[PATCH RFC 2/2] LoongArch: BPF: Eliminate zero/sign extensions for 32-bit operations
From: Tiezhu Yang
Date: Sat Jul 11 2026 - 06:17:27 EST
Eliminate frequent and redundant zero-extensions and sign-extensions
for 32-bit operations. This prevents potential functional bugs caused
by incorrect extension selections and reduces runtime overhead.
For explicit 32-bit zero-extensions (imm == 1), generate a `lu32id`
instruction to guarantee the zero-extended form when they cannot be
bypassed by the look-ahead logic.
For other 32-bit arithmetic, emit LoongArch native 32-bit instructions
which inherently perform hardware-level sign-extension.
For bitwise logical instructions, append `addiw dst, dst, 0` to enforce
the standard sign-extended form of the result.
For 32-bit signed conditional jumps, remove redundant register copies
and pre-jump `emit_sext_32` helpers to leverage native branching, as
operands are now natively sign-extended.
For 32-bit unsigned conditional jumps, use `bstrpickd` to clear the
upper 32 bits of the operands.
For JSET bit-testing, maintain `addiw t1, t1, 0` in the jmp32 path to
ensure correctness.
With this patch, deliver an optimal native execution stream and reduce
the overall JIT image size.
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/loongarch/net/bpf_jit.c | 357 +++++++++++++++++++----------------
arch/loongarch/net/bpf_jit.h | 25 +--
2 files changed, 198 insertions(+), 184 deletions(-)
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index b8cef3ea5c6d..08a5903dd5a3 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -209,7 +209,7 @@ static void build_prologue(struct jit_ctx *ctx)
ctx->stack_size = stack_adjust;
if (ctx->arena_vm_start)
- move_imm(ctx, REG_ARENA, ctx->arena_vm_start, false);
+ move_imm(ctx, REG_ARENA, ctx->arena_vm_start);
}
static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
@@ -311,7 +311,6 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn)
* goto out;
*/
tc_ninsn = insn ? ctx->offset[insn+1] - ctx->offset[insn] : ctx->offset[0];
- emit_zext_32(ctx, a2, true);
off = offsetof(struct bpf_array, map.max_entries);
emit_insn(ctx, ldwu, t1, a1, off);
@@ -361,7 +360,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn)
static void emit_store_stack_imm64(struct jit_ctx *ctx, int reg, int stack_off, u64 imm64)
{
- move_imm(ctx, reg, imm64, false);
+ move_imm(ctx, reg, imm64);
emit_insn(ctx, std, reg, LOONGARCH_GPR_FP, stack_off);
}
@@ -377,7 +376,7 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
const s32 imm = insn->imm;
const bool isdw = BPF_SIZE(insn->code) == BPF_DW;
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, addd, t1, dst, t1);
move_reg(ctx, t3, src);
@@ -434,7 +433,6 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
return -EINVAL;
}
emit_insn(ctx, amaddb, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_H:
if (!cpu_has_lam_bh) {
@@ -442,11 +440,9 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
return -EINVAL;
}
emit_insn(ctx, amaddh, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_W:
emit_insn(ctx, amaddw, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_DW:
emit_insn(ctx, amaddd, src, t1, t3);
@@ -454,28 +450,22 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
}
break;
case BPF_AND | BPF_FETCH:
- if (isdw) {
+ if (isdw)
emit_insn(ctx, amandd, src, t1, t3);
- } else {
+ else
emit_insn(ctx, amandw, src, t1, t3);
- emit_zext_32(ctx, src, true);
- }
break;
case BPF_OR | BPF_FETCH:
- if (isdw) {
+ if (isdw)
emit_insn(ctx, amord, src, t1, t3);
- } else {
+ else
emit_insn(ctx, amorw, src, t1, t3);
- emit_zext_32(ctx, src, true);
- }
break;
case BPF_XOR | BPF_FETCH:
- if (isdw) {
+ if (isdw)
emit_insn(ctx, amxord, src, t1, t3);
- } else {
+ else
emit_insn(ctx, amxorw, src, t1, t3);
- emit_zext_32(ctx, src, true);
- }
break;
/* src = atomic_xchg(dst + off, src); */
case BPF_XCHG:
@@ -486,7 +476,6 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
return -EINVAL;
}
