Fix pow error bound
The pow error bound was miscalculated, it is slightly below 0.54 ULP
when using fma and slightly above it without fma.
If 2^-400 < |pow(x,y)| < 2^400 then the error is less than 0.52 ULP
with fma.
diff --git a/math/pow.c b/math/pow.c
index ac2d974..0d6e709 100644
--- a/math/pow.c
+++ b/math/pow.c
@@ -22,9 +22,9 @@
#include "math_config.h"
/*
-Worst-case error: 0.57 ULP (~= ulperr_exp + 1024*Ln2*relerr_log*2^53)
-relerr_log: 1.3 * 2^-68 (Relative error of log, 1.4 * 2^-68 without fma)
-ulperr_exp: 0.509 ULP (ULP error of exp)
+Worst-case error: 0.54 ULP (~= ulperr_exp + 1024*Ln2*relerr_log*2^53)
+relerr_log: 1.3 * 2^-68 (Relative error of log, 1.5 * 2^-68 without fma)
+ulperr_exp: 0.509 ULP (ULP error of exp, 0.511 ULP without fma)
*/
#define T __pow_log_data.tab