[llvm] r287477 - [bpf] add BPF disassembler
Alexei Starovoitov via llvm-commits
llvm-commits at lists.llvm.org
Sat Nov 19 18:25:00 PST 2016
Author: ast
Date: Sat Nov 19 20:25:00 2016
New Revision: 287477
URL: http://llvm.org/viewvc/llvm-project?rev=287477&view=rev
Log:
[bpf] add BPF disassembler
add BPF disassembler, so tools like llvm-objdump can be used:
$ llvm-objdump -d -no-show-raw-insn ./sockex1_kern.o
./sockex1_kern.o: file format ELF64-BPF
Disassembly of section socket1:
bpf_prog1:
0: r6 = r1
8: r0 = *(u8 *)skb[23]
10: *(u32 *)(r10 - 4) = r0
18: r1 = *(u32 *)(r6 + 4)
20: if r1 != 4 goto 8
28: r2 = r10
30: r2 += -4
ld_imm64 (the only 16-byte insn) and special ld_abs/ld_ind instructions
had to be treated in a special way. The decoders for the rest of the insns
are automatically generated.
Add tests to cover new functionality.
Signed-off-by: Alexei Starovoitov <ast at kernel.org>
Added:
llvm/trunk/lib/Target/BPF/Disassembler/
llvm/trunk/lib/Target/BPF/Disassembler/BPFDisassembler.cpp
llvm/trunk/lib/Target/BPF/Disassembler/CMakeLists.txt
llvm/trunk/lib/Target/BPF/Disassembler/LLVMBuild.txt
- copied, changed from r287476, llvm/trunk/lib/Target/BPF/LLVMBuild.txt
llvm/trunk/test/CodeGen/BPF/objdump_atomics.ll
- copied, changed from r287476, llvm/trunk/test/CodeGen/BPF/atomics.ll
llvm/trunk/test/CodeGen/BPF/objdump_intrinsics.ll
llvm/trunk/test/CodeGen/BPF/objdump_trivial.ll
Modified:
llvm/trunk/lib/Target/BPF/BPFInstrInfo.td
llvm/trunk/lib/Target/BPF/CMakeLists.txt
llvm/trunk/lib/Target/BPF/LLVMBuild.txt
llvm/trunk/test/CodeGen/BPF/atomics.ll
Modified: llvm/trunk/lib/Target/BPF/BPFInstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFInstrInfo.td?rev=287477&r1=287476&r2=287477&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/BPFInstrInfo.td (original)
+++ llvm/trunk/lib/Target/BPF/BPFInstrInfo.td Sat Nov 19 20:25:00 2016
@@ -61,6 +61,7 @@ def FIri : ComplexPattern<i64, 2, "Selec
def MEMri : Operand<i64> {
let PrintMethod = "printMemOperand";
let EncoderMethod = "getMemoryOpValue";
+ let DecoderMethod = "decodeMemoryOpValue";
let MIOperandInfo = (ops GPR, i16imm);
}
@@ -267,6 +268,13 @@ def FI_ri
[(set i64:$dst, FIri:$addr)]> {
// This is a tentative instruction, and will be replaced
// with MOV_rr and ADD_ri in PEI phase
+ let Inst{63-61} = 0;
+ let Inst{60-59} = 3;
+ let Inst{51-48} = 0;
+ let Inst{55-52} = 2;
+ let Inst{47-32} = 0;
+ let Inst{31-0} = 0;
+ let BPFClass = 0;
}
@@ -476,13 +484,13 @@ class XADD<bits<2> SizeOp, string Opcode
[(set GPR:$dst, (OpNode ADDRri:$addr, GPR:$val))]> {
bits<3> mode;
bits<2> size;
- bits<4> src;
+ bits<4> dst;
bits<20> addr;
let Inst{63-61} = mode;
let Inst{60-59} = size;
let Inst{51-48} = addr{19-16}; // base reg
- let Inst{55-52} = src;
+ let Inst{55-52} = dst;
let Inst{47-32} = addr{15-0}; // offset
let mode = 6; // BPF_XADD
Modified: llvm/trunk/lib/Target/BPF/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/CMakeLists.txt?rev=287477&r1=287476&r2=287477&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/CMakeLists.txt (original)
+++ llvm/trunk/lib/Target/BPF/CMakeLists.txt Sat Nov 19 20:25:00 2016
@@ -2,6 +2,7 @@ set(LLVM_TARGET_DEFINITIONS BPF.td)
tablegen(LLVM BPFGenRegisterInfo.inc -gen-register-info)
