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LiveDebugValues: Assume calls never clobber SP.

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A call should never modify the stack pointer, but some backends are
not so sure about this and never list SP in the regmask. For the
purposes of LiveDebugValues we assume a call never clobbers SP. We
already have a similar workaround in DbgValueHistoryCalculator (which
we hopefully can retire soon).

This fixes the availabilty of local ASANified variables on AArch64.

rdar://problem/27757381

llvm-svn: 296847
This commit is contained in:
Adrian Prantl
2017-03-03 01:08:25 +00:00
parent e78d131a8d
commit ea8880b81f
2 changed files with 331 additions and 1 deletions
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6
llvm/lib/CodeGen/LiveDebugValues.cpp
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@@ -373,8 +373,12 @@ void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
SparseBitVector<> KillSet;
for (const MachineOperand &MO : MI.operands()) {
// Determine whether the operand is a register def. Assume that call
// instructions never clobber SP, because some backends (e.g., AArch64)
// never list SP in the regmask.
if (MO.isReg() && MO.isDef() && MO.getReg() &&
TRI->isPhysicalRegister(MO.getReg())) {
TRI->isPhysicalRegister(MO.getReg()) &&
!(MI.isCall() && MO.getReg() == SP)) {
// Remove ranges of all aliased registers.
for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
for (unsigned ID : OpenRanges.getVarLocs())