Index: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp =================================================================== --- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp +++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp @@ -948,6 +948,21 @@ simplifyRelocatesOffABase(GCRelocateInst *RelocatedBase, const SmallVectorImpl &Targets) { bool MadeChange = false; + // We must ensure the relocation of derived pointer is defined after + // relocation of base pointer. If we find a relocation corresponding to base + // defined earlier than relocation of base then we move relocation of base + // right before found relocation. We consider only relocation in the same + // basic block as relocation of base. Relocations from other basic block will + // be skipped by optimization and we do not care about them. + for (auto R = RelocatedBase->getParent()->getFirstInsertionPt(); + &*R != RelocatedBase; ++R) + if (auto RI = dyn_cast(R)) + if (RI->getStatepoint() == RelocatedBase->getStatepoint()) + if (RI->getBasePtrIndex() == RelocatedBase->getBasePtrIndex()) { + RelocatedBase->moveBefore(RI); + break; + } + for (GCRelocateInst *ToReplace : Targets) { assert(ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() && "Not relocating a derived object of the original base object"); Index: llvm/trunk/test/Transforms/CodeGenPrepare/statepoint-relocate.ll =================================================================== --- llvm/trunk/test/Transforms/CodeGenPrepare/statepoint-relocate.ll +++ llvm/trunk/test/Transforms/CodeGenPrepare/statepoint-relocate.ll @@ -122,6 +122,28 @@ ret i32 %ret-base } +define i32 @test_sor_noop_same_bb(i1 %external-cond, i32* %base) gc "statepoint-example" { +; CHECK-LABEL: @test_sor_noop_same_bb +; Here base relocate doesn't dominate derived relocate. Make sure that we don't +; produce undefined use of the relocated base pointer. +entry: + %ptr1 = getelementptr i32, i32* %base, i32 15 + ; CHECK: getelementptr i32, i32* %base, i32 15 + %ptr2 = getelementptr i32, i32* %base, i32 5 + ; CHECK: getelementptr i32, i32* %base, i32 5 + %tok = call token (i64, i32, i1 ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i1f(i64 0, i32 0, i1 ()* @return_i1, i32 0, i32 0, i32 0, i32 0, i32* %base, i32* %ptr1, i32* %ptr2) + ; CHECK: call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 7) + %ptr2-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 9) + %ret2-new = load i32, i32* %ptr2-new + ; CHECK: getelementptr i32, i32* %base-new, i32 5 + %ptr1-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 8) + %ret1-new = load i32, i32* %ptr1-new + ; CHECK: getelementptr i32, i32* %base-new, i32 15 + %base-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 7) + %ret-new = add i32 %ret2-new, %ret1-new + ret i32 %ret-new +} + declare token @llvm.experimental.gc.statepoint.p0f_i1f(i64, i32, i1 ()*, i32, i32, ...) declare i32* @llvm.experimental.gc.relocate.p0i32(token, i32, i32) declare [3 x i32]* @llvm.experimental.gc.relocate.p0a3i32(token, i32, i32)