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-rw-r--r--tools/perf/util/expr.y325
1 files changed, 244 insertions, 81 deletions
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index b2ada8f8309a..f969dfa525bd 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -1,42 +1,43 @@
/* Simple expression parser */
%{
#define YYDEBUG 1
-#include <stdio.h>
-#include "util.h"
+#include <assert.h>
+#include <math.h>
#include "util/debug.h"
-#include <stdlib.h> // strtod()
+#include "smt.h"
#define IN_EXPR_Y 1
#include "expr.h"
-#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
%parse-param { double *final_val }
%parse-param { struct expr_parse_ctx *ctx }
+%parse-param { bool compute_ids }
%parse-param {void *scanner}
%lex-param {void* scanner}
%union {
double num;
char *str;
+ struct ids {
+ /*
+ * When creating ids, holds the working set of event ids. NULL
+ * implies the set is empty.
+ */
+ struct hashmap *ids;
+ /*
+ * The metric value. When not creating ids this is the value
+ * read from a counter, a constant or some computed value. When
+ * creating ids the value is either a constant or BOTTOM. NAN is
+ * used as the special BOTTOM value, representing a "set of all
+ * values" case.
+ */
+ double val;
+ } ids;
}
-%token EXPR_PARSE EXPR_OTHER EXPR_ERROR
-%token <num> NUMBER
-%token <str> ID
-%destructor { free ($$); } <str>
-%token MIN MAX IF ELSE SMT_ON D_RATIO
+%token ID NUMBER MIN MAX IF ELSE SMT_ON D_RATIO EXPR_ERROR
%left MIN MAX IF
%left '|'
%left '^'
@@ -45,83 +46,245 @@ static double d_ratio(double val0, double val1)
%left '-' '+'
%left '*' '/' '%'
%left NEG NOT
-%type <num> expr if_expr
+%type <num> NUMBER
+%type <str> ID
+%destructor { free ($$); } <str>
+%type <ids> expr if_expr
+%destructor { ids__free($$.ids); } <ids>
%{
static void expr_error(double *final_val __maybe_unused,
struct expr_parse_ctx *ctx __maybe_unused,
+ bool compute_ids __maybe_unused,
void *scanner,
const char *s)
{
pr_debug("%s\n", s);
}
+/*
+ * During compute ids, the special "bottom" value uses NAN to represent the set
+ * of all values. NAN is selected as it isn't a useful constant value.
+ */
+#define BOTTOM NAN
+
+/* During computing ids, does val represent a constant (non-BOTTOM) value? */
+static bool is_const(double val)
+{
+ return isfinite(val);
+}
+
+static struct ids union_expr(struct ids ids1, struct ids ids2)
+{
+ struct ids result = {
+ .val = BOTTOM,
+ .ids = ids__union(ids1.ids, ids2.ids),
+ };
+ return result;
+}
+
+/*
+ * If we're not computing ids or $1 and $3 are constants, compute the new
+ * constant value using OP. Its invariant that there are no ids. If computing
+ * ids for non-constants union the set of IDs that must be computed.
+ */
+#define BINARY_LONG_OP(RESULT, OP, LHS, RHS) \
+ if (!compute_ids || (is_const(LHS.val) && is_const(RHS.val))) { \
+ assert(LHS.ids == NULL); \
+ assert(RHS.ids == NULL); \
+ RESULT.val = (long)LHS.val OP (long)RHS.val; \
+ RESULT.ids = NULL; \
+ } else { \
+ RESULT = union_expr(LHS, RHS); \
+ }
+
+#define BINARY_OP(RESULT, OP, LHS, RHS) \
+ if (!compute_ids || (is_const(LHS.val) && is_const(RHS.val))) { \
+ assert(LHS.ids == NULL); \
+ assert(RHS.ids == NULL); \
+ RESULT.val = LHS.val OP RHS.val; \
+ RESULT.ids = NULL; \
+ } else { \
+ RESULT = union_expr(LHS, RHS); \
+ }
+
%}
%%
-start:
-EXPR_PARSE all_expr
-|
-EXPR_OTHER all_other
+start: if_expr
+{
+ if (compute_ids)
+ ctx->ids = ids__union($1.ids, ctx->ids);
-all_other: all_other other
-|
+ if (final_val)
+ *final_val = $1.val;
+}
+;
+
+if_expr: expr IF expr ELSE expr
+{
+ if (fpclassify($3.val) == FP_ZERO) {
+ /*
+ * The IF expression evaluated to 0 so treat as false, take the
+ * ELSE and discard everything else.
+ */
+ $$.val = $5.val;
+ $$.ids = $5.ids;
+ ids__free($1.ids);
+ ids__free($3.ids);
+ } else if (!compute_ids || is_const($3.val)) {
+ /*
+ * If ids aren't computed then treat the expression as true. If
+ * ids are being computed and the IF expr is a non-zero
+ * constant, then also evaluate the true case.
+ */
+ $$.val = $1.val;
+ $$.ids = $1.ids;
+ ids__free($3.ids);
+ ids__free($5.ids);
+ } else if ($1.val == $5.val) {
+ /*
+ * LHS == RHS, so both are an identical constant. No need to
+ * evaluate any events.
+ */
+ $$.val = $1.val;
+ $$.ids = NULL;
+ ids__free($1.ids);
+ ids__free($3.ids);
+ ids__free($5.ids);
+ } else {
+ /*
+ * Value is either the LHS or RHS and we need the IF expression
+ * to compute it.