emit_insn(ctx, amswapb, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_H:
if (!cpu_has_lam_bh) {
@@ -494,11 +483,9 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
return -EINVAL;
}
emit_insn(ctx, amswaph, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_W:
emit_insn(ctx, amswapw, src, t1, t3);
- emit_zext_32(ctx, src, true);
break;
case BPF_DW:
emit_insn(ctx, amswapd, src, t1, t3);
@@ -516,13 +503,10 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4);
} else {
emit_insn(ctx, llw, r0, t1, 0);
- emit_zext_32(ctx, t2, true);
- emit_zext_32(ctx, r0, true);
emit_insn(ctx, bne, t2, r0, 4);
move_reg(ctx, t3, src);
emit_insn(ctx, scw, t3, t1, 0);
emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6);
- emit_zext_32(ctx, r0, true);
}
break;
default:
@@ -549,7 +533,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldbu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxbu, dst, src, t1);
}
break;
@@ -557,7 +541,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldhu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxhu, dst, src, t1);
}
break;
@@ -565,7 +549,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldwu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxwu, dst, src, t1);
}
break;
@@ -573,7 +557,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldd, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxd, dst, src, t1);
}
break;
@@ -596,7 +580,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxb, src, dst, t1);
}
break;
@@ -604,7 +588,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxh, src, dst, t1);
}
break;
@@ -612,7 +596,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, stw, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxw, src, dst, t1);
}
break;
@@ -620,7 +604,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, std, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxd, src, dst, t1);
}
break;
@@ -741,28 +725,32 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
switch (code) {
/* dst = src */
case BPF_ALU | BPF_MOV | BPF_X:
+ if (imm == 1) {
+ emit_insn(ctx, lu32id, reg, 0);
+ break;
+ }
+
+ emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO);
+ break;
case BPF_ALU64 | BPF_MOV | BPF_X:
if (insn_is_cast_user(insn)) {
move_reg(ctx, t1, src);
- emit_zext_32(ctx, t1, true);
- move_imm(ctx, dst, (ctx->user_vm_start >> 32) << 32, false);
+ move_imm(ctx, dst, (ctx->user_vm_start >> 32) << 32);
emit_insn(ctx, beq, t1, LOONGARCH_GPR_ZERO, 1);
emit_insn(ctx, or, t1, dst, t1);
move_reg(ctx, dst, t1);
break;
}
+
switch (off) {
case 0:
move_reg(ctx, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
case 8:
emit_insn(ctx, extwb, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
case 16:
emit_insn(ctx, extwh, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
case 32:
emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO);
@@ -773,202 +761,234 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = imm */
case BPF_ALU | BPF_MOV | BPF_K:
case BPF_ALU64 | BPF_MOV | BPF_K:
- move_imm(ctx, dst, imm, is32);
+ move_imm(ctx, dst, imm);
break;
/* dst = dst + src */
case BPF_ALU | BPF_ADD | BPF_X:
+ emit_insn(ctx, addw, dst, dst, src);
+ break;
case BPF_ALU64 | BPF_ADD | BPF_X:
emit_insn(ctx, addd, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst + imm */
case BPF_ALU | BPF_ADD | BPF_K:
+ if (is_signed_imm12(imm)) {
+ emit_insn(ctx, addiw, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, addw, dst, dst, t1);
+ }
+ break;
case BPF_ALU64 | BPF_ADD | BPF_K:
if (is_signed_imm12(imm)) {
emit_insn(ctx, addid, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, addd, dst, dst, t1);
}
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst - src */
case BPF_ALU | BPF_SUB | BPF_X:
+ emit_insn(ctx, subw, dst, dst, src);
+ break;
case BPF_ALU64 | BPF_SUB | BPF_X:
emit_insn(ctx, subd, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst - imm */
case BPF_ALU | BPF_SUB | BPF_K:
+ if (is_signed_imm12(-imm)) {
+ emit_insn(ctx, addiw, dst, dst, -imm);
+ } else {
