Another sibcall bug. If caller and callee calling conventions differ, then it's only safe to do a tail call if the results are returned in the same way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102683 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 4c0c5f6..cdbe1ad 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2326,9 +2326,11 @@
// If -tailcallopt is specified, make fastcc functions tail-callable.
const MachineFunction &MF = DAG.getMachineFunction();
const Function *CallerF = DAG.getMachineFunction().getFunction();
+ CallingConv::ID CallerCC = CallerF->getCallingConv();
+ bool CCMatch = CallerCC == CalleeCC;
+
if (GuaranteedTailCallOpt) {
- if (IsTailCallConvention(CalleeCC) &&
- CallerF->getCallingConv() == CalleeCC)
+ if (IsTailCallConvention(CalleeCC) && CCMatch)
return true;
return false;
}
@@ -2366,13 +2368,43 @@
CCState CCInfo(CalleeCC, false, getTargetMachine(),
RVLocs, *DAG.getContext());
CCInfo.AnalyzeCallResult(Ins, RetCC_X86);
- for (unsigned i = 0; i != RVLocs.size(); ++i) {
+ for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) {
CCValAssign &VA = RVLocs[i];
if (VA.getLocReg() == X86::ST0 || VA.getLocReg() == X86::ST1)
return false;
}
}
+ // If the calling conventions do not match, then we'd better make sure the
+ // results are returned in the same way as what the caller expects.
+ if (!CCMatch) {
+ SmallVector<CCValAssign, 16> RVLocs1;
+ CCState CCInfo1(CalleeCC, false, getTargetMachine(),
+ RVLocs1, *DAG.getContext());
+ CCInfo1.AnalyzeCallResult(Ins, RetCC_X86);
+
+ SmallVector<CCValAssign, 16> RVLocs2;
+ CCState CCInfo2(CallerCC, false, getTargetMachine(),
+ RVLocs2, *DAG.getContext());
+ CCInfo2.AnalyzeCallResult(Ins, RetCC_X86);
+
+ if (RVLocs1.size() != RVLocs2.size())
+ return false;
+ for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
+ if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
+ return false;
+ if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
+ return false;
+ if (RVLocs1[i].isRegLoc()) {
+ if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
+ return false;
+ } else {
+ if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
+ return false;
+ }
+ }
+ }
+
// If the callee takes no arguments then go on to check the results of the
// call.
if (!Outs.empty()) {