+ */
+ $$ = union_expr($1, union_expr($3, $5));
+ }
+}
+| expr
+;
-other: ID
+expr: NUMBER
{
- expr__add_id(ctx, $1);
-}
-|
-MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')' | ','
-|
-'<' | '>' | D_RATIO
-
-all_expr: if_expr { *final_val = $1; }
- ;
-
-if_expr:
- expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
- | expr
- ;
-
-expr: NUMBER
- | ID {
- struct expr_id_data *data;
-
- if (expr__resolve_id(ctx, $1, &data)) {
- free($1);
- YYABORT;
- }
-
- $$ = expr_id_data__value(data);
- free($1);
- }
- | 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 { $$ = $1 - $3; }
- | expr '*' expr { $$ = $1 * $3; }
- | expr '/' expr { if ($3 == 0) {
- pr_debug("division by zero\n");
- YYABORT;
- }
- $$ = $1 / $3;
- }
- | expr '%' expr { if ((long)$3 == 0) {
- pr_debug("division by zero\n");
- YYABORT;
- }
- $$ = (long)$1 % (long)$3;
- }
- | '-' expr %prec NEG { $$ = -$2; }
- | '(' if_expr ')' { $$ = $2; }
- | 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); }
- ;
+ $$.val = $1;
+ $$.ids = NULL;
+}
+| ID
+{
+ if (!compute_ids) {
+ /*
+ * Compute the event's value from ID. If the ID isn't known then
+ * it isn't used to compute the formula so set to NAN.
+ */
+ struct expr_id_data *data;
+
+ $$.val = NAN;
+ if (expr__resolve_id(ctx, $1, &data) == 0)
+ $$.val = expr_id_data__value(data);
+
+ $$.ids = NULL;
+ free($1);
+ } else {
+ /*
+ * Set the value to BOTTOM to show that any value is possible
+ * when the event is computed. Create a set of just the ID.
+ */
+ $$.val = BOTTOM;
+ $$.ids = ids__new();
+ if (!$$.ids || ids__insert($$.ids, $1))
+ YYABORT;
+ }
+}
+| expr '|' expr { BINARY_LONG_OP($$, |, $1, $3); }
+| expr '&' expr { BINARY_LONG_OP($$, &, $1, $3); }
+| expr '^' expr { BINARY_LONG_OP($$, ^, $1, $3); }
+| expr '<' expr { BINARY_OP($$, <, $1, $3); }
+| expr '>' expr { BINARY_OP($$, >, $1, $3); }
+| expr '+' expr { BINARY_OP($$, +, $1, $3); }
+| expr '-' expr { BINARY_OP($$, -, $1, $3); }
+| expr '*' expr { BINARY_OP($$, *, $1, $3); }
+| expr '/' expr
+{
+ if (fpclassify($3.val) == FP_ZERO) {
+ pr_debug("division by zero\n");
+ YYABORT;
+ } else if (!compute_ids || (is_const($1.val) && is_const($3.val))) {
+ assert($1.ids == NULL);
+ assert($3.ids == NULL);
+ $$.val = $1.val / $3.val;
+ $$.ids = NULL;
+ } else {
+ /* LHS and/or RHS need computing from event IDs so union. */
+ $$ = union_expr($1, $3);
+ }
+}
+| expr '%' expr
+{
+ if (fpclassify($3.val) == FP_ZERO) {
+ pr_debug("division by zero\n");
+ YYABORT;
+ } else if (!compute_ids || (is_const($1.val) && is_const($3.val))) {
+ assert($1.ids == NULL);
+ assert($3.ids == NULL);
+ $$.val = (long)$1.val % (long)$3.val;
+ $$.ids = NULL;
+ } else {
+ /* LHS and/or RHS need computing from event IDs so union. */
+ $$ = union_expr($1, $3);
+ }
+}
+| D_RATIO '(' expr ',' expr ')'
+{
+ if (fpclassify($5.val) == FP_ZERO) {
+ /*
+ * Division by constant zero always yields zero and no events
+ * are necessary.
+ */
+ assert($5.ids == NULL);
+ $$.val = 0.0;
+ $$.ids = NULL;
+ ids__free($3.ids);
+ } else if (!compute_ids || (is_const($3.val) && is_const($5.val))) {
+ assert($3.ids == NULL);
+ assert($5.ids == NULL);
+ $$.val = $3.val / $5.val;
+ $$.ids = NULL;
+ } else {
+ /* LHS and/or RHS need computing from event IDs so union. */
+ $$ = union_expr($3, $5);
+ }
+}
+| '-' expr %prec NEG
+{
+ $$.val = -$2.val;
+ $$.ids = $2.ids;
+}
+| '(' if_expr ')'
+{
+ $$ = $2;
+}
+| MIN '(' expr ',' expr ')'
+{
+ if (!compute_ids) {
+ $$.val = $3.val < $5.val ? $3.val : $5.val;
+ $$.ids = NULL;
+ } else {
+ $$ = union_expr($3, $5);
+ }
+}
+| MAX '(' expr ',' expr ')'
+{
+ if (!compute_ids) {
+ $$.val = $3.val > $5.val ? $3.val : $5.val;
+ $$.ids = NULL;
+ } else {
+ $$ = union_expr($3, $5);
+ }
+}
+| SMT_ON
+{
+ $$.val = smt_on() > 0 ? 1.0 : 0.0;
+ $$.ids = NULL;
+}
+;
%%
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-07 03:22:57 +0300