; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt %s -S -passes='simplify-cfg' -simplifycfg-require-and-preserve-domtree=1 | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" declare void @foo(i32) define void @test(i1 %a) { ; CHECK-LABEL: @test( ; CHECK-NEXT: [[A_OFF:%.*]] = add i1 [[A:%.*]], true ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i1 [[A_OFF]], true ; CHECK-NEXT: br i1 [[SWITCH]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: false: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; switch i1 %a, label %default [i1 1, label %true i1 0, label %false] true: call void @foo(i32 1) ret void false: call void @foo(i32 3) ret void default: call void @foo(i32 2) ret void } define void @test2(i2 %a) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: switch i2 [[A:%.*]], label [[DEFAULT1:%.*]] [ ; CHECK-NEXT: i2 0, label [[CASE0:%.*]] ; CHECK-NEXT: i2 1, label [[CASE1:%.*]] ; CHECK-NEXT: i2 -2, label [[CASE2:%.*]] ; CHECK-NEXT: i2 -1, label [[CASE3:%.*]] ; CHECK-NEXT: ] ; CHECK: case0: ; CHECK-NEXT: call void @foo(i32 0) ; CHECK-NEXT: ret void ; CHECK: case1: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: case2: ; CHECK-NEXT: call void @foo(i32 2) ; CHECK-NEXT: ret void ; CHECK: case3: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; CHECK: default1: ; CHECK-NEXT: unreachable ; switch i2 %a, label %default [i2 0, label %case0 i2 1, label %case1 i2 2, label %case2 i2 3, label %case3] case0: call void @foo(i32 0) ret void case1: call void @foo(i32 1) ret void case2: call void @foo(i32 2) ret void case3: call void @foo(i32 3) ret void default: call void @foo(i32 4) ret void } ; This one is a negative test - we know the value of the default, ; but that's about it define void @test3(i2 %a) { ; CHECK-LABEL: @test3( ; CHECK-NEXT: switch i2 [[A:%.*]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i2 0, label [[CASE0:%.*]] ; CHECK-NEXT: i2 1, label [[CASE1:%.*]] ; CHECK-NEXT: i2 -2, label [[CASE2:%.*]] ; CHECK-NEXT: ] ; CHECK: case0: ; CHECK-NEXT: call void @foo(i32 0) ; CHECK-NEXT: ret void ; CHECK: case1: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: case2: ; CHECK-NEXT: call void @foo(i32 2) ; CHECK-NEXT: ret void ; CHECK: default: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; switch i2 %a, label %default [i2 0, label %case0 i2 1, label %case1 i2 2, label %case2] case0: call void @foo(i32 0) ret void case1: call void @foo(i32 1) ret void case2: call void @foo(i32 2) ret void default: call void @foo(i32 3) ret void } ; Negative test - check for possible overflow when computing ; number of possible cases. define void @test4(i128 %a) { ; CHECK-LABEL: @test4( ; CHECK-NEXT: switch i128 [[A:%.*]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i128 0, label [[CASE0:%.*]] ; CHECK-NEXT: i128 1, label [[CASE1:%.*]] ; CHECK-NEXT: ] ; CHECK: case0: ; CHECK-NEXT: call void @foo(i32 0) ; CHECK-NEXT: ret void ; CHECK: case1: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: default: ; CHECK-NEXT: call void @foo(i32 2) ; CHECK-NEXT: ret void ; switch i128 %a, label %default [i128 0, label %case0 i128 1, label %case1] case0: call void @foo(i32 0) ret void case1: call void @foo(i32 1) ret void default: call void @foo(i32 2) ret void } ; All but one bit known zero define void @test5(i8 %a) { ; CHECK-LABEL: @test5( ; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A:%.*]], 2 ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[A_OFF:%.*]] = add i8 [[A]], -1 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i8 [[A_OFF]], 1 ; CHECK-NEXT: br i1 [[SWITCH]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: false: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; %cmp = icmp ult i8 %a, 2 call void @llvm.assume(i1 %cmp) switch i8 %a, label %default [i8 1, label %true i8 0, label %false] true: call void @foo(i32 1) ret void false: call void @foo(i32 3) ret void default: call void @foo(i32 2) ret void } ;; All but one bit known one define void @test6(i8 %a) { ; CHECK-LABEL: @test6( ; CHECK-NEXT: [[AND:%.*]] = and i8 [[A:%.*]], -2 ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[AND]], -2 ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[A_OFF:%.*]] = add i8 [[A]], 1 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i8 [[A_OFF]], 1 ; CHECK-NEXT: br i1 [[SWITCH]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: false: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; %and = and i8 %a, 254 %cmp = icmp eq i8 %and, 254 call void @llvm.assume(i1 %cmp) switch i8 %a, label %default [i8 255, label %true i8 254, label %false] true: call void @foo(i32 1) ret void false: call void @foo(i32 3) ret void default: call void @foo(i32 2) ret void } ; Check that we can eliminate both dead cases and dead defaults ; within a single run of simplify-cfg define void @test7(i8 %a) { ; CHECK-LABEL: @test7( ; CHECK-NEXT: [[AND:%.*]] = and i8 [[A:%.*]], -2 ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[AND]], -2 ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[A_OFF:%.*]] = add i8 [[A]], 1 ; CHECK-NEXT: [[SWITCH:%.*]] = icmp ult i8 [[A_OFF]], 1 ; CHECK-NEXT: br i1 [[SWITCH]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: ret void ; CHECK: false: ; CHECK-NEXT: call void @foo(i32 3) ; CHECK-NEXT: ret void ; %and = and i8 %a, 254 %cmp = icmp eq i8 %and, 254 call void @llvm.assume(i1 %cmp) switch i8 %a, label %default [i8 255, label %true i8 254, label %false i8 0, label %also_dead] true: call void @foo(i32 1) ret void false: call void @foo(i32 3) ret void also_dead: call void @foo(i32 5) ret void default: call void @foo(i32 2) ret void } declare void @llvm.assume(i1)