[llvm] r291169 - CodeGen: Assert that liveness is up to date when reading block live-ins.
Matthias Braun via llvm-commits
llvm-commits at lists.llvm.org
Thu Jan 5 12:01:19 PST 2017
Author: matze
Date: Thu Jan 5 14:01:19 2017
New Revision: 291169
URL: http://llvm.org/viewvc/llvm-project?rev=291169&view=rev
Log:
CodeGen: Assert that liveness is up to date when reading block live-ins.
Add an assert that checks whether liveins are up to date before they are
used.
- Do not print liveins into .mir files anymore in situations where they
are out of date anyway.
- The assert in the RegisterScavenger is superseded by the new one in
livein_begin().
- Skip parts of the liveness updating logic in IfConversion.cpp when
liveness isn't tracked anymore (just enough to avoid hitting the new
assert()).
Differential Revision: https://reviews.llvm.org/D27562
Modified:
llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h
llvm/trunk/lib/CodeGen/IfConversion.cpp
llvm/trunk/lib/CodeGen/MIRPrinter.cpp
llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp
llvm/trunk/lib/CodeGen/MachineVerifier.cpp
llvm/trunk/lib/CodeGen/RegisterScavenging.cpp
llvm/trunk/test/CodeGen/AArch64/machine-scheduler.mir
llvm/trunk/test/CodeGen/MIR/X86/basic-block-liveins.mir
llvm/trunk/test/CodeGen/MIR/X86/machine-verifier.mir
llvm/trunk/test/CodeGen/X86/tail-call-conditional.mir
Modified: llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h Thu Jan 5 14:01:19 2017
@@ -308,7 +308,7 @@ public:
// Iteration support for live in sets. These sets are kept in sorted
// order by their register number.
typedef LiveInVector::const_iterator livein_iterator;
- livein_iterator livein_begin() const { return LiveIns.begin(); }
+ livein_iterator livein_begin() const;
livein_iterator livein_end() const { return LiveIns.end(); }
bool livein_empty() const { return LiveIns.empty(); }
iterator_range<livein_iterator> liveins() const {
Modified: llvm/trunk/lib/CodeGen/IfConversion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/IfConversion.cpp?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/IfConversion.cpp (original)
+++ llvm/trunk/lib/CodeGen/IfConversion.cpp Thu Jan 5 14:01:19 2017
@@ -1495,16 +1495,18 @@ bool IfConverter::IfConvertSimple(BBInfo
if (TII->reverseBranchCondition(Cond))
llvm_unreachable("Unable to reverse branch condition!");
- // Initialize liveins to the first BB. These are potentiall redefined by
- // predicated instructions.
Redefs.init(*TRI);
- Redefs.addLiveIns(CvtMBB);
- Redefs.addLiveIns(NextMBB);
-
- // Compute a set of registers which must not be killed by instructions in
- // BB1: This is everything live-in to BB2.
DontKill.init(*TRI);
- DontKill.addLiveIns(NextMBB);
+
+ if (MRI->tracksLiveness()) {
+ // Initialize liveins to the first BB. These are potentiall redefined by
+ // predicated instructions.
+ Redefs.addLiveIns(CvtMBB);
+ Redefs.addLiveIns(NextMBB);
+ // Compute a set of registers which must not be killed by instructions in
+ // BB1: This is everything live-in to BB2.
+ DontKill.addLiveIns(NextMBB);
+ }
if (CvtMBB.pred_size() > 1) {
BBI.NonPredSize -= TII->removeBranch(*BBI.BB);
@@ -1602,8 +1604,10 @@ bool IfConverter::IfConvertTriangle(BBIn
// Initialize liveins to the first BB. These are potentially redefined by
// predicated instructions.
Redefs.init(*TRI);
- Redefs.addLiveIns(CvtMBB);
- Redefs.addLiveIns(NextMBB);
+ if (MRI->tracksLiveness()) {
+ Redefs.addLiveIns(CvtMBB);
+ Redefs.addLiveIns(NextMBB);
+ }
DontKill.clear();
@@ -1766,8 +1770,10 @@ bool IfConverter::IfConvertDiamondCommon
// instructions. We start with BB1 live-ins so we have the live-out regs
// after tracking the BB1 instructions.
