From ca1aa5d225ab96bdff5052a46f3a3c22fc6f1646 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Wed, 25 Sep 2019 11:56:06 -0700 Subject: [PATCH] v3d: Enable the late algebraic optimizations to get real subs. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This worked better than my original v3d-local pass for just subs, and is a huge win over not producing subs. total instructions in shared programs: 6408469 -> 6167932 (-3.75%) total threads in shared programs: 153784 -> 154104 (0.21%) total uniforms in shared programs: 2157078 -> 1905823 (-11.65%) total max-temps in shared programs: 904546 -> 895796 (-0.97%) total spills in shared programs: 4959 -> 4993 (0.69%) total fills in shared programs: 6558 -> 6670 (1.71%) total sfu-stalls in shared programs: 25845 -> 25175 (-2.59%) total inst-and-stalls in shared programs: 6434314 -> 6193107 (-3.75%) Reviewed-by: Daniel Schürmann Reviewed-by: Connor Abbott --- src/broadcom/compiler/vir.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/broadcom/compiler/vir.c b/src/broadcom/compiler/vir.c index 917ccfeaef1..802448b1e03 100644 --- a/src/broadcom/compiler/vir.c +++ b/src/broadcom/compiler/vir.c @@ -939,6 +939,22 @@ uint64_t *v3d_compile(const struct v3d_compiler *compiler, NIR_PASS_V(c->s, nir_lower_idiv); v3d_optimize_nir(c->s); + + /* Do late algebraic optimization to turn add(a, neg(b)) back into + * subs, then the mandatory cleanup after algebraic. Note that it may + * produce fnegs, and if so then we need to keep running to squash + * fneg(fneg(a)). + */ + bool more_late_algebraic = true; + while (more_late_algebraic) { + more_late_algebraic = false; + NIR_PASS(more_late_algebraic, c->s, nir_opt_algebraic_late); + NIR_PASS_V(c->s, nir_opt_constant_folding); + NIR_PASS_V(c->s, nir_copy_prop); + NIR_PASS_V(c->s, nir_opt_dce); + NIR_PASS_V(c->s, nir_opt_cse); + } + NIR_PASS_V(c->s, nir_lower_bool_to_int32); NIR_PASS_V(c->s, nir_convert_from_ssa, true); -- 2.30.2