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 = select 85; CHECK: extra2.base = select 86; CHECK: extra2 = select 87; CHECK: statepoint 88;; Both 'next' and 'extra2' are live across the backedge safepoint... 89 90loop: ; preds = %loop, %entry 91 %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ] 92 %extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ] 93 %nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1 94 %next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 95 %extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 96 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 97 br label %loop 98} 99 100define i64 addrspace(1)* @test3(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 101; CHECK-LABEL: @test3 102entry: 103 br i1 %cnd, label %merge, label %taken 104 105taken: ; preds = %entry 106 br label %merge 107 108merge: ; preds = %taken, %entry 109; CHECK-LABEL: merge: 110; CHECK-NEXT: %bdv = phi 111; CHECK-NEXT: gc.statepoint 112 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %taken ] 113 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 114 ret i64 addrspace(1)* %bdv 115} 116 117define i64 addrspace(1)* @test4(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 118; CHECK-LABEL: @test4 119entry: 120 br i1 %cnd, label %merge, label %taken 121 122taken: ; preds = %entry 123 br label %merge 124 125merge: ; preds = %taken, %entry 126; CHECK-LABEL: merge: 127; CHECK-NEXT: %bdv = phi 128; CHECK-NEXT: gc.statepoint 129 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj, %taken ] 130 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 131 ret i64 addrspace(1)* %bdv 132} 133 134define i64 addrspace(1)* @test5(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { 135; CHECK-LABEL: @test5 136entry: 137 br label %merge 138 139merge: ; preds = %merge, %entry 140; CHECK-LABEL: merge: 141; CHECK-NEXT: %bdv = phi 142; CHECK-NEXT: br i1 143 %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %merge ] 144 br i1 %cnd, label %merge, label %next 145 146next: ; preds = %merge 147 call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] 148 ret i64 addrspace(1)* %bdv 149} 150 151declare void @foo() 152