i915: Use the sin/cos lowering in nir_opt_algebraic.py

It's nearly identical.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15539>

src/gallium/drivers/i915/i915_fpc.h

@@ -287,6 +287,4 @@ extern void i915_optimize_free(struct i915_token_list *tokens);
 
 extern uint32_t i915_coord_mask(enum tgsi_opcode opcode, enum tgsi_texture_type tex);
 
-extern bool i915_nir_lower_sincos(struct nir_shader *s);
-
 #endif

src/gallium/drivers/i915/i915_nir.c

@@ -1,81 +0,0 @@
-/*
- * Copyright © 2021 Emma Anholt
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- */
-
-#include "compiler/nir/nir.h"
-#include "compiler/nir/nir_builder.h"
-#include "i915_fpc.h"
-
-static bool
-i915_sincos_filter(const nir_instr *instr, const void *data)
-{
-   if (instr->type != nir_instr_type_alu)
-      return false;
-
-   switch (nir_instr_as_alu(instr)->op) {
-   case nir_op_fcos:
-   case nir_op_fsin:
-      return true;
-   default:
-      return false;
-   }
-}
-
-/* Compute sin using a quadratic and quartic.  It gives continuity
- * that repeating the Taylor series lacks every 2*pi, and has
- * reduced error.
- *
- * The idea was described at:
- * https://web.archive.org/web/20100613230051/http://www.devmaster.net/forums/showthread.php?t=5784
- */
-static nir_ssa_def *
-i915_sincos_lower(nir_builder *b, nir_instr *instr, void *data)
-{
-   nir_alu_instr *alu = nir_instr_as_alu(instr);
-   nir_ssa_def *x = nir_ssa_for_alu_src(b, alu, 0);
-
-   /* Reduce range from repeating about [-pi,pi] to [-1,1] */
-   x = nir_fmul_imm(b, x, M_1_PI / 2.0);
-   if (alu->op == nir_op_fsin)
-      x = nir_fadd_imm(b, x, 0.5);
-   else
-      x = nir_fadd_imm(b, x, 0.75);
-   x = nir_ffract(b, x);
-   x = nir_fadd_imm(b, nir_fmul_imm(b, x, 2.0), -1.0);
-
-   nir_ssa_def *x_absx = nir_fmul(b, x, nir_fabs(b, x));
-
-   /* y is the first approximation of the result. */
-   nir_ssa_def *y =
-      nir_fadd(b, nir_fmul_imm(b, x, 4.0), nir_fmul_imm(b, x_absx, -4.0));
-
-   /* improve the accuracy. */
-   nir_ssa_def *y_absy = nir_fmul(b, y, nir_fabs(b, y));
-   return nir_fadd(b, nir_fmul_imm(b, nir_fsub(b, y_absy, y), 0.225), y);
-}
-
-bool
-i915_nir_lower_sincos(nir_shader *s)
-{
-   return nir_shader_lower_instructions(s, i915_sincos_filter,
-                                        i915_sincos_lower, NULL);
-}

src/gallium/drivers/i915/i915_screen.c

@@ -116,6 +116,7 @@ static const nir_shader_compiler_options i915_compiler_options = {
    .lower_flrp32 = true,
    .lower_fmod = true,
    .lower_rotate = true,
+   .lower_sincos = true,
    .lower_uniforms_to_ubo = true,
    .lower_vector_cmp = true,
    .use_interpolated_input_intrinsics = true,

src/gallium/drivers/i915/i915_state.c

@@ -548,8 +548,6 @@ i915_create_fs_state(struct pipe_context *pipe,
    if (templ->type == PIPE_SHADER_IR_NIR) {
       nir_shader *s = templ->ir.nir;
 
-      NIR_PASS_V(s, i915_nir_lower_sincos);
-
       static const struct nir_to_tgsi_options ntt_options = {
          .lower_fabs = true,
       };

src/gallium/drivers/i915/meson.build

@@ -35,7 +35,6 @@ files_i915 = files(
   'i915_fpc.h',
   'i915_fpc_optimize.c',
   'i915_fpc_translate.c',
-  'i915_nir.c',
   'i915_prim_emit.c',
   'i915_prim_vbuf.c',
   'i915_public.h',