Any benchmarks between LLVM vs GCC on Allegrex code?

[Heimdall]

There are lots of benchmarks about LLVM vs GCC but I haven't found any about the MIPS Allregrex code? did anyone tried to compare it?

I'd like to know which one generates "better" code. I really like LLVM and learning its code is simpler than GCC (IMHO).

It could give some people interest to improve the LLVM backend to support VFPU instructions.

[hlide]

MIPS LLVM is still experimental and incomplete. I wouldn't expect too much about LLVM for MIPS.

But, yes, if it could be complete, it would be interesting to add VFPU. But i'm quite sceptical as it is a long time ago MIPS LLVM was started and it still doesn't seem to progress.

[Heimdall]

Yeap it is true, i only tried some simple bitcode:

Code: Select all

; Declare the string constant as a global constant...
@.LC0 = internal constant [13 x i8] c"hello world\0A\00"          ; [13 x i8]*

; External declaration of the puts function
declare i32 @puts(i8 *)                                            ; i32(i8 *)*

; Definition of main function
define i32 @main() {                                                 ; i32()*
       ; Convert [13x i8 ]* to i8  *...
       %cast210 = getelementptr [13 x i8 ]* @.LC0, i64 0, i64 0 ; i8 *

       ; Call puts function to write out the string to stdout...
       call i32 @puts(i8 * %cast210)                              ; i32
       ret i32 0
}

the just used the commands:

Code: Select all

llvm-as hello.ll
opt hello.bc -o hello.opt.bc
# doesn't give anything extra in optimization
llc -march=mips -mcpu=allegrex hello.bc
psp-gcc -c hello.s -o hello.o

# now i can link the object file with psp-gcc and run it on the PSP but this is no test at all...