[llvm-commits] [llvm] r106793 - in /llvm/trunk: lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp test/CodeGen/ARM/flag-crash.ll

[Bill Wendling]

Author: void
Date: Thu Jun 24 17:00:37 2010
New Revision: 106793

URL: http://llvm.org/viewvc/llvm-project?rev=106793&view=rev
Log:
It's possible that a flag is added to the SDNode that points back to the
original SDNode. This is badness. Also, this function allows one SDNode to point
multiple flags to another SDNode. Badness as well.

Added:
    llvm/trunk/test/CodeGen/ARM/flag-crash.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp?rev=106793&r1=106792&r2=106793&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp Thu Jun 24 17:00:37 2010
@@ -110,18 +110,25 @@
 static void AddFlags(SDNode *N, SDValue Flag, bool AddFlag,
                      SelectionDAG *DAG) {
   SmallVector<EVT, 4> VTs;
+  SDNode *FlagDestNode = Flag.getNode();
 
-  for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
-    VTs.push_back(N->getValueType(i));
+  // Don't add a flag from a node to itself.
+  if (FlagDestNode == N) return;
+
+  // Don't add a flag to something which already has a flag.
+  if (N->getValueType(N->getNumValues() - 1) == MVT::Flag) return;
+
+  for (unsigned I = 0, E = N->getNumValues(); I != E; ++I)
+    VTs.push_back(N->getValueType(I));
 
   if (AddFlag)
     VTs.push_back(MVT::Flag);
 
   SmallVector<SDValue, 4> Ops;
-  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
-    Ops.push_back(N->getOperand(i));
+  for (unsigned I = 0, E = N->getNumOperands(); I != E; ++I)
+    Ops.push_back(N->getOperand(I));
 
-  if (Flag.getNode())
+  if (FlagDestNode)
     Ops.push_back(Flag);
 
   SDVTList VTList = DAG->getVTList(&VTs[0], VTs.size());
@@ -213,16 +220,17 @@
   // Cluster loads by adding MVT::Flag outputs and inputs. This also
   // ensure they are scheduled in order of increasing addresses.
   SDNode *Lead = Loads[0];
-  AddFlags(Lead, SDValue(0,0), true, DAG);
+  AddFlags(Lead, SDValue(0, 0), true, DAG);
+
+  SDValue InFlag = SDValue(Lead, Lead->getNumValues() - 1);
+  for (unsigned I = 1, E = Loads.size(); I != E; ++I) {
+    bool OutFlag = I < E - 1;
+    SDNode *Load = Loads[I];
 
-  SDValue InFlag = SDValue(Lead, Lead->getNumValues()-1);
-  for (unsigned i = 1, e = Loads.size(); i != e; ++i) {
-    bool OutFlag = i < e-1;
-    SDNode *Load = Loads[i];
     AddFlags(Load, InFlag, OutFlag, DAG);
 
     if (OutFlag)
-      InFlag = SDValue(Load, Load->getNumValues()-1);
+      InFlag = SDValue(Load, Load->getNumValues() - 1);
 
     ++LoadsClustered;
   }

Added: llvm/trunk/test/CodeGen/ARM/flag-crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/flag-crash.ll?rev=106793&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/flag-crash.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/flag-crash.ll Thu Jun 24 17:00:37 2010
@@ -0,0 +1,27 @@
+; RUN: llc < %s -O3 -mtriple=thumbv7-apple-darwin10 -mcpu=cortex-a8 -relocation-model=pic
+; PR7484
+
+%struct.gs_matrix = type { float, i32, float, i32, float, i32, float, i32, float, i32, float, i32 }
+
+define fastcc void @func(%struct.gs_matrix* nocapture %pm1) nounwind {
+entry:
+  %0 = getelementptr inbounds %struct.gs_matrix* %pm1, i32 0, i32 6
+  %1 = load float* %0, align 4
+  %2 = getelementptr inbounds %struct.gs_matrix* %pm1, i32 0, i32 8
+  %3 = load float* %2, align 4
+  %4 = getelementptr inbounds %struct.gs_matrix* %pm1, i32 0, i32 2
+  %5 = bitcast float* %4 to i32*
+  %6 = load i32* %5, align 4
+  %7 = or i32 0, %6
+  %.mask = and i32 %7, 2147483647
+  %8 = icmp eq i32 %.mask, 0
+  br i1 %8, label %bb, label %bb11
+
+bb:
+  ret void
+
+bb11:
+  %9 = fmul float %1, undef
+  %10 = fmul float %3, undef
+  ret void
+}