From: Eric Anholt <eric@anholt.net>
Date: Fri, 30 Jan 2015 21:53:39 +0000 (-0800)
Subject: nir: Add a flag for lowering fsat.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1907a3a7ee4d756b12b6fef32a6e5ea7656436d1;p=mesa.git

nir: Add a flag for lowering fsat.

vc4 cse/algebraic-disabled stats:
total instructions in shared programs: 44356 -> 44354 (-0.00%)
instructions in affected programs:     55 -> 53 (-3.64%)

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 7be1abb5743..f46ec151f6d 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1329,6 +1329,7 @@ typedef struct nir_function {
 typedef struct nir_shader_compiler_options {
    bool lower_ffma;
    bool lower_fpow;
+   bool lower_fsat;
    bool lower_fsqrt;
    /** lowers fneg and ineg to fsub and isub. */
    bool lower_negate;
diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 83a02b6dad6..c7cb651fbb4 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -85,7 +85,8 @@ optimizations = [
    (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
    (('bcsel', ('flt', a, b), a, b), ('fmin', a, b)),
    (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
-   (('fmin', ('fmax', a, 0.0), 1.0), ('fsat', a)),
+   (('fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
+   (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
    # Comparison with the same args.  Note that these are not done for
    # the float versions because NaN always returns false on float
    # inequalities.