From d8999bcdce6a3c8ab63f06c7028fd6e927bb9acb Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Thu, 22 Jan 2015 14:15:27 -0800 Subject: [PATCH] nir/search: Add support for matching unknown constants There are some algebraic transformations that we want to do but only if certain things are constants. For instance, we may want to replace a * (b + c) with (a * b) + (a * c) as long as a and either b or c is constant. While this generates more instructions, some of it will get constant folded. nir_algebraic.py doesn't handle this yet, but that's ok because the C language will make sure that false is the default for now. Reviewed-by: Kenneth Graunke --- src/glsl/nir/nir_search.c | 6 ++++++ src/glsl/nir/nir_search.h | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/src/glsl/nir/nir_search.c b/src/glsl/nir/nir_search.c index 18e0330e4ae..ec898174364 100644 --- a/src/glsl/nir/nir_search.c +++ b/src/glsl/nir/nir_search.c @@ -78,6 +78,10 @@ match_value(const nir_search_value *value, nir_alu_instr *instr, unsigned src, return true; } else { + if (var->is_constant && + instr->src[src].src.ssa->parent_instr->type != nir_instr_type_load_const) + return false; + state->variables_seen |= (1 << var->variable); state->variables[var->variable].src = instr->src[src].src; state->variables[var->variable].abs = false; @@ -236,6 +240,8 @@ construct_value(const nir_search_value *value, nir_alu_type type, nir_alu_src val; nir_alu_src_copy(&val, &state->variables[var->variable], mem_ctx); + assert(!var->is_constant); + return val; } diff --git a/src/glsl/nir/nir_search.h b/src/glsl/nir/nir_search.h index 8ec58b07139..18aa28dcc66 100644 --- a/src/glsl/nir/nir_search.h +++ b/src/glsl/nir/nir_search.h @@ -47,6 +47,13 @@ typedef struct { /** The variable index; Must be less than NIR_SEARCH_MAX_VARIABLES */ unsigned variable; + + /** Indicates that the given variable must be a constant + * + * This is only alloed in search expressions and indicates that the + * given variable is only allowed to match constant values. + */ + bool is_constant; } nir_search_variable; typedef struct { -- 2.30.2