[llvm] 653b976 - [SystemZ] Improve handling of backchain offset.
Jonas Paulsson via llvm-commits
llvm-commits at lists.llvm.org
Mon Dec 14 10:40:14 PST 2020
Author: Jonas Paulsson
Date: 2020-12-14T12:39:38-06:00
New Revision: 653b97690f0d5c26a93002fb94ddd86397ed6c1c
URL: https://github.com/llvm/llvm-project/commit/653b97690f0d5c26a93002fb94ddd86397ed6c1c
DIFF: https://github.com/llvm/llvm-project/commit/653b97690f0d5c26a93002fb94ddd86397ed6c1c.diff
LOG: [SystemZ] Improve handling of backchain offset.
- New function SDValue getBackchainAddress() used by
lowerDYNAMIC_STACKALLOC() and lowerSTACKRESTORE() to properly handle the
backchain offset also with packed-stack.
- Make a common function getBackchainOffset() for the computation of the
backchain offset and use in some places (NFC).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D93171
Added:
Modified:
llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
llvm/lib/Target/SystemZ/SystemZFrameLowering.h
llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
llvm/lib/Target/SystemZ/SystemZISelLowering.h
llvm/test/CodeGen/SystemZ/backchain.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index d9e030de5af8..994f471b75b1 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -511,13 +511,10 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF,
.addReg(SystemZ::R1D, RegState::Define).addReg(SystemZ::R15D);
emitIncrement(MBB, MBBI, DL, SystemZ::R15D, Delta, ZII);
buildCFAOffs(MBB, MBBI, DL, SPOffsetFromCFA + Delta, ZII);
- if (StoreBackchain) {
- // The back chain is stored topmost with packed-stack.
- int Offset = usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0;
+ if (StoreBackchain)
BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::STG))
.addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D)
- .addImm(Offset).addReg(0);
- }
+ .addImm(getBackchainOffset(MF)).addReg(0);
}
SPOffsetFromCFA += Delta;
}
@@ -709,13 +706,10 @@ void SystemZFrameLowering::inlineStackProbe(MachineFunction &MF,
if (Residual)
allocateAndProbe(*MBB, MBBI, Residual, true/*EmitCFI*/);
- if (StoreBackchain) {
- // The back chain is stored topmost with packed-stack.
- int Offset = usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0;
+ if (StoreBackchain)
BuildMI(*MBB, MBBI, DL, ZII->get(SystemZ::STG))
.addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D)
- .addImm(Offset).addReg(0);
- }
+ .addImm(getBackchainOffset(MF)).addReg(0);
StackAllocMI->eraseFromParent();
if (DoneMBB != nullptr) {
@@ -790,8 +784,7 @@ getOrCreateFramePointerSaveIndex(MachineFunction &MF) const {
int FI = ZFI->getFramePointerSaveIndex();
if (!FI) {
MachineFrameInfo &MFFrame = MF.getFrameInfo();
- // The back chain is stored topmost with packed-stack.
- int Offset = usePackedStack(MF) ? -8 : -SystemZMC::CallFrameSize;
+ int Offset = getBackchainOffset(MF) - SystemZMC::CallFrameSize;
FI = MFFrame.CreateFixedObject(8, Offset, false);
ZFI->setFramePointerSaveIndex(FI);
}
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.h b/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
index 001d26d4d3bb..085c31ca0f18 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
@@ -9,6 +9,7 @@
#ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
#define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
+#include "MCTargetDesc/SystemZMCTargetDesc.h"
#include "llvm/ADT/IndexedMap.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/Support/TypeSize.h"
@@ -63,6 +64,12 @@ class SystemZFrameLowering : public TargetFrameLowering {
int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const;
bool usePackedStack(MachineFunction &MF) const;
+
+ // Return the offset of the backchain.
+ unsigned getBackchainOffset(MachineFunction &MF) const {
+ // The back chain is stored topmost with packed-stack.
+ return usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0;
+ }
};
} // end namespace llvm
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 812fe80864ac..663af1d64943 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -3435,7 +3435,8 @@ lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
// If we need a backchain, save it now.
SDValue Backchain;
if (StoreBackchain)
- Backchain = DAG.getLoad(MVT::i64, DL, Chain, OldSP, MachinePointerInfo());
+ Backchain = DAG.getLoad(MVT::i64, DL, Chain, getBackchainAddress(OldSP, DAG),
+ MachinePointerInfo());
// Add extra space for alignment if needed.
