Next round of tail call changes. Register used in a tail
call must not be callee-saved; following x86, add a new
regclass to represent this. Also fixes a couple of bugs.
Still disabled by default; Thumb doesn't work yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106053 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 725d42c..1a35f6f 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1109,11 +1109,14 @@
// Build a sequence of copy-to-reg nodes chained together with token chain
// and flag operands which copy the outgoing args into the appropriate regs.
SDValue InFlag;
- for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
- Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
- RegsToPass[i].second, InFlag);
- InFlag = Chain.getValue(1);
- }
+ // Tail call byval lowering might overwrite argument registers so in case of
+ // tail call optimization the copies to registers are lowered later.
+ if (!isTailCall)
+ for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+ Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
+ RegsToPass[i].second, InFlag);
+ InFlag = Chain.getValue(1);
+ }
// For tail calls lower the arguments to the 'real' stack slot.
if (isTailCall) {