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Re: -fprefetch-loop-arrays on PowerPC
> thanks for the great new GCC 3.1.
> I have tried the new -fprefetch-loop-arrays optimizer option.
> It is very nice to have it. I know this is a young feature perhaps this
> helps improving it.
> The generated assembler code contains the following, in my oppinion
> suboptimal, instruction sequences:
> addic. 5,5,-1
> lwz 3,0(6)
> addi 12,12,16
> lwz 9,4(6)
> lwz 11,8(6)
> lwz 30,12(6)
> addi 6,6,16
> stw 3,0(8)
> stw 9,4(8)
> stw 11,8(8)
> stw 30,12(8)
> addi 8,8,16
> dcbt 0,20 < is the impact of this instruction a subset of
> < the next instruction?
> dcbtst 0,20 <
> ble- 0,L..19176
Sometimes gcc suceeds to confuse itself to believe that accesses to same
array are disjunct. WOuld be possible to see the source?