; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt %s -simplifycfg -S | FileCheck %s declare i32 @f(i32) define i32 @basic(i32 %x) { ; CHECK-LABEL: @basic( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[X_OFF:%.*]] = add i32 [[X:%.*]], -5 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i32 [[X_OFF]], 3 ; CHECK-NEXT: br i1 [[SWITCH]], label [[A:%.*]], label [[DEFAULT:%.*]] ; CHECK: default: ; CHECK-NEXT: [[TMP0:%.*]] = call i32 @f(i32 0) ; CHECK-NEXT: ret i32 [[TMP0]] ; CHECK: a: ; CHECK-NEXT: [[TMP1:%.*]] = call i32 @f(i32 1) ; CHECK-NEXT: ret i32 [[TMP1]] ; entry: switch i32 %x, label %default [ i32 5, label %a i32 6, label %a i32 7, label %a ] default: %0 = call i32 @f(i32 0) ret i32 %0 a: %1 = call i32 @f(i32 1) ret i32 %1 } define i32 @unreachable(i32 %x) { ; CHECK-LABEL: @unreachable( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[X_OFF:%.*]] = add i32 [[X:%.*]], -5 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i32 [[X_OFF]], 3 ; CHECK-NEXT: br i1 [[SWITCH]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[TMP0:%.*]] = call i32 @f(i32 0) ; CHECK-NEXT: ret i32 [[TMP0]] ; CHECK: b: ; CHECK-NEXT: [[TMP1:%.*]] = call i32 @f(i32 1) ; CHECK-NEXT: ret i32 [[TMP1]] ; entry: switch i32 %x, label %unreachable [ i32 5, label %a i32 6, label %a i32 7, label %a i32 10, label %b i32 20, label %b i32 30, label %b i32 40, label %b ] unreachable: unreachable a: %0 = call i32 @f(i32 0) ret i32 %0 b: %1 = call i32 @f(i32 1) ret i32 %1 } define i32 @unreachable2(i32 %x) { ; CHECK-LABEL: @unreachable2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[X_OFF:%.*]] = add i32 [[X:%.*]], -5 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i32 [[X_OFF]], 3 ; CHECK-NEXT: br i1 [[SWITCH]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[TMP0:%.*]] = call i32 @f(i32 0) ; CHECK-NEXT: ret i32 [[TMP0]] ; CHECK: b: ; CHECK-NEXT: [[TMP1:%.*]] = call i32 @f(i32 1) ; CHECK-NEXT: ret i32 [[TMP1]] ; entry: ; Note: folding the most popular case destination into the default ; would prevent switch-to-icmp here. switch i32 %x, label %unreachable [ i32 5, label %a i32 6, label %a i32 7, label %a i32 10, label %b i32 20, label %b ] unreachable: unreachable a: %0 = call i32 @f(i32 0) ret i32 %0 b: %1 = call i32 @f(i32 1) ret i32 %1 } ; This would crash because we did not clean up the ; default block of the switch before removing the switch. define void @PR42737(i32* %a, i1 %c) { ; CHECK-LABEL: @PR42737( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TMP0:%.*]] = xor i1 [[C:%.*]], true ; CHECK-NEXT: call void @llvm.assume(i1 [[TMP0]]) ; CHECK-NEXT: unreachable ; entry: br i1 %c, label %switch, label %else else: store i32 2, i32* %a br label %switch switch: %cleanup.dest1 = phi i32 [ 0, %else ], [ 3, %entry ] switch i32 %cleanup.dest1, label %unreach1 [ i32 0, label %cleanup1 i32 3, label %cleanup2 ] cleanup1: br label %unreach2 cleanup2: br label %unreach2 unreach1: %phi2 = phi i32 [ %cleanup.dest1, %switch ] unreachable unreach2: unreachable }