[llvm-dev] why do undefined globals end up in .data instead of .bss? (original) (raw)

Andrew Kelley via llvm-dev llvm-dev at lists.llvm.org
Sun Apr 23 10:10:51 PDT 2017


Here is a module:

@vals = internal unnamed_addr global [20000000 x i32] undef, align 4

When I compile it into an .o file:

$ clang -c test.ll $ objdump -t test.o

test.o: file format elf64-x86-64

SYMBOL TABLE: 0000000000000000 l df ABS 0000000000000000 test.ll 0000000000000000 l O .data 0000000004c4b400 vals

LLVM puts the global in the .data section, and results in a 77MB .o file of mostly zeroes. Why does this variable not go in the .bss section? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170423/db0314d5/attachment.html>



More information about the llvm-dev mailing list