diff options
| author | Matt Turner <mattst88@gmail.com> | 2013-09-17 17:44:03 -0700 |
|---|---|---|
| committer | Matt Turner <mattst88@gmail.com> | 2013-10-07 10:41:16 -0700 |
| commit | 6c125973f31addf903921647e8244abccb944e1a (patch) | |
| tree | 6ac5ede66cb84b8d064f627cbbc6ab06a5430658 | |
| parent | 499d7a7f6e47403a4a3da448eddaf15bdf56395c (diff) | |
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 <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
| -rw-r--r-- | src/glsl/builtin_functions.cpp | 21 |
1 files changed, 21 insertions, 0 deletions
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; +} /** @} */ /******************************************************************************/ |