From 88004c25c795dae031d22e5560cc4a0f98594e7c Mon Sep 17 00:00:00 2001 From: Dale Johannesen Date: Sat, 5 Jun 2010 00:30:45 +0000 Subject: Fix some liveout handling related to tail calls, see comments. I don't think this ever resulted in problems on x86, but it would on ARM. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105509 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LiveVariables.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'lib/CodeGen/LiveVariables.cpp') diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index 079684eea0..fe6b290ea9 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -609,7 +609,12 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) { // Finally, if the last instruction in the block is a return, make sure to // mark it as using all of the live-out values in the function. - if (!MBB->empty() && MBB->back().getDesc().isReturn()) { + // Things marked both call and return are tail calls; do not do this for + // them. The tail callee need not take the same registers as input + // that it produces as output, and there are dependencies for its input + // registers elsewhere. + if (!MBB->empty() && MBB->back().getDesc().isReturn() + && !MBB->back().getDesc().isCall()) { MachineInstr *Ret = &MBB->back(); for (MachineRegisterInfo::liveout_iterator -- cgit v1.2.3-18-g5258