From 08c4d76572a1289f779cca9fc5e26d6d588657d0 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 8 Oct 2015 18:52:40 +0000 Subject: [PATCH] [bpf] Do not expand UNDEF SDNode during insn selection lowering o Before this patch, BPF backend will expand UNDEF node to i64 constant 0. o For second pass of dag combiner, legalizer will run through each to-be-processed dag node. o If any new SDNode is generated and has an undef operand, dag combiner will put undef node, newly-generated constant-0 node, and any node which uses these nodes in the working list. o During this process, it is possible undef operand is generated again, and this will form an infinite loop for dag combiner pass2. o This patch allows UNDEF to be a legal type. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249718 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/BPF/BPFISelDAGToDAG.cpp | 7 --- lib/Target/BPF/BPFISelLowering.cpp | 3 -- test/CodeGen/BPF/sockex2.ll | 2 +- test/CodeGen/BPF/undef.ll | 68 ++++++++++++++++++++++++++++++ 4 files changed, 69 insertions(+), 11 deletions(-) create mode 100644 test/CodeGen/BPF/undef.ll diff --git a/lib/Target/BPF/BPFISelDAGToDAG.cpp b/lib/Target/BPF/BPFISelDAGToDAG.cpp index 44ecb181a1c..9d5f1d406d0 100644 --- a/lib/Target/BPF/BPFISelDAGToDAG.cpp +++ b/lib/Target/BPF/BPFISelDAGToDAG.cpp @@ -130,13 +130,6 @@ SDNode *BPFDAGToDAGISel::Select(SDNode *Node) { // tablegen selection should be handled here. switch (Opcode) { default: break; - - case ISD::UNDEF: { - errs() << "BUG: "; Node->dump(CurDAG); errs() << '\n'; - report_fatal_error("shouldn't see UNDEF during Select"); - break; - } - case ISD::INTRINSIC_W_CHAIN: { unsigned IntNo = cast(Node->getOperand(1))->getZExtValue(); switch (IntNo) { diff --git a/lib/Target/BPF/BPFISelLowering.cpp b/lib/Target/BPF/BPFISelLowering.cpp index 42e2b3f32c0..73418283d9b 100644 --- a/lib/Target/BPF/BPFISelLowering.cpp +++ b/lib/Target/BPF/BPFISelLowering.cpp @@ -129,9 +129,6 @@ BPFTargetLowering::BPFTargetLowering(const TargetMachine &TM, setOperationAction(ISD::SUBC, MVT::i64, Expand); setOperationAction(ISD::SUBE, MVT::i64, Expand); - // no UNDEF allowed - setOperationAction(ISD::UNDEF, MVT::i64, Expand); - setOperationAction(ISD::ROTR, MVT::i64, Expand); setOperationAction(ISD::ROTL, MVT::i64, Expand); setOperationAction(ISD::SHL_PARTS, MVT::i64, Expand); diff --git a/test/CodeGen/BPF/sockex2.ll b/test/CodeGen/BPF/sockex2.ll index d372a5982f6..2e571ef6f46 100644 --- a/test/CodeGen/BPF/sockex2.ll +++ b/test/CodeGen/BPF/sockex2.ll @@ -311,7 +311,7 @@ flow_dissector.exit.thread: ; preds = %86, %12, %196, %199 ; CHECK-LABEL: bpf_prog2: ; CHECK: ldabs_h r0, r6.data + 12 # encoding: [0x28,0x00,0x00,0x00,0x0c,0x00,0x00,0x00] ; CHECK: ldabs_h r0, r6.data + 16 # encoding: [0x28,0x00,0x00,0x00,0x10,0x00,0x00,0x00] -; CHECK-NOT: implicit +; CHECK: implicit-def: R1 ; CHECK: ld_64 r1 ; CHECK-NOT: ori ; CHECK: call 1 # encoding: [0x85,0x00,0x00,0x00,0x01,0x00,0x00,0x00] diff --git a/test/CodeGen/BPF/undef.ll b/test/CodeGen/BPF/undef.ll new file mode 100644 index 00000000000..ef712c4a595 --- /dev/null +++ b/test/CodeGen/BPF/undef.ll @@ -0,0 +1,68 @@ +; RUN: llc < %s -march=bpf | FileCheck %s + +%struct.bpf_map_def = type { i32, i32, i32, i32 } +%struct.