Hi Bruno, On 1/27/20 2:09 PM, Bruno Haible wrote: >> Not sure if the compiler is correct here, but maybe worth a look: >> >> hash.c:549:11: error: implicit conversion from 'unsigned long' to >> 'float' changes value from 18446744073709551615 to 18446744073709551616 >> [-Werror,-Wimplicit-int-float-conversion] >> if (SIZE_MAX <= new_candidate) >> ^~~~~~~~ ~~ >> /usr/include/stdint.h:227:22: note: expanded from macro 'SIZE_MAX' >> # define SIZE_MAX (18446744073709551615UL) >> ^~~~~~~~~~~~~~~~~~~~~~ > > This warning is pointless, because > - Since the next float below 18446744073709551616 = 0x10000000000000000 > would be 18446742974197923840 = 0xFFFFFF0000000000 > the comparison result is the same for the two values ...615 and ...616. > - The compiler inserts the implicit conversion only because of the '<=' > operator. > IMO you should file a ticket with the clang people. > > Inserting a cast to 'double' > > if ((double) SIZE_MAX <= (double) new_candidate) > > would not help, because > the next double-float below 18446744073709551616 = 0x10000000000000000 > would be 18446744073709549568 = 0xFFFFFFFFFFFFF800
Thanks for the understandable explanation ! Sadly, bugs.llvm.org disabled self-registration. So they won't get a bug report from me (looks like they want to encapsulate from the rest of the world). Instead -Wno-implicit-int-float-conversion will be added to the clang options. Regards, Tim
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