Remove non-functional PowerPC invsqrt.

Also remove remaining Power6-related CMake code now that there is no
Power6 CPU acceleration option.

Fixes #947, see that issue for justification.

Change-Id: I6466f3ca7297f96757097119ee7b10e7e467bfe7

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8cffe794125826a1706c7e6a13207e16041ad524..16359a254fdad05b32da9eb94fa1a33bf709c03f 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -210,8 +210,6 @@ option(GMX_MPI    "Build a parallel (message-passing) version of GROMACS" OFF)
 option(GMX_THREAD_MPI  "Build a thread-MPI-based multithreaded version of GROMACS (not compatible with MPI)" ON)
 option(GMX_SOFTWARE_INVSQRT "Use GROMACS software 1/sqrt" ON)
 mark_as_advanced(GMX_SOFTWARE_INVSQRT)
-option(GMX_POWERPC_INVSQRT "Use PowerPC hardware 1/sqrt" OFF)
-mark_as_advanced(GMX_POWERPC_INVSQRT)
 option(GMX_FAHCORE "Build a library with mdrun functionality" OFF)
 mark_as_advanced(GMX_FAHCORE)
 
@@ -372,9 +370,6 @@ endif(GMX_DOUBLE)
 if(GMX_SOFTWARE_INVSQRT)
   set(PKG_CFLAGS "${PKG_CFLAGS} -DGMX_SOFTWARE_INVSQRT")
 endif(GMX_SOFTWARE_INVSQRT)
-if(GMX_POWERPC_INVSQRT)
-  set(PKG_CFLAGS "${PKG_CFLAGS} -DGMX_POWERPC_INVSQRT")
-endif(GMX_POWERPC_INVSQRT)
 
 ########################################################################
 #Process MPI settings
@@ -864,7 +859,6 @@ elseif(${GMX_CPU_ACCELERATION} STREQUAL "BLUEGENE")
         set(BUILD_SHARED_LIBS OFF CACHE BOOL "Shared libraries not compatible with BlueGene/L, disabled!" FORCE)
     endif (${CMAKE_SYSTEM_NAME} STREQUAL "BlueGeneL")
     set(GMX_SOFTWARE_INVSQRT OFF CACHE BOOL "Do not use software reciprocal square root on BlueGene" FORCE)
-    set(GMX_POWERPC_INVSQRT ON CACHE BOOL "Use hardware reciprocal square root on BlueGene" FORCE)
     set(GMX_X11 OFF CACHE BOOL "X11 not compatible with BlueGene, disabled!" FORCE)
     set(GMX_THREAD_MPI OFF CACHE BOOL "Thread-MPI not compatible with BlueGene, disabled!" FORCE)
     set(GMX_MPI ON CACHE BOOL "Use MPI on BlueGene" FORCE)
@@ -875,10 +869,6 @@ elseif(${GMX_CPU_ACCELERATION} STREQUAL "BLUEGENE")
 # The automatic testing for endianness does not work for the BlueGene cross-compiler
     set(GMX_IEEE754_BIG_ENDIAN_BYTE_ORDER 1 CACHE INTERNAL "BlueGene has big endian FP byte order (by default)" FORCE)
     set(GMX_IEEE754_BIG_ENDIAN_WORD_ORDER 1 CACHE INTERNAL "BlueGene has big endian FP word order (by default)" FORCE)
-elseif(${GMX_CPU_ACCELERATION} STREQUAL "POWER6")
-    set(GMX_POWER6 1)
-    set(GMX_SOFTWARE_INVSQRT OFF CACHE BOOL "Do not use software reciprocal square root on Power6" FORCE)
-    set(GMX_POWERPC_INVSQRT ON CACHE BOOL "Use hardware reciprocal square root on Power6" FORCE)
 else(${GMX_CPU_ACCELERATION} STREQUAL "NONE")
     MESSAGE(FATAL_ERROR "Unrecognized option for accelerated kernels: ${GMX_CPU_ACCELERATION}. Pick one of None, SSE2, SSE4.1, AVX_128_FMA, AVX_256, BlueGene")
 endif(${GMX_CPU_ACCELERATION} STREQUAL "NONE")

diff --git a/include/vec.h b/include/vec.h
index 6c9995f2770bcb528c39216b0d36ac27d83e2e54..410b35e53613db3097fb933c8c9cd913885c52b3 100644 (file)
--- a/include/vec.h
+++ b/include/vec.h
@@ -183,40 +183,6 @@ static real gmx_software_invsqrt(real x)
 #define INVSQRT_DONE 
 #endif /* gmx_invsqrt */
 
-#ifdef GMX_POWERPC_SQRT
-static real gmx_powerpc_invsqrt(real x)
-{
-  const real  half=0.5;
-  const real  three=3.0;
-  t_convert   result,bit_pattern;
-  unsigned int exp,fract;
-  real        lu;
-  real        y;
-#ifdef GMX_DOUBLE
-  real        y2;
-#endif
-
-  lu = __frsqrte((double)x);
-
-  y=(half*lu*(three-((x*lu)*lu)));
-
-#if (GMX_POWERPC_SQRT==2)
-  /* Extra iteration required */
-  y=(half*y*(three-((x*y)*y)));
-#endif
-
-#ifdef GMX_DOUBLE
-  y2=(half*y*(three-((x*y)*y)));
-
-  return y2;                    /* 10 Flops */
-#else
-  return y;                     /* 5  Flops */
-#endif
-}
-#define gmx_invsqrt(x) gmx_powerpc_invsqrt(x)
-#define INVSQRT_DONE
-#endif /* powerpc_invsqrt */
-
 #ifndef INVSQRT_DONE
 #    ifdef GMX_DOUBLE
 #        ifdef HAVE_RSQRT

diff --git a/src/config.h.cmakein b/src/config.h.cmakein
index 74e28486f9364727b3cb628f1811a8580ac6052c..528b0bea7997deb8875b02547b5264f8920cd543 100644 (file)
--- a/src/config.h.cmakein
+++ b/src/config.h.cmakein
@@ -161,9 +161,6 @@
 /* Use the GROMACS software 1/sqrt(x) */
 #cmakedefine GMX_SOFTWARE_INVSQRT
 
-/* Use the PowerPC hardware 1/sqrt(x) */
-#cmakedefine GMX_POWERPC_INVSQRT
-
 /* Use sub-counters */
 #cmakedefine GMX_CYCLE_SUBCOUNTERS