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Commit 6035b3fa authored by David Daney's avatar David Daney Committed by David S. Miller
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MIPS,bpf: Cache value of BPF_OP(insn->code) in eBPF JIT. 



The code looks a little cleaner if we replace BPF_OP(insn->code) with
the local variable bpf_op.  Caching the value this way also saves 300
bytes (about 1%) in the code size of the JIT.

Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a67b375f

arch/mips/net/ebpf_jit.c

+34 −33
Original line number Diff line number Diff line
@@ -670,6 +670,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
	unsigned int target;

	u64 t64;

	s64 t64s;

	int bpf_op = BPF_OP(insn->code);



	switch (insn->code) {

	case BPF_ALU64 | BPF_ADD | BPF_K: /* ALU64_IMM */
@@ -758,13 +759,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, sll, dst, dst, 0);

		if (insn->imm == 1) {

			/* div by 1 is a nop, mod by 1 is zero */

			if (BPF_OP(insn->code) == BPF_MOD)

			if (bpf_op == BPF_MOD)

				emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);

			break;

		}

		gen_imm_to_reg(insn, MIPS_R_AT, ctx);

		emit_instr(ctx, divu, dst, MIPS_R_AT);

		if (BPF_OP(insn->code) == BPF_DIV)

		if (bpf_op == BPF_DIV)

			emit_instr(ctx, mflo, dst);

		else

			emit_instr(ctx, mfhi, dst);
@@ -786,13 +787,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 


		if (insn->imm == 1) {

			/* div by 1 is a nop, mod by 1 is zero */

			if (BPF_OP(insn->code) == BPF_MOD)

			if (bpf_op == BPF_MOD)

				emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);

			break;

		}

		gen_imm_to_reg(insn, MIPS_R_AT, ctx);

		emit_instr(ctx, ddivu, dst, MIPS_R_AT);

		if (BPF_OP(insn->code) == BPF_DIV)

		if (bpf_op == BPF_DIV)

			emit_instr(ctx, mflo, dst);

		else

			emit_instr(ctx, mfhi, dst);
@@ -817,7 +818,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);

		did_move = false;

		if (insn->src_reg == BPF_REG_10) {

			if (BPF_OP(insn->code) == BPF_MOV) {

			if (bpf_op == BPF_MOV) {

				emit_instr(ctx, daddiu, dst, MIPS_R_SP, MAX_BPF_STACK);

				did_move = true;

			} else {
@@ -827,7 +828,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
		} else if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {

			int tmp_reg = MIPS_R_AT;



			if (BPF_OP(insn->code) == BPF_MOV) {

			if (bpf_op == BPF_MOV) {

				tmp_reg = dst;

				did_move = true;

			}
@@ -835,7 +836,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, dinsu, tmp_reg, MIPS_R_ZERO, 32, 32);

			src = MIPS_R_AT;

		}

		switch (BPF_OP(insn->code)) {

		switch (bpf_op) {

		case BPF_MOV:

			if (!did_move)

				emit_instr(ctx, daddu, dst, src, MIPS_R_ZERO);
@@ -867,7 +868,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);

			emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);

			emit_instr(ctx, ddivu, dst, src);

			if (BPF_OP(insn->code) == BPF_DIV)

			if (bpf_op == BPF_DIV)

				emit_instr(ctx, mflo, dst);

			else

				emit_instr(ctx, mfhi, dst);
@@ -911,7 +912,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
		if (ts == REG_64BIT || ts == REG_32BIT_ZERO_EX) {

			int tmp_reg = MIPS_R_AT;



			if (BPF_OP(insn->code) == BPF_MOV) {

			if (bpf_op == BPF_MOV) {

				tmp_reg = dst;

				did_move = true;

			}
@@ -919,7 +920,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, sll, tmp_reg, src, 0);

			src = MIPS_R_AT;

		}

		switch (BPF_OP(insn->code)) {

		switch (bpf_op) {

		case BPF_MOV:

			if (!did_move)

				emit_instr(ctx, addu, dst, src, MIPS_R_ZERO);
@@ -950,7 +951,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);

			emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);

			emit_instr(ctx, divu, dst, src);

			if (BPF_OP(insn->code) == BPF_DIV)

			if (bpf_op == BPF_DIV)

				emit_instr(ctx, mflo, dst);

			else

				emit_instr(ctx, mfhi, dst);
@@ -977,7 +978,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
		break;

	case BPF_JMP | BPF_JEQ | BPF_K: /* JMP_IMM */

	case BPF_JMP | BPF_JNE | BPF_K: /* JMP_IMM */

		cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);

		cmp_eq = (bpf_op == BPF_JEQ);

		dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);

		if (dst < 0)

			return dst;
@@ -1012,18 +1013,18 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, sll, MIPS_R_AT, dst, 0);

			dst = MIPS_R_AT;

		}

		if (BPF_OP(insn->code) == BPF_JSET) {

		if (bpf_op == BPF_JSET) {

			emit_instr(ctx, and, MIPS_R_AT, dst, src);

			cmp_eq = false;

			dst = MIPS_R_AT;

			src = MIPS_R_ZERO;

		} else if (BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSLE) {

		} else if (bpf_op == BPF_JSGT || bpf_op == BPF_JSLE) {

			emit_instr(ctx, dsubu, MIPS_R_AT, dst, src);

			if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {

				b_off = b_imm(exit_idx, ctx);

				if (is_bad_offset(b_off))

					return -E2BIG;

				if (BPF_OP(insn->code) == BPF_JSGT)

				if (bpf_op == BPF_JSGT)

					emit_instr(ctx, blez, MIPS_R_AT, b_off);

				else

					emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
@@ -1033,18 +1034,18 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			b_off = b_imm(this_idx + insn->off + 1, ctx);

			if (is_bad_offset(b_off))

				return -E2BIG;

			if (BPF_OP(insn->code) == BPF_JSGT)

			if (bpf_op == BPF_JSGT)

				emit_instr(ctx, bgtz, MIPS_R_AT, b_off);

			else

				emit_instr(ctx, blez, MIPS_R_AT, b_off);

			emit_instr(ctx, nop);

			break;

