From cee313d288a4faf0355d76fb6e0e927e211d08a5 Mon Sep 17 00:00:00 2001 From: Eric Christopher Date: Wed, 17 Apr 2019 04:52:47 +0000 Subject: Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552 --- .../RewriteStatepointsForGC/base-pointers.ll | 155 +++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll (limited to 'llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll') diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll new file mode 100644 index 00000000000..46a73c28f1e --- /dev/null +++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll @@ -0,0 +1,155 @@ +; RUN: opt < %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s +; RUN: opt < %s -passes=rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s + +; The rewriting needs to make %obj loop variant by inserting a phi +; of the original value and it's relocation. + +declare i64 addrspace(1)* @generate_obj() "gc-leaf-function" + +declare void @use_obj(i64 addrspace(1)*) "gc-leaf-function" + +define void @def_use_safepoint() gc "statepoint-example" { +; CHECK-LABEL: def_use_safepoint +; CHECK: phi i64 addrspace(1)* +; CHECK-DAG: [ %obj.relocated.casted, %loop ] +; CHECK-DAG: [ %obj, %entry ] +entry: + %obj = call i64 addrspace(1)* @generate_obj() + br label %loop + +loop: ; preds = %loop, %entry + call void @use_obj(i64 addrspace(1)* %obj) + call void @do_safepoint() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] + br label %loop +} + +declare void @do_safepoint() + +declare void @parse_point(i64 addrspace(1)*) + +define i64 addrspace(1)* @test1(i32 %caller, i8 addrspace(1)* %a, i8 addrspace(1)* %b, i32 %unknown) gc "statepoint-example" { +; CHECK-LABEL: test1 +entry: + br i1 undef, label %left, label %right + +left: ; preds = %entry +; CHECK: left: +; CHECK-NEXT: %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* +; CHECK-NEXT: [[CAST_L:%.*]] = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* +; Our safepoint placement pass calls removeUnreachableBlocks, which does a bunch +; of simplifications to branch instructions. This bug is visible only when +; there are multiple branches into the same block from the same predecessor, and +; the following ceremony is to make that artefact survive a call to +; removeUnreachableBlocks. As an example, "br i1 undef, label %merge, label %merge" +; will get simplified to "br label %merge" by removeUnreachableBlocks. + %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)* + switch i32 %unknown, label %right [ + i32 0, label %merge + i32 1, label %merge + i32 5, label %merge + i32 3, label %right + ] + +right: ; preds = %left, %left, %entry +; CHECK: right: +; CHECK-NEXT: %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* +; CHECK-NEXT: [[CAST_R:%.*]] = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* + %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)* + br label %merge + +merge: ; preds = %right, %left, %left, %left +; CHECK: merge: +; CHECK-NEXT: %value.base = phi i64 addrspace(1)* [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_R]], %right ], !is_base_value !0 + %value = phi i64 addrspace(1)* [ %a.cast, %left ], [ %a.cast, %left ], [ %a.cast, %left ], [ %b.cast, %right ] + call void @parse_point(i64 addrspace(1)* %value) [ "deopt"(i32 0, i32 0, i32 0, i32 0, i32 0) ] + ret i64 addrspace(1)* %value +} + +;; The purpose of this test is to ensure that when two live values share a +;; base defining value with inherent conflicts, we end up with a *single* +;; base phi/select per such node. This is testing an optimization, not a +;; fundemental correctness criteria +define void @test2(i1 %cnd, i64 addrspace(1)* %base_obj, i64 addrspace(1)* %base_arg2) gc "statepoint-example" { +; CHECK-LABEL: @test2 +entry: + %obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1 + br label %loop +; CHECK-LABEL: loop +; CHECK: %current.base = phi i64 addrspace(1)* +; CHECK-DAG: [ %base_obj, %entry ] + +; Given the two selects are equivelent, so are their base phis - ideally, +; we'd have commoned these, but that's a missed optimization, not correctness. +; CHECK-DAG: [ [[DISCARD:%.*.base.relocated.casted]], %loop ] +; CHECK-NOT: extra.base +; CHECK: next.base = select +; CHECK: next = select +; CHECK: extra2.base = select +; CHECK: extra2 = select +; CHECK: statepoint +;; Both 'next' and 'extra2' are live across the backedge safepoint... + +loop: ; preds = %loop, %entry + %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ] + %extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ] + %nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1 + %next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 + %extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2 + call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] + br label %loop +} + +define i64 addrspace(1)* @test3(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { +; CHECK-LABEL: @test3 +entry: + br i1 %cnd, label %merge, label %taken + +taken: ; preds = %entry + br label %merge + +merge: ; preds = %taken, %entry +; CHECK-LABEL: merge: +; CHECK-NEXT: phi +; CHECK-NEXT: phi +; CHECK-NEXT: gc.statepoint + %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %taken ] + call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] + ret i64 addrspace(1)* %bdv +} + +define i64 addrspace(1)* @test4(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { +; CHECK-LABEL: @test4 +entry: + br i1 %cnd, label %merge, label %taken + +taken: ; preds = %entry + br label %merge + +merge: ; preds = %taken, %entry +; CHECK-LABEL: merge: +; CHECK-NEXT: phi +; CHECK-NEXT: gc.statepoint + %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj, %taken ] + call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] + ret i64 addrspace(1)* %bdv +} + +define i64 addrspace(1)* @test5(i1 %cnd, i64 addrspace(1)* %obj, i64 addrspace(1)* %obj2) gc "statepoint-example" { +; CHECK-LABEL: @test5 +entry: + br label %merge + +merge: ; preds = %merge, %entry +; CHECK-LABEL: merge: +; CHECK-NEXT: phi +; CHECK-NEXT: phi +; CHECK-NEXT: br i1 + %bdv = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj2, %merge ] + br i1 %cnd, label %merge, label %next + +next: ; preds = %merge + call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ] + ret i64 addrspace(1)* %bdv +} + +declare void @foo() -- cgit v1.2.3