Fix pr3954. The register scavenger asserts for inline assembly with
register destinations that are tied to source operands. The
TargetInstrDescr::findTiedToSrcOperand method silently fails for inline
assembly. The existing MachineInstr::isRegReDefinedByTwoAddr was very
close to doing what is needed, so this revision makes a few changes to
that method and also renames it to isRegTiedToUseOperand (for consistency
with the very similar isRegTiedToDefOperand and because it handles both
two-address instructions and inline assembly with tied registers).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68714 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index 5c646c6..3caf7ac 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -241,9 +241,11 @@
/// none is found.
int findFirstPredOperandIdx() const;
- /// isRegReDefinedByTwoAddr - Given the index of a register def operand,
- /// check if the register def is a re-definition due to two addr elimination.
- bool isRegReDefinedByTwoAddr(unsigned DefIdx) const;
+ /// isRegTiedToUseOperand - Given the index of a register def operand,
+ /// check if the register def is tied to a source operand, due to either
+ /// two-address elimination or inline assembly constraints. Returns the
+ /// first tied use operand index by reference is UseOpIdx is not null.
+ bool isRegTiedToUseOperand(unsigned DefOpIdx, unsigned *UseOpIdx = 0);
/// isRegTiedToDefOperand - Return true if the use operand of the specified
/// index is tied to an def operand. It also returns the def operand index by
diff --git a/include/llvm/Target/TargetInstrDesc.h b/include/llvm/Target/TargetInstrDesc.h
index 6a0a396..b389a4f 100644
--- a/include/llvm/Target/TargetInstrDesc.h
+++ b/include/llvm/Target/TargetInstrDesc.h
@@ -131,10 +131,6 @@
return -1;
}
- /// findTiedToSrcOperand - Returns the operand that is tied to the specified
- /// dest operand. Returns -1 if there isn't one.
- int findTiedToSrcOperand(unsigned OpNum) const;
-
/// getOpcode - Return the opcode number for this descriptor.
unsigned getOpcode() const {
return Opcode;
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index cb08fe7..3bc05a9 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -469,7 +469,7 @@
// must be due to phi elimination or two addr elimination. If this is
// the result of two address elimination, then the vreg is one of the
// def-and-use register operand.
- if (mi->isRegReDefinedByTwoAddr(MOIdx)) {
+ if (mi->isRegTiedToUseOperand(MOIdx)) {
// If this is a two-address definition, then we have already processed
// the live range. The only problem is that we didn't realize there
// are actually two values in the live interval. Because of this we
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index ade8683..d3b2e9a 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -690,12 +690,14 @@
return -1;
}
-/// isRegReDefinedByTwoAddr - Given the index of a register operand,
-/// check if the register def is a re-definition due to two addr elimination.
-bool MachineInstr::isRegReDefinedByTwoAddr(unsigned DefIdx) const{
+/// isRegTiedToUseOperand - Given the index of a register def operand,
+/// check if the register def is tied to a source operand, due to either
+/// two-address elimination or inline assembly constraints. Returns the
+/// first tied use operand index by reference is UseOpIdx is not null.
+bool MachineInstr::isRegTiedToUseOperand(unsigned DefOpIdx, unsigned *UseOpIdx){
if (getOpcode() == TargetInstrInfo::INLINEASM) {
- assert(DefIdx >= 2);
- const MachineOperand &MO = getOperand(DefIdx);
+ assert(DefOpIdx >= 2);
+ const MachineOperand &MO = getOperand(DefOpIdx);
if (!MO.isReg() || !MO.isDef())
return false;
// Determine the actual operand no corresponding to this index.
@@ -705,7 +707,7 @@
assert(FMO.isImm());
// Skip over this def.
i += InlineAsm::getNumOperandRegisters(FMO.getImm()) + 1;
- if (i > DefIdx)
+ if (i > DefOpIdx)
break;
++DefNo;
}
@@ -717,18 +719,24 @@
continue;
unsigned Idx;
if (InlineAsm::isUseOperandTiedToDef(FMO.getImm(), Idx) &&
- Idx == DefNo)
+ Idx == DefNo) {
+ if (UseOpIdx)
+ *UseOpIdx = (unsigned)i + 1;
return true;
+ }
}
}
- assert(getOperand(DefIdx).isDef() && "DefIdx is not a def!");
+ assert(getOperand(DefOpIdx).isDef() && "DefOpIdx is not a def!");
const TargetInstrDesc &TID = getDesc();
for (unsigned i = 0, e = TID.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = getOperand(i);
if (MO.isReg() && MO.isUse() &&
- TID.getOperandConstraint(i, TOI::TIED_TO) == (int)DefIdx)
+ TID.getOperandConstraint(i, TOI::TIED_TO) == (int)DefOpIdx) {
+ if (UseOpIdx)
+ *UseOpIdx = (unsigned)i;
return true;
+ }
}
return false;
}
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index 311ad28..f4e958c 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -500,7 +500,7 @@
if (Reg == 0) continue;
if (!MO.isDef()) continue;
// Ignore two-addr defs.
