subject:"\[Mesa\-dev\] \[PATCH\] radv\: lower ffma in nir."

Re: [Mesa-dev] [PATCH] radv: lower ffma in nir.

2017-10-03 Thread Roland Scheidegger

Am 03.10.2017 um 22:58 schrieb Dave Airlie: > From: Dave Airlie > > So it appears the Vulkan SPIR-V fma opcode can be equivalent to a > mad operation, and the fma hw opcode on AMD hw is issued like a double > opcode so is slower. Also the radeonsi stack does this. > > This

Re: [Mesa-dev] [PATCH] radv: lower ffma in nir.

2017-10-03 Thread Matt Arsenault

> On Oct 3, 2017, at 13:58, Dave Airlie wrote: > > From: Dave Airlie > > So it appears the Vulkan SPIR-V fma opcode can be equivalent to a > mad operation, and the fma hw opcode on AMD hw is issued like a double > opcode so is slower. Also the radeonsi

[Mesa-dev] [PATCH] radv: lower ffma in nir.

2017-10-03 Thread Dave Airlie

From: Dave Airlie So it appears the Vulkan SPIR-V fma opcode can be equivalent to a mad operation, and the fma hw opcode on AMD hw is issued like a double opcode so is slower. Also the radeonsi stack does this. This appears to improve performance on a number of games from