[Mesa-dev] [PATCH 12/12] i965: Enable nir_opt_idiv_const for all bit sizes

Jason Ekstrand jason at jlekstrand.net
Sat Oct 6 04:10:20 UTC 2018


Shader-db results on Sky Lake:

    total instructions in shared programs: 15105795 -> 15111403 (0.04%)
    instructions in affected programs: 72774 -> 78382 (7.71%)
    helped: 0
    HURT: 265

Note that hurt here actually means helped because we're getting rid of
integer quotient operations (which are a send on some platforms!) and
replacing them with fairly cheap ALU ops.
---
 src/intel/compiler/brw_nir.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index f61baee230a..48380039cd5 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -569,6 +569,7 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
       OPT(nir_opt_cse);
       OPT(nir_opt_peephole_select, 0);
       OPT(nir_opt_intrinsics);
+      OPT(nir_opt_idiv_const, 0);
       OPT(nir_opt_algebraic);
       OPT(nir_opt_constant_folding);
       OPT(nir_opt_dead_cf);
@@ -675,7 +676,8 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir)
     */
    nir_lower_int64(nir, nir_lower_imul64 |
                         nir_lower_isign64 |
-                        nir_lower_divmod64);
+                        nir_lower_divmod64 |
+                        nir_lower_imul_high64);
 
    nir = brw_nir_optimize(nir, compiler, is_scalar, true);
 
-- 
2.19.0



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