Return

16
llvm/test/CodeGen/SystemZ/zos-prologue-epilog.ll
View File

@ -312,6 +312,22 @@ define i64 @func5(i64 %n) {
ret i64 %call
}
; CHECK-LABEL: large_stack
; CHECK64: agfi 4, -1048768
; CHECK64-NEXT: llgt 3, 1208
; CHECK64-NEXT: cg 4, 64(3)
; CHECK64-NEXT: jhe
; CHECK64: * %bb.1:
; CHECK64: lg 3, 72(3)
; CHECK64: basr 3, 3
; CHECK64: stmg 6, 7, 2064(4)
define void @large_stack() {
%arr = alloca [131072 x i64], align 8
%ptr = bitcast [131072 x i64]* %arr to i8*
call i64 (i8*) @fun1(i8* %ptr)
ret void
}
declare i64 @fun(i64 %arg0)
declare i64 @fun1(i8* %ptr)
declare i64 @fun2(i64 %n, i64* %arr0, i64* %arr1)