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bc: code shrink

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function                                             old     new   delta
bc_parse_operator                                    181     184      +3
bc_parse_ops                                          50      25     -25
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 3/-25)             Total: -22 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-05 19:37:19 +01:00
parent f381a88234
commit 6543758b13
1 changed files with 18 additions and 19 deletions
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37
miscutils/bc.c
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@ -627,11 +627,6 @@ typedef struct BcLex {
BC_PARSE_FLAG_LOOP | BC_PARSE_FLAG_LOOP_INNER | BC_PARSE_FLAG_IF | \
BC_PARSE_FLAG_ELSE | BC_PARSE_FLAG_IF_END)))
typedef struct BcOp {
char prec;
bool left;
} BcOp;
typedef struct BcParseNext {
uint32_t len;
BcLexType tokens[4];
@ -822,18 +817,22 @@ static const bool bc_parse_exprs[] = {
};
// This is an array of data for operators that correspond to token types.
static const BcOp bc_parse_ops[] = {
{ 0, false }, { 0, false },
{ 1, false },
{ 2, false },
{ 3, true }, { 3, true }, { 3, true },
{ 4, true }, { 4, true },
{ 6, true }, { 6, true }, { 6, true }, { 6, true }, { 6, true }, { 6, true },
{ 1, false },
{ 7, true }, { 7, true },
{ 5, false }, { 5, false }, { 5, false }, { 5, false }, { 5, false },
{ 5, false }, { 5, false },
static const uint8_t bc_parse_ops[] = {
#define OP(p,l) ((int)(l) * 0x10 + (p))
OP(0, false), OP( 0, false ),
OP(1, false),
OP(2, false),
OP(3, true ), OP( 3, true ), OP( 3, true ),
OP(4, true ), OP( 4, true ),
OP(6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ),
OP(1, false),
OP(7, true ), OP( 7, true ),
OP(5, false), OP( 5, false ), OP( 5, false ), OP( 5, false ), OP( 5, false ),
OP(5, false), OP( 5, false ),
#undef OP
};
#define bc_parse_op_PREC(i) (bc_parse_ops[i] & 0x0f)
#define bc_parse_op_LEFT(i) (bc_parse_ops[i] & 0x10)
// These identify what tokens can come after expressions in certain cases.
static const BcParseNext bc_parse_next_expr =
@ -3624,15 +3623,15 @@ static BcStatus bc_parse_operator(BcParse *p, BcLexType type, size_t start,
{
BcStatus s = BC_STATUS_SUCCESS;
BcLexType t;
char l, r = bc_parse_ops[type - BC_LEX_OP_INC].prec;
bool left = bc_parse_ops[type - BC_LEX_OP_INC].left;
char l, r = bc_parse_op_PREC(type - BC_LEX_OP_INC);
bool left = bc_parse_op_LEFT(type - BC_LEX_OP_INC);
while (p->ops.len > start) {
t = BC_PARSE_TOP_OP(p);
if (t == BC_LEX_LPAREN) break;
l = bc_parse_ops[t - BC_LEX_OP_INC].prec;
l = bc_parse_op_PREC(t - BC_LEX_OP_INC);
if (l >= r && (l != r || !left)) break;
bc_parse_push(p, BC_PARSE_TOKEN_INST(t));