[swift-dev] SIL proposal: remove multiple results from SILValue
eeckstein at apple.com
Fri Dec 4 11:06:40 CST 2015
currently some instructions, like alloc_stack and alloc_box (I think they are the only ones) return 2 values. For this we have the "result number" in SILValue, e.g. %3#0, %3#1
We could represent the same by using a projection instruction, e.g.
%3 = alloc_stack $Type // == the old %3#0
%4 = project_stack %1 // == the old %3#1
And actually we already have the project_box instruction.
This would simplify SILValues and many places in optimization passes/analysis. Yesterday I spent several hours to debug a problem where in some pass the wrong result number was used.
What do you think?
More information about the swift-dev