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, subw, dst, dst, t1);
+ }
+ break;
case BPF_ALU64 | BPF_SUB | BPF_K:
if (is_signed_imm12(-imm)) {
emit_insn(ctx, addid, dst, dst, -imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, subd, dst, dst, t1);
}
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst * src */
case BPF_ALU | BPF_MUL | BPF_X:
+ emit_insn(ctx, mulw, dst, dst, src);
+ break;
case BPF_ALU64 | BPF_MUL | BPF_X:
emit_insn(ctx, muld, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst * imm */
case BPF_ALU | BPF_MUL | BPF_K:
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, mulw, dst, dst, t1);
+ break;
case BPF_ALU64 | BPF_MUL | BPF_K:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, muld, dst, dst, t1);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst / src */
case BPF_ALU | BPF_DIV | BPF_X:
+ if (!off)
+ emit_insn(ctx, divwu, dst, dst, src);
+ else
+ emit_insn(ctx, divw, dst, dst, src);
+ break;
case BPF_ALU64 | BPF_DIV | BPF_X:
- if (!off) {
- emit_zext_32(ctx, dst, is32);
- move_reg(ctx, t1, src);
- emit_zext_32(ctx, t1, is32);
- emit_insn(ctx, divdu, dst, dst, t1);
- emit_zext_32(ctx, dst, is32);
- } else {
- emit_sext_32(ctx, dst, is32);
- move_reg(ctx, t1, src);
- emit_sext_32(ctx, t1, is32);
- emit_insn(ctx, divd, dst, dst, t1);
- emit_sext_32(ctx, dst, is32);
- }
+ if (!off)
+ emit_insn(ctx, divdu, dst, dst, src);
+ else
+ emit_insn(ctx, divd, dst, dst, src);
break;
/* dst = dst / imm */
case BPF_ALU | BPF_DIV | BPF_K:
+ move_imm(ctx, t1, imm);
+ if (!off)
+ emit_insn(ctx, divwu, dst, dst, t1);
+ else
+ emit_insn(ctx, divw, dst, dst, t1);
+ break;
case BPF_ALU64 | BPF_DIV | BPF_K:
- if (!off) {
- move_imm(ctx, t1, imm, is32);
- emit_zext_32(ctx, dst, is32);
+ move_imm(ctx, t1, imm);
+ if (!off)
emit_insn(ctx, divdu, dst, dst, t1);
- emit_zext_32(ctx, dst, is32);
- } else {
- move_imm(ctx, t1, imm, false);
- emit_sext_32(ctx, t1, is32);
- emit_sext_32(ctx, dst, is32);
+ else
emit_insn(ctx, divd, dst, dst, t1);
- emit_sext_32(ctx, dst, is32);
- }
break;
/* dst = dst % src */
case BPF_ALU | BPF_MOD | BPF_X:
+ if (!off)
+ emit_insn(ctx, modwu, dst, dst, src);
+ else
+ emit_insn(ctx, modw, dst, dst, src);
+ break;
case BPF_ALU64 | BPF_MOD | BPF_X:
- if (!off) {
- emit_zext_32(ctx, dst, is32);
- move_reg(ctx, t1, src);
- emit_zext_32(ctx, t1, is32);
- emit_insn(ctx, moddu, dst, dst, t1);
- emit_zext_32(ctx, dst, is32);
- } else {
- emit_sext_32(ctx, dst, is32);
- move_reg(ctx, t1, src);
- emit_sext_32(ctx, t1, is32);
- emit_insn(ctx, modd, dst, dst, t1);
- emit_sext_32(ctx, dst, is32);
- }
+ if (!off)
+ emit_insn(ctx, moddu, dst, dst, src);
+ else
+ emit_insn(ctx, modd, dst, dst, src);
break;
/* dst = dst % imm */
case BPF_ALU | BPF_MOD | BPF_K:
+ move_imm(ctx, t1, imm);
+ if (!off)
+ emit_insn(ctx, modwu, dst, dst, t1);
+ else
+ emit_insn(ctx, modw, dst, dst, t1);
+ break;
case BPF_ALU64 | BPF_MOD | BPF_K:
- if (!off) {
- move_imm(ctx, t1, imm, is32);
- emit_zext_32(ctx, dst, is32);
+ move_imm(ctx, t1, imm);
+ if (!off)
emit_insn(ctx, moddu, dst, dst, t1);
- emit_zext_32(ctx, dst, is32);
- } else {
- move_imm(ctx, t1, imm, false);
- emit_sext_32(ctx, t1, is32);
- emit_sext_32(ctx, dst, is32);
+ else
emit_insn(ctx, modd, dst, dst, t1);
- emit_sext_32(ctx, dst, is32);
- }
break;
/* dst = -dst */
case BPF_ALU | BPF_NEG:
+ emit_insn(ctx, subw, dst, LOONGARCH_GPR_ZERO, dst);
+ break;
case BPF_ALU64 | BPF_NEG:
emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst & src */
case BPF_ALU | BPF_AND | BPF_X:
+ emit_insn(ctx, and, dst, dst, src);
+ emit_insn(ctx, addiw, dst, dst, 0);
+ break;
case BPF_ALU64 | BPF_AND | BPF_X:
emit_insn(ctx, and, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst & imm */
case BPF_ALU | BPF_AND | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, andi, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, and, dst, dst, t1);
+ }
+ emit_insn(ctx, addiw, dst, dst, 0);
case BPF_ALU64 | BPF_AND | BPF_K:
