1; RUN: opt < %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s 2 3; The rewriting needs to make %obj loop variant by inserting a phi 4; of the original value and it's relocation. 5 6declare i64 addrspace(1)* @generate_obj() "gc-leaf-function" 7 8declare void @use_obj(i64 addrspace(1)*) "gc-leaf-function" 9 10define void @def_use_safepoint() gc "statepoint-example" { 11; CHECK-LABEL: def_use_safepoint 12; CHECK: phi i64 addrspace(1)* 13; CHECK-DAG: [ %obj.relocated.casted, %loop ] 14; CHECK-DAG: [ %obj, %entry ] 15entry: 16 %obj = call i64 addrspace(1)* @generate_obj() 17 br label %loop 18 19loop: ; preds = %loop, %entry 20 call void @use_obj(i64 addrspace(1)* %obj) 21 call void @do_safepoint() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 22 br label %loop 23} 24 25declare void @do_safepoint() 26 27declare void @parse_point(i64 addrspace(1)*) 28 29define i64 addrspace(1)* @test1(i32 %caller, i8 addrspace(1)* %a, i8 addrspace(1)* %b, i32 %unknown) gc "statepoint-example" { 30; CHECK-LABEL: test1 31entry: 32 br i1 undef, label %left, label %right 33 34left: ; preds = %entry 35; CHECK: left: 36; CHECK-NEXT: %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 37; CHECK-NEXT: [[CAST_L:%.*]] = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 38; Our safepoint placement pass calls removeUnreachableBlocks, which does a bunch 39; of simplifications to branch instructions. This bug is visible only when 40; there are multiple branches into the same block from the same predecessor, and 41; the following ceremony is to make that artefact survive a call to 42; removeUnreachableBlocks. As an example, "br i1 undef, label %merge, label %merge" 43; will get simplified to "br label %merge" by removeUnreachableBlocks. 44 %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 45 switch i32 %unknown, label %right [ 46 i32 0, label %merge 47 i32 1, label %merge 48 i32 5, label %merge 49 i32 3, label %right 50 ] 51 52right: ; preds = %left, %left, %entry 53; CHECK: right: 54; CHECK-NEXT: %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 55; CHECK-NEXT: [[CAST_R:%.*]] = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 56 %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 57 br label %merge 58 59merge: ; preds = %right, %left, %left, %left 60; CHECK: merge: 61; CHECK-NEXT: %value.base = phi i64 addrspace(1)* [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_R]], %right ], !is_base_value !0 62 %value = phi i64 addrspace(1)* [ %a.cast, %left ], [ %a.cast, %left ], [ %a.cast, %left ], [ %b.cast, %right ] 63 call void @parse_point(i64 addrspace(1)* %value) [ "deopt"(i32 0, i32 0, i32 0, i32 0, i32 0) ] 64 ret i64 addrspace(1)* %value 65} 66 67;; The purpose of this test is to ensure that when two live values share a 68;; base defining value with inherent conflicts, we end up with a *single* 69;; base phi/select per such node. This is testing an optimization, not a 70;; fundemental correctness criteria 71define void @test2(i1 %cnd, i64 addrspace(1)* %base_obj, i64 addrspace(1)* %base_arg2) gc "statepoint-example" { 72; CHECK-LABEL: @test2 73entry: 74 %obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1 75 br label %loop 76; CHECK-LABEL: loop 77; CHECK: %current.base = phi i64 addrspace(1)* 78; CHECK-DAG: [ %base_obj, %entry ] 79 80; Given the two selects are equivelent, so are their base phis - ideally, 81; we'd have commoned these, but that's a missed optimization, not correctness. 82; CHECK-DAG: [ [[DISCARD:%.*.base.relocated.casted]], %loop ] 83; CHECK-NOT: extra.base 84; CHECK: next.base = select 85; CHECK: next = select 86; CHECK: extra2.base = select 87; CHECK: extra2 = select 88; CHECK: statepoint 89;; Both 'next' and 'extra2' are live across the backedge safepoint... 90 91loop: ; preds = %loop, %entry 92 %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ] 93 %extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ] 94 %nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1 95 %next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 96 %extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 97 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 98 br label %loop 99} 100 101define i64 addrspace(1)* @test3(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 102; CHECK-LABEL: @test3 103entry: 104 br i1 %cnd, label %merge, label %taken 105 106taken: ; preds = %entry 107 br label %merge 108 109merge: ; preds = %taken, %entry 110; CHECK-LABEL: merge: 111; CHECK-NEXT: phi 112; CHECK-NEXT: phi 113; CHECK-NEXT: gc.statepoint 114 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %taken ] 115 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 116 ret i64 addrspace(1)* %bdv 117} 118 119define i64 addrspace(1)* @test4(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 120; CHECK-LABEL: @test4 121entry: 122 br i1 %cnd, label %merge, label %taken 123 124taken: ; preds = %entry 125 br label %merge 126 127merge: ; preds = %taken, %entry 128; CHECK-LABEL: merge: 129; CHECK-NEXT: phi 130; CHECK-NEXT: gc.statepoint 131 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj, %taken ] 132 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 133 ret i64 addrspace(1)* %bdv 134} 135 136define i64 addrspace(1)* @test5(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 137; CHECK-LABEL: @test5 138entry: 139 br label %merge 140 141merge: ; preds = %merge, %entry 142; CHECK-LABEL: merge: 143; CHECK-NEXT: phi 144; CHECK-NEXT: phi 145; CHECK-NEXT: br i1 146 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %merge ] 147 br i1 %cnd, label %merge, label %next 148 149next: ; preds = %merge 150 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 151 ret i64 addrspace(1)* %bdv 152} 153 154declare void @foo() 155