From a8fde221a8f9a561c592a7d51a656d10037c7912 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Tue, 23 May 2017 21:03:14 -0700 Subject: [PATCH] i965: Set the "Float Blend Optimization Enable" bit on Gen9+. This is woefully undocumented. It's some kind of optimization that avoids unnecessary render target reads when blending with a floating point render target, using independent alpha blending modes. The internal documentation indicates that this bit exists on Cherryview as well, but the other driver doesn't appear to set it on that platform. There's also some confusing wording that indicates that it may exist on Broadwell, but the documentation says it's reserved, so who knows. I was not able to find any workload that benefited from setting this bit, but it seems like a good idea to set it nonetheless. Reviewed-by: Plamena Manolova Acked-by: Jason Ekstrand --- src/mesa/drivers/dri/i965/brw_defines.h | 1 + src/mesa/drivers/dri/i965/brw_state_upload.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h index ace83ef57af..312dddafd77 100644 --- a/src/mesa/drivers/dri/i965/brw_defines.h +++ b/src/mesa/drivers/dri/i965/brw_defines.h @@ -1609,6 +1609,7 @@ enum brw_pixel_shader_coverage_mask_mode { #define GEN7_GPGPU_DISPATCHDIMZ 0x2508 #define GEN7_CACHE_MODE_1 0x7004 +# define GEN9_FLOAT_BLEND_OPTIMIZATION_ENABLE (1 << 4) # define GEN8_HIZ_NP_PMA_FIX_ENABLE (1 << 11) # define GEN8_HIZ_NP_EARLY_Z_FAILS_DISABLE (1 << 13) # define GEN9_PARTIAL_RESOLVE_DISABLE_IN_VC (1 << 1) diff --git a/src/mesa/drivers/dri/i965/brw_state_upload.c b/src/mesa/drivers/dri/i965/brw_state_upload.c index bcb7ff1231e..4647f1c41e0 100644 --- a/src/mesa/drivers/dri/i965/brw_state_upload.c +++ b/src/mesa/drivers/dri/i965/brw_state_upload.c @@ -65,7 +65,9 @@ brw_upload_initial_gpu_state(struct brw_context *brw) BEGIN_BATCH(3); OUT_BATCH(MI_LOAD_REGISTER_IMM | (3 - 2)); OUT_BATCH(GEN7_CACHE_MODE_1); - OUT_BATCH(REG_MASK(GEN9_PARTIAL_RESOLVE_DISABLE_IN_VC) | + OUT_BATCH(REG_MASK(GEN9_FLOAT_BLEND_OPTIMIZATION_ENABLE) | + REG_MASK(GEN9_PARTIAL_RESOLVE_DISABLE_IN_VC) | + GEN9_FLOAT_BLEND_OPTIMIZATION_ENABLE | GEN9_PARTIAL_RESOLVE_DISABLE_IN_VC); ADVANCE_BATCH(); } -- 2.30.2