diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-04-12 11:44:17 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-21 22:52:33 +1000 |
| commit | e7de0023e1232f42a10ef6af03352538cc27eaf6 (patch) | |
| tree | 1d64a3c35e86d7b7c89c4a4e6d92a7c81846ccc6 /arch/powerpc/net | |
| parent | d228cc4969663623e6b5a749b02e4619352a0a8d (diff) | |
powerpc/ebpf32: Rework 64 bits shifts to avoid tests and branches
Re-implement BPF_ALU64 | BPF_{LSH/RSH/ARSH} | BPF_X with branchless
implementation copied from misc_32.S.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/03167350b05b2fe8b741e53363ee37709d0f878d.1618227846.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/net')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp32.c | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index ca6fe1583460..ef21b09df76e 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -548,16 +548,15 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg)); break; case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ - EMIT(PPC_RAW_ADDIC_DOT(__REG_R0, src_reg, -32)); - PPC_BCC_SHORT(COND_LT, (ctx->idx + 4) * 4); - EMIT(PPC_RAW_SLW(dst_reg_h, dst_reg, __REG_R0)); - EMIT(PPC_RAW_LI(dst_reg, 0)); - PPC_JMP((ctx->idx + 6) * 4); + bpf_set_seen_register(ctx, tmp_reg); EMIT(PPC_RAW_SUBFIC(__REG_R0, src_reg, 32)); EMIT(PPC_RAW_SLW(dst_reg_h, dst_reg_h, src_reg)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); EMIT(PPC_RAW_SRW(__REG_R0, dst_reg, __REG_R0)); - EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_SLW(tmp_reg, dst_reg, tmp_reg)); EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, __REG_R0)); + EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, tmp_reg)); break; case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<= (u32) imm */ if (!imm) @@ -585,16 +584,15 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg)); break; case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ - EMIT(PPC_RAW_ADDIC_DOT(__REG_R0, src_reg, -32)); - PPC_BCC_SHORT(COND_LT, (ctx->idx + 4) * 4); - EMIT(PPC_RAW_SRW(dst_reg, dst_reg_h, __REG_R0)); - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - PPC_JMP((ctx->idx + 6) * 4); - EMIT(PPC_RAW_SUBFIC(0, src_reg, 32)); + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_SUBFIC(__REG_R0, src_reg, 32)); EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); EMIT(PPC_RAW_SLW(__REG_R0, dst_reg_h, __REG_R0)); - EMIT(PPC_RAW_SRW(dst_reg_h, dst_reg_h, src_reg)); + EMIT(PPC_RAW_SRW(tmp_reg, dst_reg_h, tmp_reg)); EMIT(PPC_RAW_OR(dst_reg, dst_reg, __REG_R0)); + EMIT(PPC_RAW_SRW(dst_reg_h, dst_reg_h, src_reg)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg)); break; case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ if (!imm) @@ -622,16 +620,17 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_SRAW(dst_reg_h, dst_reg, src_reg)); break; case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ - EMIT(PPC_RAW_ADDIC_DOT(__REG_R0, src_reg, -32)); - PPC_BCC_SHORT(COND_LT, (ctx->idx + 4) * 4); - EMIT(PPC_RAW_SRAW(dst_reg, dst_reg_h, __REG_R0)); - EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg_h, 31)); - PPC_JMP((ctx->idx + 6) * 4); - EMIT(PPC_RAW_SUBFIC(0, src_reg, 32)); + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_SUBFIC(__REG_R0, src_reg, 32)); EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg)); EMIT(PPC_RAW_SLW(__REG_R0, dst_reg_h, __REG_R0)); - EMIT(PPC_RAW_SRAW(dst_reg_h, dst_reg_h, src_reg)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); EMIT(PPC_RAW_OR(dst_reg, dst_reg, __REG_R0)); + EMIT(PPC_RAW_RLWINM(__REG_R0, tmp_reg, 0, 26, 26)); + EMIT(PPC_RAW_SRAW(tmp_reg, dst_reg_h, tmp_reg)); + EMIT(PPC_RAW_SRAW(dst_reg_h, dst_reg_h, src_reg)); + EMIT(PPC_RAW_SLW(tmp_reg, tmp_reg, __REG_R0)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg)); break; case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */ if (!imm) |