driconf: Add a limit_trig_input_range option

With this option enabled range of input values for fsin and fcos is
limited to [-2*pi : 2*pi] by calculating the reminder after 2*pi modulo
division. This helps to improve calculation precision for large input
arguments on Intel.

-v2: Add limit_trig_input_range option to prog_key to update shader
     cache (Lionel)

Signed-off-by: Vadym Shovkoplias <vadym.shovkoplias@globallogic.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16388>

src/intel/compiler/brw_compiler.h

@@ -247,6 +247,13 @@ struct brw_base_prog_key {
 
    enum brw_subgroup_size_type subgroup_size_type;
    bool robust_buffer_access;
+
+   /**
+    * Apply workarounds for SIN and COS input range problems.
+    * This limits input range for SIN and COS to [-2p : 2p] to
+    * avoid precision issues.
+    */
+   bool limit_trig_input_range;
    struct brw_sampler_prog_key_data tex;
 };
 

src/intel/compiler/brw_nir.c

@@ -1409,6 +1409,9 @@ brw_nir_apply_key(nir_shader *nir,
    };
    OPT(nir_lower_subgroups, &subgroups_options);
 
+   if (key->limit_trig_input_range)
+      OPT(brw_nir_limit_trig_input_range_workaround);
+
    if (progress)
       brw_nir_optimize(nir, compiler, is_scalar, false);
 }

src/intel/compiler/brw_nir.h

@@ -142,6 +142,8 @@ bool brw_nir_apply_attribute_workarounds(nir_shader *nir,
 
 bool brw_nir_apply_trig_workarounds(nir_shader *nir);
 
+bool brw_nir_limit_trig_input_range_workaround(nir_shader *nir);
+
 void brw_nir_apply_tcs_quads_workaround(nir_shader *nir);
 
 void brw_nir_apply_key(nir_shader *nir,

src/intel/compiler/brw_nir_trig_workarounds.py

@@ -33,12 +33,17 @@
 
 import argparse
 import sys
+from math import pi
 
 TRIG_WORKAROUNDS = [
     (('fsin', 'x(is_not_const)'), ('fmul', ('fsin', 'x'), 0.99997)),
     (('fcos', 'x(is_not_const)'), ('fmul', ('fcos', 'x'), 0.99997)),
 ]
 
+LIMIT_TRIG_INPUT_RANGE_WORKAROUND = [
+    (('fsin', 'x(is_not_const)'), ('fsin', ('fmod', 'x', 2.0 * pi))),
+    (('fcos', 'x(is_not_const)'), ('fcos', ('fmod', 'x', 2.0 * pi))),
+]
 
 def main():
     parser = argparse.ArgumentParser()
@@ -54,6 +59,8 @@ def run():
     print('#include "brw_nir.h"')
     print(nir_algebraic.AlgebraicPass("brw_nir_apply_trig_workarounds",
                                       TRIG_WORKAROUNDS).render())
+    print(nir_algebraic.AlgebraicPass("brw_nir_limit_trig_input_range_workaround",
+                                      LIMIT_TRIG_INPUT_RANGE_WORKAROUND).render())
 
 
 if __name__ == '__main__':