Hello,
dropping the builtin as early as possible seems like it can only help us
optimize the code. Jakub suggested in the PR that he liked this approach
better than using __builtin_shuffle in the header. There is already some
coverage in the testsuite (as I noticed when I tried to restrict the
argument to [0, 3]...).
If this one is ok, I may add a few more (say shufps to begin with) later.
Bootstrap+regtest on x86_64-pc-linux-gnu.
2019-05-20 Marc Glisse <marc.gli...@inria.fr>
PR rtl-optimization/43147
* config/i386/i386.c (ix86_gimple_fold_builtin): Handle
IX86_BUILTIN_SHUFPD.
--
Marc GlisseIndex: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c (revision 271376)
+++ gcc/config/i386/i386.c (working copy)
@@ -17290,21 +17290,21 @@ ix86_fold_builtin (tree fndecl, int n_ar
bool
ix86_gimple_fold_builtin (gimple_stmt_iterator *gsi)
{
gimple *stmt = gsi_stmt (*gsi);
tree fndecl = gimple_call_fndecl (stmt);
gcc_checking_assert (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_MD));
int n_args = gimple_call_num_args (stmt);
enum ix86_builtins fn_code = (enum ix86_builtins) DECL_FUNCTION_CODE
(fndecl);
tree decl = NULL_TREE;
- tree arg0, arg1;
+ tree arg0, arg1, arg2;
enum rtx_code rcode;
unsigned HOST_WIDE_INT count;
bool is_vshift;
switch (fn_code)
{
case IX86_BUILTIN_TZCNT32:
decl = builtin_decl_implicit (BUILT_IN_CTZ);
goto fold_tzcnt_lzcnt;
@@ -17594,20 +17594,46 @@ ix86_gimple_fold_builtin (gimple_stmt_it
arithmetic right shift the result is zero. */
location_t loc = gimple_location (stmt);
gimple *g = gimple_build_assign (gimple_call_lhs (stmt),
build_zero_cst (TREE_TYPE (arg0)));
gimple_set_location (g, loc);
gsi_replace (gsi, g, false);
return true;
}
break;
+ case IX86_BUILTIN_SHUFPD:
+ arg2 = gimple_call_arg (stmt, 2);
+ if (TREE_CODE (arg2) == INTEGER_CST)
+ {
+ location_t loc = gimple_location (stmt);
+ unsigned HOST_WIDE_INT imask = TREE_INT_CST_LOW (arg2);
+ arg0 = gimple_call_arg (stmt, 0);
+ arg1 = gimple_call_arg (stmt, 1);
+ tree itype = long_long_integer_type_node;
+ tree vtype = build_vector_type (itype, 2); /* V2DI */
+ tree_vector_builder elts (vtype, 2, 1);
+ /* Ignore bits other than the lowest 2. */
+ elts.quick_push (build_int_cst (itype, imask & 1));
+ imask >>= 1;
+ elts.quick_push (build_int_cst (itype, 2 + (imask & 1)));
+ tree omask = elts.build ();
+ gimple *g = gimple_build_assign (gimple_call_lhs (stmt),
+ VEC_PERM_EXPR,
+ arg0, arg1, omask);
+ gimple_set_location (g, loc);
+ gsi_replace (gsi, g, false);
+ return true;
+ }
+ // Do not error yet, the constant could be propagated later?
+ break;
+
default:
break;
}
return false;
}
/* Handler for an SVML-style interface to
a library with vectorized intrinsics. */
