1; RUN: opt %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s 2 3declare i64 addrspace(1)* @generate_obj() 4declare void @use_obj(i64 addrspace(1)*) 5 6; The rewriting needs to make %obj loop variant by inserting a phi 7; of the original value and it's relocation. 8define void @def_use_safepoint() gc "statepoint-example" { 9; CHECK-LABEL: def_use_safepoint 10entry: 11 %obj = call i64 addrspace(1)* @generate_obj() 12 br label %loop 13 14loop: 15; CHECK: phi i64 addrspace(1)* 16; CHECK-DAG: [ %obj.relocated, %loop ] 17; CHECK-DAG: [ %obj, %entry ] 18 call void @use_obj(i64 addrspace(1)* %obj) 19 %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0) 20 br label %loop 21} 22 23declare void @do_safepoint() 24 25declare void @parse_point(i64 addrspace(1)*) 26 27define i64 addrspace(1)* @test1(i32 %caller, i8 addrspace(1)* %a, i8 addrspace(1)* %b, i32 %unknown) gc "statepoint-example" { 28; CHECK-LABEL: test1 29 entry: 30 br i1 undef, label %left, label %right 31 32 left: 33 %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 34; CHECK: left: 35; CHECK-NEXT: %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 36; CHECK-NEXT: [[CAST_L:%.*]] = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* 37 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 switch i32 %unknown, label %right [ i32 0, label %merge 45 i32 1, label %merge 46 i32 5, label %merge 47 i32 3, label %right ] 48 49 right: 50 %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 51 br label %merge 52; CHECK: right: 53; CHECK-NEXT: %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 54; CHECK-NEXT: [[CAST_R:%.*]] = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* 55 56 merge: 57; CHECK: merge: 58; CHECK-NEXT: %base_phi = phi i64 addrspace(1)* [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_R]], %right ], !is_base_value !0 59 %value = phi i64 addrspace(1)* [ %a.cast, %left], [ %a.cast, %left], [ %a.cast, %left], [ %b.cast, %right] 60 %safepoint_token = call i32 (void (i64 addrspace(1)*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(void (i64 addrspace(1)*)* @parse_point, i32 1, i32 0, i64 addrspace(1)* %value, i32 5, i32 0, i32 0, i32 0, i32 0, i32 0) 61 62 ret i64 addrspace(1)* %value 63} 64 65;; The purpose of this test is to ensure that when two live values share a 66;; base defining value with inherent conflicts, we end up with a *single* 67;; base phi/select per such node. This is testing an optimization, not a 68;; fundemental correctness criteria 69define void @test2(i1 %cnd, i64 addrspace(1)* %base_obj, i64 addrspace(1)* %base_arg2) gc "statepoint-example" { 70; CHECK-LABEL: @test2 71entry: 72 %obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1 73 br label %loop 74 75loop: ; preds = %loop, %entry 76; CHECK-LABEL: loop 77; CHECK: %base_phi = phi i64 addrspace(1)* 78; CHECK-DAG: [ %base_obj, %entry ] 79; Given the two selects are equivelent, so are their base phis - ideally, 80; we'd have commoned these, but that's a missed optimization, not correctness. 81; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated]], %loop ] 82; CHECK-NOT: base_phi2 83; CHECK: next = select 84; CHECK: base_select 85; CHECK: extra2 = select 86; CHECK: base_select 87; CHECK: statepoint 88;; Both 'next' and 'extra2' are live across the backedge safepoint... 89 %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ] 90 %extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ] 91 %nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1 92 %next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 93 %extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 94 %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0) 95 br label %loop 96} 97 98declare void @foo() 99declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...) 100declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(void (i64 addrspace(1)*)*, i32, i32, ...) 101