Mesa (master): nir: Add optional lowering of flrp.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: afa9fc15613c3ebdc59245c9d4d8c1280b2a2a37
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=afa9fc15613c3ebdc59245c9d4d8c1280b2a2a37

Author: Eric Anholt <eric at anholt.net>
Date:   Wed Feb 18 12:24:38 2015 -0800

nir: Add optional lowering of flrp.

Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>

---

 src/glsl/nir/nir.h                |    1 +
 src/glsl/nir/nir_opt_algebraic.py |    1 +
 2 files changed, 2 insertions(+)

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 29fe942..7b886e3 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1365,6 +1365,7 @@ typedef struct nir_function {
 
 typedef struct nir_shader_compiler_options {
    bool lower_ffma;
+   bool lower_flrp;
    bool lower_fpow;
    bool lower_fsat;
    bool lower_fsqrt;
diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 1ee51a0..20ec4d3 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -75,6 +75,7 @@ optimizations = [
    (('flrp', a, b, 1.0), b),
    (('flrp', a, a, b), a),
    (('flrp', 0.0, a, b), ('fmul', a, b)),
+   (('flrp', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp'),
    (('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