Hi, This patch folds builtin_isfinite on IBM long double to builtin_isfinite on its high-order double.
The isfinite_optab was already implemented in this patch. https://gcc.gnu.org/g:44eb45c2ef7192eb6a811fd46fcb2c7fbeb6f865 Bootstrapped and tested on powerpc64-linux BE and LE with no regressions. Is it OK for the trunk? Thanks Gui Haochen ChangeLog Builtins: Fold isfinite on IBM long double to isfinite on high-order double For IBM long double, INF and NAN is encoded in the high-order double value only. So the builtin_isfinite on IBM long double can be folded to builtin_isfinite on double type. As former patch implemented DFmode isfinite_optab, this patch converts builtin_isfinite on IBM long double to builtin_isfinite on double type if the DFmode isfinite_optab exists. gcc/ PR target/97786 * builtins.cc (fold_builtin_interclass_mathfn): Fold isfinite on IBM long double to isfinite on high-order double when DFmode isfinite_optab exists. gcc/testsuite/ PR target/97786 * gcc.target/powerpc/pr97786-6.c: New test. patch.diff diff --git a/gcc/builtins.cc b/gcc/builtins.cc index c20bd7b5f31..c3d8ce5313a 100644 --- a/gcc/builtins.cc +++ b/gcc/builtins.cc @@ -9601,6 +9601,15 @@ fold_builtin_interclass_mathfn (location_t loc, tree fndecl, tree arg) type = double_type_node; mode = DFmode; arg = fold_build1_loc (loc, NOP_EXPR, type, arg); + + /* If isfinite icode exists, build the call with high-order + double value only. */ + tree const isfinite_fn = builtin_decl_explicit (BUILT_IN_ISFINITE); + if (interclass_mathfn_icode (arg, isfinite_fn) != CODE_FOR_nothing) + { + result = build_call_expr (isfinite_fn, 1, arg); + return result; + } } get_max_float (REAL_MODE_FORMAT (mode), buf, sizeof (buf), false); real_from_string (&r, buf); diff --git a/gcc/testsuite/gcc.target/powerpc/pr97786-6.c b/gcc/testsuite/gcc.target/powerpc/pr97786-6.c new file mode 100644 index 00000000000..1b25bcecd5a --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr97786-6.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target ppc_float128_hw } */ +/* { dg-options "-O2 -mdejagnu-cpu=power9 -mvsx -mabi=ibmlongdouble -Wno-psabi" } */ +/* { dg-require-effective-target powerpc_vsx } */ + +int test1 (long double x) +{ + return __builtin_isfinite (x); +} + +/* { dg-final { scan-assembler-not {\mfcmpu\M} } } */ +/* { dg-final { scan-assembler {\mxststdcdp\M} } } */
