[Mesa-dev] [PATCH 4/9] glsl: Implement min3 built-in function

[=?UTF-8?q?Maxence=20Le=20Dor=C3=A9?= <Maxence Le Doré>]

---
 src/glsl/builtin_functions.cpp | 45 ++++++++++++++++++++++++++++++++++++++++++
 src/glsl/ir_builder.cpp        |  5 +++++
 src/glsl/ir_builder.h          |  2 ++
 3 files changed, 52 insertions(+)

diff --git a/src/glsl/builtin_functions.cpp b/src/glsl/builtin_functions.cpp
index 481a456..7399e8f 100644
--- a/src/glsl/builtin_functions.cpp
+++ b/src/glsl/builtin_functions.cpp
@@ -402,6 +402,8 @@ private:
 
    ir_expression *asin_expr(ir_variable *x);
 
+   ir_expression *min3_expr(ir_variable *x, ir_variable *y, ir_variable *z);
+
    /**
     * Call function \param f with parameters specified as the linked
     * list \param params of \c ir_variable objects.  \param ret should
@@ -576,6 +578,11 @@ private:
    ir_function_signature *_atomic_op(const char *intrinsic,
                                      builtin_available_predicate avail);
 
+   ir_function_signature *_min3(builtin_available_predicate avail,
+                                const glsl_type *x_type,
+                                const glsl_type *y_type,
+                                const glsl_type *z_type);
+
 #undef B0
 #undef B1
 #undef B2
@@ -2112,6 +2119,23 @@ builtin_builder::create_builtins()
                            shader_atomic_counters),
                 NULL);
 
+   add_function("min3",
+                _min3(shader_trinary_mimax, glsl_type::float_type, glsl_type::float_type, glsl_type::float_type),
+                _min3(shader_trinary_mimax, glsl_type::vec2_type, glsl_type::vec2_type, glsl_type::vec2_type),
+                _min3(shader_trinary_mimax, glsl_type::vec3_type, glsl_type::vec3_type, glsl_type::vec3_type),
+                _min3(shader_trinary_mimax, glsl_type::vec4_type, glsl_type::vec4_type, glsl_type::vec4_type),
+
+                _min3(shader_trinary_mimax, glsl_type::int_type, glsl_type::int_type, glsl_type::int_type),
+                _min3(shader_trinary_mimax, glsl_type::ivec2_type, glsl_type::ivec2_type, glsl_type::ivec2_type),
+                _min3(shader_trinary_mimax, glsl_type::ivec3_type, glsl_type::ivec3_type, glsl_type::ivec3_type),
+                _min3(shader_trinary_mimax, glsl_type::ivec4_type, glsl_type::ivec4_type, glsl_type::ivec4_type),
+
+                _min3(shader_trinary_mimax, glsl_type::uint_type, glsl_type::uint_type, glsl_type::uint_type),
+                _min3(shader_trinary_mimax, glsl_type::uvec2_type, glsl_type::uvec2_type, glsl_type::uvec2_type),
+                _min3(shader_trinary_mimax, glsl_type::uvec3_type, glsl_type::uvec3_type, glsl_type::uvec3_type),
+                _min3(shader_trinary_mimax, glsl_type::uvec4_type, glsl_type::uvec4_type, glsl_type::uvec4_type),
+                NULL);
+
 #undef F
 #undef FI
 #undef FIU
@@ -2327,6 +2351,12 @@ builtin_builder::asin_expr(ir_variable *x)
                                           mul(abs(x), imm(-0.03102955f))))))))));
 }
 
+ir_expression *
+builtin_builder::min3_expr(ir_variable *x, ir_variable *y, ir_variable *z)
+{
+   return min(x, min(y,z));
+}
+
 ir_call *
 builtin_builder::call(ir_function *f, ir_variable *ret, exec_list params)
 {
@@ -3997,6 +4027,21 @@ builtin_builder::_atomic_op(const char *intrinsic,
    return sig;
 }
 
+ir_function_signature *
+builtin_builder::_min3(builtin_available_predicate avail,
+                      const glsl_type *x_type, const glsl_type *y_type,
+                      const glsl_type *z_type)
+{
+   ir_variable *x = in_var(x_type, "x");
+   ir_variable *y = in_var(y_type, "y");
+   ir_variable *z = in_var(z_type, "z");
+   MAKE_SIG(x_type, avail, 3, x, y, z);
+
+   body.emit(ret(min3_expr(x, y, z)));
+
+   return sig;
+}
+
 /** @} */
 
 /******************************************************************************/
diff --git a/src/glsl/ir_builder.cpp b/src/glsl/ir_builder.cpp
index 6c49734..7091e9a 100644
--- a/src/glsl/ir_builder.cpp
+++ b/src/glsl/ir_builder.cpp
@@ -211,6 +211,11 @@ ir_expression *sub(operand a, operand b)
    return expr(ir_binop_sub, a, b);
 }
 
+ir_expression *min(operand a, operand b)
+{
+   return expr(ir_binop_min, a, b);
+}
+
 ir_expression *mul(operand a, operand b)
 {
    return expr(ir_binop_mul, a, b);
diff --git a/src/glsl/ir_builder.h b/src/glsl/ir_builder.h
index 1f07788..f564b07 100644
--- a/src/glsl/ir_builder.h
+++ b/src/glsl/ir_builder.h
@@ -184,6 +184,8 @@ ir_expression *i2b(operand a);
 ir_expression *f2b(operand a);
 ir_expression *b2f(operand a);
 
+ir_expression *min(operand a, operand b);
+
 ir_expression *fma(operand a, operand b, operand c);
 ir_expression *lrp(operand x, operand y, operand a);
 ir_expression *csel(operand a, operand b, operand c);
-- 
1.8.5.1