From 5d85a0a55b8c061fa6644ac24163542e3025834c Mon Sep 17 00:00:00 2001 From: Alyssa Rosenzweig Date: Wed, 2 May 2018 02:04:55 +0000 Subject: [PATCH] nir: Implement optional b2f->iand lowering This pass is required by the Midgard compiler; our instruction set uses NIR-style booleans (~0 for true) but lacks a dedicated b2f instruction. Normally, this lowering pass would be implemented in a backend-specific algebraic pass, but this conflicts with the existing iand->b2f pass in nir_opt_algebraic.py, hanging the compiler. This patch thus makes the existing pass optional (default on -- all other backends should remain unaffected), adding an optional pass for lowering the opposite direction. v2: Defer lowering until late algebraic optimisations to allow optimising the b2f instruction itself. Signed-off-by: Alyssa Rosenzweig Reviewed-by: Matt Turner Reviewed-by: Christian Gmeiner --- src/compiler/nir/nir.h | 3 +++ src/compiler/nir/nir_opt_algebraic.py | 5 ++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index a379928cdcd..f6086bd6c05 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -1894,6 +1894,9 @@ typedef struct nir_shader_compiler_options { /** enables rules to lower idiv by power-of-two: */ bool lower_idiv; + /* lower b2f to iand */ + bool lower_b2f; + /* Does the native fdot instruction replicate its result for four * components? If so, then opt_algebraic_late will turn all fdotN * instructions into fdot_replicatedN instructions. diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index 96232f0e549..909ea3daf42 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -321,7 +321,7 @@ optimizations = [ (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))), (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))), (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))), - (('iand', 'a@bool', 1.0), ('b2f', a)), + (('iand', 'a@bool', 1.0), ('b2f', a), '!options->lower_b2f'), # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True). (('ineg', ('b2i@32', a)), a), (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF. @@ -724,6 +724,9 @@ late_optimizations = [ # we do these late so that we don't get in the way of creating ffmas (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))), (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))), + + # Lowered for backends without a dedicated b2f instruction + (('b2f@32', a), ('iand', a, 1.0), 'options->lower_b2f'), ] print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render() -- 2.30.2