cp2k, libxc, libint: fix builds with %intel, resp. intel-parallel-studio+mkl (#19522)

* cp2k: locate correct include dir when using intel-parallel-studio+mkl for fftw-api

* libxc: drop arch-specific intel opt. flags

fixes #17794

* libint: drop arch-specific intel opt. flags, always build Fortran example with FC

fixes #17509

3 files changed, 23 insertions, 39 deletions

diff --git a/var/spack/repos/builtin/packages/cp2k/package.py b/var/spack/repos/builtin/packages/cp2k/package.py
index 9b0e3b69d7..1b248506da 100644
--- a/var/spack/repos/builtin/packages/cp2k/package.py
+++ b/var/spack/repos/builtin/packages/cp2k/package.py
@@ -193,7 +193,12 @@ class Cp2k(MakefilePackage, CudaPackage):
             fftw_header_dir = fftw.headers.directories[0] + '/fftw'
         elif '^intel-parallel-studio+mkl' in spec:
             fftw = spec['intel-parallel-studio']
-            fftw_header_dir = fftw.headers.directories[0] + '/fftw'
+            fftw_header_dir = '<NOTFOUND>'
+            for incdir in [join_path(f, 'fftw')
+                           for f in fftw.headers.directories]:
+                if os.path.exists(incdir):
+                    fftw_header_dir = incdir
+                    break
 
         optimization_flags = {
             'gcc': [
diff --git a/var/spack/repos/builtin/packages/libint/package.py b/var/spack/repos/builtin/packages/libint/package.py
index f7248f61ab..a3b39495f9 100644
--- a/var/spack/repos/builtin/packages/libint/package.py
+++ b/var/spack/repos/builtin/packages/libint/package.py
@@ -78,10 +78,10 @@ class Libint(AutotoolsPackage):
     @property
     def optflags(self):
         flags = '-O2'
-        # Optimizations for the Intel compiler, suggested by CP2K
-        # See ../libxc/package.py for rationale and doc.
-        if '%intel' in self.spec:
-            flags += ' -xSSE4.2 -axAVX,CORE-AVX2 -ipo'
+
+        # microarchitecture-specific optimization flags should be controlled
+        # by Spack, otherwise we may end up with contradictory or invalid flags
+        # see https://github.com/spack/spack/issues/17794
 
         return flags
 
@@ -99,18 +99,16 @@ class Libint(AutotoolsPackage):
 
         config_args = ['--enable-shared']
 
-        optflags = self.optflags
-
         # Optimization flag names have changed in libint 2
         if self.version < Version('2.0.0'):
             config_args.extend([
-                '--with-cc-optflags={0}'.format(optflags),
-                '--with-cxx-optflags={0}'.format(optflags)
+                '--with-cc-optflags={0}'.format(self.optflags),
+                '--with-cxx-optflags={0}'.format(self.optflags)
             ])
         else:
             config_args.extend([
-                '--with-cxx-optflags={0}'.format(optflags),
-                '--with-cxxgen-optflags={0}'.format(optflags)
+                '--with-cxx-optflags={0}'.format(self.optflags),
+                '--with-cxxgen-optflags={0}'.format(self.optflags)
             ])
 
         # Options required by CP2K, removed in libint 2
@@ -199,6 +197,6 @@ class Libint(AutotoolsPackage):
     def patch(self):
         # Use Fortran compiler to link the Fortran example, not the C++
         # compiler
-        if '+fortran' in self.spec and self.spec.satisfies('%nvhpc'):
+        if '+fortran' in self.spec:
             filter_file('$(CXX) $(CXXFLAGS)', '$(FC) $(FCFLAGS)',
                         'export/fortran/Makefile', string=True)
diff --git a/var/spack/repos/builtin/packages/libxc/package.py b/var/spack/repos/builtin/packages/libxc/package.py
index 178b6cbcde..f054bfa72c 100644
--- a/var/spack/repos/builtin/packages/libxc/package.py
+++ b/var/spack/repos/builtin/packages/libxc/package.py
@@ -64,37 +64,18 @@ class Libxc(AutotoolsPackage, CudaPackage):
         )
 
     def setup_build_environment(self, env):
-        optflags = '-O2'
-        if self.compiler.name == 'intel':
-            # Optimizations for the Intel compiler, suggested by CP2K
-            #
-            # Note that not every lowly login node has advanced CPUs:
-            #
-            #   $ icc  -xAVX -axCORE-AVX2 -ipo hello.c
-            #   $ ./a.out
-            #   Please verify that both the operating system and the \
-            #   processor support Intel(R) AVX instructions.
-            #
-            # NB: The same flags are applied in:
-            #   - ../libint/package.py
-            #
-            # Related:
-            #   - ../fftw/package.py        variants: simd, fma
-            #   - ../c-blosc/package.py     variant:  avx2
-            #   - ../r-rcppblaze/package.py AVX* in "info" but not in code?
-            #   - ../openblas/package.py    variants: cpu_target!?!
-            #   - ../cp2k/package.py
-            #
-            # Documentation at:
-            # https://software.intel.com/en-us/cpp-compiler-18.0-developer-guide-and-reference-ax-qax
-            #
-            optflags += ' -xSSE4.2 -axAVX,CORE-AVX2 -ipo'
-            if which('xiar'):
-                env.set('AR', 'xiar')
+        # microarchitecture-specific optimization flags should be controlled
+        # by Spack, otherwise we may end up with contradictory or invalid flags
+        # see https://github.com/spack/spack/issues/17794
+        # libxc on the other hand only sets the generic -O2 when it detects GCC
 
+        optflags = '-O2'
         env.append_flags('CFLAGS',  optflags)
         env.append_flags('FCFLAGS', optflags)
 
+        if '%intel' in self.spec and which('xiar'):
+            env.set('AR', 'xiar')
+
         if '+cuda' in self.spec:
             nvcc = self.spec['cuda'].prefix.bin.nvcc
             env.set('CCLD', '{0} -ccbin {1}'.format(nvcc, spack_cc))