; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -instcombine --instcombine-max-iterations=0 -S | FileCheck %s --check-prefix=ZERO ; RUN: opt < %s -instcombine --instcombine-max-iterations=1 -S | FileCheck %s --check-prefix=ONE ; RUN: opt < %s -instcombine -S | FileCheck %s --check-prefix=FIXPOINT ; RUN: not opt < %s -instcombine -S --instcombine-infinite-loop-threshold=3 2>&1 | FileCheck %s --check-prefix=LOOP ; Based on xor-of-icmps-with-extra-uses.ll. This requires multiple iterations of ; InstCombine to reach a fixpoint. define i1 @v0_select_of_consts(i32 %X, i32* %selected) { ; ZERO-LABEL: @v0_select_of_consts( ; ZERO-NEXT: [[COND0:%.*]] = icmp sgt i32 [[X:%.*]], 32767 ; ZERO-NEXT: [[COND1:%.*]] = icmp sgt i32 [[X]], -32768 ; ZERO-NEXT: [[SELECT:%.*]] = select i1 [[COND0]], i32 32767, i32 -32768 ; ZERO-NEXT: store i32 [[SELECT]], i32* [[SELECTED:%.*]] ; ZERO-NEXT: [[RES:%.*]] = xor i1 [[COND0]], [[COND1]] ; ZERO-NEXT: ret i1 [[RES]] ; ONE-LABEL: @v0_select_of_consts( ; ONE-NEXT: [[COND0:%.*]] = icmp sle i32 [[X:%.*]], 32767 ; ONE-NEXT: [[COND0_NOT:%.*]] = xor i1 [[COND0]], true ; ONE-NEXT: [[COND1:%.*]] = icmp sgt i32 [[X]], -32768 ; ONE-NEXT: [[SELECT:%.*]] = select i1 [[COND0_NOT]], i32 32767, i32 -32768 ; ONE-NEXT: store i32 [[SELECT]], i32* [[SELECTED:%.*]], align 4 ; ONE-NEXT: [[TMP1:%.*]] = and i1 [[COND0]], [[COND1]] ; ONE-NEXT: ret i1 [[TMP1]] ; FIXPOINT-LABEL: @v0_select_of_consts( ; FIXPOINT-NEXT: [[COND0_INV:%.*]] = icmp sgt i32 [[X:%.*]], 32767 ; FIXPOINT-NEXT: [[SELECT:%.*]] = select i1 [[COND0_INV]], i32 32767, i32 -32768 ; FIXPOINT-NEXT: store i32 [[SELECT]], i32* [[SELECTED:%.*]], align 4 ; FIXPOINT-NEXT: [[X_OFF:%.*]] = add i32 [[X]], 32767 ; FIXPOINT-NEXT: [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65535 ; FIXPOINT-NEXT: ret i1 [[TMP1]] ; LOOP: LLVM ERROR: Instruction Combining seems stuck in an infinite loop after 3 iterations. %cond0 = icmp sgt i32 %X, 32767 %cond1 = icmp sgt i32 %X, -32768 %select = select i1 %cond0, i32 32767, i32 -32768 store i32 %select, i32* %selected %res = xor i1 %cond0, %cond1 ret i1 %res }