Hi, This patch folds builtin_isinf on IBM long double to builtin_isinf on its high-order double.
The isinf_optab was already implemented in this patch. https://gcc.gnu.org/g:53945be1efb502f235d84ff67ceafe4a764b6e1c Bootstrapped and tested on powerpc64-linux BE and LE with no regressions. Is it OK for the trunk? Thanks Gui Haochen ChangeLog Builtins: Fold isinf on IBM long double to isinf on high-order double For IBM long double, Inf is encoded in the high-order double value only. So the builtin_isinf on IBM long double can be folded to builtin_isinf on double type. As former patch implemented DFmode isinf_optab, this patch converts builtin_isinf on IBM long double to builtin_isinf on double type if the DFmode isinf_optab exists. gcc/ PR target/97786 * builtins.cc (fold_builtin_interclass_mathfn): Fold isinf on IBM long double to isinf on high_order double when DFmode isinf_optab exists. gcc/testsuite/ PR target/97786 * gcc.target/powerpc/pr97786-3.c: New test. patch.diff diff --git a/gcc/builtins.cc b/gcc/builtins.cc index 0b902896ddd..c20bd7b5f31 100644 --- a/gcc/builtins.cc +++ b/gcc/builtins.cc @@ -9568,6 +9568,15 @@ 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 isinf icode exists, build the call with high-order + double value only. */ + tree const isinf_fn = builtin_decl_explicit (BUILT_IN_ISINF); + if (interclass_mathfn_icode (arg, isinf_fn) != CODE_FOR_nothing) + { + result = build_call_expr (isinf_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/pr97786-3.c b/gcc/testsuite/gcc.target/powerpc/pr97786-3.c new file mode 100644 index 00000000000..6a8d9f2df53 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr97786-3.c @@ -0,0 +1,17 @@ +/* { 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_isinf (x); +} + +int test2 (long double x) +{ + return __builtin_isinfl (x); +} + +/* { dg-final { scan-assembler-not {\mfcmpu\M} } } */ +/* { dg-final { scan-assembler-times {\mxststdcdp\M} 2 } } */
