Bugs: missing partial uses and redundant partial defs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40688 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index d1ebaf1..e8d07bf 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -281,10 +281,24 @@
PhysRegUsed[SubReg] = true;
}
- // Remember the partial uses.
for (const unsigned *SuperRegs = RegInfo->getSuperRegisters(Reg);
- unsigned SuperReg = *SuperRegs; ++SuperRegs)
- PhysRegPartUse[SuperReg] = MI;
+ unsigned SuperReg = *SuperRegs; ++SuperRegs) {
+ // Remember the partial use of this superreg if it was previously defined.
+ bool HasPrevDef = PhysRegInfo[SuperReg] != NULL;
+ if (!HasPrevDef) {
+ for (const unsigned *SSRegs = RegInfo->getSuperRegisters(SuperReg);
+ unsigned SSReg = *SSRegs; ++SSRegs) {
+ if (PhysRegInfo[SSReg] != NULL) {
+ HasPrevDef = true;
+ break;
+ }
+ }
+ }
+ if (HasPrevDef) {
+ PhysRegInfo[SuperReg] = MI;
+ PhysRegPartUse[SuperReg] = MI;
+ }
+ }
}
bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *RefMI,
@@ -342,7 +356,7 @@
addRegisterKilled(Reg, PhysRegPartUse[Reg], true);
}
} else if (PhysRegPartUse[Reg])
- // Add implicit use / kill to last use of a sub-register.
+ // Add implicit use / kill to last partial use.
addRegisterKilled(Reg, PhysRegPartUse[Reg], true);
else
addRegisterDead(Reg, LastRef);
@@ -385,11 +399,13 @@
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = false;
+ PhysRegPartDef[Reg].clear();
PhysRegPartUse[Reg] = NULL;
for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg);
unsigned SubReg = *SubRegs; ++SubRegs) {
PhysRegInfo[SubReg] = MI;
PhysRegUsed[SubReg] = false;
+ PhysRegPartDef[SubReg].clear();
PhysRegPartUse[SubReg] = NULL;
}
}