tablegen(LLVM BPFGenInstrInfo.inc -gen-instr-info)
+tablegen(LLVM BPFGenDisassemblerTables.inc -gen-disassembler)
tablegen(LLVM BPFGenAsmWriter.inc -gen-asm-writer)
tablegen(LLVM X86GenAsmMatcher.inc -gen-asm-matcher)
tablegen(LLVM BPFGenDAGISel.inc -gen-dag-isel)
@@ -22,6 +23,7 @@ add_llvm_target(BPFCodeGen
BPFTargetMachine.cpp
)
+add_subdirectory(Disassembler)
add_subdirectory(InstPrinter)
add_subdirectory(TargetInfo)
add_subdirectory(MCTargetDesc)
Added: llvm/trunk/lib/Target/BPF/Disassembler/BPFDisassembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/Disassembler/BPFDisassembler.cpp?rev=287477&view=auto
==============================================================================
--- llvm/trunk/lib/Target/BPF/Disassembler/BPFDisassembler.cpp (added)
+++ llvm/trunk/lib/Target/BPF/Disassembler/BPFDisassembler.cpp Sat Nov 19 20:25:00 2016
@@ -0,0 +1,154 @@
+//===- BPFDisassembler.cpp - Disassembler for BPF ---------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is part of the BPF Disassembler.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPF.h"
+#include "BPFRegisterInfo.h"
+#include "BPFSubtarget.h"
+#include "MCTargetDesc/BPFMCTargetDesc.h"
+
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/MC/MCFixedLenDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Support/TargetRegistry.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "bpf-disassembler"
+
+typedef MCDisassembler::DecodeStatus DecodeStatus;
+
+namespace {
+
+/// A disassembler class for BPF.
+class BPFDisassembler : public MCDisassembler {
+public:
+ BPFDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
+ : MCDisassembler(STI, Ctx) {}
+ virtual ~BPFDisassembler() {}
+
+ DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
+ ArrayRef<uint8_t> Bytes, uint64_t Address,
+ raw_ostream &VStream,
+ raw_ostream &CStream) const override;
+};
+}
+
+static MCDisassembler *createBPFDisassembler(const Target &T,
+ const MCSubtargetInfo &STI,
+ MCContext &Ctx) {
+ return new BPFDisassembler(STI, Ctx);
+}
+
+
+extern "C" void LLVMInitializeBPFDisassembler() {
+ // Register the disassembler.
+ TargetRegistry::RegisterMCDisassembler(getTheBPFTarget(),
+ createBPFDisassembler);
+ TargetRegistry::RegisterMCDisassembler(getTheBPFleTarget(),
+ createBPFDisassembler);
+ TargetRegistry::RegisterMCDisassembler(getTheBPFbeTarget(),
+ createBPFDisassembler);
+}
+
+static const unsigned GPRDecoderTable[] = {
+ BPF::R0, BPF::R1, BPF::R2, BPF::R3, BPF::R4, BPF::R5,
+ BPF::R6, BPF::R7, BPF::R8, BPF::R9, BPF::R10, BPF::R11};
+
+static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
+ uint64_t /*Address*/,
+ const void * /*Decoder*/) {
+ if (RegNo > 11)
+ return MCDisassembler::Fail;
+
+ unsigned Reg = GPRDecoderTable[RegNo];
+ Inst.addOperand(MCOperand::createReg(Reg));
+ return MCDisassembler::Success;
+}
+
+static DecodeStatus decodeMemoryOpValue(MCInst &Inst, unsigned Insn,
+ uint64_t Address, const void *Decoder) {
+ unsigned Register = (Insn >> 16) & 0xf;
+ Inst.addOperand(MCOperand::createReg(GPRDecoderTable[Register]));
+ unsigned Offset = (Insn & 0xffff);
+ Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Offset)));
+
+ return MCDisassembler::Success;
+}
+
+#include "BPFGenDisassemblerTables.inc"
