Correctly compute live variable information for physical registers
when an implicitely defined register is later used by an alias. For example:
call foo
%reg1024 = mov %AL
The call implicitely defines EAX but only AL is used. Before this fix
no information was available on AL. Now EAX and all its aliases except
AL get defined and die at the call instruction whereas AL lives to be
killed by the assignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10813 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index fe47a36..f8c83f1 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -261,6 +261,8 @@
if (reg < MRegisterInfo::FirstVirtualRegister) {
if (allocatableRegisters_[reg]) {
handlePhysicalRegisterDef(mbb, mi, reg);
+ for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
+ handlePhysicalRegisterDef(mbb, mi, *as);
}
}
else {
@@ -300,10 +302,8 @@
instr->print(std::cerr, *tm_););
// handle implicit defs
- for (const unsigned* id = tid.ImplicitDefs; *id; ++id) {
- unsigned physReg = *id;
- handlePhysicalRegisterDef(mbb, mi, physReg);
- }
+ for (const unsigned* id = tid.ImplicitDefs; *id; ++id)
+ handleRegisterDef(mbb, mi, *id);
// handle explicit defs
for (int i = instr->getNumOperands() - 1; i >= 0; --i) {
@@ -312,14 +312,9 @@
if (!mop.isRegister())
continue;
- unsigned reg = mop.getAllocatedRegNum();
// handle defs - build intervals
- if (mop.isDef()) {
- if (reg < MRegisterInfo::FirstVirtualRegister)
- handlePhysicalRegisterDef(mbb, mi, reg);
- else
- handleVirtualRegisterDef(mbb, mi, reg);
- }
+ if (mop.isDef())
+ handleRegisterDef(mbb, mi, mop.getAllocatedRegNum());
}
}
}