glsl: Kill __intrinsic_atomic_sub

Just generate an __intrinsic_atomic_add with a negated parameter.

Some background on the non-obvious reasons for the the big change to
builtin_builder::call()... this is cribbed from some discussion with
Ilia on mesa-dev.

Why change builtin_builder::call() to allow taking dereferences and
create them here rather than just feeding in the ir_variables directly?
The problem is the neg_data ir_variable node would have to be in two
lists at the same time: the instruction stream and parameters.  The
ir_variable node is automatically added to the instruction stream by the
call to make_temp.  Restructuring the code so that the ir_variables
could be in parameters then move them to the instruction stream would
have been pretty terrible.

ir_call in the instruction stream has an exec_list that contains
ir_dereference_variable nodes.

The builtin_builder::call method previously took an exec_list of
ir_variables and created a list of ir_dereference_variable.  All of the
original users of that method wanted to make a function call using
exactly the set of parameters passed to the built-in function (i.e.,
call __intrinsic_atomic_add using the parameters to atomicAdd).  For
these users, the list of ir_variables already existed:  the list of
parameters in the built-in function signature.

This new caller doesn't do that.  It wants to call a function with a
parameter from the function and a value calculated in the function.  So,
I changed builtin_builder::call to take a list that could either be a
list of ir_variable or a list of ir_dereference_variable.  In the former
case it behaves just as it previously did.  In the latter case, it uses
(and removes from the input list) the ir_dereference_variable nodes
instead of creating new ones.

   text	   data	    bss	    dec	    hex	filename
6036395	 283160	  28608	6348163	 60dd83	lib64/i965_dri.so before
6036923	 283160	  28608	6348691	 60df93	lib64/i965_dri.so after

Signed-off-by: Ian Romanick <[email protected]>
Acked-by: Ilia Mirkin <[email protected]>

1 files changed, 0 insertions, 10 deletions

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 749008b0fe1..bb88196780e 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -3218,15 +3218,6 @@ glsl_to_tgsi_visitor::visit_atomic_counter_intrinsic(ir_call *ir)
          data2 = this->result;
          break;
       }
-      case ir_intrinsic_atomic_counter_sub: {
-         opcode = TGSI_OPCODE_ATOMUADD;
-         st_src_reg res = get_temp(glsl_type::uvec4_type);
-         st_dst_reg dstres = st_dst_reg(res);
-         dstres.writemask = dst.writemask;
-         emit_asm(ir, TGSI_OPCODE_INEG, dstres, data);
-         data = res;
-         break;
-      }
       default:
          assert(!"Unexpected intrinsic");
          return;
@@ -3672,7 +3663,6 @@ glsl_to_tgsi_visitor::visit(ir_call *ir)
    case ir_intrinsic_atomic_counter_increment:
    case ir_intrinsic_atomic_counter_predecrement:
    case ir_intrinsic_atomic_counter_add:
-   case ir_intrinsic_atomic_counter_sub:
    case ir_intrinsic_atomic_counter_min:
    case ir_intrinsic_atomic_counter_max:
    case ir_intrinsic_atomic_counter_and: