nir: Add a flag for lowering ffma.

vc4 cse/algebraic-disabled stats:
total uniforms in shared programs: 13966 -> 13791 (-1.25%)
uniforms in affected programs:     435 -> 260 (-40.23%)
total instructions in shared programs: 44732 -> 44356 (-0.84%)
instructions in affected programs:     9599 -> 9223 (-3.92%)

v2: Rebase to master (no TGSI->NIR present)

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> (v1)

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 6448d4a0f401140472565a9c62b077ef367c4dba..7be1abb574360bb7b977e9b2ac176d3b821c172c 100644 (file)
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1327,6 +1327,7 @@ typedef struct nir_function {
                   exec_list_get_head(&(func)->overload_list), node)
 
 typedef struct nir_shader_compiler_options {
+   bool lower_ffma;
    bool lower_fpow;
    bool lower_fsqrt;
    /** lowers fneg and ineg to fsub and isub. */

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 8d5c03b0be7824478df3c36decff33b51ae84c3d..83a02b6dad68f0d43c7ddfa9aac85af80d76b6ed 100644 (file)
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -71,7 +71,8 @@ optimizations = [
    (('flrp', a, b, 1.0), b),
    (('flrp', a, a, b), a),
    (('flrp', 0.0, a, b), ('fmul', a, b)),
-   (('fadd', ('fmul', a, b), c), ('ffma', a, b, c)),
+   (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
+   (('fadd', ('fmul', a, b), c), ('ffma', a, b, c), '!options->lower_ffma'),
    # Comparison simplifications
    (('inot', ('flt', a, b)), ('fge', a, b)),
    (('inot', ('fge', a, b)), ('flt', a, b)),