glamor doesn't accelerate PutImage from 1bpp sources
PutImage from 1bpp source to >1bpp dest is a special case, where 1 bits in the source expand to the GC's foreground color (resp. 0 bits and background).
There's been at least two attempts to implement this. My attempt simply performed the color expansion to a host-memory pixmap and uploaded the image from that. Keith's series does more work on the GPU but still has some interesting performance tradeoffs. We should pick a strategy and finish this.