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, andi, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, and, dst, dst, t1);
}
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst | src */
case BPF_ALU | BPF_OR | BPF_X:
+ emit_insn(ctx, or, dst, dst, src);
+ emit_insn(ctx, addiw, dst, dst, 0);
+ break;
case BPF_ALU64 | BPF_OR | BPF_X:
emit_insn(ctx, or, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst | imm */
case BPF_ALU | BPF_OR | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, ori, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, or, dst, dst, t1);
+ }
+ emit_insn(ctx, addiw, dst, dst, 0);
+ break;
case BPF_ALU64 | BPF_OR | BPF_K:
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, ori, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, or, dst, dst, t1);
}
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst ^ src */
case BPF_ALU | BPF_XOR | BPF_X:
+ emit_insn(ctx, xor, dst, dst, src);
+ emit_insn(ctx, addiw, dst, dst, 0);
+ break;
case BPF_ALU64 | BPF_XOR | BPF_X:
emit_insn(ctx, xor, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst ^ imm */
case BPF_ALU | BPF_XOR | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, xori, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, xor, dst, dst, t1);
+ }
+ emit_insn(ctx, addiw, dst, dst, 0);
+ break;
case BPF_ALU64 | BPF_XOR | BPF_K:
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, xori, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, xor, dst, dst, t1);
}
- emit_zext_32(ctx, dst, is32);
break;
/* dst = dst << src (logical) */
case BPF_ALU | BPF_LSH | BPF_X:
emit_insn(ctx, sllw, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_LSH | BPF_X:
emit_insn(ctx, slld, dst, dst, src);
break;
@@ -976,9 +996,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst << imm (logical) */
case BPF_ALU | BPF_LSH | BPF_K:
emit_insn(ctx, slliw, dst, dst, imm);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_LSH | BPF_K:
emit_insn(ctx, sllid, dst, dst, imm);
break;
@@ -986,9 +1004,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst >> src (logical) */
case BPF_ALU | BPF_RSH | BPF_X:
emit_insn(ctx, srlw, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_RSH | BPF_X:
emit_insn(ctx, srld, dst, dst, src);
break;
@@ -996,9 +1012,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst >> imm (logical) */
case BPF_ALU | BPF_RSH | BPF_K:
emit_insn(ctx, srliw, dst, dst, imm);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_RSH | BPF_K:
emit_insn(ctx, srlid, dst, dst, imm);
break;
@@ -1006,9 +1020,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst >> src (arithmetic) */
case BPF_ALU | BPF_ARSH | BPF_X:
emit_insn(ctx, sraw, dst, dst, src);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_ARSH | BPF_X:
emit_insn(ctx, srad, dst, dst, src);
break;
@@ -1016,9 +1028,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst >> imm (arithmetic) */
case BPF_ALU | BPF_ARSH | BPF_K:
emit_insn(ctx, sraiw, dst, dst, imm);
- emit_zext_32(ctx, dst, is32);
break;
-
case BPF_ALU64 | BPF_ARSH | BPF_K:
emit_insn(ctx, sraid, dst, dst, imm);
break;
@@ -1031,8 +1041,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
break;
case 32:
- /* zero-extend 32 bits into 64 bits */
- emit_zext_32(ctx, dst, is32);
+ emit_insn(ctx, addiw, dst, dst, 0);
break;
case 64:
/* do nothing */
@@ -1050,8 +1059,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
break;
case 32:
emit_insn(ctx, revb2w, dst, dst);
- /* clear the upper 32 bits */
- emit_zext_32(ctx, dst, true);
break;
case 64:
emit_insn(ctx, revbd, dst, dst);
@@ -1070,6 +1077,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ if (emit_cond_jmp(ctx, cond, dst, src, jmp_offset) < 0)
+ goto toofar;
+ break;
+
case BPF_JMP32 | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_X:
case BPF_JMP32 | BPF_JGT | BPF_X:
@@ -1081,17 +1093,15 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_JMP32 | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_X:
jmp_offset = bpf2la_offset(i, off, ctx);
- move_reg(ctx, t1, dst);