+
+static DecodeStatus readInstruction64(ArrayRef<uint8_t> Bytes, uint64_t Address,
+ uint64_t &Size, uint64_t &Insn) {
+ uint64_t Lo, Hi;
+
+ if (Bytes.size() < 8) {
+ Size = 0;
+ return MCDisassembler::Fail;
+ }
+
+ Size = 8;
+ Hi = (Bytes[0] << 24) | (Bytes[1] << 16) | (Bytes[2] << 0) | (Bytes[3] << 8);
+ Lo = (Bytes[4] << 0) | (Bytes[5] << 8) | (Bytes[6] << 16) | (Bytes[7] << 24);
+ Insn = Make_64(Hi, Lo);
+
+ return MCDisassembler::Success;
+}
+
+DecodeStatus BPFDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
+ ArrayRef<uint8_t> Bytes,
+ uint64_t Address,
+ raw_ostream &VStream,
+ raw_ostream &CStream) const {
+ uint64_t Insn;
+ DecodeStatus Result;
+
+ Result = readInstruction64(Bytes, Address, Size, Insn);
+ if (Result == MCDisassembler::Fail) return MCDisassembler::Fail;
+
+ Result = decodeInstruction(DecoderTableBPF64, Instr, Insn,
+ Address, this, STI);
+ if (Result == MCDisassembler::Fail) return MCDisassembler::Fail;
+
+ switch (Instr.getOpcode()) {
+ case BPF::LD_imm64: {
+ if (Bytes.size() < 16) {
+ Size = 0;
+ return MCDisassembler::Fail;
+ }
+ Size = 16;
+ uint64_t Hi = (Bytes[12] << 0) | (Bytes[13] << 8) | (Bytes[14] << 16) | (Bytes[15] << 24);
+ auto& Op = Instr.getOperand(1);
+ Op.setImm(Make_64(Hi, Op.getImm()));
+ break;
+ }
+ case BPF::LD_ABS_B:
+ case BPF::LD_ABS_H:
+ case BPF::LD_ABS_W:
+ case BPF::LD_IND_B:
+ case BPF::LD_IND_H:
+ case BPF::LD_IND_W: {
+ auto Op = Instr.getOperand(0);
+ Instr.clear();
+ Instr.addOperand(MCOperand::createReg(BPF::R6));
+ Instr.addOperand(Op);
+ break;
+ }
+ }
+
+ return Result;
+}
+
+typedef DecodeStatus (*DecodeFunc)(MCInst &MI, unsigned insn, uint64_t Address,
+ const void *Decoder);
Added: llvm/trunk/lib/Target/BPF/Disassembler/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/Disassembler/CMakeLists.txt?rev=287477&view=auto
==============================================================================
--- llvm/trunk/lib/Target/BPF/Disassembler/CMakeLists.txt (added)
+++ llvm/trunk/lib/Target/BPF/Disassembler/CMakeLists.txt Sat Nov 19 20:25:00 2016
@@ -0,0 +1,4 @@
+add_llvm_library(LLVMBPFDisassembler
+ BPFDisassembler.cpp
+)
+
Copied: llvm/trunk/lib/Target/BPF/Disassembler/LLVMBuild.txt (from r287476, llvm/trunk/lib/Target/BPF/LLVMBuild.txt)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/Disassembler/LLVMBuild.txt?p2=llvm/trunk/lib/Target/BPF/Disassembler/LLVMBuild.txt&p1=llvm/trunk/lib/Target/BPF/LLVMBuild.txt&r1=287476&r2=287477&rev=287477&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/LLVMBuild.txt (original)
+++ llvm/trunk/lib/Target/BPF/Disassembler/LLVMBuild.txt Sat Nov 19 20:25:00 2016
@@ -1,4 +1,4 @@
-;===- ./lib/Target/BPF/LLVMBuild.txt ---------------------------*- Conf -*--===;
+;===- ./lib/Target/BPF/Disassembler/LLVMBuild.txt --------------*- Conf -*--===;
;
; The LLVM Compiler Infrastructure
;
@@ -15,28 +15,9 @@
;
;===------------------------------------------------------------------------===;
-[common]
-subdirectories = InstPrinter MCTargetDesc TargetInfo
-
[component_0]
-type = TargetGroup
-name = BPF
-parent = Target
-has_asmprinter = 1
-
-[component_1]
type = Library
-name = BPFCodeGen
+name = BPFDisassembler
parent = BPF
-required_libraries =
