Now that RegistersDefinedFromSameValue handles one instruction being an

implicit_def, the other instruction can be anything, including instructions
that define multiple values. Be careful about that and don't assume what operand
0 is.
Fixes pr13249.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159509 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 31 insertions, 14 deletions

diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 6ef098d1a1..733312fbd0 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -1175,28 +1175,18 @@ static bool RegistersDefinedFromSameValue(LiveIntervals &li,
   if (!MI || CP.isPartial() || CP.isPhys())
     return false;
 
-  unsigned Dst = MI->getOperand(0).getReg();
-  if (!TargetRegisterInfo::isVirtualRegister(Dst))
+  unsigned A = CP.getDstReg();
+  if (!TargetRegisterInfo::isVirtualRegister(A))
     return false;
 
-  unsigned A = CP.getDstReg();
   unsigned B = CP.getSrcReg();
-
-  if (B == Dst)
-    std::swap(A, B);
-  assert(Dst == A);
+  if (!TargetRegisterInfo::isVirtualRegister(B))
+    return false;
 
   MachineInstr *OtherMI = li.getInstructionFromIndex(OtherVNI->def);
-
   if (!OtherMI)
     return false;
 
-  unsigned OtherDst = OtherMI->getOperand(0).getReg();
-  if (!TargetRegisterInfo::isVirtualRegister(OtherDst))
-    return false;
-
-  assert(OtherDst == B);
-
   if (MI->isImplicitDef()) {
     DupCopies.push_back(MI);
     return true;
diff --git a/test/CodeGen/ARM/pr13249.ll b/test/CodeGen/ARM/pr13249.ll
new file mode 100644
index 0000000000..4bc8810354
--- /dev/null
+++ b/test/CodeGen/ARM/pr13249.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s -mtriple armv7--linux-gnueabi
+
+define arm_aapcscc i8* @__strtok_r_1c(i8* %arg, i8 signext %arg1, i8** nocapture %arg2) nounwind {
+bb:
+  br label %bb3
+
+bb3:                                              ; preds = %bb3, %bb
+  %tmp = phi i8* [ %tmp5, %bb3 ], [ %arg, %bb ]
+  %tmp4 = load i8* %tmp, align 1
+  %tmp5 = getelementptr inbounds i8* %tmp, i32 1
+  br i1 undef, label %bb3, label %bb7
+
+bb7:                                              ; preds = %bb13, %bb3
+  %tmp8 = phi i8 [ %tmp14, %bb13 ], [ %tmp4, %bb3 ]
+  %tmp9 = phi i8* [ %tmp12, %bb13 ], [ %tmp, %bb3 ]
+  %tmp10 = icmp ne i8 %tmp8, %arg1
+  %tmp12 = getelementptr inbounds i8* %tmp9, i32 1
+  br i1 %tmp10, label %bb13, label %bb15
+
+bb13:                                             ; preds = %bb7
+  %tmp14 = load i8* %tmp12, align 1
+  br label %bb7
+
+bb15:                                             ; preds = %bb7
+  store i8* %tmp9, i8** %arg2, align 4
+  ret i8* %tmp
+}