• Cherry Zhang's avatar
    cmd/compile: remove redundant constant shift rules · 7846500a
    Cherry Zhang authored
    Normal shift rules plus constant folding are enough to generate
    efficient shift-by-constant instructions.
    
    Add test to make sure we don't generate comparisons for constant
    shifts.
    
    TODO: there are still constant shift rules on PPC64. If they
    are removed, the constant folding rules are not enough to remove
    all the test and mask stuff for constant shifts. Leave them in
    for now.
    
    Fixes #20663.
    
    Change-Id: I724cc324aa8607762d0c8aacf9bfa641bda5c2a1
    Reviewed-on: https://go-review.googlesource.com/60330
    Run-TryBot: Cherry Zhang <cherryyz@google.com>
    TryBot-Result: Gobot Gobot <gobot@golang.org>
    Reviewed-by: default avatarKeith Randall <khr@golang.org>
    7846500a
rewriteMIPS64.go 226 KB