- move_reg(ctx, t2, src);
if (is_signed_bpf_cond(BPF_OP(code))) {
- emit_sext_32(ctx, t1, is32);
- emit_sext_32(ctx, t2, is32);
+ if (emit_cond_jmp(ctx, cond, dst, src, jmp_offset) < 0)
+ goto toofar;
} else {
- emit_zext_32(ctx, t1, is32);
- emit_zext_32(ctx, t2, is32);
+ emit_insn(ctx, bstrpickd, t1, dst, 31, 0);
+ emit_insn(ctx, bstrpickd, t2, src, 31, 0);
+ if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0)
+ goto toofar;
}
- if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0)
- goto toofar;
break;
/* PC += off if dst cond imm */
@@ -1105,6 +1115,17 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_K:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ if (imm) {
+ move_imm(ctx, t1, imm);
+ tm = t1;
+ } else {
+ tm = LOONGARCH_GPR_ZERO;
+ }
+
+ if (emit_cond_jmp(ctx, cond, dst, tm, jmp_offset) < 0)
+ goto toofar;
+ break;
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_K:
@@ -1117,41 +1138,55 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_JMP32 | BPF_JSLE | BPF_K:
jmp_offset = bpf2la_offset(i, off, ctx);
if (imm) {
- move_imm(ctx, t1, imm, false);
+ move_imm(ctx, t1, imm);
tm = t1;
} else {
- /* If imm is 0, simply use zero register. */
tm = LOONGARCH_GPR_ZERO;
}
- move_reg(ctx, t2, dst);
+
if (is_signed_bpf_cond(BPF_OP(code))) {
- emit_sext_32(ctx, tm, is32);
- emit_sext_32(ctx, t2, is32);
+ if (emit_cond_jmp(ctx, cond, dst, tm, jmp_offset) < 0)
+ goto toofar;
} else {
- emit_zext_32(ctx, tm, is32);
- emit_zext_32(ctx, t2, is32);
+ emit_insn(ctx, bstrpickd, t2, dst, 31, 0);
+ if (imm)
+ emit_insn(ctx, bstrpickd, t1, tm, 31, 0);
+ else
+ t1 = LOONGARCH_GPR_ZERO;
+
+ if (emit_cond_jmp(ctx, cond, t2, t1, jmp_offset) < 0)
+ goto toofar;
}
- if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0)
- goto toofar;
break;
/* PC += off if dst & src */
case BPF_JMP | BPF_JSET | BPF_X:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ emit_insn(ctx, and, t1, dst, src);
+ if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+ break;
case BPF_JMP32 | BPF_JSET | BPF_X:
jmp_offset = bpf2la_offset(i, off, ctx);
emit_insn(ctx, and, t1, dst, src);
- emit_zext_32(ctx, t1, is32);
+ emit_insn(ctx, addiw, t1, t1, 0);
if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
goto toofar;
break;
/* PC += off if dst & imm */
case BPF_JMP | BPF_JSET | BPF_K:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ move_imm(ctx, t1, imm);
+ emit_insn(ctx, and, t1, dst, t1);
+ if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+ break;
case BPF_JMP32 | BPF_JSET | BPF_K:
jmp_offset = bpf2la_offset(i, off, ctx);
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
emit_insn(ctx, and, t1, dst, t1);
- emit_zext_32(ctx, t1, is32);
+ emit_insn(ctx, addiw, t1, t1, 0);
if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
goto toofar;
break;
@@ -1241,7 +1276,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (bpf_pseudo_func(insn))
move_addr(ctx, dst, imm64);
else
- move_imm(ctx, dst, imm64, is32);
+ move_imm(ctx, dst, imm64);
return 1;
}
@@ -1282,7 +1317,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldbu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxb, dst, src, t1);
else
@@ -1296,7 +1331,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldhu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxh, dst, src, t1);
else
@@ -1310,7 +1345,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldwu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxw, dst, src, t1);
else
@@ -1318,7 +1353,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
}
break;
case BPF_DW:
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxd, dst, src, t1);
break;
}
@@ -1353,42 +1388,42 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
switch (BPF_SIZE(code)) {
case BPF_B:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxb, t1, dst, t2);
}
break;
case BPF_H:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxh, t1, dst, t2);
}
break;
case BPF_W:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, stw, t1, dst, off);
