CODEWITHSUNDEEP
assemblyarm
Douglas
Douglas

Reputation: 13

ARM Assembly: What is the difference between LDMFD and LDMLEFD?

I'm new to assembly language and there is a lot of info on what the LDMFD instruction does, but nothing on what the LDMLEFD instruction does. I thought they might be the same and that it is just a a different way to write it, but when I try interchanging them in my code they give different results. Here is one example of it being used in another stack overflow question. (ARM Assembly optimization) I'm trying to understand how it is different from the regular LDMFD. Thanks

Upvotes: 1

Views: 3258

Answers (1)

jasonharper
jasonharper

Reputation: 9597

LDMLEFD is a combination of the LDM (load multiple) operation, the FD (full descending) increment/decrement mode, and the LE (signed less than or equal to) condition code. So, the same thing as LDMFD, but only executes in specific circumstances. (I would have expected the condition code to be at the end rather than in the middle, but perhaps the assembler accepts it both ways.)

Upvotes: 1

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