Add unconditional byteswap instructions (#180)

* Add unconditional byteswap instructions Addresses more of issue #152 Signed-off-by: Dave Thaler <dthaler1968@gmail.com> * Simplify swap tests Signed-off-by: Dave Thaler <dthaler1968@gmail.com> --------- Signed-off-by: Dave Thaler <dthaler1968@gmail.com> Co-authored-by: Alan Jowett <alanjo@microsoft.com>
Alan-Jowett · Jan 16, 2024 · d25c3f2 · d25c3f2
1 parent 3a32dae
commit d25c3f2
Show file tree

Hide file tree

Showing 6 changed files with 37 additions and 1 deletion.
diff --git a/src/bpf_assembler.cc b/src/bpf_assembler.cc
@@ -58,6 +58,7 @@ typedef class _bpf_assembler
         {"arsh", 0xc},
         {"le", 0xd},
         {"be", 0xd},
+        {"swap", 0xd},
     };
 
     const std::unordered_map<std::string, int> _bpf_encode_jmp_ops{
@@ -246,6 +247,11 @@ typedef class _bpf_assembler
             inst.dst = _decode_register(operands[0]);
             inst.imm = _decode_imm32(mnemonic.substr(2));
             return inst;
+        } else if (mnemonic.starts_with("swap")) {
+            inst.opcode = EBPF_OP_SWAP;
+            inst.dst = _decode_register(operands[0]);
+            inst.imm = _decode_imm32(mnemonic.substr(4));
+            return inst;
         }
         if (mnemonic.starts_with("sdiv") || mnemonic.starts_with("smod")) {
             inst.offset = 1;
@@ -479,7 +485,9 @@ typedef class _bpf_assembler
         {"stxb", {&_bpf_assembler::_encode_stx, 2}},  {"stxdw", {&_bpf_assembler::_encode_stx, 2}},
         {"stxh", {&_bpf_assembler::_encode_stx, 2}},  {"stxw", {&_bpf_assembler::_encode_stx, 2}},
         {"sub", {&_bpf_assembler::_encode_alu, 2}},   {"sub32", {&_bpf_assembler::_encode_alu, 2}},
-        {"xor", {&_bpf_assembler::_encode_alu, 2}},   {"xor32", {&_bpf_assembler::_encode_alu, 2}},
+        {"swap16", {&_bpf_assembler::_encode_alu, 1}},{"swap32", {&_bpf_assembler::_encode_alu, 1}},
+        {"swap64", {&_bpf_assembler::_encode_alu, 1}},{"xor", {&_bpf_assembler::_encode_alu, 2}},
+        {"xor32", {&_bpf_assembler::_encode_alu, 2}},
     };
 
     const std::unordered_map<std::string, std::tuple<bpf_encode_t, size_t>> _bpf_encode_atomic_ops{

diff --git a/src/ebpf.h b/src/ebpf.h
@@ -135,6 +135,7 @@ typedef struct ebpf_inst
 #define EBPF_OP_MOV64_REG (EBPF_CLS_ALU64 | EBPF_SRC_REG | EBPF_ALU_OP_MOV)
 #define EBPF_OP_ARSH64_IMM (EBPF_CLS_ALU64 | EBPF_SRC_IMM | EBPF_ALU_OP_ARSH)
 #define EBPF_OP_ARSH64_REG (EBPF_CLS_ALU64 | EBPF_SRC_REG | EBPF_ALU_OP_ARSH)
+#define EBPF_OP_SWAP (EBPF_CLS_ALU64 | EBPF_SRC_IMM | EBPF_ALU_OP_END)
 
 #define EBPF_OP_LDXW (EBPF_CLS_LDX | EBPF_MODE_MEM | EBPF_SIZE_W)
 #define EBPF_OP_LDXH (EBPF_CLS_LDX | EBPF_MODE_MEM | EBPF_SIZE_H)

diff --git a/src/opcode_names.h b/src/opcode_names.h
@@ -338,6 +338,9 @@ static const std::set<bpf_conformance_instruction_t, InstCmp> instructions_from_
     {bpf_conformance_test_cpu_version_t::v1, 0xd4, 0x00, 0x40},
     {bpf_conformance_test_cpu_version_t::v2, 0xd5},
     {bpf_conformance_test_cpu_version_t::v3, 0xd6},
+    {bpf_conformance_test_cpu_version_t::v4, 0xd7, 0x00, 0x10},
+    {bpf_conformance_test_cpu_version_t::v4, 0xd7, 0x00, 0x20},
+    {bpf_conformance_test_cpu_version_t::v4, 0xd7, 0x00, 0x40},
     {bpf_conformance_test_cpu_version_t::v3, 0xdb, 0x00, 0x00},
     {bpf_conformance_test_cpu_version_t::v3, 0xdb, 0x00, 0x01},
     {bpf_conformance_test_cpu_version_t::v3, 0xdb, 0x00, 0x40},

diff --git a/tests/swap16.data b/tests/swap16.data
@@ -0,0 +1,8 @@
+# Copyright (c) Big Switch Networks, Inc
+# SPDX-License-Identifier: Apache-2.0
+-- asm
+lddw %r0, 0x8877665544332211
+swap16 %r0
+exit
+-- result
+0x1122
diff --git a/tests/swap32.data b/tests/swap32.data
@@ -0,0 +1,8 @@
+# Copyright (c) Big Switch Networks, Inc
+# SPDX-License-Identifier: Apache-2.0
+-- asm
+lddw %r0, 0x8877665544332211
+swap32 %r0
+exit
+-- result
+0x11223344
diff --git a/tests/swap64.data b/tests/swap64.data
@@ -0,0 +1,8 @@
+# Copyright (c) Big Switch Networks, Inc
+# SPDX-License-Identifier: Apache-2.0
+-- asm
+lddw %r0, 0x8877665544332211
+swap64 %r0
+exit
+-- result
+0x1122334455667788