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrw, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxw, t1, dst, t2);
}
break;
case BPF_DW:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, std, t1, dst, off);
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrd, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxd, t1, dst, t2);
}
break;
@@ -1419,7 +1454,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxb, src, dst, t1);
}
break;
@@ -1427,7 +1462,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxh, src, dst, t1);
}
break;
@@ -1437,7 +1472,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrw, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxw, src, dst, t1);
}
break;
@@ -1447,7 +1482,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrd, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxd, src, dst, t1);
}
break;
@@ -1559,7 +1594,7 @@ static int emit_jump_and_link(struct jit_ctx *ctx, u8 rd, u64 target)
return -EFAULT;
}
- move_imm(ctx, LOONGARCH_GPR_T1, target, false);
+ move_imm(ctx, LOONGARCH_GPR_T1, target);
emit_insn(ctx, jirl, rd, LOONGARCH_GPR_T1, 0);
return 0;
@@ -1733,7 +1768,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *n,
emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off);
/* arg1: prog */
- move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
+ move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p);
/* arg2: &run_ctx */
emit_insn(ctx, addid, LOONGARCH_GPR_A1, LOONGARCH_GPR_FP, -run_ctx_off);
ret = emit_call(ctx, (const u64)bpf_trampoline_enter(p));
@@ -1754,7 +1789,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *n,
/* arg1: &args_off */
emit_insn(ctx, addid, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -args_off);
if (!p->jited)
- move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi, false);
+ move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi);
ret = emit_call(ctx, (const u64)p->bpf_func);
if (ret)
return ret;
@@ -1771,7 +1806,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *n,
}
/* arg1: prog */
- move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
+ move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p);
/* arg2: prog start time */
move_reg(ctx, LOONGARCH_GPR_A1, LOONGARCH_GPR_S1);
/* arg3: &run_ctx */
diff --git a/arch/loongarch/net/bpf_jit.h b/arch/loongarch/net/bpf_jit.h
index bb58c42c2f2a..2bd0dc5b911c 100644
--- a/arch/loongarch/net/bpf_jit.h
+++ b/arch/loongarch/net/bpf_jit.h
@@ -72,24 +72,6 @@ static inline int epilogue_offset(const struct jit_ctx *ctx)
return (to - from);
}
-/* Zero-extend 32 bits into 64 bits */
-static inline void emit_zext_32(struct jit_ctx *ctx, enum loongarch_gpr reg, bool is32)
-{
- if (!is32)
- return;
-
- emit_insn(ctx, lu32id, reg, 0);
-}
-
-/* Signed-extend 32 bits into 64 bits */
-static inline void emit_sext_32(struct jit_ctx *ctx, enum loongarch_gpr reg, bool is32)
-{
- if (!is32)
- return;
-
- emit_insn(ctx, addiw, reg, reg, 0);
-}
-
/* Emit proper extension according to ABI requirements.
* Note that it requires a value of size `size` already resides in register `reg`.
*/
@@ -137,7 +119,7 @@ static inline void move_addr(struct jit_ctx *ctx, enum loongarch_gpr rd, u64 add
emit_insn(ctx, lu52id, rd, rd, imm_63_52);
}
-static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm, bool is32)
+static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm)
{
long imm_11_0, imm_31_12, imm_51_32, imm_63_52, imm_51_0, imm_51_31;
@@ -150,7 +132,7 @@ static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm
/* addiw rd, $zero, imm_11_0 */
if (is_signed_imm12(imm)) {
emit_insn(ctx, addiw, rd, LOONGARCH_GPR_ZERO, imm);
- goto zext;
+ return;
}
/* ori rd, $zero, imm_11_0 */
@@ -195,9 +177,6 @@ static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm
if (!is_signed_imm52(imm))
emit_insn(ctx, lu52id, rd, rd, imm_63_52);
}
-
-zext:
- emit_zext_32(ctx, rd, is32);
}
static inline void move_reg(struct jit_ctx *ctx, enum loongarch_gpr rd,
--
2.42.0