Displaying 3 results from an estimated 3 matches for "instref".
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instreg
2011 Jul 27
0
[LLVMdev] XOR Optimization
2011/7/26 Daniel Nicácio <dnicacios at gmail.com>:
>
> I also would like to see why the "XOR A, -1" is not turned into a NOT, any
>
Probably because NOT (like NEG) doesn't exist :)
<http://llvm.org/docs/LangRef.html#instref>
I assume the decision was made that it wasn't worth adding the extra
unary instructions when they can easily be handled in codegen by
matching "XOR X, -1" or "SUB 0, X".
~ Scott
2012 Jul 16
2
[LLVMdev] what is "intrinsic"?
hi,
i found the term "intrinsic" in some LLVM docs i am reading, and
nowhere explains what that means.
i did try to google, but nothing helpful came up. anybody please help?
many thanks,
Jun
2011 Jul 27
2
[LLVMdev] XOR Optimization
After a few more tests, I found out that if we set -unroll-threshold to a
value large enough, and run "opt -std-compile-opts" or "opt -O3" 3 times,
the unroll will be able to unroll the original loop 32 times, and when you
have it unrolled for at least 32 times a optimization is triggered, folding
it to a single "%xor.3.3.1 = xor i32 %tmp6, -1" (dont know why it does