• Thibaud Michaud's avatar
    [wasm][x64] Fix unordered floating-point select · fb51aa40
    Thibaud Michaud authored
    Unordered floating-point (non-)equality is implemented using two flags
    on x64: kUnorderedNotEqual as "not_equal OR parity_even" and
    kUnorderedEqual as "equal AND parity_odd". Only the first flag was
    checked.
    
    This change fixes the kUnorderedNotEqual case by emitting a second
    cmov to also move the "true" value if the parity_even flag is set. The
    kUnorderedEqual case is covered by inverting the condition in the
    instruction selector.
    
    This should also be optimal according to the code emitted by clang -O3
    for equivalent C++ code.
    
    Drive-by: remove unused overload of EmitWithContinuation.
    
    R=neis@chromium.org
    CC=ahaas@chromium.org
    
    Bug: chromium:1200184
    Change-Id: Iae438d29fb5897ca910a154f140a5a6a904490ec
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2844651
    Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
    Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#74122}
    fb51aa40
instruction-selector.cc 132 KB