Adding Fortran list too ping
________________________________________ From: Wilco Dijkstra Sent: 17 September 2025 18:19 To: GCC Patches <[email protected]> Subject: [PATCH] fortran: Allow vector math functions only with fast-math [PR 118955] Vector math functions are currently always enabled in Fortran. This is incorrect since vector math functions are designed to be Ofast only. Add a new 'fastmath' option which only accepts vector functions if fast-math is enabled: !GCC$ builtin (sin) attributes simd (notinbranch) if('fastmath') Passes regress. gcc: PR fortran/118955 * fortran/decl.cc (gfc_match_gcc_builtin): Add 'fastmath' option which checks for fast-math before accepting a vector function. * fortran/gfortran.texi (!GCC$ builtin): Update documentation. gcc/testsuite: PR fortran/118955 * gfortran.dg/simd-builtins-9.f90: Add new test. * gfortran.dg/simd-builtins-9.h: Likewise. --- diff --git a/gcc/fortran/decl.cc b/gcc/fortran/decl.cc index 9fe697cd5498467df2600fe878956e8050a28adb..04ed9075491d3ec2c9d7fb75bced34f9ffb9f577 100644 --- a/gcc/fortran/decl.cc +++ b/gcc/fortran/decl.cc @@ -29,6 +29,7 @@ along with GCC; see the file COPYING3. If not see #include "parse.h" #include "constructor.h" #include "target.h" +#include "flags.h" /* Macros to access allocate memory for gfc_data_variable, gfc_data_value and gfc_data. */ @@ -12562,9 +12563,17 @@ gfc_match_gcc_builtin (void) if (gfc_match (" if ( '%n' ) ", target) == MATCH_YES) { - const char *abi = targetm.get_multilib_abi_name (); - if (abi == NULL || strcmp (abi, target) != 0) - return MATCH_YES; + if (strcmp (target, "fastmath") == 0) + { + if (!fast_math_flags_set_p (&global_options)) + return MATCH_YES; + } + else + { + const char *abi = targetm.get_multilib_abi_name (); + if (abi == NULL || strcmp (abi, target) != 0) + return MATCH_YES; + } } if (gfc_vectorized_builtins == NULL) diff --git a/gcc/fortran/gfortran.texi b/gcc/fortran/gfortran.texi index 841f6135066043935ca31496e910c69908c0c53e..e76c37f8123d0b5885730f01928d821606d42752 100644 --- a/gcc/fortran/gfortran.texi +++ b/gcc/fortran/gfortran.texi @@ -3470,6 +3470,13 @@ for the built-in that should be vectorized. Example usage: !GCC$ builtin (sinf) attributes simd (notinbranch) if('x86_64') @end smallexample +The special target @code{'fastmath'} is used to specify the vector +implementation is only valid if fast-math is enabled: + +@smallexample +!GCC$ builtin (exp) attributes simd (notinbranch) if('fastmath') +@end smallexample + The purpose of the directive is to provide an API among the GCC compiler and the GNU C Library which would define vector implementations of math routines. diff --git a/gcc/testsuite/gfortran.dg/simd-builtins-9.f90 b/gcc/testsuite/gfortran.dg/simd-builtins-9.f90 new file mode 100644 index 0000000000000000000000000000000000000000..02944e578533afccc90768516cafb473f098f19d --- /dev/null +++ b/gcc/testsuite/gfortran.dg/simd-builtins-9.f90 @@ -0,0 +1,16 @@ +! { dg-do compile { target { aarch64*-*-linux* } } } +! { dg-additional-options "-nostdinc -O3 -fpre-include=simd-builtins-9.h -fdump-tree-optimized" } + +program test_overloaded_intrinsic + real(8) :: x8(3200), y8(3200) + + y8 = sin(x8) + print *, y8 + + x8 = cos(y8) + print *, x8 +end + +! { dg-final { scan-tree-dump-not "sin.simdclone" "optimized" } } */ + +! { dg-final { scan-tree-dump "cos.simdclone" "optimized" } } */ diff --git a/gcc/testsuite/gfortran.dg/simd-builtins-9.h b/gcc/testsuite/gfortran.dg/simd-builtins-9.h new file mode 100644 index 0000000000000000000000000000000000000000..3ca3ea8062c9d1c99ccabc9dd5466befd6e6d4f6 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/simd-builtins-9.h @@ -0,0 +1,2 @@ +!GCC$ builtin (sin) attributes simd (notinbranch) if('fastmath') +!GCC$ builtin (cos) attributes simd (notinbranch)