__sk_buff = type opaque +%struct.routing_key_2 = type { [6 x i8] } + +@routing = global %struct.bpf_map_def { i32 1, i32 6, i32 12, i32 1024 }, section "maps", align 4 +@routing_miss_0 = global %struct.bpf_map_def { i32 1, i32 1, i32 12, i32 1 }, section "maps", align 4 +@test1 = global %struct.bpf_map_def { i32 2, i32 4, i32 8, i32 1024 }, section "maps", align 4 +@test1_miss_4 = global %struct.bpf_map_def { i32 2, i32 1, i32 8, i32 1 }, section "maps", align 4 +@_license = global [4 x i8] c"GPL\00", section "license", align 1 +@llvm.used = appending global [6 x i8*] [i8* getelementptr inbounds ([4 x i8], [4 x i8]* @_license, i32 0, i32 0), i8* bitcast (i32 (%struct.__sk_buff*)* @ebpf_filter to i8*), i8* bitcast (%struct.bpf_map_def* @routing to i8*), i8* bitcast (%struct.bpf_map_def* @routing_miss_0 to i8*), i8* bitcast (%struct.bpf_map_def* @test1 to i8*), i8* bitcast (%struct.bpf_map_def* @test1_miss_4 to i8*)], section "llvm.metadata" + +; Function Attrs: nounwind uwtable +define i32 @ebpf_filter(%struct.__sk_buff* nocapture readnone %ebpf_packet) #0 section "socket1" { + %key = alloca %struct.routing_key_2, align 1 + %1 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 0 +; CHECK: mov r1, 5 +; CHECK: stb -8(r10), r1 + store i8 5, i8* %1, align 1 + %2 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 1 +; CHECK: mov r1, 6 +; CHECK: stb -7(r10), r1 + store i8 6, i8* %2, align 1 + %3 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 2 +; CHECK: mov r1, 7 +; CHECK: stb -6(r10), r1 + store i8 7, i8* %3, align 1 + %4 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 3 +; CHECK: mov r1, 8 +; CHECK: stb -5(r10), r1 + store i8 8, i8* %4, align 1 + %5 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 4 +; CHECK: mov r1, 9 +; CHECK: stb -4(r10), r1 + store i8 9, i8* %5, align 1 + %6 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 0, i32 0, i64 5 +; CHECK: mov r1, 10 +; CHECK: stb -3(r10), r1 + store i8 10, i8* %6, align 1 + %7 = getelementptr inbounds %struct.routing_key_2, %struct.routing_key_2* %key, i64 1, i32 0, i64 0 +; CHECK: mov r1, r10 +; CHECK: addi r1, -2 +; CHECK: mov r2, 0 +; CHECK: sth 6(r1), r2 +; CHECK: sth 4(r1), r2 +; CHECK: sth 2(r1), r2 +; CHECK: sth 24(r10), r2 +; CHECK: sth 22(r10), r2 +; CHECK: sth 20(r10), r2 +; CHECK: sth 18(r10), r2 +; CHECK: sth 16(r10), r2 +; CHECK: sth 14(r10), r2 +; CHECK: sth 12(r10), r2 +; CHECK: sth 10(r10), r2 +; CHECK: sth 8(r10), r2 +; CHECK: sth 6(r10), r2 +; CHECK: sth -2(r10), r2 +; CHECK: sth 26(r10), r2 + call void @llvm.memset.p0i8.i64(i8* %7, i8 0, i64 30, i32 1, i1 false) + %8 = call i32 (%struct.bpf_map_def*, %struct.routing_key_2*, ...) bitcast (i32 (...)* @bpf_map_lookup_elem to i32 (%struct.bpf_map_def*, %struct.routing_key_2*, ...)*)(%struct.bpf_map_def* nonnull @routing, %struct.routing_key_2* nonnull %key) #3 + ret i32 undef +} + +; Function Attrs: nounwind argmemonly +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #1 + +declare i32 @bpf_map_lookup_elem(...) #2 -- 2.34.1