[llvm-commits] [llvm] r95339 - in /llvm/trunk: lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp test/CodeGen/X86/2010-02-04-SchedulerBug.ll

[Evan Cheng]

Author: evancheng
Date: Thu Feb  4 19:27:11 2010
New Revision: 95339

URL: http://llvm.org/viewvc/llvm-project?rev=95339&view=rev
Log:
When the scheduler unfold a load folding instruction it move some of the predecessors to the unfolded load. It decides what gets moved to the load by checking whether the new load is using the predecessor as an operand. The check neglects the cases whether the predecessor is a flagged scheduling unit.
rdar://7604000

Added:
    llvm/trunk/test/CodeGen/X86/2010-02-04-SchedulerBug.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp?rev=95339&r1=95338&r2=95339&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Thu Feb  4 19:27:11 2010
@@ -345,6 +345,15 @@
   ++NumBacktracks;
 }
 
+static bool isOperandOf(const SUnit *SU, SDNode *N) {
+  for (const SDNode *SUNode = SU->getNode(); SUNode;
+       SUNode = SUNode->getFlaggedNode()) {
+    if (SUNode->isOperandOf(N))
+      return true;
+  }
+  return false;
+}
+
 /// CopyAndMoveSuccessors - Clone the specified node and move its scheduled
 /// successors to the newly created node.
 SUnit *ScheduleDAGRRList::CopyAndMoveSuccessors(SUnit *SU) {
@@ -427,8 +436,7 @@
          I != E; ++I) {
       if (I->isCtrl())
         ChainPreds.push_back(*I);
-      else if (I->getSUnit()->getNode() &&
-               I->getSUnit()->getNode()->isOperandOf(LoadNode))
+      else if (isOperandOf(I->getSUnit(), LoadNode))
         LoadPreds.push_back(*I);
       else
         NodePreds.push_back(*I);

Added: llvm/trunk/test/CodeGen/X86/2010-02-04-SchedulerBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2010-02-04-SchedulerBug.ll?rev=95339&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2010-02-04-SchedulerBug.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2010-02-04-SchedulerBug.ll Thu Feb  4 19:27:11 2010
@@ -0,0 +1,28 @@
+; RUN: llc < %s -mtriple=i386-apple-darwin11
+; rdar://7604000
+
+%struct.a_t = type { i8*, i64*, i8*, i32, i32, i64*, i64*, i64* }
+%struct.b_t = type { i32, i32, i32, i32, i64, i64, i64, i64 }
+
+define void @t(i32 %cNum, i64 %max) nounwind optsize ssp noimplicitfloat {
+entry:
+  %0 = load %struct.b_t** null, align 4 ; <%struct.b_t*> [#uses=1]
+  %1 = getelementptr inbounds %struct.b_t* %0, i32 %cNum, i32 5 ; <i64*> [#uses=1]
+  %2 = load i64* %1, align 4                      ; <i64> [#uses=1]
+  %3 = icmp ult i64 %2, %max            ; <i1> [#uses=1]
+  %4 = getelementptr inbounds %struct.a_t* null, i32 0, i32 7 ; <i64**> [#uses=1]
+  %5 = load i64** %4, align 4                     ; <i64*> [#uses=0]
+  %6 = load i64* null, align 4                    ; <i64> [#uses=1]
+  br i1 %3, label %bb2, label %bb
+
+bb:                                               ; preds = %entry
+  br label %bb3
+
+bb2:                                              ; preds = %entry
+  %7 = or i64 %6, undef                           ; <i64> [#uses=1]
+  br label %bb3
+
+bb3:                                              ; preds = %bb2, %bb
+  %misc_enables.0 = phi i64 [ undef, %bb ], [ %7, %bb2 ] ; <i64> [#uses=0]
+  ret void
+}