From: Lukas Schwaighofer <lukas@schwaighofer.name>

Date: Tue, 26 Feb 2019 23:13:58 +0100

Subject: Prevent optimizing the pow() function

With the current GCC 8.2.0 from Debian, a section of code calling pow() in

zzjson_parse.c is turned into a sequence calling exp(). Since no exp()

implementation is available in syslinux those optimizations need to be

disabled.

---

 com32/gpllib/zzjson/zzjson_parse.c | 6 +++++-

 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/com32/gpllib/zzjson/zzjson_parse.c b/com32/gpllib/zzjson/zzjson_parse.c

index ecb6f61..e66a9d8 100644

--- a/com32/gpllib/zzjson/zzjson_parse.c

+++ b/com32/gpllib/zzjson/zzjson_parse.c

@@ -138,6 +138,10 @@ static ZZJSON *parse_string2(ZZJSON_CONFIG *config) {

     return zzjson;

 }

+static double __attribute__((optimize("O0"))) pow_noopt(double x, double y) {

+	return pow(x, y);

+}

+

 static ZZJSON *parse_number(ZZJSON_CONFIG *config) {

     ZZJSON *zzjson;

     unsigned long long ival = 0, expo = 0;

@@ -213,7 +217,7 @@ skipexpo:

     if (dbl) {

         dval = sign * (long long) ival;

         dval += sign * frac;

-        dval *= pow(10.0, (double) signexpo * expo);

+        dval *= pow_noopt(10.0, (double) signexpo * expo);

     }

     zzjson = config->calloc(1, sizeof(ZZJSON));