From c0efbb6dc2726785482d85a284c883d541a6e0be Mon Sep 17 00:00:00 2001 From: Franck Bui-Huu Date: Thu, 3 Aug 2006 09:29:15 +0200 Subject: [PATCH] [MIPS] Make get_frame_info() more readable. Signed-off-by: Atsushi Nemoto Signed-off-by: Franck Bui-Huu Signed-off-by: Ralf Baechle --- arch/mips/kernel/process.c | 67 ++++++++++++++++++++------------------ 1 file changed, 36 insertions(+), 31 deletions(-) diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 8709a46a45c1..93d5432759db 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -281,48 +281,53 @@ static struct mips_frame_info { } *schedule_frame, mfinfo[64]; static int mfinfo_num; +static inline int is_ra_save_ins(union mips_instruction *ip) +{ + /* sw / sd $ra, offset($sp) */ + return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && + ip->i_format.rs == 29 && + ip->i_format.rt == 31; +} + +static inline int is_jal_jalr_jr_ins(union mips_instruction *ip) +{ + if (ip->j_format.opcode == jal_op) + return 1; + if (ip->r_format.opcode != spec_op) + return 0; + return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; +} + +static inline int is_sp_move_ins(union mips_instruction *ip) +{ + /* addiu/daddiu sp,sp,-imm */ + if (ip->i_format.rs != 29 || ip->i_format.rt != 29) + return 0; + if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) + return 1; + return 0; +} + static int get_frame_info(struct mips_frame_info *info) { - int i; - void *func = info->func; - union mips_instruction *ip = (union mips_instruction *)func; + union mips_instruction *ip = info->func; + int i, max_insns = + min(128UL, info->func_size / sizeof(union mips_instruction)); + info->pc_offset = -1; info->frame_size = 0; - for (i = 0; i < 128; i++, ip++) { - /* if jal, jalr, jr, stop. */ - if (ip->j_format.opcode == jal_op || - (ip->r_format.opcode == spec_op && - (ip->r_format.func == jalr_op || - ip->r_format.func == jr_op))) - break; - if (info->func_size && i >= info->func_size / 4) + for (i = 0; i < max_insns; i++, ip++) { + + if (is_jal_jalr_jr_ins(ip)) break; - if ( -#ifdef CONFIG_32BIT - ip->i_format.opcode == addiu_op && -#endif -#ifdef CONFIG_64BIT - ip->i_format.opcode == daddiu_op && -#endif - ip->i_format.rs == 29 && - ip->i_format.rt == 29) { - /* addiu/daddiu sp,sp,-imm */ + if (is_sp_move_ins(ip)) { if (info->frame_size) continue; info->frame_size = - ip->i_format.simmediate; } - if ( -#ifdef CONFIG_32BIT - ip->i_format.opcode == sw_op && -#endif -#ifdef CONFIG_64BIT - ip->i_format.opcode == sd_op && -#endif - ip->i_format.rs == 29 && - ip->i_format.rt == 31) { - /* sw / sd $ra, offset($sp) */ + if (is_ra_save_ins(ip)) { if (info->pc_offset != -1) continue; info->pc_offset = -- 2.30.2