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Date: Fri,  9 Feb 2024 12:49:44 -0800
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Subject: [PATCH v1 1/4] perf expr: Allow NaN to be a valid number
From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
	Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, 
	Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>, 
	John Garry <john.g.garry@oracle.com>, Kan Liang <kan.liang@linux.intel.com>, 
	James Clark <james.clark@arm.com>, K Prateek Nayak <kprateek.nayak@amd.com>, Kaige Ye <ye@kaige.org>, 
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
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Currently only floating point numbers can be parsed, add a special
case for NaN.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/expr.l | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index 0feef0726c48..a2fc43159ee9 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -94,6 +94,14 @@ static int literal(yyscan_t scanner, const struct expr_scanner_ctx *sctx)
 	}
 	return LITERAL;
 }
+
+static int nan_value(yyscan_t scanner)
+{
+	YYSTYPE *yylval = expr_get_lval(scanner);
+
+	yylval->num = NAN;
+	return NUMBER;
+}
 %}
 
 number		([0-9]+\.?[0-9]*|[0-9]*\.?[0-9]+)(e-?[0-9]+)?
@@ -115,6 +123,7 @@ else		{ return ELSE; }
 source_count	{ return SOURCE_COUNT; }
 has_event	{ return HAS_EVENT; }
 strcmp_cpuid_str	{ return STRCMP_CPUID_STR; }
+NaN		{ return nan_value(yyscanner); }
 {literal}	{ return literal(yyscanner, sctx); }
 {number}	{ return value(yyscanner); }
 {symbol}	{ return str(yyscanner, ID, sctx->runtime); }
-- 
2.43.0.687.g38aa6559b0-goog