Issue #75 (frontend function to bypass cpu-id and to set arch_id): re…

…worked API which allows to get/set the target architecture: renamed libxsmm_get_target_archid <-> libxsmm_get_target_arch. Fixed function signatures (forbid arguments). Removed internal state which was tracking the name of the target architecture (now solely relying on target id). Introduced internal_get_target_arch function, which converts target id into target name. The latter simplifies a number of internal tasks, and fosters a single point of responsibility (code reuse). Fixed libxsmm_cpuid_x86 such that the code path cannot fall below LIBXSMM_STATIC_TARGET_ARCH.

include/libxsmm_typedefs.h

@@ -33,7 +33,7 @@
 
 /**
  * Enumerates the available target architectures and instruction
- * set extensions as returned by libxsmm_get_target_arch().
+ * set extensions as returned by libxsmm_get_target_archid().
  */
 #define LIBXSMM_TARGET_ARCH_UNKNOWN 0
 #define LIBXSMM_TARGET_ARCH_GENERIC 1

src/libxsmm.template.f

@@ -111,7 +111,7 @@ MODULE LIBXSMM
      &        LIBXSMM_PREFETCH_BL2_VIA_C, LIBXSMM_PREFETCH_AL2_AHEAD)
 
         ! Enumerates the available target architectures and instruction
-        ! set extensions as returned by libxsmm_get_target_arch().
+        ! set extensions as returned by libxsmm_get_target_archid().
         INTEGER(C_INT), PARAMETER ::                                    &
      &    LIBXSMM_TARGET_ARCH_UNKNOWN = 0,                              &
      &    LIBXSMM_TARGET_ARCH_GENERIC = 1,                              &
@@ -242,9 +242,9 @@ PURE SUBROUTINE LIBXSMM_MMFUNCTION1(a, b, c,                  &
         END INTERFACE
 
         !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_init, libxsmm_finalize
-        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_get_target_arch
-        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_set_target_arch
+        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_get_target_archid
         !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_set_target_archid
+        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_set_target_arch
         !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_timer_duration
         !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_timer_tick
         !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_omp_sgemm
@@ -262,20 +262,20 @@ SUBROUTINE libxsmm_finalize() BIND(C)
           ! as determined by the CPUID flags. 0 != LIBXSMM_JIT and
           ! LIBXSMM_X86_AVX <= result, then this instruction set
           ! extension is targeted by the JIT code generator.
-          INTEGER(C_INT) PURE FUNCTION libxsmm_get_target_arch() BIND(C)
+          INTEGER(C_INT) PURE FUNCTION libxsmm_get_target_archid() BIND(C)
             IMPORT :: C_INT
           END FUNCTION
 
           ! Set target architecture (archid: see PARAMETER enumeration)
           ! for subsequent code generation (JIT).
-          SUBROUTINE libxsmm_set_target_arch(archid) BIND(C)
+          SUBROUTINE libxsmm_set_target_archid(archid) BIND(C)
             IMPORT :: C_INT
             INTEGER(C_INT), INTENT(IN), VALUE :: archid
           END SUBROUTINE
 
           ! Set target architecture (id=0|wsm|snb|hsw|knl|skx, 0/NULL: CPUID)
           ! for subsequent code generation (JIT).
-          SUBROUTINE libxsmm_set_target_archid(name) BIND(C)
+          SUBROUTINE libxsmm_set_target_arch(name) BIND(C)
             IMPORT :: C_CHAR
             CHARACTER(C_CHAR), INTENT(IN) :: name(*)
           END SUBROUTINE
@@ -320,19 +320,19 @@ SUBROUTINE libxsmm_omp_dgemm(transa, transb, m, n, k,         &
       CONTAINS
         ! Returns a name for the target architecture as identified
         ! by libxsmm_get_target_arch().
-        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_get_target_archid
-        FUNCTION libxsmm_get_target_archid() RESULT(name)
+        !DIR$ ATTRIBUTES OFFLOAD:MIC :: libxsmm_get_target_arch
+        FUNCTION libxsmm_get_target_arch() RESULT(name)
           CHARACTER(LEN=:), ALLOCATABLE :: name
           CHARACTER(LEN=16) :: tmp
-          !DIR$ ATTRIBUTES OFFLOAD:MIC :: get_target_archid
+          !DIR$ ATTRIBUTES OFFLOAD:MIC :: get_target_arch
           INTERFACE
-            PURE SUBROUTINE get_target_archid(name, length) BIND(C)
+            PURE SUBROUTINE get_target_arch(name, length) BIND(C)
               IMPORT :: C_CHAR, C_INT
               CHARACTER(C_CHAR), INTENT(OUT) :: name(*)
               INTEGER(C_INT), VALUE, INTENT(IN) :: length
             END SUBROUTINE
           END INTERFACE
-          CALL get_target_archid(tmp, LEN(tmp))
+          CALL get_target_arch(tmp, LEN(tmp))
           name = TRIM(tmp)
         END FUNCTION
 