- AsmPrinter
- CodeGen
- Core
- MC
- BPFAsmPrinter
- BPFDesc
- BPFInfo
- SelectionDAG
- Support
- Target
+required_libraries = MCDisassembler BPFInfo Support
add_to_library_groups = BPF
Modified: llvm/trunk/lib/Target/BPF/LLVMBuild.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/LLVMBuild.txt?rev=287477&r1=287476&r2=287477&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/LLVMBuild.txt (original)
+++ llvm/trunk/lib/Target/BPF/LLVMBuild.txt Sat Nov 19 20:25:00 2016
@@ -16,13 +16,14 @@
;===------------------------------------------------------------------------===;
[common]
-subdirectories = InstPrinter MCTargetDesc TargetInfo
+subdirectories = InstPrinter Disassembler MCTargetDesc TargetInfo
[component_0]
type = TargetGroup
name = BPF
parent = Target
has_asmprinter = 1
+has_disassembler = 1
[component_1]
type = Library
Modified: llvm/trunk/test/CodeGen/BPF/atomics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/atomics.ll?rev=287477&r1=287476&r2=287477&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/atomics.ll (original)
+++ llvm/trunk/test/CodeGen/BPF/atomics.ll Sat Nov 19 20:25:00 2016
@@ -1,8 +1,8 @@
; RUN: llc < %s -march=bpfel -verify-machineinstrs -show-mc-encoding | FileCheck %s
; CHECK-LABEL: test_load_add_32
-; CHECK: lock *(u32 *)
-; CHECK: encoding: [0xc3
+; CHECK: lock *(u32 *)(r1 + 0) += r2
+; CHECK: encoding: [0xc3,0x21
define void @test_load_add_32(i32* %p, i32 zeroext %v) {
entry:
atomicrmw add i32* %p, i32 %v seq_cst
@@ -10,8 +10,8 @@ entry:
}
; CHECK-LABEL: test_load_add_64
-; CHECK: lock *(u64 *)
-; CHECK: encoding: [0xdb
+; CHECK: lock *(u64 *)(r1 + 0) += r2
+; CHECK: encoding: [0xdb,0x21
define void @test_load_add_64(i64* %p, i64 zeroext %v) {
entry:
atomicrmw add i64* %p, i64 %v seq_cst
Copied: llvm/trunk/test/CodeGen/BPF/objdump_atomics.ll (from r287476, llvm/trunk/test/CodeGen/BPF/atomics.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/objdump_atomics.ll?p2=llvm/trunk/test/CodeGen/BPF/objdump_atomics.ll&p1=llvm/trunk/test/CodeGen/BPF/atomics.ll&r1=287476&r2=287477&rev=287477&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/atomics.ll (original)
+++ llvm/trunk/test/CodeGen/BPF/objdump_atomics.ll Sat Nov 19 20:25:00 2016
@@ -1,8 +1,8 @@
-; RUN: llc < %s -march=bpfel -verify-machineinstrs -show-mc-encoding | FileCheck %s
+; RUN: llc -march=bpfel -filetype=obj -o - %s | llvm-objdump -d - | FileCheck %s
; CHECK-LABEL: test_load_add_32
-; CHECK: lock *(u32 *)
-; CHECK: encoding: [0xc3
+; CHECK: c3 21
+; CHECK: lock *(u32 *)(r1 + 0) += r2
define void @test_load_add_32(i32* %p, i32 zeroext %v) {
entry:
atomicrmw add i32* %p, i32 %v seq_cst
@@ -10,8 +10,8 @@ entry:
}
; CHECK-LABEL: test_load_add_64
-; CHECK: lock *(u64 *)
-; CHECK: encoding: [0xdb
+; CHECK: db 21
+; CHECK: lock *(u64 *)(r1 + 0) += r2
define void @test_load_add_64(i64* %p, i64 zeroext %v) {
entry:
atomicrmw add i64* %p, i64 %v seq_cst
Added: llvm/trunk/test/CodeGen/BPF/objdump_intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/objdump_intrinsics.ll?rev=287477&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/objdump_intrinsics.ll (added)
+++ llvm/trunk/test/CodeGen/BPF/objdump_intrinsics.ll Sat Nov 19 20:25:00 2016
@@ -0,0 +1,88 @@
