[PATCH] D60427: [ARM] Glue register copies to tail calls.

[Dave Green via Phabricator via llvm-commits]

dmgreen accepted this revision.
dmgreen added a comment.
This revision is now accepted and ready to land.

LGTM then.



================
Comment at: lib/Target/ARM/ARMISelLowering.cpp:1991
   SDValue InFlag;
-  // 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) {
-    // Force all the incoming stack arguments to be loaded from the stack
-    // before any new outgoing arguments are stored to the stack, because the
-    // outgoing stack slots may alias the incoming argument stack slots, and
-    // the alias isn't otherwise explicit. This is slightly more conservative
-    // than necessary, because it means that each store effectively depends
-    // on every argument instead of just those arguments it would clobber.
-
-    // Do not flag preceding copytoreg stuff together with the following stuff.
-    InFlag = SDValue();
-    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);
-    }
-    InFlag = SDValue();
+  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
----------------
for (auto &RegToPass : RegsToPass)


Repository:
  rL LLVM

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  https://reviews.llvm.org/D60427/new/

https://reviews.llvm.org/D60427