[PATCH bpf-next v3 6/6] riscv, bpf: Optimize bswap insns with Zbb support
Pu Lehui
pulehui at huawei.com
Mon Jan 15 04:54:27 PST 2024
Optimize bswap instructions by rev8 Zbb instruction conbined with srli
instruction. And Optimize 16-bit zero-extension with Zbb support.
Signed-off-by: Pu Lehui <pulehui at huawei.com>
---
arch/riscv/net/bpf_jit.h | 69 +++++++++++++++++++++++++++++++++
arch/riscv/net/bpf_jit_comp64.c | 50 +-----------------------
2 files changed, 71 insertions(+), 48 deletions(-)
diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h
index b00c5c0591d2..8b35f12a4452 100644
--- a/arch/riscv/net/bpf_jit.h
+++ b/arch/riscv/net/bpf_jit.h
@@ -1146,12 +1146,81 @@ static inline void emit_sextw(u8 rd, u8 rs, struct rv_jit_context *ctx)
emit_addiw(rd, rs, 0, ctx);
}
+static inline void emit_zexth(u8 rd, u8 rs, struct rv_jit_context *ctx)
+{
+ if (rvzbb_enabled()) {
+ emit(rvzbb_zexth(rd, rs), ctx);
+ return;
+ }
+
+ emit_slli(rd, rs, 48, ctx);
+ emit_srli(rd, rd, 48, ctx);
+}
+
static inline void emit_zextw(u8 rd, u8 rs, struct rv_jit_context *ctx)
{
emit_slli(rd, rs, 32, ctx);
emit_srli(rd, rd, 32, ctx);
}
+static inline void emit_bswap(u8 rd, s32 imm, struct rv_jit_context *ctx)
+{
+ if (rvzbb_enabled()) {
+ int bits = 64 - imm;
+
+ emit(rvzbb_rev8(rd, rd), ctx);
+ if (bits)
+ emit_srli(rd, rd, bits, ctx);
+ return;
+ }
+
+ emit_li(RV_REG_T2, 0, ctx);
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+ if (imm == 16)
+ goto out_be;
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+ if (imm == 32)
+ goto out_be;
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+ emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
+ emit_srli(rd, rd, 8, ctx);
+out_be:
+ emit_andi(RV_REG_T1, rd, 0xff, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
+
+ emit_mv(rd, RV_REG_T2, ctx);
+}
+
#endif /* __riscv_xlen == 64 */
void bpf_jit_build_prologue(struct rv_jit_context *ctx);
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 18bbf8122eb3..e86e83649820 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1176,8 +1176,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
case BPF_ALU | BPF_END | BPF_FROM_LE:
switch (imm) {
case 16:
- emit_slli(rd, rd, 48, ctx);
- emit_srli(rd, rd, 48, ctx);
+ emit_zexth(rd, rd, ctx);
break;
case 32:
if (!aux->verifier_zext)
@@ -1188,54 +1187,9 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
break;
}
break;
-
case BPF_ALU | BPF_END | BPF_FROM_BE:
case BPF_ALU64 | BPF_END | BPF_FROM_LE:
- emit_li(RV_REG_T2, 0, ctx);
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
- if (imm == 16)
- goto out_be;
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
- if (imm == 32)
- goto out_be;
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
-
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
- emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx);
- emit_srli(rd, rd, 8, ctx);
-out_be:
- emit_andi(RV_REG_T1, rd, 0xff, ctx);
- emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx);
-
- emit_mv(rd, RV_REG_T2, ctx);
+ emit_bswap(rd, imm, ctx);
break;
/* dst = imm */
--
2.34.1
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