		} else if (BPF_OP(insn->code) == BPF_JSGE || BPF_OP(insn->code) == BPF_JSLT) {

		} else if (bpf_op == BPF_JSGE || bpf_op == BPF_JSLT) {

			emit_instr(ctx, slt, MIPS_R_AT, dst, src);

			cmp_eq = BPF_OP(insn->code) == BPF_JSGE;

			cmp_eq = bpf_op == BPF_JSGE;

			dst = MIPS_R_AT;

			src = MIPS_R_ZERO;

		} else if (BPF_OP(insn->code) == BPF_JGT || BPF_OP(insn->code) == BPF_JLE) {

		} else if (bpf_op == BPF_JGT || bpf_op == BPF_JLE) {

			/* dst or src could be AT */

			emit_instr(ctx, dsubu, MIPS_R_T8, dst, src);

			emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
@@ -1052,16 +1053,16 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			emit_instr(ctx, movz, MIPS_R_T9, MIPS_R_SP, MIPS_R_T8);

			emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_ZERO, MIPS_R_T8);

			emit_instr(ctx, or, MIPS_R_AT, MIPS_R_T9, MIPS_R_AT);

			cmp_eq = BPF_OP(insn->code) == BPF_JGT;

			cmp_eq = bpf_op == BPF_JGT;

			dst = MIPS_R_AT;

			src = MIPS_R_ZERO;

		} else if (BPF_OP(insn->code) == BPF_JGE || BPF_OP(insn->code) == BPF_JLT) {

		} else if (bpf_op == BPF_JGE || bpf_op == BPF_JLT) {

			emit_instr(ctx, sltu, MIPS_R_AT, dst, src);

			cmp_eq = BPF_OP(insn->code) == BPF_JGE;

			cmp_eq = bpf_op == BPF_JGE;

			dst = MIPS_R_AT;

			src = MIPS_R_ZERO;

		} else { /* JNE/JEQ case */

			cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);

			cmp_eq = (bpf_op == BPF_JEQ);

		}

jeq_common:

		/*
@@ -1122,7 +1123,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
	case BPF_JMP | BPF_JSGE | BPF_K: /* JMP_IMM */

	case BPF_JMP | BPF_JSLT | BPF_K: /* JMP_IMM */

	case BPF_JMP | BPF_JSLE | BPF_K: /* JMP_IMM */

		cmp_eq = (BPF_OP(insn->code) == BPF_JSGE);

		cmp_eq = (bpf_op == BPF_JSGE);

		dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);

		if (dst < 0)

			return dst;
@@ -1132,7 +1133,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
				b_off = b_imm(exit_idx, ctx);

				if (is_bad_offset(b_off))

					return -E2BIG;

				switch (BPF_OP(insn->code)) {

				switch (bpf_op) {

				case BPF_JSGT:

					emit_instr(ctx, blez, dst, b_off);

					break;
@@ -1152,7 +1153,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			b_off = b_imm(this_idx + insn->off + 1, ctx);

			if (is_bad_offset(b_off))

				return -E2BIG;

			switch (BPF_OP(insn->code)) {

			switch (bpf_op) {

			case BPF_JSGT:

				emit_instr(ctx, bgtz, dst, b_off);

				break;
@@ -1173,14 +1174,14 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
		 * only "LT" compare available, so we must use imm + 1

		 * to generate "GT" and imm -1 to generate LE

		 */

		if (BPF_OP(insn->code) == BPF_JSGT)

		if (bpf_op == BPF_JSGT)

			t64s = insn->imm + 1;

		else if (BPF_OP(insn->code) == BPF_JSLE)

		else if (bpf_op == BPF_JSLE)

			t64s = insn->imm + 1;

		else

			t64s = insn->imm;



		cmp_eq = BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSGE;

		cmp_eq = bpf_op == BPF_JSGT || bpf_op == BPF_JSGE;

		if (t64s >= S16_MIN && t64s <= S16_MAX) {

			emit_instr(ctx, slti, MIPS_R_AT, dst, (int)t64s);

			src = MIPS_R_AT;
@@ -1197,7 +1198,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
	case BPF_JMP | BPF_JGE | BPF_K:

	case BPF_JMP | BPF_JLT | BPF_K:

	case BPF_JMP | BPF_JLE | BPF_K:

		cmp_eq = (BPF_OP(insn->code) == BPF_JGE);

		cmp_eq = (bpf_op == BPF_JGE);

		dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);

		if (dst < 0)

			return dst;
@@ -1205,14 +1206,14 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
		 * only "LT" compare available, so we must use imm + 1

		 * to generate "GT" and imm -1 to generate LE

		 */

		if (BPF_OP(insn->code) == BPF_JGT)

		if (bpf_op == BPF_JGT)

			t64s = (u64)(u32)(insn->imm) + 1;

		else if (BPF_OP(insn->code) == BPF_JLE)

		else if (bpf_op == BPF_JLE)

			t64s = (u64)(u32)(insn->imm) + 1;

		else

			t64s = (u64)(u32)(insn->imm);



		cmp_eq = BPF_OP(insn->code) == BPF_JGT || BPF_OP(insn->code) == BPF_JGE;

		cmp_eq = bpf_op == BPF_JGT || bpf_op == BPF_JGE;



		emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);

		emit_instr(ctx, sltu, MIPS_R_AT, dst, MIPS_R_AT);