perf tools: Expression parser enhancements for metrics

Enhance the expression parser for more complex metric formulas.

- Support python style IF ELSE operators
- Add an #SMT_On magic variable for formulas that depend on the SMT
status.

Example: 4 *( CPU_CLK_UNHALTED.THREAD_ANY / 2 ) if #SMT_on else cycles

- Support MIN/MAX operations

Example: min(1 , IDQ.MITE_UOPS / ( UPI * 16 * ( ICACHE.HIT + ICACHE.MISSES ) / 4.0 ) )

This is useful to fix up problems caused by multiplexing.

- Support | & ^ operators
- Minor cleanups and fixes
- Support an \ escape for operators. This allows to specify event names
like c2-residency
- Support @ as an alternative for / to be able to specify pmus without
conflicts with operators (like msr/tsc/ as msr@tsc@)

Example: (cstate_core@c3\\-residency@ / msr@tsc@) * 100

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170811232634.30465-8-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index e93903295532a732eee2e6f4201421cef2eea14b..cb251bf523e7baf6679e945c185d81fa47d7c009 100644 (file)
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -31,6 +31,11 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
        ret |= test(&ctx, "(BAR/2)%2", 1);
        ret |= test(&ctx, "1 - -4",  5);
        ret |= test(&ctx, "(FOO-1)*2 + (BAR/2)%2 - -4",  5);
+       ret |= test(&ctx, "1-1 | 1", 1);
+       ret |= test(&ctx, "1-1 & 1", 0);
+       ret |= test(&ctx, "min(1,2) + 1", 2);
+       ret |= test(&ctx, "max(1,2) + 1", 3);
+       ret |= test(&ctx, "1+1 if 3*4 else 0", 2);
 
        if (ret)
                return ret;

diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 953e65ba2cc7135c7e3fd35e929d607f6c74d9e5..5753c4f21534a0bad6a4def087fb947bed999277 100644 (file)
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -4,6 +4,7 @@
 #include "util/debug.h"
 #define IN_EXPR_Y 1
 #include "expr.h"
+#include "smt.h"
 #include <string.h>
 
 #define MAXIDLEN 256
@@ -22,13 +23,15 @@
 
 %token <num> NUMBER
 %token <id> ID
+%token MIN MAX IF ELSE SMT_ON
+%left MIN MAX IF
 %left '|'
 %left '^'
 %left '&'
 %left '-' '+'
 %left '*' '/' '%'
 %left NEG NOT
-%type <num> expr
+%type <num> expr if_expr
 
 %{
 static int expr__lex(YYSTYPE *res, const char **pp);
@@ -57,7 +60,12 @@ static int lookup_id(struct parse_ctx *ctx, char *id, double *val)
 %}
 %%
 
-all_expr: expr                 { *final_val = $1; }
+all_expr: if_expr                      { *final_val = $1; }
+       ;
+
+if_expr:
+       expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
+       | expr
        ;
 
 expr:    NUMBER
@@ -66,13 +74,19 @@ expr:         NUMBER
                                        YYABORT;
                                  }
                                }
+       | expr '|' expr         { $$ = (long)$1 | (long)$3; }
+       | expr '&' expr         { $$ = (long)$1 & (long)$3; }
+       | expr '^' expr         { $$ = (long)$1 ^ (long)$3; }
        | expr '+' expr         { $$ = $1 + $3; }
        | expr '-' expr         { $$ = $1 - $3; }
        | expr '*' expr         { $$ = $1 * $3; }
        | expr '/' expr         { if ($3 == 0) YYABORT; $$ = $1 / $3; }
        | expr '%' expr         { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }
        | '-' expr %prec NEG    { $$ = -$2; }
-       | '(' expr ')'          { $$ = $2; }
+       | '(' if_expr ')'       { $$ = $2; }
+       | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
+       | MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
+       | SMT_ON                 { $$ = smt_on() > 0; }
        ;
 
 %%
@@ -82,13 +96,47 @@ static int expr__symbol(YYSTYPE *res, const char *p, const char **pp)
        char *dst = res->id;
        const char *s = p;
 
-       while (isalnum(*p) || *p == '_' || *p == '.') {
+       if (*p == '#')
+               *dst++ = *p++;
+
+       while (isalnum(*p) || *p == '_' || *p == '.' || *p == ':' || *p == '@' || *p == '\\') {
                if (p - s >= MAXIDLEN)
                        return -1;
-               *dst++ = *p++;
+               /*
+                * Allow @ instead of / to be able to specify pmu/event/ without
+                * conflicts with normal division.
+                */
+               if (*p == '@')
+                       *dst++ = '/';
+               else if (*p == '\\')
+                       *dst++ = *++p;
+               else
+                       *dst++ = *p;
+               p++;
        }
        *dst = 0;
        *pp = p;
+       dst = res->id;
+       switch (dst[0]) {
+       case 'm':
+               if (!strcmp(dst, "min"))
+                       return MIN;
+               if (!strcmp(dst, "max"))
+                       return MAX;
+               break;
+       case 'i':
+               if (!strcmp(dst, "if"))
+                       return IF;
+               break;
+       case 'e':
+               if (!strcmp(dst, "else"))
+                       return ELSE;
+               break;
+       case '#':
+               if (!strcasecmp(dst, "#smt_on"))
+                       return SMT_ON;
+               break;
+       }
        return ID;
 }
 
@@ -102,6 +150,7 @@ static int expr__lex(YYSTYPE *res, const char **pp)
                p++;
        s = p;
        switch (*p++) {
+       case '#':
        case 'a' ... 'z':
        case 'A' ... 'Z':
                return expr__symbol(res, p - 1, pp);
@@ -151,7 +200,7 @@ int expr__find_other(const char *p, const char *one, const char ***other,
                        err = 0;
                        break;
                }
-               if (tok == ID && strcasecmp(one, val.id)) {
+               if (tok == ID && (!one || strcasecmp(one, val.id))) {
                        if (num_other >= EXPR_MAX_OTHER - 1) {
                                pr_debug("Too many extra events in %s\n", orig);
                                break;