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 *
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 * permit persons to whom the Software is furnished to do so, subject to
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 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
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 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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/**
 * @file
 * Helper
 *
 * LLVM IR doesn't support all basic arithmetic operations we care about (most
 * notably min/max and saturated operations), and it is often necessary to
 * resort machine-specific intrinsics directly. The functions here hide all
 * these implementation details from the other modules.
 *
 * We also do simple expressions simplification here. Reasons are:
 * - it is very easy given we have all necessary information readily available
 * - LLVM optimization passes fail to simplify several vector expressions
 * - We often know value constraints which the optimization passes have no way
 *   of knowing, such as when source arguments are known to be in [0, 1] range.
 *
 * @author Jose Fonseca <jfonseca@vmware.com>
 */


#include "util/u_debug.h"

#include "lp_bld_intr.h"


LLVMValueRef
lp_build_intrinsic_binary(LLVMBuilderRef builder,
                          const char *name,
                          LLVMTypeRef ret_type,
                          LLVMValueRef a,
                          LLVMValueRef b)
{
   LLVMModuleRef module = LLVMGetGlobalParent(LLVMGetBasicBlockParent(LLVMGetInsertBlock(builder)));
   LLVMValueRef function;
   LLVMValueRef args[2];

   function = LLVMGetNamedFunction(module, name);
   if(!function) {
      LLVMTypeRef arg_types[2];
      arg_types[0] = LLVMTypeOf(a);
      arg_types[1] = LLVMTypeOf(b);
      function = LLVMAddFunction(module, name, LLVMFunctionType(ret_type, arg_types, 2, 0));
      LLVMSetFunctionCallConv(function, LLVMCCallConv);
      LLVMSetLinkage(function, LLVMExternalLinkage);
   }
   assert(LLVMIsDeclaration(function));

#ifdef DEBUG
   /* We shouldn't use only constants with intrinsics, as they won't be
    * propagated by LLVM optimization passes.
    */
   if(LLVMIsConstant(a) && LLVMIsConstant(b))
      debug_printf("warning: invoking intrinsic \"%s\" with constants\n");
#endif

   args[0] = a;
   args[1] = b;

   return LLVMBuildCall(builder, function, args, 2, "");
}