From 97e6992e3ecfd354a53142f0488769b399242295 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Tue, 13 Apr 2010 18:37:58 +0000
Subject: [PATCH] Temporarily revert r101075, it's causing invalid iterator
 assertions in a nightly tester.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101158 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86InstrInfo.cpp | 47 +--------------------------------
 test/CodeGen/X86/brcond.ll      | 39 ---------------------------
 2 files changed, 1 insertion(+), 85 deletions(-)

diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 094164ec7cf..e67bf3d7ad2 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -1684,7 +1684,6 @@ bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
   // Start from the bottom of the block and work up, examining the
   // terminator instructions.
   MachineBasicBlock::iterator I = MBB.end();
-  MachineBasicBlock::iterator UnCondBrIter = MBB.end();
   while (I != MBB.begin()) {
     --I;
     if (I->isDebugValue())
@@ -1702,8 +1701,6 @@ bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
 
     // Handle unconditional branches.
     if (I->getOpcode() == X86::JMP_4) {
-      UnCondBrIter = I;
-
       if (!AllowModify) {
         TBB = I->getOperand(0).getMBB();
         continue;
@@ -1721,11 +1718,10 @@ bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
         TBB = 0;
         I->eraseFromParent();
         I = MBB.end();
-        UnCondBrIter = MBB.end();
         continue;
       }
 
-      // TBB is used to indicate the unconditional destination.
+      // TBB is used to indicate the unconditinal destination.
       TBB = I->getOperand(0).getMBB();
       continue;
     }
@@ -1737,48 +1733,7 @@ bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
 
     // Working from the bottom, handle the first conditional branch.
     if (Cond.empty()) {
-      MachineBasicBlock *TargetBB = I->getOperand(0).getMBB();
-      if (AllowModify && UnCondBrIter != MBB.end() &&
-          MBB.isLayoutSuccessor(TargetBB)) {
-        // If we can modify the code and it ends in something like:
-        //
-        //     jCC L1
-        //     jmp L2
-        //   L1:
-        //     ...
-        //   L2:
-        //
-        // Then we can change this to:
-        //
-        //     jnCC L2
-        //   L1:
-        //     ...
-        //   L2:
-        //
-        // Which is a bit more efficient.
-        // We conditionally jump to the fall-through block.
-        BranchCode = GetOppositeBranchCondition(BranchCode);
-        unsigned JNCC = GetCondBranchFromCond(BranchCode);
-        MachineBasicBlock::iterator OldInst = I;
-        --I;
-
-        BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(JNCC))
-          .addMBB(UnCondBrIter->getOperand(0).getMBB());
-        BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(X86::JMP_4))
-          .addMBB(TargetBB);
-        MBB.addSuccessor(TargetBB);
-
-        OldInst->eraseFromParent();
-        UnCondBrIter->eraseFromParent();
-
-        // Restart the analysis.
-        UnCondBrIter = MBB.end();
-        I = MBB.end();
-        continue;
-      }
-
       FBB = TBB;
-      TBB = TargetBB;
       TBB = I->getOperand(0).getMBB();
       Cond.push_back(MachineOperand::CreateImm(BranchCode));
       continue;
diff --git a/test/CodeGen/X86/brcond.ll b/test/CodeGen/X86/brcond.ll
index 14ee9e50fa8..130483ad841 100644
--- a/test/CodeGen/X86/brcond.ll
+++ b/test/CodeGen/X86/brcond.ll
@@ -67,42 +67,3 @@ return:                                           ; preds = %entry
 ; CHECK-NEXT:	orl	8(%esp), %eax
 ; CHECK-NEXT:	je	LBB3_2
 }
-
-; <rdar://problem/7598384>:
-;
-;    jCC  L1
-;    jmp  L2
-; L1:
-;   ...
-; L2:
-;   ...
-;
-; to:
-; 
-;    jnCC L2
-; L1:
-;   ...
-; L2:
-;   ...
-define float @test4(float %x, float %y) nounwind readnone optsize ssp {
-entry:
-  %0 = fpext float %x to double                   ; <double> [#uses=1]
-  %1 = fpext float %y to double                   ; <double> [#uses=1]
-  %2 = fmul double %0, %1                         ; <double> [#uses=3]
-  %3 = fcmp oeq double %2, 0.000000e+00           ; <i1> [#uses=1]
-  br i1 %3, label %bb2, label %bb1
-
-; CHECK:      jne
-; CHECK-NEXT: jnp
-; CHECK-NOT:  jmp
-; CHECK:      LBB
-
-bb1:                                              ; preds = %entry
-  %4 = fadd double %2, -1.000000e+00              ; <double> [#uses=1]
-  br label %bb2
-
-bb2:                                              ; preds = %entry, %bb1
-  %.0.in = phi double [ %4, %bb1 ], [ %2, %entry ] ; <double> [#uses=1]
-  %.0 = fptrunc double %.0.in to float            ; <float> [#uses=1]
-  ret float %.0
-}
-- 
2.34.1