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1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 22; RUN: opt -S -passes=jump-threading %s | FileCheck %s3 4; Value of predicate known on all inputs (trivial case)5; Note: InstCombine/EarlyCSE would also get this case6define void @test(ptr %p, ptr %addr) {7; CHECK-LABEL: define void @test8; CHECK-SAME: (ptr [[P:%.*]], ptr [[ADDR:%.*]]) {9; CHECK-NEXT: entry:10; CHECK-NEXT: [[CMP0:%.*]] = icmp eq ptr [[P]], null11; CHECK-NEXT: br i1 [[CMP0]], label [[EXIT:%.*]], label [[LOOP:%.*]]12; CHECK: loop:13; CHECK-NEXT: [[P1:%.*]] = phi ptr [ [[P]], [[ENTRY:%.*]] ], [ [[P1]], [[LOOP]] ]14; CHECK-NEXT: br label [[LOOP]]15; CHECK: exit:16; CHECK-NEXT: ret void17;18entry:19 %cmp0 = icmp eq ptr %p, null20 br i1 %cmp0, label %exit, label %loop21loop:22 %p1 = phi ptr [%p, %entry], [%p1, %loop]23 %cmp1 = icmp eq ptr %p1, null24 br i1 %cmp1, label %exit, label %loop25exit:26 ret void27}28 29; Value of predicate known on all inputs (non-trivial)30define void @test2(ptr %p) {31; CHECK-LABEL: define void @test232; CHECK-SAME: (ptr [[P:%.*]]) {33; CHECK-NEXT: entry:34; CHECK-NEXT: [[CMP0:%.*]] = icmp eq ptr [[P]], null35; CHECK-NEXT: br i1 [[CMP0]], label [[EXIT:%.*]], label [[BACKEDGE:%.*]]36; CHECK: backedge:37; CHECK-NEXT: [[P1:%.*]] = phi ptr [ [[P]], [[ENTRY:%.*]] ], [ [[P2:%.*]], [[BACKEDGE]] ]38; CHECK-NEXT: [[P2]] = load ptr, ptr [[P1]], align 839; CHECK-NEXT: [[CMP2:%.*]] = icmp eq ptr [[P2]], null40; CHECK-NEXT: br i1 [[CMP2]], label [[EXIT]], label [[BACKEDGE]]41; CHECK: exit:42; CHECK-NEXT: ret void43;44entry:45 %cmp0 = icmp eq ptr %p, null46 br i1 %cmp0, label %exit, label %loop47loop:48 %p1 = phi ptr [%p, %entry], [%p2, %backedge]49 %cmp1 = icmp eq ptr %p1, null50 br i1 %cmp1, label %exit, label %backedge51backedge:52 %p2 = load ptr, ptr %p153 %cmp2 = icmp eq ptr %p2, null54 br i1 %cmp2, label %exit, label %loop55exit:56 ret void57}58 59; If the inputs don't branch the same way, we can't rewrite60; Well, we could unroll this loop exactly twice, but that's61; a different transform.62define void @test_mixed(ptr %p) {63; CHECK-LABEL: define void @test_mixed64; CHECK-SAME: (ptr [[P:%.*]]) {65; CHECK-NEXT: entry:66; CHECK-NEXT: [[CMP0:%.*]] = icmp eq ptr [[P]], null67; CHECK-NEXT: br i1 [[CMP0]], label [[EXIT:%.*]], label [[LOOP:%.*]]68; CHECK: loop:69; CHECK-NEXT: br label [[EXIT]]70; CHECK: exit:71; CHECK-NEXT: ret void72;73entry:74 %cmp0 = icmp eq ptr %p, null75 br i1 %cmp0, label %exit, label %loop76loop:77 %p1 = phi ptr [%p, %entry], [%p1, %loop]78 %cmp1 = icmp ne ptr %p1, null79 br i1 %cmp1, label %exit, label %loop80exit:81 ret void82}83 84; The eq predicate is always true if we go through the path from85; L1 to L3, no matter the phi result %t5 is on the lhs or rhs of86; the predicate.87declare void @goo()88declare void @hoo()89 90define void @test3(i32 %m, ptr %t1) {91; CHECK-LABEL: define void @test392; CHECK-SAME: (i32 [[M:%.*]], ptr [[T1:%.*]]) {93; CHECK-NEXT: L1:94; CHECK-NEXT: [[T0:%.*]] = add i32 [[M]], 795; CHECK-NEXT: [[T2:%.*]] = load ptr, ptr [[T1]], align 896; CHECK-NEXT: [[T3:%.*]] = icmp eq ptr [[T2]], null97; CHECK-NEXT: br i1 [[T3]], label [[L4:%.*]], label [[L3:%.*]]98; CHECK: L3:99; CHECK-NEXT: [[T4:%.*]] = load i32, ptr [[T2]], align 4100; CHECK-NEXT: [[T6:%.*]] = icmp eq i32 [[T0]], [[T4]]101; CHECK-NEXT: br i1 [[T6]], label [[L4]], label [[L5:%.*]]102; CHECK: L4:103; CHECK-NEXT: call void @goo()104; CHECK-NEXT: ret void105; CHECK: L5:106; CHECK-NEXT: call void @hoo()107; CHECK-NEXT: ret void108;109L1:110 %t0 = add i32 %m, 7111 %t2 = load ptr, ptr %t1, align 8112 113 %t3 = icmp eq ptr %t2, null114 br i1 %t3, label %L3, label %L2115 116L2:117 %t4 = load i32, ptr %t2, align 4118 br label %L3119 120L3:121 %t5 = phi i32 [ %t0, %L1 ], [ %t4, %L2 ]122 %t6 = icmp eq i32 %t0, %t5123 br i1 %t6, label %L4, label %L5124 125L4:126 call void @goo()127 ret void128 129L5:130 call void @hoo()131 ret void132}133