4 Commits

Author	SHA1	Message	Date
Yonghong Song	149d4d3730	bpf: signal error instead of silent drop for certain invalid asm insn ... Currently, an invalid asm insn, either in an asm file or in an inline asm format, might be silently dropped. This patch fixed two places where this may happen by signaling the error so user knows what goes wrong. The following is an example to demonstrate error messages: -bash-4.2$ cat t.c int test(void *ctx) { #if defined(NO_ERROR) asm volatile("r0 = *(u16 *)skb[%0]" : : "i"(2)); #elif defined(ERROR_1) asm volatile("r20 = *(u16 *)skb[%0]" : : "i"(2)); #elif defined(ERROR_2) asm volatile("r0 = *(u16 *)(r1 + ?)" : :); #endif return 0; } -bash-4.2$ cat run.sh for macro in NO_ERROR ERROR_1 ERROR_2; do echo "===== compile for macro" $macro clang -D${macro} -O2 -target bpf -emit-llvm -S t.c echo "==llc==" llc -march=bpf -filetype=obj t.ll done -bash-4.2$ ./run.sh ===== compile for macro NO_ERROR ==llc== ===== compile for macro ERROR_1 ==llc== <inline asm>:1:2: error: invalid register/token name r20 = *(u16 *)skb[2] ^ note: !srcloc = 135 ===== compile for macro ERROR_2 ==llc== <inline asm>:1:21: error: unexpected token r0 = *(u16 *)(r1 + ?) ^ note: !srcloc = 210 -bash-4.2$ Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 329849	2018-04-11 20:24:52 +00:00
Oliver Stannard	4191b9eaea	[Asm] Add debug tracing in table-generated assembly matcher ... This adds debug tracing to the table-generated assembly instruction matcher, enabled by the -debug-only=asm-matcher option. The changes in the target AsmParsers are to add an MCInstrInfo reference under a consistent name, so that we can use it from table-generated code. This was already being used this way for targets that use deprecation warnings, but 5 targets did not have it, and Hexagon had it under a different name to the other backends. llvm-svn: 315445	2017-10-11 09:17:43 +00:00
Yonghong Song	e9165f8720	bpf: add new insns for bswap_to_le and negation ... This patch adds new insn, "reg = be16/be32/be64 reg", for bswap to little endian for big-endian target (bpfeb). It also adds new insn for negation "reg = -reg". Currently, for source code, e.g., b = -a LLVM still prefers to generate: b = 0 - a But "reg = -reg" format can be used in assembly code. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 314376	2017-09-28 02:46:11 +00:00
Yonghong Song	06ff655e59	bpf: Add BPF AsmParser support in LLVM ... Reviewed-by: Yonghong Song <yhs@fb.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> llvm-svn: 313055	2017-09-12 17:55:23 +00:00