Author: jilles
Date: Sat Jan 30 19:59:58 2016
New Revision: 295082
URL: https://svnweb.freebsd.org/changeset/base/295082
Log:
test: Optimize operator lookup.
The linear search using strcmp() shows up in pmcstat for several percent.
Split the operators into lengths and whether they start with '-' and compare
bytes using == instead of strcmp().
A simple test
sh -c 'i=0; w=$(printf %0100d 7); while [ "$i" -lt 1000000 ]; do
v=$(printf %sx%s "$w" "$w"); i=$((i+1)); done'
is over 4% faster on an amd64 bhyve VM.
Modified:
head/bin/test/test.c
Modified: head/bin/test/test.c
==============================================================================
--- head/bin/test/test.c Sat Jan 30 18:41:56 2016 (r295081)
+++ head/bin/test/test.c Sat Jan 30 19:59:58 2016 (r295082)
@@ -120,51 +120,53 @@ enum token {
#define TOKEN_TYPE(token) ((token) & 0xff00)
-static struct t_op {
- char op_text[4];
+static const struct t_op {
+ char op_text[2];
short op_num;
-} const ops [] = {
- {"-r", FILRD},
- {"-w", FILWR},
- {"-x", FILEX},
- {"-e", FILEXIST},
- {"-f", FILREG},
- {"-d", FILDIR},
- {"-c", FILCDEV},
- {"-b", FILBDEV},
- {"-p", FILFIFO},
- {"-u", FILSUID},
- {"-g", FILSGID},
- {"-k", FILSTCK},
- {"-s", FILGZ},
- {"-t", FILTT},
- {"-z", STREZ},
- {"-n", STRNZ},
- {"-h", FILSYM}, /* for backwards compat */
- {"-O", FILUID},
- {"-G", FILGID},
- {"-L", FILSYM},
- {"-S", FILSOCK},
+} ops1[] = {
{"=", STREQ},
- {"==", STREQ},
- {"!=", STRNE},
{"<", STRLT},
{">", STRGT},
- {"-eq", INTEQ},
- {"-ne", INTNE},
- {"-ge", INTGE},
- {"-gt", INTGT},
- {"-le", INTLE},
- {"-lt", INTLT},
- {"-nt", FILNT},
- {"-ot", FILOT},
- {"-ef", FILEQ},
{"!", UNOT},
- {"-a", BAND},
- {"-o", BOR},
{"(", LPAREN},
{")", RPAREN},
- {"", 0}
+}, opsm1[] = {
+ {"r", FILRD},
+ {"w", FILWR},
+ {"x", FILEX},
+ {"e", FILEXIST},
+ {"f", FILREG},
+ {"d", FILDIR},
+ {"c", FILCDEV},
+ {"b", FILBDEV},
+ {"p", FILFIFO},
+ {"u", FILSUID},
+ {"g", FILSGID},
+ {"k", FILSTCK},
+ {"s", FILGZ},
+ {"t", FILTT},
+ {"z", STREZ},
+ {"n", STRNZ},
+ {"h", FILSYM}, /* for backwards compat */
+ {"O", FILUID},
+ {"G", FILGID},
+ {"L", FILSYM},
+ {"S", FILSOCK},
+ {"a", BAND},
+ {"o", BOR},
+}, ops2[] = {
+ {"==", STREQ},
+ {"!=", STRNE},
+}, opsm2[] = {
+ {"eq", INTEQ},
+ {"ne", INTNE},
+ {"ge", INTGE},
+ {"gt", INTGT},
+ {"le", INTLE},
+ {"lt", INTLT},
+ {"nt", FILNT},
+ {"ot", FILOT},
+ {"ef", FILEQ},
};
static int nargc;
@@ -416,35 +418,71 @@ filstat(char *nm, enum token mode)
}
}
-static enum token
-t_lex(char *s)
+static int
+find_op_1char(const struct t_op *op, const struct t_op *end, const char *s)
{
- struct t_op const *op = ops;
+ char c;
- if (s == 0) {
- return EOI;
+ c = s[0];
+ while (op != end) {
+ if (c == *op->op_text)
+ return op->op_num;
+ op++;
}
- while (*op->op_text) {
- if (strcmp(s, op->op_text) == 0) {
- if (((TOKEN_TYPE(op->op_num) == UNOP ||
- TOKEN_TYPE(op->op_num) == BUNOP)
- && isunopoperand()) ||
- (op->op_num == LPAREN && islparenoperand()) ||
- (op->op_num == RPAREN && isrparenoperand()))
- break;
+ return OPERAND;
+}
+
+static int
+find_op_2char(const struct t_op *op, const struct t_op *end, const char *s)
+{
+ while (op != end) {
+ if (s[0] == op->op_text[0] && s[1] == op->op_text[1])
return op->op_num;
- }
op++;
}
return OPERAND;
}
static int
+find_op(const char *s)
+{
+ if (s[0] == '\0')
+ return OPERAND;
+ else if (s[1] == '\0')
+ return find_op_1char(ops1, (&ops1)[1], s);
+ else if (s[2] == '\0')
+ return s[0] == '-' ? find_op_1char(opsm1, (&opsm1)[1], s + 1) :
+ find_op_2char(ops2, (&ops2)[1], s);
+ else if (s[3] == '\0')
+ return s[0] == '-' ? find_op_2char(opsm2, (&opsm2)[1], s + 1) :
+ OPERAND;
+ else
+ return OPERAND;
+}
+
+static enum token
+t_lex(char *s)
+{
+ int num;
+
+ if (s == 0) {
+ return EOI;
+ }
+ num = find_op(s);
+ if (((TOKEN_TYPE(num) == UNOP || TOKEN_TYPE(num) == BUNOP)
+ && isunopoperand()) ||
+ (num == LPAREN && islparenoperand()) ||
+ (num == RPAREN && isrparenoperand()))
+ return OPERAND;
+ return num;
+}
+
+static int
isunopoperand(void)
{
- struct t_op const *op = ops;
char *s;
char *t;
+ int num;
if (nargc == 1)
return 1;
@@ -452,20 +490,16 @@ isunopoperand(void)
if (nargc == 2)
return parenlevel == 1 && strcmp(s, ")") == 0;
t = *(t_wp + 2);
- while (*op->op_text) {
- if (strcmp(s, op->op_text) == 0)
- return TOKEN_TYPE(op->op_num) == BINOP &&
- (parenlevel == 0 || t[0] != ')' || t[1] != '\0');
- op++;
- }
- return 0;
+ num = find_op(s);
+ return TOKEN_TYPE(num) == BINOP &&
+ (parenlevel == 0 || t[0] != ')' || t[1] != '\0');
}
static int
islparenoperand(void)
{
- struct t_op const *op = ops;
char *s;
+ int num;
if (nargc == 1)
return 1;
@@ -474,12 +508,8 @@ islparenoperand(void)
return parenlevel == 1 && strcmp(s, ")") == 0;
if (nargc != 3)
return 0;
- while (*op->op_text) {
- if (strcmp(s, op->op_text) == 0)
- return TOKEN_TYPE(op->op_num) == BINOP;
- op++;
- }
- return 0;
+ num = find_op(s);
+ return TOKEN_TYPE(num) == BINOP;
}
static int
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