[Mesa-dev] [PATCH] nir: Add optional lowering of flrp.

[Eric Anholt]

---

I missed this one when I was doing my other lowering bits.  I don't
have ffma, and I certainly don't have flrp.

 src/gallium/drivers/vc4/vc4_program.c | 1 +
 src/glsl/nir/nir.h                    | 1 +
 src/glsl/nir/nir_opt_algebraic.py     | 1 +
 3 files changed, 3 insertions(+)

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 26816ca..e768b1a 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -2005,6 +2005,7 @@ nir_to_qir(struct vc4_compile *c)
 
 static const nir_shader_compiler_options nir_options = {
         .lower_ffma = true,
+        .lower_flrp = true,
         .lower_fpow = true,
         .lower_fsat = true,
         .lower_fsqrt = true,
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
-- 
2.1.4