if (ExtraAlignSpace)
@@ -3472,7 +3473,8 @@ lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
}
if (StoreBackchain)
- Chain = DAG.getStore(Chain, DL, Backchain, NewSP, MachinePointerInfo());
+ Chain = DAG.getStore(Chain, DL, Backchain, getBackchainAddress(NewSP, DAG),
+ MachinePointerInfo());
SDValue Ops[2] = { Result, Chain };
return DAG.getMergeValues(Ops, DL);
@@ -4095,13 +4097,15 @@ SDValue SystemZTargetLowering::lowerSTACKRESTORE(SDValue Op,
if (StoreBackchain) {
SDValue OldSP = DAG.getCopyFromReg(Chain, DL, SystemZ::R15D, MVT::i64);
- Backchain = DAG.getLoad(MVT::i64, DL, Chain, OldSP, MachinePointerInfo());
+ Backchain = DAG.getLoad(MVT::i64, DL, Chain, getBackchainAddress(OldSP, DAG),
+ MachinePointerInfo());
}
Chain = DAG.getCopyToReg(Chain, DL, SystemZ::R15D, NewSP);
if (StoreBackchain)
- Chain = DAG.getStore(Chain, DL, Backchain, NewSP, MachinePointerInfo());
+ Chain = DAG.getStore(Chain, DL, Backchain, getBackchainAddress(NewSP, DAG),
+ MachinePointerInfo());
return Chain;
}
@@ -8144,6 +8148,16 @@ MachineBasicBlock *SystemZTargetLowering::emitProbedAlloca(
return DoneMBB;
}
+SDValue SystemZTargetLowering::
+getBackchainAddress(SDValue SP, SelectionDAG &DAG) const {
+ MachineFunction &MF = DAG.getMachineFunction();
+ auto *TFL =
+ static_cast<const SystemZFrameLowering *>(Subtarget.getFrameLowering());
+ SDLoc DL(SP);
+ return DAG.getNode(ISD::ADD, DL, MVT::i64, SP,
+ DAG.getIntPtrConstant(TFL->getBackchainOffset(MF), DL));
+}
+
MachineBasicBlock *SystemZTargetLowering::EmitInstrWithCustomInserter(
MachineInstr &MI, MachineBasicBlock *MBB) const {
switch (MI.getOpcode()) {
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index 1ab6366ec016..955587da626f 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -698,6 +698,8 @@ class SystemZTargetLowering : public TargetLowering {
MachineBasicBlock *emitProbedAlloca(MachineInstr &MI,
MachineBasicBlock *MBB) const;
+ SDValue getBackchainAddress(SDValue SP, SelectionDAG &DAG) const;
+
MachineMemOperand::Flags
getTargetMMOFlags(const Instruction &I) const override;
const TargetRegisterClass *getRepRegClassFor(MVT VT) const override;
diff --git a/llvm/test/CodeGen/SystemZ/backchain.ll b/llvm/test/CodeGen/SystemZ/backchain.ll
index c7c9d03b838a..b295c75c1072 100644
--- a/llvm/test/CodeGen/SystemZ/backchain.ll
+++ b/llvm/test/CodeGen/SystemZ/backchain.ll
@@ -82,3 +82,36 @@ define void @f5(i32 %count1, i32 %count2) "backchain" {
store volatile i8 0, i8 *%array2
ret void
}
+
+; same, but with the kernel backchain
+define void @f6(i32 %count1, i32 %count2) #0 {
+; CHECK-LABEL: f6:
+; CHECK: stmg %r11, %r15, 112(%r15)
+; CHECK: lgr %r1, %r15
+; CHECK: aghi %r15, -48
+; CHECK: stg %r1, 152(%r15)
+; CHECK: lgr %r11, %r15
+; CHECK-DAG: lgr [[SAVESP:%r[0-9]+]], %r15
+; CHECK-DAG: lg [[BC:%r[0-9]+]], 152(%r15)
+; CHECK-DAG: lgr [[NEWSP:%r[0-9]+]], %r15
+; CHECK-DAG: lgr %r15, [[NEWSP]]
+; CHECK-DAG: stg [[BC]], 152([[NEWSP]])
+; CHECK-DAG: lg [[BC2:%r[0-9]+]], 152(%r15)
+; CHECK-DAG: lgr %r15, [[SAVESP]]
+; CHECK-DAG: stg [[BC2]], 152([[SAVESP]])
+; CHECK-DAG: lg [[BC3:%r[0-9]+]], 152(%r15)
+; CHECK-DAG: lgr [[NEWSP2:%r[0-9]+]], %r15
+; CHECK-DAG: lgr %r15, [[NEWSP2]]
+; CHECK-DAG: stg [[BC3]], 152([[NEWSP2]])
+; CHECK: lmg %r11, %r15, 160(%r11)
+; CHECK: br %r14
+ %src = call i8 *@llvm.stacksave()
+ %array1 = alloca i8, i32 %count1
+ store volatile i8 0, i8 *%array1
+ call void @llvm.stackrestore(i8 *%src)
+ %array2 = alloca i8, i32 %count2
+ store volatile i8 0, i8 *%array2
+ ret void
+}
+
+attributes #0 = { "backchain" "packed-stack" "use-soft-float"="true" }
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