+; RUN: llc -march=bpfel -filetype=obj -o - %s | llvm-objdump -d - | FileCheck %s
+
+; Function Attrs: nounwind uwtable
+define i32 @ld_b(i64 %foo, i64* nocapture %bar, i8* %ctx, i8* %ctx2) #0 {
+ %1 = tail call i64 @llvm.bpf.load.byte(i8* %ctx, i64 123) #2
+ %2 = add i64 %1, %foo
+ %3 = load volatile i64, i64* %bar, align 8
+ %4 = add i64 %2, %3
+ %5 = tail call i64 @llvm.bpf.load.byte(i8* %ctx2, i64 %foo) #2
+ %6 = add i64 %4, %5
+ %7 = load volatile i64, i64* %bar, align 8
+ %8 = add i64 %6, %7
+ %9 = trunc i64 %8 to i32
+ ret i32 %9
+; CHECK-LABEL: ld_b:
+; CHECK: r0 = *(u8 *)skb[123]
+; CHECK: r0 = *(u8 *)skb[r
+}
+
+declare i64 @llvm.bpf.load.byte(i8*, i64) #1
+
+; Function Attrs: nounwind uwtable
+define i32 @ld_h(i8* %ctx, i8* %ctx2, i32 %foo) #0 {
+ %1 = tail call i64 @llvm.bpf.load.half(i8* %ctx, i64 123) #2
+ %2 = sext i32 %foo to i64
+ %3 = tail call i64 @llvm.bpf.load.half(i8* %ctx2, i64 %2) #2
+ %4 = add i64 %3, %1
+ %5 = trunc i64 %4 to i32
+ ret i32 %5
+; CHECK-LABEL: ld_h:
+; CHECK: r0 = *(u16 *)skb[r
+; CHECK: r0 = *(u16 *)skb[123]
+}
+
+declare i64 @llvm.bpf.load.half(i8*, i64) #1
+
+; Function Attrs: nounwind uwtable
+define i32 @ld_w(i8* %ctx, i8* %ctx2, i32 %foo) #0 {
+ %1 = tail call i64 @llvm.bpf.load.word(i8* %ctx, i64 123) #2
+ %2 = sext i32 %foo to i64
+ %3 = tail call i64 @llvm.bpf.load.word(i8* %ctx2, i64 %2) #2
+ %4 = add i64 %3, %1
+ %5 = trunc i64 %4 to i32
+ ret i32 %5
+; CHECK-LABEL: ld_w:
+; CHECK: r0 = *(u32 *)skb[r
+; CHECK: r0 = *(u32 *)skb[123]
+}
+
+declare i64 @llvm.bpf.load.word(i8*, i64) #1
+
+define i32 @ld_pseudo() #0 {
+entry:
+ %call = tail call i64 @llvm.bpf.pseudo(i64 2, i64 3)
+ tail call void @bar(i64 %call, i32 4) #2
+ ret i32 0
+; CHECK-LABEL: ld_pseudo:
+; CHECK: ld_pseudo r1, 2, 3
+}
+
+declare void @bar(i64, i32) #1
+
+declare i64 @llvm.bpf.pseudo(i64, i64) #2
+
+define i32 @bswap(i64 %a, i64 %b, i64 %c) #0 {
+entry:
+ %0 = tail call i64 @llvm.bswap.i64(i64 %a)
+ %conv = trunc i64 %b to i32
+ %1 = tail call i32 @llvm.bswap.i32(i32 %conv)
+ %conv1 = zext i32 %1 to i64
+ %add = add i64 %conv1, %0
+ %conv2 = trunc i64 %c to i16
+ %2 = tail call i16 @llvm.bswap.i16(i16 %conv2)
+ %conv3 = zext i16 %2 to i64
+ %add4 = add i64 %add, %conv3
+ %conv5 = trunc i64 %add4 to i32
+ ret i32 %conv5
+; CHECK-LABEL: bswap:
+; CHECK: bswap64 r1
+; CHECK: bswap32 r2
+; CHECK: r2 += r1
+; CHECK: bswap16 r3
+; CHECK: r2 += r3
+}
+
+declare i64 @llvm.bswap.i64(i64) #1
+declare i32 @llvm.bswap.i32(i32) #1
+declare i16 @llvm.bswap.i16(i16) #1
Added: llvm/trunk/test/CodeGen/BPF/objdump_trivial.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/BPF/objdump_trivial.ll?rev=287477&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/BPF/objdump_trivial.ll (added)
+++ llvm/trunk/test/CodeGen/BPF/objdump_trivial.ll Sat Nov 19 20:25:00 2016
@@ -0,0 +1,19 @@
+; RUN: llc -march=bpfel -filetype=obj -o - %s | llvm-objdump -d - | FileCheck %s
+
+; CHECK: if r2 s> r1 goto
+; CHECK: call
+; CHECK: exit
+
+declare void @a()
+declare void @b()
+
+define void @foo(i32 %a) {
+%b = icmp sgt i32 %a, -1
+br i1 %b, label %x, label %y
+x:
+call void @a()
+ret void
+y:
+call void @b()
+ret void
+}
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