1; RUN: opt < %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s 2; RUN: opt < %s -passes=rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s 3 4; The rewriting needs to make %obj loop variant by inserting a phi 5; of the original value and it's relocation. 6 7declare i64 addrspace(1)* @generate_obj() "gc-leaf-function" 8 9declare void @use_obj(i64 addrspace(1)*) "gc-leaf-function" 10 11define void @def_use_safepoint() gc "statepoint-example" { 12; CHECK-LABEL: def_use_safepoint 13; CHECK: phi i64 addrspace(1)* 14; CHECK-DAG: [ %obj.relocated.casted, %loop ] 15; CHECK-DAG: [ %obj, %entry ] 16entry: 17 %obj = call i64 addrspace(1)* @generate_obj() 18 br label %loop 19 20loop: ; preds = %loop, %entry 21 call void @use_obj(i64 addrspace(1)* %obj) 22 call void @do_safepoint() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 23 br label %loop 24} 25 26declare void @do_safepoint() 27 28declare void @parse_point(i64 addrspace(1)*) 29 30define i64 addrspace(1)* @test1(i32 %caller, i8 addrspace(1)* %a, i8 addrspace(1)* %b, i32 %unknown) gc "statepoint-example" { 31; CHECK-LABEL: test1 32entry: 33 br i1 undef, label %left, label %right 34 35left: ; preds = %entry 36; CHECK: left: 37; CHECK-NEXT: %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 38; CHECK-NEXT: [[CAST_L:%.*]] = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 39; Our safepoint placement pass calls removeUnreachableBlocks, which does a bunch 40; of simplifications to branch instructions. This bug is visible only when 41; there are multiple branches into the same block from the same predecessor, and 42; the following ceremony is to make that artefact survive a call to 43; removeUnreachableBlocks. As an example, "br i1 undef, label %merge, label %merge" 44; will get simplified to "br label %merge" by removeUnreachableBlocks. 45 %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 46 switch i32 %unknown, label %right [ 47 i32 0, label %merge 48 i32 1, label %merge 49 i32 5, label %merge 50 i32 3, label %right 51 ] 52 53right: ; preds = %left, %left, %entry 54; CHECK: right: 55; CHECK-NEXT: %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 56; CHECK-NEXT: [[CAST_R:%.*]] = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 57 %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 58 br label %merge 59 60merge: ; preds = %right, %left, %left, %left 61; CHECK: merge: 62; CHECK-NEXT: %value.base = phi i64 addrspace(1)* [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_R]], %right ], !is_base_value !0 63 %value = phi i64 addrspace(1)* [ %a.cast, %left ], [ %a.cast, %left ], [ %a.cast, %left ], [ %b.cast, %right ] 64 call void @parse_point(i64 addrspace(1)* %value) [ "deopt"(i32 0, i32 0, i32 0, i32 0, i32 0) ] 65 ret i64 addrspace(1)* %value 66} 67 68;; The purpose of this test is to ensure that when two live values share a 69;; base defining value with inherent conflicts, we end up with a *single* 70;; base phi/select per such node. This is testing an optimization, not a 71;; fundemental correctness criteria 72define void @test2(i1 %cnd, i64 addrspace(1)* %base_obj, i64 addrspace(1)* %base_arg2) gc "statepoint-example" { 73; CHECK-LABEL: @test2 74entry: 75 %obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1 76 br label %loop 77; CHECK-LABEL: loop 78; CHECK: %current.base = phi i64 addrspace(1)* 79; CHECK-DAG: [ %base_obj, %entry ] 80 81; Given the two selects are equivelent, so are their base phis - ideally, 82; we'd have commoned these, but that's a missed optimization, not correctness. 83; CHECK-DAG: [ [[DISCARD:%.*.base.relocated.casted]], %loop ] 84; CHECK-NOT: extra.base 85; CHECK: next.base = select 86; CHECK: next = select 87; CHECK: extra2.base = select 88; CHECK: extra2 = select 89; CHECK: statepoint 90;; Both 'next' and 'extra2' are live across the backedge safepoint... 91 92loop: ; preds = %loop, %entry 93 %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ] 94 %extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ] 95 %nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1 96 %next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 97 %extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 98 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 99 br label %loop 100} 101 102define i64 addrspace(1)* @test3(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 103; CHECK-LABEL: @test3 104entry: 105 br i1 %cnd, label %merge, label %taken 106 107taken: ; preds = %entry 108 br label %merge 109 110merge: ; preds = %taken, %entry 111; CHECK-LABEL: merge: 112; CHECK-NEXT: phi 113; CHECK-NEXT: phi 114; CHECK-NEXT: gc.statepoint 115 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %taken ] 116 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 117 ret i64 addrspace(1)* %bdv 118} 119 120define i64 addrspace(1)* @test4(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 121; CHECK-LABEL: @test4 122entry: 123 br i1 %cnd, label %merge, label %taken 124 125taken: ; preds = %entry 126 br label %merge 127 128merge: ; preds = %taken, %entry 129; CHECK-LABEL: merge: 130; CHECK-NEXT: phi 131; CHECK-NEXT: gc.statepoint 132 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj, %taken ] 133 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 134 ret i64 addrspace(1)* %bdv 135} 136 137define i64 addrspace(1)* @test5(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 138; CHECK-LABEL: @test5 139entry: 140 br label %merge 141 142merge: ; preds = %merge, %entry 143; CHECK-LABEL: merge: 144; CHECK-NEXT: phi 145; CHECK-NEXT: phi 146; CHECK-NEXT: br i1 147 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %merge ] 148 br i1 %cnd, label %merge, label %next 149 150next: ; preds = %merge 151 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 152 ret i64 addrspace(1)* %bdv 153} 154 155declare void @foo() 156