[llvm] [InstCombine] Canonicalize more saturated-add variants (PR #100008)

[Craig Topper via llvm-commits]

topperc wrote:

> > > @topperc Do you have any objections to this PR as it is of now?
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> > 
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> > Remove the nuw handling unless you can show a real world test that benefits from it. We don't have to solve every possible case in InstCombine.
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> 
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> X > -C ? -1 : X + C is the canonicalization of the literal definition of sat.add.
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> 
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> X + C has to be nuw for this to work. 
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> 
> 
> X >= -C + 1 is basically a weird version of this. 

Write a C function that generates IR with nuw on the add.

https://github.com/llvm/llvm-project/pull/100008