diff options
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 47 | ||||
| -rw-r--r-- | test/CodeGen/X86/brcond.ll | 39 |
2 files changed, 1 insertions, 85 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 094164e..e67bf3d 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 14ee9e5..130483a 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 -} |