[PATCH v1 1/3] LoongArch: BPF: Remove redundant zext jumping in move_imm()

[Tiezhu Yang]

In move_imm(), when an immediate hits the 12-bit unsigned range, an
`ori rd, $zero, imm` instruction is emitted.

According to the manual, the ori instruction inherently performs a
logical or with zero-extended immediate operands against $zero, so
the upper 32 bits of the destination register `rd` are already 0.

However, the existing JIT code unconditionally executes `goto zext;`
after ori, forcing it to fallthrough into `emit_zext_32()` to clear
the upper 32 bits for 32-bit ALU operations.

Fix this redundancy by directly returning from the function inside
the `is_unsigned_imm12` block.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
 arch/loongarch/net/bpf_jit.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/loongarch/net/bpf_jit.h b/arch/loongarch/net/bpf_jit.h
index a8e29be35fa8..bb58c42c2f2a 100644
--- a/arch/loongarch/net/bpf_jit.h
+++ b/arch/loongarch/net/bpf_jit.h
@@ -156,7 +156,7 @@ static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm
 	/* ori rd, $zero, imm_11_0 */
 	if (is_unsigned_imm12(imm)) {
 		emit_insn(ctx, ori, rd, LOONGARCH_GPR_ZERO, imm);
-		goto zext;
+		return;
 	}
 
 	/* lu52id rd, $zero, imm_63_52 */
-- 
2.42.0