Redefs.init(*TRI);
- Redefs.addLiveIns(MBB1);
- Redefs.addLiveIns(MBB2);
+ if (MRI->tracksLiveness()) {
+ Redefs.addLiveIns(MBB1);
+ Redefs.addLiveIns(MBB2);
+ }
// Remove the duplicated instructions at the beginnings of both paths.
// Skip dbg_value instructions
@@ -1792,12 +1798,14 @@ bool IfConverter::IfConvertDiamondCommon
// This is everything used+live in BB2 after the duplicated instructions. We
// can compute this set by simulating liveness backwards from the end of BB2.
DontKill.init(*TRI);
- for (const MachineInstr &MI : make_range(MBB2.rbegin(), ++DI2.getReverse()))
- DontKill.stepBackward(MI);
-
- for (const MachineInstr &MI : make_range(MBB1.begin(), DI1)) {
- SmallVector<std::pair<unsigned, const MachineOperand*>, 4> IgnoredClobbers;
- Redefs.stepForward(MI, IgnoredClobbers);
+ if (MRI->tracksLiveness()) {
+ for (const MachineInstr &MI : make_range(MBB2.rbegin(), ++DI2.getReverse()))
+ DontKill.stepBackward(MI);
+
+ for (const MachineInstr &MI : make_range(MBB1.begin(), DI1)) {
+ SmallVector<std::pair<unsigned, const MachineOperand*>, 4> Dummy;
+ Redefs.stepForward(MI, Dummy);
+ }
}
BBI.BB->splice(BBI.BB->end(), &MBB1, MBB1.begin(), DI1);
MBB2.erase(MBB2.begin(), DI2);
Modified: llvm/trunk/lib/CodeGen/MIRPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MIRPrinter.cpp?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MIRPrinter.cpp (original)
+++ llvm/trunk/lib/CodeGen/MIRPrinter.cpp Thu Jan 5 14:01:19 2017
@@ -488,16 +488,16 @@ void MIPrinter::print(const MachineBasic
}
// Print the live in registers.
- const auto *TRI = MBB.getParent()->getSubtarget().getRegisterInfo();
- assert(TRI && "Expected target register info");
- if (!MBB.livein_empty()) {
+ const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
+ if (MRI.tracksLiveness() && !MBB.livein_empty()) {
+ const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
OS.indent(2) << "liveins: ";
bool First = true;
for (const auto &LI : MBB.liveins()) {
if (!First)
OS << ", ";
First = false;
- printReg(LI.PhysReg, OS, TRI);
+ printReg(LI.PhysReg, OS, &TRI);
if (!LI.LaneMask.all())
OS << ":0x" << PrintLaneMask(LI.LaneMask);
}
Modified: llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp Thu Jan 5 14:01:19 2017
@@ -286,7 +286,7 @@ void MachineBasicBlock::print(raw_ostrea
if (!livein_empty()) {
if (Indexes) OS << '\t';
OS << " Live Ins:";
- for (const auto &LI : make_range(livein_begin(), livein_end())) {
+ for (const auto &LI : LiveIns) {
OS << ' ' << PrintReg(LI.PhysReg, TRI);
if (!LI.LaneMask.all())
OS << ':' << PrintLaneMask(LI.LaneMask);
@@ -1292,3 +1292,10 @@ MachineBasicBlock::getEndClobberMask(con
void MachineBasicBlock::clearLiveIns() {
LiveIns.clear();
}
+
+MachineBasicBlock::livein_iterator MachineBasicBlock::livein_begin() const {
+ assert(getParent()->getProperties().hasProperty(
+ MachineFunctionProperties::Property::TracksLiveness) &&
+ "Liveness information is accurate");
+ return LiveIns.begin();
+}
Modified: llvm/trunk/lib/CodeGen/MachineVerifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineVerifier.cpp?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineVerifier.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineVerifier.cpp Thu Jan 5 14:01:19 2017
@@ -566,7 +566,7 @@ MachineVerifier::visitMachineBasicBlockB
FirstTerminator = nullptr;
if (!MF->getProperties().hasProperty(
- MachineFunctionProperties::Property::NoPHIs)) {
+ MachineFunctionProperties::Property::NoPHIs) && MRI->tracksLiveness()) {
// If this block has allocatable physical registers live-in, check that
// it is an entry block or landing pad.
