When verifying two-address instructions, check the following:
- Kill is implicit when use and def registers are identical.
- Only virtual registers can differ.
Add a -verify-fast-regalloc to run the verifier before the fast allocator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103797 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 0b75c55..fdfe2cb 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -47,7 +47,7 @@
MachineVerifier(Pass *pass, bool allowDoubleDefs) :
PASS(pass),
allowVirtDoubleDefs(allowDoubleDefs),
- allowPhysDoubleDefs(allowDoubleDefs),
+ allowPhysDoubleDefs(true),
OutFileName(getenv("LLVM_VERIFY_MACHINEINSTRS"))
{}
@@ -552,19 +552,23 @@
regsLiveInButUnused.erase(Reg);
bool isKill = false;
- if (MO->isKill()) {
- isKill = true;
- // Tied operands on two-address instuctions MUST NOT have a <kill> flag.
- if (MI->isRegTiedToDefOperand(MONum))
+ unsigned defIdx;
+ if (MI->isRegTiedToDefOperand(MONum, &defIdx)) {
+ // A two-addr use counts as a kill if use and def are the same.
+ unsigned DefReg = MI->getOperand(defIdx).getReg();
+ if (Reg == DefReg) {
+ isKill = true;
+ // ANd in that case an explicit kill flag is not allowed.
+ if (MO->isKill())
report("Illegal kill flag on two-address instruction operand",
MO, MONum);
- } else {
- // TwoAddress instr modifying a reg is treated as kill+def.
- unsigned defIdx;
- if (MI->isRegTiedToDefOperand(MONum, &defIdx) &&
- MI->getOperand(defIdx).getReg() == Reg)
- isKill = true;
- }
+ } else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
+ report("Two-address instruction operands must be identical",
+ MO, MONum);
+ }
+ } else
+ isKill = MO->isKill();
+
if (isKill) {
addRegWithSubRegs(regsKilled, Reg);