; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s ; https://alive2.llvm.org/ce/z/5eCiWi define i8 @urem_assume(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_assume( ; CHECK-NEXT: [[X_FR:%.*]] = freeze i8 [[X:%.*]] ; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[X_FR]], [[N:%.*]] ; CHECK-NEXT: tail call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X_FR]], 1 ; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[ADD]], [[N]] ; CHECK-NEXT: [[OUT:%.*]] = select i1 [[TMP1]], i8 0, i8 [[ADD]] ; CHECK-NEXT: ret i8 [[OUT]] ; %cmp = icmp ult i8 %x, %n tail call void @llvm.assume(i1 %cmp) %add = add nuw i8 %x, 1 %out = urem i8 %add, %n ret i8 %out } ; https://alive2.llvm.org/ce/z/MGgtYN define i8 @urem_assume_without_nuw(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_assume_without_nuw( ; CHECK-NEXT: [[X_FR:%.*]] = freeze i8 [[X:%.*]] ; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[X_FR]], [[N:%.*]] ; CHECK-NEXT: tail call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X_FR]], 1 ; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[ADD]], [[N]] ; CHECK-NEXT: [[OUT:%.*]] = select i1 [[TMP1]], i8 0, i8 [[ADD]] ; CHECK-NEXT: ret i8 [[OUT]] ; %cmp = icmp ult i8 %x, %n tail call void @llvm.assume(i1 %cmp) %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out } ; Negative test: The assume is false define i8 @urem_assume_eq(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_assume_eq( ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[N:%.*]] ; CHECK-NEXT: tail call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 1 ; CHECK-NEXT: [[OUT:%.*]] = urem i8 [[ADD]], [[N]] ; CHECK-NEXT: ret i8 [[OUT]] ; %cmp = icmp eq i8 %x, %n tail call void @llvm.assume(i1 %cmp) %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out } ; Negative test: The assume is false define i8 @urem_assume_ne(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_assume_ne( ; CHECK-NEXT: start: ; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], [[N:%.*]] ; CHECK-NEXT: tail call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 1 ; CHECK-NEXT: [[OUT:%.*]] = urem i8 [[ADD]], [[N]] ; CHECK-NEXT: ret i8 [[OUT]] ; start: %cmp = icmp ne i8 %x, %n tail call void @llvm.assume(i1 %cmp) %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out } ; Negative test: The add constant is not 1 define i8 @urem_assume_with_unexpected_const(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_assume_with_unexpected_const( ; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]] ; CHECK-NEXT: tail call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 2 ; CHECK-NEXT: [[OUT:%.*]] = urem i8 [[ADD]], [[N]] ; CHECK-NEXT: ret i8 [[OUT]] ; %cmp = icmp ult i8 %x, %n tail call void @llvm.assume(i1 %cmp) %add = add i8 %x, 2 ; Transform only when the constant is 1 %out = urem i8 %add, %n ret i8 %out } ; https://alive2.llvm.org/ce/z/gNhZ2x define i8 @urem_without_assume(i8 %arg, i8 %arg2) { ; CHECK-LABEL: @urem_without_assume( ; CHECK-NEXT: [[X:%.*]] = urem i8 [[ARG:%.*]], [[ARG2:%.*]] ; CHECK-NEXT: [[X_FR:%.*]] = freeze i8 [[X]] ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X_FR]], 1 ; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[ADD]], [[ARG2]] ; CHECK-NEXT: [[OUT:%.*]] = select i1 [[TMP1]], i8 0, i8 [[ADD]] ; CHECK-NEXT: ret i8 [[OUT]] ; %x = urem i8 %arg, %arg2 %add = add i8 %x, 1 %out = urem i8 %add, %arg2 ret i8 %out } ; https://alive2.llvm.org/ce/z/eHkgRa define i8 @urem_with_dominating_condition(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_with_dominating_condition( ; CHECK-NEXT: start: ; CHECK-NEXT: [[X_FR:%.*]] = freeze i8 [[X:%.*]] ; CHECK-NEXT: [[COND:%.*]] = icmp ult i8 [[X_FR]], [[N:%.*]] ; CHECK-NEXT: br i1 [[COND]], label [[DOTBB0:%.*]], label [[DOTBB1:%.*]] ; CHECK: .bb0: ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X_FR]], 1 ; CHECK-NEXT: [[TMP0:%.*]] = icmp eq i8 [[ADD]], [[N]] ; CHECK-NEXT: [[OUT:%.*]] = select i1 [[TMP0]], i8 0, i8 [[ADD]] ; CHECK-NEXT: ret i8 [[OUT]] ; CHECK: .bb1: ; CHECK-NEXT: ret i8 0 ; start: %cond = icmp ult i8 %x, %n br i1 %cond, label %.bb0, label %.bb1 ; Should also works for a dominating condition .bb0: %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out .bb1: ret i8 0 } ; Revert the dominating condition and target branch at the same time. define i8 @urem_with_dominating_condition_false(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_with_dominating_condition_false( ; CHECK-NEXT: start: ; CHECK-NEXT: [[X_FR:%.*]] = freeze i8 [[X:%.*]] ; CHECK-NEXT: [[COND_NOT:%.*]] = icmp ult i8 [[X_FR]], [[N:%.*]] ; CHECK-NEXT: br i1 [[COND_NOT]], label [[DOTBB0:%.*]], label [[DOTBB1:%.*]] ; CHECK: .bb0: ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X_FR]], 1 ; CHECK-NEXT: [[TMP0:%.*]] = icmp eq i8 [[ADD]], [[N]] ; CHECK-NEXT: [[OUT:%.*]] = select i1 [[TMP0]], i8 0, i8 [[ADD]] ; CHECK-NEXT: ret i8 [[OUT]] ; CHECK: .bb1: ; CHECK-NEXT: ret i8 0 ; start: %cond = icmp uge i8 %x, %n br i1 %cond, label %.bb1, label %.bb0 ; Swap the branch targets .bb0: %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out .bb1: ret i8 0 } ; Negative test define noundef i8 @urem_with_opposite_condition(i8 %x, i8 %n) { ; CHECK-LABEL: @urem_with_opposite_condition( ; CHECK-NEXT: [[COND:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]] ; CHECK-NEXT: br i1 [[COND]], label [[DOTBB1:%.*]], label [[DOTBB0:%.*]] ; CHECK: .bb0: ; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 1 ; CHECK-NEXT: [[OUT:%.*]] = urem i8 [[ADD]], [[N]] ; CHECK-NEXT: ret i8 [[OUT]] ; CHECK: .bb1: ; CHECK-NEXT: ret i8 0 ; %cond = icmp ult i8 %x, %n br i1 %cond, label %.bb1, label %.bb0 ; Revert the condition .bb0: %add = add i8 %x, 1 %out = urem i8 %add, %n ret i8 %out .bb1: ret i8 0 } declare void @llvm.assume(i1 noundef)