search for: ieee_double

Hi R-devel, I have a question about the differentiation between NA and NaN values as implemented in R. In arithmetic.c, we have int R_IsNA(double x) { if (isnan(x)) { ieee_double y; y.value = x; return (y.word[lw] == 1954); } return 0; } ieee_double is just used for type punning so we can check the final bits and see if they're equal to 1954; if they are, x is NA, if they're not, x is NaN (as defined for R_IsNaN). My question is -- I can see a substantial...

...ut errors. Bottom line, it appears that R_NaReal was not being set properly. It would take the value of nan(0x8000000000000) instead of nan(0x80000000007a2). This is set in R_NaReal = R_ValueOfNA(). The present version in arithmetic.c is: 117 static double R_ValueOfNA(void) 118 { 119 ieee_double x; 120 x.word[hw] = 0x7ff00000; 121 x.word[lw] = 1954; 122 return x.value; 123 } The change is in line 119 to: volatile ieee_double x; This has resolved the problem and now results in no errors being reported during make check with the default ./configure. Thus, now using:...

Dear R developers, I spotted that R_isNA and R_IsNaN could be improved when applied on a vector where we could take out small part of their logic, run it once, and then reuse inside the loop. I setup tiny plain-C experiment. Taking R_IsNA, R_IsNaN from R's arithmetic.c, and building R_vIsNA and R_vIsNaN accordingly. For double input of size 1e9 (having some NA and NaN) I observed following