From 43b07eb60faba1c65fc6f7a99087d051b00e9c0f Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 9 Oct 2015 14:17:32 -0700 Subject: [PATCH] glsl: Allow built-in functions as constant expressions in OpenGL ES 1.00 In d4a24745 (August 2012), Paul made functions calls not be constant expressions in GLSL ES 1.00. Since this feature was added in desktop GLSL 1.20, we believed that it was added in GLSL ES 3.00. That turns out to be completely wrong. Built-in functions have always been allowed as constant expressions in GLSL ES, and the patch adds the (many) spec quotations to prove it. While we never previously encountered this, a later patch enforces a GLSL ES 1.00 rule that global variable initializers must be constant expressions. Without this fix, several dEQP tests fail. Fixes: tests/spec/glsl-es-1.00/compiler/const-initializer/from-function.frag tests/spec/glsl-es-1.00/compiler/const-initializer/from-function.vert tests/spec/glsl-es-1.00/compiler/const-initializer/from-sequence-in-function.frag tests/spec/glsl-es-1.00/compiler/const-initializer/from-sequence-in-function.vert Signed-off-by: Ian Romanick Reviewed-by: Matt Turner Cc: "10.0 10.1 10.2 10.3 10.4 10.5 10.6 11.0" Yes, I know we don't maintain stable branches that far back, but that *is* how far back this bug goes! --- src/glsl/ast_function.cpp | 51 +++++++++++++++++++++++++++++++++++---- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp index 26d4c62ce36..6538992ae0e 100644 --- a/src/glsl/ast_function.cpp +++ b/src/glsl/ast_function.cpp @@ -437,13 +437,54 @@ generate_call(exec_list *instructions, ir_function_signature *sig, } } - /* If the function call is a constant expression, don't generate any - * instructions; just generate an ir_constant. + /* Section 4.3.2 (Const) of the GLSL 1.10.59 spec says: + * + * "Initializers for const declarations must be formed from literal + * values, other const variables (not including function call + * paramaters), or expressions of these. + * + * Constructors may be used in such expressions, but function calls may + * not." + * + * Section 4.3.3 (Constant Expressions) of the GLSL 1.20.8 spec says: + * + * "A constant expression is one of + * + * ... + * + * - a built-in function call whose arguments are all constant + * expressions, with the exception of the texture lookup + * functions, the noise functions, and ftransform. The built-in + * functions dFdx, dFdy, and fwidth must return 0 when evaluated + * inside an initializer with an argument that is a constant + * expression." + * + * Section 5.10 (Constant Expressions) of the GLSL ES 1.00.17 spec says: * - * Function calls were first allowed to be constant expressions in GLSL - * 1.20 and GLSL ES 3.00. + * "A constant expression is one of + * + * ... + * + * - a built-in function call whose arguments are all constant + * expressions, with the exception of the texture lookup + * functions." + * + * Section 4.3.3 (Constant Expressions) of the GLSL ES 3.00.4 spec says: + * + * "A constant expression is one of + * + * ... + * + * - a built-in function call whose arguments are all constant + * expressions, with the exception of the texture lookup + * functions. The built-in functions dFdx, dFdy, and fwidth must + * return 0 when evaluated inside an initializer with an argument + * that is a constant expression." + * + * If the function call is a constant expression, don't generate any + * instructions; just generate an ir_constant. */ - if (state->is_version(120, 300)) { + if (state->is_version(120, 100)) { ir_constant *value = sig->constant_expression_value(actual_parameters, NULL); if (value != NULL) { return value; -- 2.30.2