llvm-mirror/test/SafepointIRVerifier/from-same-relocation-in-phi-nodes.ll
Max Kazantsev ee9e4fc042 [SafepointIRVerifier] Allow non-dereferencing uses of unrelocated or poisoned PHI nodes
PHI that has at least one unrelocated input cannot cause any issues by itself,
though its uses should be carefully verified. With this patch PHIs are allowed
to have any inputs but when all inputs are unrelocated the PHI is marked as
unrelocated and if not all inputs are unrelocated then the PHI is marked as
poisoned. Poisoned pointers can be used only in three ways: to derive new
pointers, in PHIs or in comparisons against constants that are exclusively
derived from null.

Patch by Daniil Suchkov!

Differential Revision: https://reviews.llvm.org/D41006

llvm-svn: 321438
2017-12-25 09:35:10 +00:00

27 lines
1.1 KiB
LLVM

; XFAIL: *
; RUN: opt -safepoint-ir-verifier-print-only -verify-safepoint-ir -S %s 2>&1 | FileCheck %s
; In %merge %val.unrelocated, %ptr and %arg should be unrelocated.
; FIXME: if this test fails it is a false-positive alarm. IR is correct.
define void @test.unrelocated-phi.ok(i8 addrspace(1)* %arg) gc "statepoint-example" {
; CHECK-LABEL: Verifying gc pointers in function: test.unrelocated-phi.ok
bci_0:
%ptr = getelementptr i8, i8 addrspace(1)* %arg, i64 4
br i1 undef, label %left, label %right
left:
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %merge
right:
br label %merge
merge:
; CHECK: No illegal uses found by SafepointIRVerifier in: test.unrelocated-phi.ok
%val.unrelocated = phi i8 addrspace(1)* [ %arg, %left ], [ %ptr, %right ]
%c = icmp eq i8 addrspace(1)* %val.unrelocated, %arg
ret void
}
declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)