diff options
| -rw-r--r-- | config/cmake/ConfigureChecks.cmake | 10 | ||||
| -rw-r--r-- | config/cmake/ConversionTests.c | 118 |
2 files changed, 120 insertions, 8 deletions
diff --git a/config/cmake/ConfigureChecks.cmake b/config/cmake/ConfigureChecks.cmake index a709a4d..80b44cb 100644 --- a/config/cmake/ConfigureChecks.cmake +++ b/config/cmake/ConfigureChecks.cmake @@ -370,10 +370,7 @@ H5ConversionTests (H5_FP_TO_INTEGER_OVERFLOW_WORKS "Checking IF overflows norma # The machine's conversion gets the correct value. We define the macro and disable # this kind of test until we figure out what algorithm they use. # -if (H5_LDOUBLE_TO_LONG_SPECIAL MATCHES ^H5_LDOUBLE_TO_LONG_SPECIAL$) - set (H5_LDOUBLE_TO_LONG_SPECIAL 0 CACHE INTERNAL "Define if your system converts long double to (unsigned) long values with special algorithm") - message (STATUS "Checking IF your system converts long double to (unsigned) long values with special algorithm... no") -endif (H5_LDOUBLE_TO_LONG_SPECIAL MATCHES ^H5_LDOUBLE_TO_LONG_SPECIAL$) +H5ConversionTests (H5_LDOUBLE_TO_LONG_SPECIAL "Checking IF your system converts long double to (unsigned) long values with special algorithm") # ---------------------------------------------------------------------- # Set the flag to indicate that the machine is using a special algorithm # to convert some values of '(unsigned) long' to 'long double' values. @@ -382,10 +379,7 @@ endif (H5_LDOUBLE_TO_LONG_SPECIAL MATCHES ^H5_LDOUBLE_TO_LONG_SPECIAL$) # ..., 7fffff..., the compiler uses a unknown algorithm. We define a # macro and skip the test for now until we know about the algorithm. # -if (H5_LONG_TO_LDOUBLE_SPECIAL MATCHES ^H5_LONG_TO_LDOUBLE_SPECIAL$) - set (H5_LONG_TO_LDOUBLE_SPECIAL 0 CACHE INTERNAL "Define if your system can convert (unsigned) long to long double values with special algorithm") - message (STATUS "Checking IF your system can convert (unsigned) long to long double values with special algorithm... no") -endif (H5_LONG_TO_LDOUBLE_SPECIAL MATCHES ^H5_LONG_TO_LDOUBLE_SPECIAL$) +H5ConversionTests (H5_LONG_TO_LDOUBLE_SPECIAL "Checking IF your system can convert (unsigned) long to long double values with special algorithm") # ---------------------------------------------------------------------- # Set the flag to indicate that the machine can accurately convert # 'long double' to '(unsigned) long long' values. (This flag should be set for diff --git a/config/cmake/ConversionTests.c b/config/cmake/ConversionTests.c index 1ee9842..010ee32 100644 --- a/config/cmake/ConversionTests.c +++ b/config/cmake/ConversionTests.c @@ -90,6 +90,124 @@ done: #endif +#ifdef H5_LDOUBLE_TO_LONG_SPECIAL_TEST + +int main(void) +{ + long double ld = 20041683600089727.779961L; + long ll; + unsigned long ull; + unsigned char s[16]; + unsigned char s2[8]; + int ret = 1; + + if(sizeof(long double) == 16 && sizeof(long) == 8) { + /*make sure the long double type has 16 bytes in size and + * 11 bits of exponent. If it is, + *the bit sequence should be like below. It's not + *a decent way to check but this info isn't available. */ + memcpy(s, &ld, 16); + if(s[0]==0x43 && s[1]==0x51 && s[2]==0xcc && s[3]==0xf3 && + s[4]==0x85 && s[5]==0xeb && s[6]==0xc8 && s[7]==0xa0 && + s[8]==0xbf && s[9]==0xcc && s[10]==0x2a && s[11]==0x3c) { + + /* Assign the hexadecimal value of long