- if (MI->isRegReDefinedByTwoAddr(i)) continue;
+ if (MI->isRegTiedToUseOperand(i)) continue;
DefIndices[Reg] = Count;
KillIndices[Reg] = ~0u;
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp
index d9775f9..c4bda48 100644
--- a/lib/CodeGen/PreAllocSplitting.cpp
+++ b/lib/CodeGen/PreAllocSplitting.cpp
@@ -803,7 +803,7 @@
MachineInstr* MI = LIs->getInstructionFromIndex(*KI);
unsigned DefIdx = MI->findRegisterDefOperandIdx(CurrLI->reg);
if (DefIdx == ~0U) continue;
- if (MI->isRegReDefinedByTwoAddr(DefIdx)) {
+ if (MI->isRegTiedToUseOperand(DefIdx)) {
VNInfo* NextVN =
CurrLI->findDefinedVNInfo(LiveIntervals::getDefIndex(*KI));
if (NextVN == OldVN) continue;
@@ -1214,7 +1214,7 @@
NonSpills++;
int DefIdx = (*UI)->findRegisterDefOperandIdx(Reg);
- if (DefIdx != -1 && (*UI)->isRegReDefinedByTwoAddr(DefIdx))
+ if (DefIdx != -1 && (*UI)->isRegTiedToUseOperand(DefIdx))
FeedsTwoAddr = true;
}
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index b965dc9..14346e9 100644
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -633,7 +633,7 @@
// Check if this is a two address instruction. If so, then
// the def does not kill the use.
if (last->second.first == I &&
- I->isRegReDefinedByTwoAddr(i))
+ I->isRegTiedToUseOperand(i))
continue;
MachineOperand& lastUD =
diff --git a/lib/CodeGen/RegAllocSimple.cpp b/lib/CodeGen/RegAllocSimple.cpp
index 5e5290c..447e54c 100644
--- a/lib/CodeGen/RegAllocSimple.cpp
+++ b/lib/CodeGen/RegAllocSimple.cpp
@@ -204,8 +204,8 @@
unsigned physReg = Virt2PhysRegMap[virtualReg];
if (physReg == 0) {
if (MO.isDef()) {
- int TiedOp = Desc.findTiedToSrcOperand(i);
- if (TiedOp == -1) {
+ unsigned TiedOp;
+ if (!MI->isRegTiedToUseOperand(i, &TiedOp)) {
physReg = getFreeReg(virtualReg);
} else {
// must be same register number as the source operand that is
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 9447ff2..944468e 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -188,7 +188,6 @@
MachineInstr *MI = MBBI;
DistanceMap.insert(std::make_pair(MI, CurrDist++));
- const TargetInstrDesc &TID = MI->getDesc();
if (MI == ScavengeRestore) {
ScavengedReg = 0;
@@ -256,7 +255,7 @@
}
// Skip two-address destination operand.
- if (TID.findTiedToSrcOperand(Idx) != -1) {
+ if (MI->isRegTiedToUseOperand(Idx)) {
assert(isUsed(Reg) && "Using an undefined register!");
continue;
}
@@ -284,7 +283,6 @@
MachineInstr *MI = MBBI;
DistanceMap.erase(MI);
--CurrDist;
- const TargetInstrDesc &TID = MI->getDesc();
// Separate register operands into 3 classes: uses, defs, earlyclobbers.
SmallVector<std::pair<const MachineOperand*,unsigned>, 4> UseMOs;
@@ -313,7 +311,7 @@
? DefMOs[i].second : EarlyClobberMOs[i-NumDefs].second;
// Skip two-address destination operand.
- if (TID.findTiedToSrcOperand(Idx) != -1)
+ if (MI->isRegTiedToUseOperand(Idx))
continue;
unsigned Reg = MO.getReg();
diff --git a/lib/CodeGen/Spiller.cpp b/lib/CodeGen/Spiller.cpp
index 7b2a32f..354ff0a 100644
--- a/lib/CodeGen/Spiller.cpp
+++ b/lib/CodeGen/Spiller.cpp
@@ -1589,8 +1589,8 @@
// If this def is part of a two-address operand, make sure to execute
// the store from the correct physical register.
unsigned PhysReg;
- int TiedOp = MI.getDesc().findTiedToSrcOperand(i);
- if (TiedOp != -1) {
+ unsigned TiedOp;
+ if (MI.isRegTiedToUseOperand(i, &TiedOp)) {
PhysReg = MI.getOperand(TiedOp).getReg();
if (SubIdx) {
unsigned SuperReg = findSuperReg(RC, PhysReg, SubIdx, TRI);
diff --git a/lib/Target/TargetInstrInfo.cpp b/lib/Target/TargetInstrInfo.cpp
index 10a5cdb..1bdeef4 100644
--- a/lib/Target/TargetInstrInfo.cpp
+++ b/lib/Target/TargetInstrInfo.cpp
@@ -16,19 +16,6 @@
#include "llvm/DerivedTypes.h"
using namespace llvm;
-/// findTiedToSrcOperand - Returns the operand that is tied to the specified
-/// dest operand. Returns -1 if there isn't one.
-int TargetInstrDesc::findTiedToSrcOperand(unsigned OpNum) const {
- for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
- if (i == OpNum)
- continue;
- if (getOperandConstraint(i, TOI::TIED_TO) == (int)OpNum)
- return i;
- }
- return -1;
-}
-
-
TargetInstrInfo::TargetInstrInfo(const TargetInstrDesc* Desc,
unsigned numOpcodes)
: Descriptors(Desc), NumOpcodes(numOpcodes) {
diff --git a/test/CodeGen/ARM/2009-04-09-RegScavengerAsm.ll b/test/CodeGen/ARM/2009-04-09-RegScavengerAsm.ll
new file mode 100644
index 0000000..223fa0f
--- /dev/null
+++ b/test/CodeGen/ARM/2009-04-09-RegScavengerAsm.ll
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | llc -march=arm
+; PR3954
+
+define void @foo(...) nounwind {
+entry:
+ %rr = alloca i32 ; <i32*> [#uses=2]
+ %0 = load i32* %rr ; <i32> [#uses=1]
+ %1 = call i32 asm "nop", "=r,0"(i32 %0) nounwind ; <i32> [#uses=1]
+ store i32 %1, i32* %rr
+ br label %return
+
+return: ; preds = %entry
+ ret void
+}