for (const auto &LI : MBB->liveins()) {
@@ -741,14 +741,16 @@ MachineVerifier::visitMachineBasicBlockB
}
regsLive.clear();
- for (const auto &LI : MBB->liveins()) {
- if (!TargetRegisterInfo::isPhysicalRegister(LI.PhysReg)) {
- report("MBB live-in list contains non-physical register", MBB);
- continue;
+ if (MRI->tracksLiveness()) {
+ for (const auto &LI : MBB->liveins()) {
+ if (!TargetRegisterInfo::isPhysicalRegister(LI.PhysReg)) {
+ report("MBB live-in list contains non-physical register", MBB);
+ continue;
+ }
+ for (MCSubRegIterator SubRegs(LI.PhysReg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
+ regsLive.insert(*SubRegs);
}
- for (MCSubRegIterator SubRegs(LI.PhysReg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- regsLive.insert(*SubRegs);
}
regsLiveInButUnused = regsLive;
Modified: llvm/trunk/lib/CodeGen/RegisterScavenging.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterScavenging.cpp?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterScavenging.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterScavenging.cpp Thu Jan 5 14:01:19 2017
@@ -48,11 +48,6 @@ void RegScavenger::init(MachineBasicBloc
assert((NumRegUnits == 0 || NumRegUnits == TRI->getNumRegUnits()) &&
"Target changed?");
- // It is not possible to use the register scavenger after late optimization
- // passes that don't preserve accurate liveness information.
- assert(MRI->tracksLiveness() &&
- "Cannot use register scavenger with inaccurate liveness");
-
// Self-initialize.
if (!this->MBB) {
NumRegUnits = TRI->getNumRegUnits();
Modified: llvm/trunk/test/CodeGen/AArch64/machine-scheduler.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/machine-scheduler.mir?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/machine-scheduler.mir (original)
+++ llvm/trunk/test/CodeGen/AArch64/machine-scheduler.mir Thu Jan 5 14:01:19 2017
@@ -21,8 +21,9 @@
# CHECK: LDRWui %x0, 0
# CHECK: LDRWui %x0, 1
# CHECK: STRWui %w1, %x0, 2
-name: load_imp-def
-body: |
+name: load_imp-def
+tracksRegLiveness: true
+body: |
bb.0.entry:
liveins: %w1, %x0
%w8 = LDRWui %x0, 1, implicit-def %x8 :: (load 4 from %ir.0)
Modified: llvm/trunk/test/CodeGen/MIR/X86/basic-block-liveins.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/MIR/X86/basic-block-liveins.mir?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/MIR/X86/basic-block-liveins.mir (original)
+++ llvm/trunk/test/CodeGen/MIR/X86/basic-block-liveins.mir Thu Jan 5 14:01:19 2017
@@ -22,7 +22,8 @@
...
---
-name: test
+name: test
+tracksRegLiveness: true
body: |
; CHECK-LABEL: bb.0.body:
; CHECK-NEXT: liveins: %edi, %esi
@@ -33,7 +34,8 @@ body: |
RETQ %eax
...
---
-name: test2
+name: test2
+tracksRegLiveness: true
body: |
; CHECK-LABEL: name: test2
; Verify that we can have multiple lists of liveins that will be merged into
@@ -48,7 +50,8 @@ body: |
RETQ %eax
...
---
-name: test3
+name: test3
+tracksRegLiveness: true
body: |
; Verify that we can have an empty list of liveins.
; CHECK-LABEL: name: test3
Modified: llvm/trunk/test/CodeGen/MIR/X86/machine-verifier.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/MIR/X86/machine-verifier.mir?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/MIR/X86/machine-verifier.mir (original)
+++ llvm/trunk/test/CodeGen/MIR/X86/machine-verifier.mir Thu Jan 5 14:01:19 2017
@@ -10,7 +10,8 @@
...
---
-name: inc
+name: inc
+tracksRegLiveness: true
body: |
bb.0.entry:
liveins: %edi
Modified: llvm/trunk/test/CodeGen/X86/tail-call-conditional.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/tail-call-conditional.mir?rev=291169&r1=291168&r2=291169&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/tail-call-conditional.mir (original)
+++ llvm/trunk/test/CodeGen/X86/tail-call-conditional.mir Thu Jan 5 14:01:19 2017
@@ -26,7 +26,8 @@
...
---
-name: test
+name: test
+tracksRegLiveness: true
liveins:
- { reg: '%rdi' }
- { reg: '%rsi' }
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