1; RUN: opt -S -jump-threading < %s | FileCheck %s 2 3declare void @foo() 4declare void @bar() 5declare void @baz() 6declare void @quux() 7 8 9; Jump threading of branch with select as condition. 10; Mostly theoretical since instruction combining simplifies all selects of 11; booleans where at least one operand is true/false/undef. 12 13; CHECK: @test_br 14; CHECK-NEXT: entry: 15; CHECK-NEXT: br i1 %cond, label %L1, 16define void @test_br(i1 %cond, i1 %value) nounwind { 17entry: 18 br i1 %cond, label %L0, label %L3 19L0: 20 %expr = select i1 %cond, i1 true, i1 %value 21 br i1 %expr, label %L1, label %L2 22 23L1: 24 call void @foo() 25 ret void 26L2: 27 call void @bar() 28 ret void 29L3: 30 call void @baz() 31 br label %L0 32} 33 34 35; Jump threading of switch with select as condition. 36 37; CHECK: @test_switch 38; CHECK-NEXT: entry: 39; CHECK-NEXT: br i1 %cond, label %L1, 40define void @test_switch(i1 %cond, i8 %value) nounwind { 41entry: 42 br i1 %cond, label %L0, label %L4 43L0: 44 %expr = select i1 %cond, i8 1, i8 %value 45 switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2] 46 47L1: 48 call void @foo() 49 ret void 50L2: 51 call void @bar() 52 ret void 53L3: 54 call void @baz() 55 ret void 56L4: 57 call void @quux() 58 br label %L0 59} 60 61; Make sure the blocks in the indirectbr test aren't trivially removable as 62; successors by taking their addresses. 63@anchor = constant [3 x i8*] [ 64 i8* blockaddress(@test_indirectbr, %L1), 65 i8* blockaddress(@test_indirectbr, %L2), 66 i8* blockaddress(@test_indirectbr, %L3) 67] 68 69 70; Jump threading of indirectbr with select as address. 71 72; CHECK: @test_indirectbr 73; CHECK-NEXT: entry: 74; CHECK-NEXT: br i1 %cond, label %L1, label %L3 75define void @test_indirectbr(i1 %cond, i8* %address) nounwind { 76entry: 77 br i1 %cond, label %L0, label %L3 78L0: 79 %indirect.goto.dest = select i1 %cond, i8* blockaddress(@test_indirectbr, %L1), i8* %address 80 indirectbr i8* %indirect.goto.dest, [label %L1, label %L2, label %L3] 81 82L1: 83 call void @foo() 84 ret void 85L2: 86 call void @bar() 87 ret void 88L3: 89 call void @baz() 90 ret void 91} 92 93 94; A more complicated case: the condition is a select based on a comparison. 95 96; CHECK: @test_switch_cmp 97; CHECK-NEXT: entry: 98; CHECK-NEXT: br i1 %cond, label %L0, label %[[THREADED:[A-Za-z.0-9]+]] 99; CHECK: [[THREADED]]: 100; CHECK-NEXT: call void @quux 101; CHECK-NEXT: br label %L1 102define void @test_switch_cmp(i1 %cond, i32 %val, i8 %value) nounwind { 103entry: 104 br i1 %cond, label %L0, label %L4 105L0: 106 %val.phi = phi i32 [%val, %entry], [-1, %L4] 107 %cmp = icmp slt i32 %val.phi, 0 108 %expr = select i1 %cmp, i8 1, i8 %value 109 switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2] 110 111L1: 112 call void @foo() 113 ret void 114L2: 115 call void @bar() 116 ret void 117L3: 118 call void @baz() 119 ret void 120L4: 121 call void @quux() 122 br label %L0 123} 124 125; Make sure the edge value of %0 from entry to L2 includes 0 and L3 is 126; reachable. 127; CHECK: test_switch_default 128; CHECK: entry: 129; CHECK: load 130; CHECK: switch 131; CHECK: [[THREADED:[A-Za-z.0-9]+]]: 132; CHECK: store 133; CHECK: br 134; CHECK: L2: 135; CHECK: icmp 136define void @test_switch_default(i32* nocapture %status) nounwind { 137entry: 138 %0 = load i32* %status, align 4 139 switch i32 %0, label %L2 [ 140 i32 5061, label %L1 141 i32 0, label %L2 142 ] 143 144L1: 145 store i32 10025, i32* %status, align 4 146 br label %L2 147 148L2: 149 %1 = load i32* %status, align 4 150 %cmp57.i = icmp eq i32 %1, 0 151 br i1 %cmp57.i, label %L3, label %L4 152 153L3: 154 store i32 10000, i32* %status, align 4 155 br label %L4 156 157L4: 158 ret void 159} 160