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Changing mips-elf-as behavior on delayed branches

nkavv@physics.auth.gr nkavv@physics.auth.gr
Mon Jun 25 12:57:00 GMT 2007 
Hi fellow binutilers

i have to comment on something that caught me by surprise. The binutils MIPS
target (actually for binutils-2.15.94 of a build for a no-cost development
environment) does not provide any options on delayed branching.

The "mips-elf-as" assembler supposes that what is ALWAYS targeted is a MIPS
microarchitecture with delayed branches (this applies for example for -mips1
and -mips32). It does not even provide the option to switch this assumption
off. At first i expected that there would exist something close to the gcc
option (-fno-delayed-branch) that is resolved by gcc RTL emission. But is seems
impossible to the assembler making the decision.

I work on embedded systems (embedded processor architecture) since 2000 and i
always thought that delayed branching is a bad-to-the-bone design practice.

Is it possible to disable assembly-code restructuring by "mips-elf-as" as it
could be for a clean microarchitecture with no delayed branching.

Thank you in advance
Nikolaos Kavvadias
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