• Pierre Langlois's avatar
    [cctest] Support testing Simd128 moves and swaps · 0761b55d
    Pierre Langlois authored
    Extend the code-generator tests to cover AssembleMove and AssembleSwap with
    Simd128 registers and stack slots, for targets that support them.
    
    For this to work however, we need support for passing Simd128 stack parameters
    in TurboFan which this patch implements for Arm and x86. PPC and S390 both do
    not support the Simd128 representation and it appears MIPS and MIPS64's
    implementation of AssembleMove and AssembleSwap do not support it either.
    
    As per the design of the tests, the set of values to perform moves on are
    represented in a FixedArray of Smis (for kTagged) and HeapNumbers (for kFloat32
    and kFloat64). They are converted to raw values for the moves to be performed
    on, to be then converted back into a FixedArray. For the kSimd128
    representation, we represent values as a FixedArray of 4 Smis, each representing
    a lane. They are converted to a raw Simd128 vector using the `I32x4ReplaceLane`
    and `I32x4ExtractLane` operations.
    
    Finally, these tests need Simd128 variables mixed with the CodeStubAssembler
    which is not a use-case officially supported. And as a result, the `RecordWrite`
    stub does not guarantee to preserve Simd128 registers. To get around this, we
    have to be careful to skip write barriers when dealing with Simd128 parameters
    inside the "teardown" function, and we've had to move all allocations to the
    "setup" function.
    
    Thanks to this, we are able to catch bugs such as this one
    https://bugs.chromium.org/p/v8/issues/detail?id=6843.
    
    Bug: v8:6848
    Change-Id: I8787d6339cdbfcd9356c5e8995925f0b45c562fa
    Reviewed-on: https://chromium-review.googlesource.com/728599
    Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
    Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
    Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#50326}
    0761b55d
instruction-codes-ia32.h 10.7 KB