[llvm] r314465 - [SystemZ] Fix fall-out from r314428

[Ulrich Weigand via llvm-commits]

Author: uweigand
Date: Thu Sep 28 15:08:25 2017
New Revision: 314465

URL: http://llvm.org/viewvc/llvm-project?rev=314465&view=rev
Log:
[SystemZ] Fix fall-out from r314428

The expensive-checks build bot found a problem with the r314428 commit:
if CC is live after a ATOMIC_CMP_SWAPW instruction, it needs to be
marked as live-in to the block after the loop the pseudo gets expanded
to.  This actually fixes a code-gen bug as well, since if the CC isn't
live, the CR and JLH are merged to a CRJLH which doesn't actually set
the condition code any more.


Modified:
    llvm/trunk/lib/Target/SystemZ/SystemZISelLowering.cpp
    llvm/trunk/test/CodeGen/SystemZ/cmpxchg-01.ll
    llvm/trunk/test/CodeGen/SystemZ/cmpxchg-02.ll

Modified: llvm/trunk/lib/Target/SystemZ/SystemZISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/SystemZ/SystemZISelLowering.cpp?rev=314465&r1=314464&r2=314465&view=diff
==============================================================================
--- llvm/trunk/lib/Target/SystemZ/SystemZISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/SystemZ/SystemZISelLowering.cpp Thu Sep 28 15:08:25 2017
@@ -6027,6 +6027,12 @@ SystemZTargetLowering::emitAtomicCmpSwap
   MBB->addSuccessor(LoopMBB);
   MBB->addSuccessor(DoneMBB);
 
+  // If the CC def wasn't dead in the ATOMIC_CMP_SWAPW, mark CC as live-in
+  // to the block after the loop.  At this point, CC may have been defined
+  // either by the CR in LoopMBB or by the CS in SetMBB.
+  if (!MI.registerDefIsDead(SystemZ::CC))
+    DoneMBB->addLiveIn(SystemZ::CC);
+
   MI.eraseFromParent();
   return DoneMBB;
 }

Modified: llvm/trunk/test/CodeGen/SystemZ/cmpxchg-01.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/SystemZ/cmpxchg-01.ll?rev=314465&r1=314464&r2=314465&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/SystemZ/cmpxchg-01.ll (original)
+++ llvm/trunk/test/CodeGen/SystemZ/cmpxchg-01.ll Thu Sep 28 15:08:25 2017
@@ -65,7 +65,8 @@ define i32 @f3(i8 %dummy, i8 *%src, i8 %
 ; CHECK-MAIN: [[LOOP:\.[^ ]*]]:
 ; CHECK-MAIN: rll [[TMP:%r[0-9]+]], [[OLD]], 8(%r3)
 ; CHECK-MAIN: risbg %r4, [[TMP]], 32, 55, 0
-; CHECK-MAIN: crjlh [[TMP]], %r4, [[EXIT:\.[^ ]*]]
+; CHECK-MAIN: cr [[TMP]], %r4
+; CHECK-MAIN: jlh [[EXIT:\.[^ ]*]]
 ; CHECK-MAIN: risbg %r5, [[TMP]], 32, 55, 0
 ; CHECK-MAIN: rll [[NEW:%r[0-9]+]], %r5, -8({{%r[1-9]+}})
 ; CHECK-MAIN: cs [[OLD]], [[NEW]], 0([[RISBG]])

Modified: llvm/trunk/test/CodeGen/SystemZ/cmpxchg-02.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/SystemZ/cmpxchg-02.ll?rev=314465&r1=314464&r2=314465&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/SystemZ/cmpxchg-02.ll (original)
+++ llvm/trunk/test/CodeGen/SystemZ/cmpxchg-02.ll Thu Sep 28 15:08:25 2017
@@ -65,7 +65,8 @@ define i32 @f3(i16 %dummy, i16 *%src, i1
 ; CHECK-MAIN: [[LOOP:\.[^ ]*]]:
 ; CHECK-MAIN: rll [[TMP:%r[0-9]+]], [[OLD]], 16(%r3)
 ; CHECK-MAIN: risbg %r4, [[TMP]], 32, 47, 0
-; CHECK-MAIN: crjlh [[TMP]], %r4, [[EXIT:\.[^ ]*]]
+; CHECK-MAIN: cr [[TMP]], %r4
+; CHECK-MAIN: jlh [[EXIT:\.[^ ]*]]
 ; CHECK-MAIN: risbg %r5, [[TMP]], 32, 47, 0
 ; CHECK-MAIN: rll [[NEW:%r[0-9]+]], %r5, -16({{%r[1-9]+}})
 ; CHECK-MAIN: cs [[OLD]], [[NEW]], 0([[RISBG]])