[PATCH 1/2] perf expr: Add d_ratio operation

[Ian Rogers]

This simplifies computing ratios in json expressions.

Signed-off-by: Ian Rogers <irog...@google.com>
---
 tools/perf/util/expr.l |  1 +
 tools/perf/util/expr.y | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index f397bf8b1a48..298d86660a96 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -100,6 +100,7 @@ symbol              ({spec}|{sym})+
                }
        }
 
+d_ratio                { return D_RATIO; }
 max            { return MAX; }
 min            { return MIN; }
 if             { return IF; }
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index bf3e898e3055..fe145344bb39 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -10,6 +10,14 @@
 #include "smt.h"
 #include <string.h>
 
+static double d_ratio(double val0, double val1)
+{
+       if (val1 == 0) {
+               return 0;
+       }
+       return  val0 / val1;
+}
+
 %}
 
 %define api.pure full
@@ -28,7 +36,7 @@
 %token <num> NUMBER
 %token <str> ID
 %destructor { free ($$); } <str>
-%token MIN MAX IF ELSE SMT_ON
+%token MIN MAX IF ELSE SMT_ON D_RATIO
 %left MIN MAX IF
 %left '|'
 %left '^'
@@ -64,7 +72,8 @@ other: ID
 }
 |
 MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | 
'/' | '%' | '(' | ')' | ','
-
+|
+D_RATIO
 
 all_expr: if_expr                      { *final_val = $1; }
        ;
@@ -105,6 +114,7 @@ expr:         NUMBER
        | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
        | MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
        | SMT_ON                 { $$ = smt_on() > 0; }
+       | D_RATIO '(' expr ',' expr ')' { $$ = d_ratio($3,$5); }
        ;
 
 %%
-- 
2.27.0.278.ge193c7cf3a9-goog