Index: llvm/lib/Target/SystemZ/SystemZISelLowering.h =================================================================== --- llvm/lib/Target/SystemZ/SystemZISelLowering.h +++ llvm/lib/Target/SystemZ/SystemZISelLowering.h @@ -423,6 +423,7 @@ return TargetLoweringBase::getPreferredVectorAction(VT); } bool isCheapToSpeculateCtlz() const override { return true; } + bool preferZeroCompareBranch() const override { return true; } EVT getSetCCResultType(const DataLayout &DL, LLVMContext &, EVT) const override; bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF, Index: llvm/test/CodeGen/SystemZ/codegenprepare-form-OF-ops.ll =================================================================== --- llvm/test/CodeGen/SystemZ/codegenprepare-form-OF-ops.ll +++ llvm/test/CodeGen/SystemZ/codegenprepare-form-OF-ops.ll @@ -52,3 +52,41 @@ %tmp12 = select i1 %tmp10, i64 %tmp11, i64 %arg ret i64 %tmp12 } + +define i32 @optbranch_32(i32 %Arg) { +; CHECK-LABEL: optbranch_32: +; CHECK: alhsik %r2, %r2, 1 +; CHECK-NEXT: bler %r14 +; CHECK-NEXT: .LBB4_1: +; CHECK-NEXT: lhi %r2, -1 +; CHECK-NEXT: br %r14 +bb: + %i1 = icmp eq i32 %Arg, -1 + br i1 %i1, label %bb2, label %bb3 + +bb2: + ret i32 -1 + +bb3: + %i4 = add nuw i32 %Arg, 1 + ret i32 %i4 +} + +define i64 @optbranch_64(i64 %Arg) { +; CHECK-LABEL: optbranch_64: +; CHECK: alghsik %r2, %r2, 1 +; CHECK-NEXT: bler %r14 +; CHECK-NEXT: .LBB5_1: +; CHECK-NEXT: lghi %r2, -1 +; CHECK-NEXT: br %r14 +bb: + %i1 = icmp eq i64 %Arg, -1 + br i1 %i1, label %bb2, label %bb3 + +bb2: + ret i64 -1 + +bb3: + %i4 = add nuw i64 %Arg, 1 + ret i64 %i4 +}