From 6c125973f31addf903921647e8244abccb944e1a Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Tue, 17 Sep 2013 17:44:03 -0700 Subject: glsl: Implement uaddCarry() built-in for ARB_gpu_shader5. i965 implements this with a single (multiple destination) instruction, ADDC. Emitting ADDC directly from uaddCarry() would be ideal, but our optimization passes don't know how to copy with expressions with side-effects. Radeon has an ADDC_UINT instruction that only generates the carry bit. I've chosen to go this route and implement uaddCarry() by doing the addition and the carry operations separately. Reviewed-by: Kenneth Graunke Reviewed-by: Ian Romanick --- src/glsl/builtin_functions.cpp | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/src/glsl/builtin_functions.cpp b/src/glsl/builtin_functions.cpp index b6451089c03..9465ee3e785 100644 --- a/src/glsl/builtin_functions.cpp +++ b/src/glsl/builtin_functions.cpp @@ -531,6 +531,7 @@ private: B1(fma) B2(ldexp) B2(frexp) + B1(uaddCarry) #undef B0 #undef B1 #undef B2 @@ -1947,6 +1948,12 @@ builtin_builder::create_builtins() _frexp(glsl_type::vec3_type, glsl_type::ivec3_type), _frexp(glsl_type::vec4_type, glsl_type::ivec4_type), NULL); + add_function("uaddCarry", + _uaddCarry(glsl_type::uint_type), + _uaddCarry(glsl_type::uvec2_type), + _uaddCarry(glsl_type::uvec3_type), + _uaddCarry(glsl_type::uvec4_type), + NULL); #undef F #undef FI #undef FIU @@ -3720,6 +3727,20 @@ builtin_builder::_frexp(const glsl_type *x_type, const glsl_type *exp_type) return sig; } + +ir_function_signature * +builtin_builder::_uaddCarry(const glsl_type *type) +{ + ir_variable *x = in_var(type, "x"); + ir_variable *y = in_var(type, "y"); + ir_variable *carry = out_var(type, "carry"); + MAKE_SIG(type, gpu_shader5, 3, x, y, carry); + + body.emit(assign(carry, ir_builder::carry(x, y))); + body.emit(ret(add(x, y))); + + return sig; +} /** @} */ /******************************************************************************/ -- cgit v1.2.3