perf expr: More explicit NAN handling

Comparison and logical operations on NAN won't ensure the result is
NAN. Ensure NANs are propogated so that threshold expressions like
"tma_fetch_latency > 0.1 & tma_frontend_bound > 0.15" don't yield a
number when the components are NAN.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Link: https://lore.kernel.org/r/20230219092848.639226-38-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/expr.y

@@ -127,7 +127,11 @@ static struct ids handle_id(struct expr_parse_ctx *ctx, char *id,
 	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;		\
+		if (isnan(LHS.val) || isnan(RHS.val)) {			\
+			RESULT.val = NAN;				\
+		} else {						\
+			RESULT.val = (long)LHS.val OP (long)RHS.val;	\
+		}							\
 		RESULT.ids = NULL;					\
 	} else {							\
 	        RESULT = union_expr(LHS, RHS);				\
@@ -137,7 +141,11 @@ static struct ids handle_id(struct expr_parse_ctx *ctx, char *id,
 	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;			\
+		if (isnan(LHS.val) || isnan(RHS.val)) {			\
+			RESULT.val = NAN;				\
+		} else {						\
+			RESULT.val = LHS.val OP RHS.val;		\
+		}							\
 		RESULT.ids = NULL;					\
 	} else {							\
 	        RESULT = union_expr(LHS, RHS);				\