diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2018-04-06 18:55:35 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2018-04-06 19:01:51 +0200 |
| commit | 2c9970281083a99acfa3aec8c6d41db955cb583d (patch) | |
| tree | a23a795566d790478d3d1b7a17edc0cea96c2dd6 | |
| parent | 2ab994f7079daa052f8816b72e215e1609d41f76 (diff) | |
| download | busybox-2c9970281083a99acfa3aec8c6d41db955cb583d.tar.gz | |
i386: make stack size optimization selectable, and allow i486 insns (bswap)
It's hard to imagine someone still using non-bswap equipped CPU
function old new delta
xmalloc_optname_optval 888 879 -9
write_leases 214 205 -9
write32 36 27 -9
update_status 612 603 -9
udhcpd_main 1468 1459 -9
udhcpc_main 2708 2699 -9
udhcp_run_script 804 795 -9
sha256_process_block64 423 414 -9
sha1_process_block64 337 328 -9
sha1_end 80 71 -9
send_ACK 161 152 -9
select_lease_time 64 55 -9
rpm_getint 118 109 -9
readprofile_main 1719 1710 -9
read32 33 24 -9
rdate_main 236 227 -9
machtime 39 30 -9
inet_addr_match 103 94 -9
get_prefix 344 335 -9
f_write32 31 22 -9
f_read32 31 22 -9
dumpleases_main 620 611 -9
KeyExpansion 197 188 -9
udhcp_str2optset 536 518 -18
read_config 222 204 -18
lfp_to_d 55 37 -18
ipaddr_modify 1226 1208 -18
dnsd_main 1278 1260 -18
des_crypt 1344 1326 -18
d_to_lfp 106 88 -18
bb_bswap_64 29 11 -18
INET_setroute 827 809 -18
read_leases 330 309 -21
zcip_main 1256 1229 -27
send_offer 476 449 -27
ipcalc_main 534 507 -27
handle_incoming_and_exit 2821 2794 -27
fmt_time_bernstein_25 131 104 -27
common_traceroute_main 3804 3768 -36
rpm_gettags 451 397 -54
parse_args 1412 1358 -54
volume_id_probe_hfs_hfsplus 627 564 -63
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/42 up/down: 0/-732) Total: -732 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | Config.in | 8 | ||||
| -rw-r--r-- | arch/i386/Makefile | 8 |
2 files changed, 15 insertions, 1 deletions
@@ -518,6 +518,14 @@ config USE_PORTABLE_CODE compiler other than gcc. If you do use gcc, this option may needlessly increase code size. +config STACK_OPTIMIZATION_386 + bool "Use -mpreferred-stack-boundary=2 on i386 arch" + default y + help + This option makes for smaller code, but some libc versions + do not work with it (they use SSE instructions without + ensuring stack alignment). + comment 'Installation Options ("make install" behavior)' choice diff --git a/arch/i386/Makefile b/arch/i386/Makefile index e6c99c67d..425361fd9 100644 --- a/arch/i386/Makefile +++ b/arch/i386/Makefile @@ -2,6 +2,12 @@ # Build system # ========================================================================== +# Allow i486 insns (basically, bswap insn) +# Do not try to tune for 486+ (might add padding) +CFLAGS += $(call cc-option,-march=i486 -mtune=i386,) + +ifeq ($(CONFIG_STACK_OPTIMIZATION_386),y) # -mpreferred-stack-boundary=2 is essential in preventing gcc 4.2.x # from aligning stack to 16 bytes. (Which is gcc's way of supporting SSE). -CFLAGS += $(call cc-option,-march=i386 -mpreferred-stack-boundary=2,) +CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2,) +endif |