From a8ef92b031729fca86f8615d0ca113ddf0965af9 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Tue, 8 Nov 2016 13:21:39 -0800 Subject: [PATCH] i965/compiler: Disable trig workarounds on KBL+ The precision of our trig instructions appears to have been fixed on Kaby Lake. Neither Ben nor I can find any documentation for this. However, the dEQP precision tests now pass with INTEL_PRECISE_TRIG=0 where they fail on Sky Lake. Signed-off-by: Jason Ekstrand Reviewed-by: Matt Turner --- src/mesa/drivers/dri/i965/brw_nir.c | 5 ++++- src/mesa/drivers/dri/i965/brw_nir_trig_workarounds.py | 7 ++++--- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c index e454180..763e3ec 100644 --- a/src/mesa/drivers/dri/i965/brw_nir.c +++ b/src/mesa/drivers/dri/i965/brw_nir.c @@ -449,6 +449,7 @@ nir_optimize(nir_shader *nir, bool is_scalar) nir_shader * brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir) { + const struct gen_device_info *devinfo = compiler->devinfo; bool progress; /* Written by OPT and OPT_V */ (void)progress; @@ -457,7 +458,9 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir) if (nir->stage == MESA_SHADER_GEOMETRY) OPT(nir_lower_gs_intrinsics); - if (compiler->precise_trig) + /* See also brw_nir_trig_workarounds.py */ + if (compiler->precise_trig && + !(devinfo->gen >= 10 || devinfo->is_kabylake)) OPT(brw_nir_apply_trig_workarounds); static const nir_lower_tex_options tex_options = { diff --git a/src/mesa/drivers/dri/i965/brw_nir_trig_workarounds.py b/src/mesa/drivers/dri/i965/brw_nir_trig_workarounds.py index 67dab9a..3b8d0ce 100755 --- a/src/mesa/drivers/dri/i965/brw_nir_trig_workarounds.py +++ b/src/mesa/drivers/dri/i965/brw_nir_trig_workarounds.py @@ -23,9 +23,10 @@ import nir_algebraic -# The SIN and COS instructions on Intel hardware can produce values -# slightly outside of the [-1.0, 1.0] range for a small set of values. -# Obviously, this can break everyone's expectations about trig functions. +# Prior to Kaby Lake, The SIN and COS instructions on Intel hardware can +# produce values slightly outside of the [-1.0, 1.0] range for a small set of +# values. Obviously, this can break everyone's expectations about trig +# functions. This appears to be fixed in Kaby Lake. # # According to an internal presentation, the COS instruction can produce # a value up to 1.000027 for inputs in the range (0.08296, 0.09888). One -- 2.7.4