On Tue, Apr 19, 2016 at 12:44 PM, Matt Turner <matts...@gmail.com> wrote: > On Mon, Apr 18, 2016 at 11:52 PM, Kenneth Graunke <kenn...@whitecape.org> > wrote: >> Previously, opt_vector_float() always interpreted MOV sources as >> floating point, and always created a MOV with a F-type destination. >> >> This meant that we could mess up sequences of integer loads, such as: >> >> mov vgrf6.0.x:D, 0D >> mov vgrf6.0.y:D, 1D >> mov vgrf6.0.z:D, 2D >> mov vgrf6.0.w:D, 3D >> >> Here, integer 0/1/2/3 become approximately 0.0f, so we generated: >> >> mov vgrf6.0:F, [0F, 0F, 0F, 0F] >> >> which is clearly wrong. We can properly handle this by converting >> integer values to float (rather than bitcasting), and emitting a type >> converting MOV: >> >> mov vgrf6.0:D, [0F, 1F, 2F, 3F] >> >> To do this, see first see if the integer values (converted to float) >> are representable. If so, we use a D-type MOV. If not, we then try >> the floating point values and an F-type MOV. We make zero not impose >> type restrictions. This is important because 0D would imply a D-type >> MOV, but is often used in sequences such as MOV 0D, MOV 0x3f800000D, >> where we want to use an F-type MOV. >> >> Fixes about 54 dEQP-GLES2 failures with the vec4 VS backend. This >> recently became visible due to changes in opt_vector_float() which >> made it optimize more cases, but it was a pre-existing bug. >> >> v2: Handle the type of zero better. >> >> Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> > > This patch has these shader-db stats on HSW: > > total instructions in shared programs: 7084195 -> 7082191 (-0.03%) > instructions in affected programs: 246027 -> 244023 (-0.81%) > helped: 1937 > > total cycles in shared programs: 65669642 -> 65651968 (-0.03%) > cycles in affected programs: 531064 -> 513390 (-3.33%) > helped: 1177
Looks like a lot of vertex shaders benefit because they compare against ivec4(0, 1, 2, 3) which we now load as a VF in one instruction. Neat! The series is Reviewed-by: Matt Turner <matts...@gmail.com> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
