From: Iago Toral Quiroga <ito...@igalia.com>
Currently, we only consider precision qualifiers at compile-time. This patch
adds precision information to ir_variable so we can also do link time checks.
Specifically, from the GLSL ES3 spec, 4.5.3 Precision Qualifiers:
"The same uniform declared in different shaders that are linked together
must have the same precision qualification."
v2 (Ian Romanick):
- Remove unused precision field from glsl_type.
- Fix comments stating that desktop OpenGL ignores precision qualifiers.
- Make the precision field in ir_variable a bitfield and use pahole to
place it in an available hole so we don't increase memory storage
requirements for ir_variable.
v3 (Topi):
- Split out the checking logic in linker which did not apply to master
---
src/glsl/ast_to_hir.cpp | 12 ++++++++++++
src/glsl/glsl_types.cpp | 4 ++++
src/glsl/glsl_types.h | 12 ++++++++++++
src/glsl/ir.h | 13 +++++++++++++
4 files changed, 41 insertions(+)
diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 14e6309..7d5bb1d 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2450,6 +2450,10 @@ apply_type_qualifier_to_variable(const struct
ast_type_qualifier *qual,
if (qual->flags.q.sample)
var->data.sample = 1;
+ /* Precision qualifiers do not hold any meaning in Desktop GLSL */
+ if (state->es_shader && qual->precision)
+ var->data.precision = qual->precision;
+
if (state->stage == MESA_SHADER_GEOMETRY &&
qual->flags.q.out && qual->flags.q.stream) {
var->data.stream = qual->stream;
@@ -5301,6 +5305,10 @@ ast_process_structure_or_interface_block(exec_list
*instructions,
fields[i].centroid = qual->flags.q.centroid ? 1 : 0;
fields[i].sample = qual->flags.q.sample ? 1 : 0;
+ /* Precision qualifiers do not hold any meaning in Desktop GLSL */
+ fields[i].precision = state->es_shader ? qual->precision :
+ GLSL_PRECISION_NONE;
+
/* Only save explicitly defined streams in block's field */
fields[i].stream = qual->flags.q.explicit_stream ? qual->stream : -1;
@@ -5804,6 +5812,10 @@ ast_interface_block::hir(exec_list *instructions,
if (var_mode == ir_var_shader_in || var_mode == ir_var_uniform)
var->data.read_only = true;
+ /* Precision qualifiers do not hold any meaning in Desktop GLSL */
+ var->data.precision = state->es_shader ? fields[i].precision :
+ GLSL_PRECISION_NONE;
+
if (fields[i].matrix_layout == GLSL_MATRIX_LAYOUT_INHERITED) {
var->data.matrix_layout = matrix_layout ==
GLSL_MATRIX_LAYOUT_INHERITED
? GLSL_MATRIX_LAYOUT_COLUMN_MAJOR : matrix_layout;
diff --git a/src/glsl/glsl_types.cpp b/src/glsl/glsl_types.cpp
index 9c9b7ef..46c8bf1 100644
--- a/src/glsl/glsl_types.cpp
+++ b/src/glsl/glsl_types.cpp
@@ -122,6 +122,7 @@ glsl_type::glsl_type(const glsl_struct_field *fields,
unsigned num_fields,
this->fields.structure[i].centroid = fields[i].centroid;
this->fields.structure[i].sample = fields[i].sample;
this->fields.structure[i].matrix_layout = fields[i].matrix_layout;
+ this->fields.structure[i].precision = fields[i].precision;
}
mtx_unlock(&glsl_type::mutex);
@@ -716,6 +717,9 @@ glsl_type::record_compare(const glsl_type *b) const
if (this->fields.structure[i].sample
!= b->fields.structure[i].sample)
return false;
+ if (this->fields.structure[i].precision
+ != b->fields.structure[i].precision)
+ return false;
}
return true;
diff --git a/src/glsl/glsl_types.h b/src/glsl/glsl_types.h
index 5645dcd..25c4d30 100644
--- a/src/glsl/glsl_types.h
+++ b/src/glsl/glsl_types.h
@@ -100,6 +100,13 @@ enum glsl_matrix_layout {
GLSL_MATRIX_LAYOUT_ROW_MAJOR
};
+enum {
+ GLSL_PRECISION_NONE = 0,
+ GLSL_PRECISION_HIGH,
+ GLSL_PRECISION_MEDIUM,
+ GLSL_PRECISION_LOW
+};
+
#ifdef __cplusplus
#include "GL/gl.h"
#include "util/ralloc.h"
@@ -768,6 +775,11 @@ struct glsl_struct_field {
* streams (as in ir_variable::stream). -1 otherwise.
*/
int stream;
+
+ /**
+ * Precission qualifier
+ */
+ unsigned precision;
};
static inline unsigned int
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index fab1cd2..5ef9e68 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -755,6 +755,19 @@ public:
unsigned index:1;
/**
+ * Precision qualifier.
+ *
+ * In desktop GLSL we do not care about precision qualifiers at all, in
+ * fact, the spec says that precision qualifiers are ignored.
+ *
+ * To make things easy, we make it so that this field is always
+ * GLSL_PRECISION_NONE on desktop shaders. This way all the variables
+ * have the same precision value and the checks we add in the compiler
+ * for this field will never break a desktop shader compile.
+ */
+ unsigned precision:2;
+
+ /**
* \brief Layout qualifier for gl_FragDepth.
*
* This is not equal to \c ir_depth_layout_none if and only if this
--
1.9.3
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