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Altera_Forum's avatar
Altera_Forum
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21 years ago

Unnecessary instructions

Hello, it's my first post. I have question about GCC generated code. We can find several unnecessary instructions. --- sample code --- unsigned short uh; uh = IORD_16DIRECT(base,ofst)...
Altera_Forum's avatar
Altera_Forum
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21 years ago

Scott,

If no "volatile", sign-extending operations (andi, slli+sari) are eliminated. If "volatile" exists, sign-extending is used. Similar code as MACRO will be generated.

I must use volatile because target address is shared-memory.

It seems there is less way to avoid this issue... assembler?