Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
Currently, ir3 backend compiler is lowering integer multiplication from:
dst = a * b
to:
dst = (al * bl) + (ah * bl << 16) + (al * bh << 16)
by emitting this code:
mull.u tmp0, a, b ; mul low, i.e. al * bl
madsh.m16 tmp1, a, b, tmp0 ; mul-add shift high mix, i.e. ah * bl << 16
madsh.m16 dst, b, a, tmp1 ; i.e. al * bh << 16
which at that point has very low chances of being optimized.
This patch adds a new nir_algebraic.AlgebraicPass to performs this
lowering during NIR algebraic optimization passes, giving it a better
chance for optimizing the resulting code.
Reviewed-by: Eric Anholt <eric@anholt.net>
Eric Engestrom
Rob Clark
Eduardo Lima Mitev