Fix a memory bug: increment an iterator of a deleted machine instr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48853 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 31 insertions, 2 deletions

diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index f81f3a7..b7de1cf 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -200,7 +200,8 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
   for (MachineFunction::iterator mbbi = MF.begin(), mbbe = MF.end();
        mbbi != mbbe; ++mbbi) {
     for (MachineBasicBlock::iterator mi = mbbi->begin(), me = mbbi->end();
-         mi != me; ++mi) {
+         mi != me; ) {
+      MachineBasicBlock::iterator nmi = next(mi);
       const TargetInstrDesc &TID = mi->getDesc();
 
       bool FirstTied = true;
@@ -298,7 +299,10 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
                   // then one instruction.
                   Sunk = Sink3AddrInstruction(mbbi, New, regB, mi);
                 mbbi->erase(mi);                 // Nuke the old inst.
-                if (!Sunk) mi = New;
+                if (!Sunk) {
+                  mi = New;
+                  nmi = next(mi);
+                }
                 ++NumConvertedTo3Addr;
                 // Done with this instruction.
                 break;
@@ -337,6 +341,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
 
         DOUT << "\t\trewrite to:\t"; DEBUG(mi->print(*cerr.stream(), &TM));
       }
+      mi = nmi;
     }
   }
 
diff --git a/test/CodeGen/X86/2008-03-25-TwoAddrPassBug.ll b/test/CodeGen/X86/2008-03-25-TwoAddrPassBug.ll
new file mode 100644
index 0000000..1e5ab99
--- /dev/null
+++ b/test/CodeGen/X86/2008-03-25-TwoAddrPassBug.ll
@@ -0,0 +1,24 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse2
+
+define void @t() {
+entry:
+	%tmp455 = shufflevector <4 x float> zeroinitializer, <4 x float> undef, <4 x i32> < i32 1, i32 0, i32 3, i32 2 >		; <<4 x float>> [#uses=1]
+	%tmp457 = mul <4 x float> zeroinitializer, %tmp455		; <<4 x float>> [#uses=2]
+	%tmp461 = shufflevector <4 x float> %tmp457, <4 x float> undef, <4 x i32> zeroinitializer		; <<4 x float>> [#uses=1]
+	%tmp465 = shufflevector <4 x float> %tmp457, <4 x float> undef, <4 x i32> < i32 1, i32 1, i32 1, i32 1 >		; <<4 x float>> [#uses=1]
+	%tmp466 = sub <4 x float> %tmp461, %tmp465		; <<4 x float>> [#uses=1]
+	%tmp536 = shufflevector <4 x float> zeroinitializer, <4 x float> %tmp466, <4 x i32> < i32 0, i32 4, i32 1, i32 5 >		; <<4 x float>> [#uses=1]
+	%tmp542 = shufflevector <4 x float> %tmp536, <4 x float> zeroinitializer, <4 x i32> < i32 6, i32 7, i32 2, i32 3 >		; <<4 x float>> [#uses=1]
+	%tmp580 = bitcast <4 x float> %tmp542 to <4 x i32>		; <<4 x i32>> [#uses=1]
+	%tmp582 = and <4 x i32> %tmp580, zeroinitializer		; <<4 x i32>> [#uses=1]
+	%tmp591 = or <4 x i32> %tmp582, zeroinitializer		; <<4 x i32>> [#uses=1]
+	%tmp592 = bitcast <4 x i32> %tmp591 to <4 x float>		; <<4 x float>> [#uses=1]
+	%tmp609 = fdiv <4 x float> < float 1.000000e+00, float 1.000000e+00, float 1.000000e+00, float 1.000000e+00 >, %tmp592		; <<4 x float>> [#uses=1]
+	%tmp652 = shufflevector <4 x float> %tmp609, <4 x float> undef, <4 x i32> < i32 3, i32 3, i32 3, i32 3 >		; <<4 x float>> [#uses=1]
+	%tmp662 = mul <4 x float> zeroinitializer, %tmp652		; <<4 x float>> [#uses=1]
+	%tmp678 = shufflevector <4 x float> %tmp662, <4 x float> undef, <4 x i32> < i32 1, i32 1, i32 1, i32 1 >		; <<4 x float>> [#uses=1]
+	%tmp753 = mul <4 x float> zeroinitializer, %tmp678		; <<4 x float>> [#uses=1]
+	%tmp754 = sub <4 x float> zeroinitializer, %tmp753		; <<4 x float>> [#uses=1]
+	store <4 x float> %tmp754, <4 x float>* null, align 16
+	unreachable
+}