[LLVMdev] difference in function prologue generated with clang and gcc

[Anton Korobeynikov]

Hello

> The prologue length in .debug_line is 157 for clang generated one, whereas
> it is 34 for gcc generated one. I am curious about the results of making
> prologue generated by clang look similar with one generated by gcc.
> Could anyone let me know why this difference exists and if it is for good
> /better purposes than for gcc. ?
1. This is not function prologue length. It's the header (aka
'prologue') length of .debug_line section
2. The length of function prologue is 3 instructions in case of clang
(12 bytes) and 2 instruction (8 bytes) in case of gcc
3. Comparison of code size of unoptimized code does not make any sense.

Hope this makes the stuff clear.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University