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authorDenys Vlasenko <vda.linux@googlemail.com>2018-12-11 19:29:35 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2018-12-11 19:33:09 +0100
commit09d8df84ee908b940a31822c3480f36f817e4f09 (patch)
tree0d0f74ee0ad31cea2f31090161ac22b457650f00
parent7f4daa4f5842b26c5f3e233819e583573eeebaf6 (diff)
downloadbusybox-09d8df84ee908b940a31822c3480f36f817e4f09.tar.gz
bc: do not use "(cond ? f1 : f2)(params)" idiom, it messes up static function optimizations
With direct calls, GCC no longer thinks that we take addresses of the functions, and can use "more optimal" internal ABI for _all_ calls to these functions, not only at this callsite. On i486, regparm is used, and: function old new delta zbc_num_inv 56 57 +1 zbc_num_k 852 851 -1 zbc_program_modexp 558 556 -2 zbc_num_d 541 539 -2 bc_num_ulong2num 59 57 -2 zbc_program_num 840 836 -4 bc_num_zero 11 7 -4 bc_num_one 28 24 -4 bc_program_exec 3928 3918 -10 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/8 up/down: 1/-29) Total: -28 bytes text data bss dec hex filename 982237 485 7296 990018 f1b42 busybox_old 982209 485 7296 989990 f1b26 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--miscutils/bc.c60
1 files changed, 21 insertions, 39 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c
index 5ede8598d..e7f48fcea 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -5943,6 +5943,7 @@ static BcStatus bc_program_logical(char inst)
s = zbc_program_binOpPrep(&opd1, &n1, &opd2, &n2, false);
if (s) return s;
+
bc_num_init_DEF_SIZE(&res.d.n);
if (inst == BC_INST_BOOL_AND)
@@ -5950,50 +5951,31 @@ static BcStatus bc_program_logical(char inst)
else if (inst == BC_INST_BOOL_OR)
cond = bc_num_cmp(n1, &G.prog.zero) || bc_num_cmp(n2, &G.prog.zero);
else {
-
cmp = bc_num_cmp(n1, n2);
-
switch (inst) {
-
- case BC_INST_REL_EQ:
- {
- cond = cmp == 0;
- break;
- }
-
- case BC_INST_REL_LE:
- {
- cond = cmp <= 0;
- break;
- }
-
- case BC_INST_REL_GE:
- {
- cond = cmp >= 0;
- break;
- }
-
- case BC_INST_REL_NE:
- {
- cond = cmp != 0;
- break;
- }
-
- case BC_INST_REL_LT:
- {
- cond = cmp < 0;
- break;
- }
-
- case BC_INST_REL_GT:
- {
- cond = cmp > 0;
- break;
- }
+ case BC_INST_REL_EQ:
+ cond = cmp == 0;
+ break;
+ case BC_INST_REL_LE:
+ cond = cmp <= 0;
+ break;
+ case BC_INST_REL_GE:
+ cond = cmp >= 0;
+ break;
+ case BC_INST_REL_NE:
+ cond = cmp != 0;
+ break;
+ case BC_INST_REL_LT:
+ cond = cmp < 0;
+ break;
+ case BC_INST_REL_GT:
+ cond = cmp > 0;
+ break;
}
}
- (cond ? bc_num_one : bc_num_zero)(&res.d.n);
+ if (cond) bc_num_one(&res.d.n);
+ //else bc_num_zero(&res.d.n); - already is
bc_program_binOpRetire(&res);