[llvm] r249718 - [bpf] Do not expand UNDEF SDNode during insn selection lowering
Alexei Starovoitov via llvm-commits
llvm-commits at lists.llvm.org
Thu Oct 8 11:52:41 PDT 2015
Author: ast
Date: Thu Oct 8 13:52:40 2015
New Revision: 249718
URL: http://llvm.org/viewvc/llvm-project?rev=249718&view=rev
Log:
[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 <yhs at plumgrid.com>
Signed-off-by: Alexei Starovoitov <ast at plumgrid.com>
Added:
llvm/trunk/test/CodeGen/BPF/undef.ll
Modified:
llvm/trunk/lib/Target/BPF/BPFISelDAGToDAG.cpp
llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp
llvm/trunk/test/CodeGen/BPF/sockex2.ll
Modified: llvm/trunk/lib/Target/BPF/BPFISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFISelDAGToDAG.cpp?rev=249718&r1=249717&r2=249718&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/BPFISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/BPF/BPFISelDAGToDAG.cpp Thu Oct 8 13:52:40 2015
@@ -130,13 +130,6 @@ SDNode *BPFDAGToDAGISel::Select(SDNode *
// 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<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
switch (IntNo) {
Modified: llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp?rev=249718&r1=249717&r2=249718&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp Thu Oct 8 13:52:40 2015
@@ -129,9 +129,6 @@ BPFTargetLowering::BPFTargetLowering(con
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);
Modified: llvm/trunk/test/CodeGen/BPF/sockex2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/sockex2.ll?rev=249718&r1=249717&r2=249718&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/sockex2.ll (original)
+++ llvm/trunk/test/CodeGen/BPF/sockex2.ll Thu Oct 8 13:52:40 2015
@@ -311,7 +311,7 @@ flow_dissector.exit.thread:
; 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]
Added: llvm/trunk/test/CodeGen/BPF/undef.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/undef.ll?rev=249718&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/undef.ll (added)
+++ llvm/trunk/test/CodeGen/BPF/undef.ll Thu Oct 8 13:52:40 2015
@@ -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] }
+
+ at routing = global %struct.bpf_map_def { i32 1, i32 6, i32 12, i32 1024 }, section "maps", align 4
+ at routing_miss_0 = global %struct.bpf_map_def { i32 1, i32 1, i32 12, i32 1 }, section "maps", align 4
+ at test1 = global %struct.bpf_map_def { i32 2, i32 4, i32 8, i32 1024 }, section "maps", align 4
+ at test1_miss_4 = global %struct.bpf_map_def { i32 2, i32 1, i32 8, i32 1 }, section "maps", align 4
+ at _license = global [4 x i8] c"GPL\00", section "license", align 1
+ at 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
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