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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_LOOP | BC_PARSE_FLAG_LOOP_INNER | BC_PARSE_FLAG_IF | \
BC_PARSE_FLAG_ELSE | BC_PARSE_FLAG_IF_END))) BC_PARSE_FLAG_ELSE | BC_PARSE_FLAG_IF_END)))
typedef struct BcOp {
char prec;
bool left;
} BcOp;
typedef struct BcParseNext { typedef struct BcParseNext {
uint32_t len; uint32_t len;
BcLexType tokens[4]; 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. // This is an array of data for operators that correspond to token types.
static const BcOp bc_parse_ops[] = { static const uint8_t bc_parse_ops[] = {
{ 0, false }, { 0, false }, #define OP(p,l) ((int)(l) * 0x10 + (p))
{ 1, false }, OP(0, false), OP( 0, false ),
{ 2, false }, OP(1, false),
{ 3, true }, { 3, true }, { 3, true }, OP(2, false),
{ 4, true }, { 4, true }, OP(3, true ), OP( 3, true ), OP( 3, true ),
{ 6, true }, { 6, true }, { 6, true }, { 6, true }, { 6, true }, { 6, true }, OP(4, true ), OP( 4, true ),
{ 1, false }, OP(6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ), OP( 6, true ),
{ 7, true }, { 7, true }, OP(1, false),
{ 5, false }, { 5, false }, { 5, false }, { 5, false }, { 5, false }, OP(7, true ), OP( 7, true ),
{ 5, false }, { 5, false }, 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. // These identify what tokens can come after expressions in certain cases.
static const BcParseNext bc_parse_next_expr = 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; BcStatus s = BC_STATUS_SUCCESS;
BcLexType t; BcLexType t;
char l, r = bc_parse_ops[type - BC_LEX_OP_INC].prec; char l, r = bc_parse_op_PREC(type - BC_LEX_OP_INC);
bool left = bc_parse_ops[type - BC_LEX_OP_INC].left; bool left = bc_parse_op_LEFT(type - BC_LEX_OP_INC);
while (p->ops.len > start) { while (p->ops.len > start) {
t = BC_PARSE_TOP_OP(p); t = BC_PARSE_TOP_OP(p);
if (t == BC_LEX_LPAREN) break; 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; if (l >= r && (l != r || !left)) break;
bc_parse_push(p, BC_PARSE_TOKEN_INST(t)); bc_parse_push(p, BC_PARSE_TOKEN_INST(t));