src/libxsmm.template.h

@@ -94,14 +94,14 @@ LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE void libxsmm_finalize(void);
  * If 0 != LIBXSMM_JIT and LIBXSMM_X86_AVX <= result, then this instruction set extension
  * is targeted by the JIT code generator.
  */
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_get_target_arch();
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_get_target_archid(void);
 /** Set target architecture (archid: see libxsmm_typedefs.h) for subsequent code generation (JIT). */
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE void libxsmm_set_target_arch(int archid);
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE void libxsmm_set_target_archid(int archid);
 
-/** Returns a name for the target architecture as identified by libxsmm_get_target_arch(). */
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE const char* libxsmm_get_target_archid();
+/** Returns a name for the target architecture as identified by libxsmm_get_target_archid(). */
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE const char* libxsmm_get_target_arch(void);
 /** Set target architecture (name=0|wsm|snb|hsw|knl|skx, 0/NULL: CPUID) for subsequent code generation (JIT). */
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE void libxsmm_set_target_archid(const char* name);
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE void libxsmm_set_target_arch(const char* name);
 
 /** Query or JIT-generate a function; return zero if it does not exist or if JIT is not supported (descriptor form). */
 LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE libxsmm_xmmfunction libxsmm_xmmdispatch(const libxsmm_gemm_descriptor* descriptor);

src/libxsmm_cpuid_x86.c

@@ -42,11 +42,10 @@
 #endif
 
 
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_cpuid_x86(const char** archid)
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_cpuid_x86(void)
 {
   int target_arch = LIBXSMM_STATIC_TARGET_ARCH;
   unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
-  if (archid) *archid = "x86";
 
   LIBXSMM_CPUID_X86(0, eax, ebx, ecx, edx);
   if (1 <= eax) { /* CPUID */
@@ -68,23 +67,19 @@ LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_cpuid_x86(const char** archid)
              AVX512ER(0x08000000) */
           if (0x1C010000 == (0x1C010000 & ebx)) {
             target_arch = LIBXSMM_X86_AVX512_MIC;
-            if (archid) *archid = "knl";
           }
           /* AVX512F(0x00010000), AVX512CD(0x10000000), AVX512DQ(0x00020000),
              AVX512BW(0x40000000), AVX512VL(0x80000000) */
           else if (0xD0030000 == (0xD0030000 & ebx)) {
             target_arch = LIBXSMM_X86_AVX512_CORE;
-            if (archid) *archid = "skx";
           }
         }
         else if (0x10000000 == (0x10000000 & ecx)) { /* AVX(0x10000000) */
           if (0x00001000 == (0x00001000 & ecx)) { /* FMA(0x00001000) */
             target_arch = LIBXSMM_X86_AVX2;
-            if (archid) *archid = "hsw";
           }
           else {
             target_arch = LIBXSMM_X86_AVX;
-            if (archid) *archid = "snb";
           }
         }
       }

src/libxsmm_cpuid_x86.h

@@ -34,12 +34,8 @@
 #include <libxsmm.h>
 
 
-/**
- * Returns the target architecture and instruction set extension (code path),
- * and thereby (via argument list) optionally returns an internal name of the
- * target architecture.
- */
-LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_cpuid_x86(const char** archid);
+/** Returns the target architecture and instruction set extension (code path). */
+LIBXSMM_EXTERN_C LIBXSMM_RETARGETABLE int libxsmm_cpuid_x86(void);
 
 
 #if defined(LIBXSMM_BUILD) && !defined(LIBXSMM_CPUID_X86_NOINLINE)

tests/dispatch.c

@@ -32,7 +32,7 @@ int main()
   if (size != nerrors) {
     return size == i ? EXIT_SUCCESS : (i + 1)/*EXIT_FAILURE*/;
   }
-  else if (LIBXSMM_X86_AVX > libxsmm_get_target_arch()) {
+  else if (LIBXSMM_X86_AVX > libxsmm_get_target_archid()) {
     /* potentially unsupported platforms due to not supporting AVX, due to calling convention,
      * or due to the environment variable LIBXSMM_JIT being set to zero.
      */

version.txt

@@ -1 +1 @@
-master-1.4.1-73
+master-1.4.1-74