double type. */ + s[0]=0x43; s[1]=0x51; s[2]=0xcc; s[3]=0xf3; + s[4]=0x85; s[5]=0xeb; s[6]=0xc8; s[7]=0xa0; + s[8]=0xbf; s[9]=0xcc; s[10]=0x2a; s[11]=0x3c; + s[12]=0x3d; s[13]=0x85; s[14]=0x56; s[15]=0x20; + + memcpy(&ld, s, 16); + + ll = (long)ld; + memcpy(s2, &ll, 8); + + /* The library's algorithm converts it to 0x 00 47 33 ce 17 af 22 82 + * and gets wrong value 20041683600089730 on the IBM Power6 Linux. + * But the IBM Power6 Linux converts it to 0x00 47 33 ce 17 af 22 7f + * and gets the correct value 20041683600089727. It uses some special + * algorithm. We're going to define the macro and skip the test until + * we can figure out how they do it. */ + if(s2[0]==0x00 && s2[1]==0x47 && s2[2]==0x33 && s2[3]==0xce && + s2[4]==0x17 && s2[5]==0xaf && s2[6]==0x22 && s2[7]==0x7f) + ret = 0; + + ull = (unsigned long)ld; + memcpy(s2, &ull, 8); + + /* The unsigned long is the same as signed long. */ + if(s2[0]==0x00 && s2[1]==0x47 && s2[2]==0x33 && s2[3]==0xce && + s2[4]==0x17 && s2[5]==0xaf && s2[6]==0x22 && s2[7]==0x7f) + ret = 0; + } + } + +done: + exit(ret); +} + +#endif + +#ifdef H5_LONG_TO_LDOUBLE_SPECIAL_TEST + +int main(void) +{ + long double ld; + long ll; + unsigned long ull; + unsigned char s[16]; + int flag=0, ret=1; + + /*Determine if long double has 16 byte in size, 11 bit exponent, and + *the bias is 0x3ff */ + if(sizeof(long double) == 16) { + ld = 1.0L; + memcpy(s, &ld, 16); + if(s[0]==0x3f && s[1]==0xf0 && s[2]==0x00 && s[3]==0x00 && + s[4]==0x00 && s[5]==0x00 && s[6]==0x00 && s[7]==0x00) + flag = 1; + } + + if(flag==1 && sizeof(long)==8) { + ll = 0x003fffffffffffffL; + ld = (long double)ll; + memcpy(s, &ld, 16); + /* The library converts the value to 0x434fffffffffffff8000000000000000. + * In decimal it is 18014398509481982.000000, one value short of the original. + * The IBM Power6 Linux converts it to 0x4350000000000000bff0000000000000. + * The value is correct in decimal. It uses some special + * algorithm. We're going to define the macro and skip the test until + * we can figure out how they do it. */ + if(s[0]==0x43 && s[1]==0x50 && s[2]==0x00 && s[3]==0x00 && + s[4]==0x00 && s[5]==0x00 && s[6]==0x00 && s[7]==0x00 && + s[8]==0xbf && s[9]==0xf0 && s[10]==0x00 && s[11]==0x00 && + s[12]==0x00 && s[13]==0x00 && s[14]==0x00 && s[15]==0x00) + ret = 0; + } + if(flag==1 && sizeof(unsigned long)==8) { + ull = 0xffffffffffffffffUL; + ld = (long double)ull; + memcpy(s, &ld, 16); + /* Use a different value from signed long to test. The problem is the same + * for both long and unsigned long. The value is 18446744073709551615. + * The library converts the value to 0x43effffffffffffffe000000000000000. + * In decimal it's 18446744073709548544.000000, very different from the original. + * The IBM Power6 Linux converts it to 0x43f0000000000000bff0000000000000. + * The value is correct in decimal. It uses some special + * algorithm. We're going to define the macro and skip the test until + * we can figure out how they do it. */ + if(s[0]==0x43 && s[1]==0xf0 && s[2]==0x00 && s[3]==0x00 && + s[4]==0x00 && s[5]==0x00 && s[6]==0x00 && s[7]==0x00 && + s[8]==0xbf && s[9]==0xf0 && s[10]==0x00 && s[11]==0x00 && + s[12]==0x00 && s[13]==0x00 && s[14]==0x00 && s[15]==0x00) + ret = 0; + } +done: + exit(ret); +} + +#endif + #ifdef H5_LDOUBLE_TO_LLONG_ACCURATE_TEST int main(void) { |