nir: add lowering for ffract

Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 4e4543ad5ec992e88cf7224af8d00b8f31366645..fffb2f45719a430a9355e81cdcaffccd9f0fff34 100644 (file)
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1440,6 +1440,9 @@ typedef struct nir_shader_compiler_options {
     */
    bool fdot_replicates;
 
+   /** lowers ffract to fsub+ffloor: */
+   bool lower_ffract;
+
    /**
     * Does the driver support real 32-bit integers?  (Otherwise, integers
     * are simulated by floats.)

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index acc3b04b118089e366f83c7f6eb331da149b0c46..43558a547b4fbc8670ef4bf4b1db4bee91c913d5 100644 (file)
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -76,6 +76,7 @@ optimizations = [
    (('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'),
+   (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
    (('fadd', ('fmul', a, ('fadd', 1.0, ('fneg', c))), ('fmul', b, c)), ('flrp', a, b, c), '!options->lower_flrp'),
    (('fadd', a, ('fmul', c, ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp'),
    (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),