pkginclude_HEADERS += ct.h
libbase_la_SOURCES += ct.c
+## CPU-specific dispatch.
+pkginclude_HEADERS += dispatch.h
+libbase_la_SOURCES += dispatch.c
+
## Acceptable key-size descriptions.
pkginclude_HEADERS += keysz.h
libbase_la_SOURCES += keysz.c keysz-conv.c
--- /dev/null
+/* -*-c-*-
+ *
+ * CPU-specific dispatch
+ *
+ * (c) 2015 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include "config.h"
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mLib/macros.h>
+
+#include "dispatch.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+#ifdef CPUFAM_X86
+
+#define EFLAGS_ID (1u << 21)
+#define CPUID1D_SSE2 (1u << 26)
+
+struct cpuid { unsigned a, b, c, d; };
+
+/* --- @cpuid@ --- *
+ *
+ * Arguments: @struct cpuid *cc@ = where to write the result
+ * @unsigned a, c@ = EAX and ECX registers to set
+ *
+ * Returns: ---
+ *
+ * Use: Minimal C wrapper around the x86 `CPUID' instruction. Checks
+ * that the instruction is actually available before invoking
+ * it; fills the output structure with zero if it's not going to
+ * work.
+ */
+
+#ifdef __GNUC__
+static __inline__ unsigned getflags(void)
+ { unsigned f; __asm__ ("pushf; popl %0" : "=g" (f)); return (f); }
+static __inline__ unsigned setflags(unsigned f)
+{
+ unsigned ff;
+ __asm__ ("pushf; pushl %1; popf; pushf; popl %0; popf"
+ : "=g" (ff)
+ : "g" (f));
+ return (ff);
+}
+#endif
+
+static void cpuid(struct cpuid *cc, unsigned a, unsigned c)
+{
+#ifdef __GNUC__
+ unsigned f;
+#endif
+
+ cc->a = cc->b = cc->c = cc->d = 0;
+
+#ifdef __GNUC__
+ /* Stupid dance to detect whether the CPUID instruction is available. */
+ f = getflags();
+ if (!(setflags(f | EFLAGS_ID) & EFLAGS_ID)) return;
+ if ( setflags(f & ~EFLAGS_ID) & EFLAGS_ID ) return;
+ setflags(f);
+
+ /* Alas, EBX is magical in PIC code, so abuse ESI instead. This isn't
+ * pretty, but it works.
+ */
+ __asm__ ("pushl %%ebx; cpuid; movl %%ebx, %%esi; popl %%ebx"
+ : "=a" (cc->a), "=S" (cc->b), "=c" (cc->c), "=d" (cc->d)
+ : "a" (a) , "c" (c));
+#endif
+}
+
+static unsigned cpuid_maxleaf(void)
+ { struct cpuid c; cpuid(&c, 0, 0); return (c.a); }
+
+static int cpuid_features_p(unsigned dbits, unsigned cbits)
+{
+ struct cpuid c;
+ if (cpuid_maxleaf() < 1) return (0);
+ cpuid(&c, 1, 0);
+ return ((c.d & dbits) == dbits && (c.c & cbits) == cbits);
+}
+
+#endif
+
+/* --- @check_env@ --- *
+ *
+ * Arguments: @const char *ftok@ = feature token
+ *
+ * Returns: Zero if the feature is forced off; positive if it's forced
+ * on; negative if the user hasn't decided.
+ *
+ * Use: Checks the environment variable `CATACOMB_CPUFEAT' for the
+ * feature token @ftok@. The variable, if it exists, should be
+ * a space-separated sequence of `+tok' and `-tok' items. These
+ * tokens may end in `*', which matches any suffix.
+ */
+
+static int IGNORABLE check_env(const char *ftok)
+{
+ const char *p, *q, *pp;
+ int d;
+
+ p = getenv("CATACOMB_CPUFEAT");
+ if (!p) return (-1);
+
+ for (;;) {
+ while (isspace((unsigned char)*p)) p++;
+ if (!*p) return (-1);
+ switch (*p) {
+ case '+': d = +1; p++; break;
+ case '-': d = 0; p++; break;
+ default: d = -1; break;
+ }
+ for (q = p; *q && !isspace((unsigned char)*q); q++);
+ if (d >= 0) {
+ for (pp = ftok; p < q && *pp && *p == *pp; p++, pp++);
+ if ((p == q && !*pp) || (*p == '*' && p + 1 == q)) return (d);
+ }
+ p = q;
+ }
+ return (-1);
+}
+
+/* --- @cpu_feature_p@ --- *
+ *
+ * Arguments: @unsigned feat@ = a @CPUFEAT_...@ code
+ *
+ * Returns: Nonzero if the feature is available.
+ */
+
+#include <stdio.h>
+
+int cpu_feature_p(int feat)
+{
+ int IGNORABLE f;
+ IGNORE(f);
+#define CHECK_ENV(ftok) \
+ do { if ((f = check_env(ftok)) >= 0) return (f); } while (0)
+
+ switch (feat) {
+#ifdef CPUFAM_X86
+ case CPUFEAT_X86_SSE2: {
+ CHECK_ENV("x86:sse2");
+ return (cpuid_features_p(CPUID1D_SSE2, 0));
+ }
+#endif
+ default:
+ return (0);
+ }
+#undef CHECK_ENV
+}
+
+/*----- That's all, folks -------------------------------------------------*/
--- /dev/null
+/* -*-c-*-
+ *
+ * CPU-specific dispatch
+ *
+ * (c) 2015 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#ifndef CATACOMB_DISPATCH_H
+#define CATACOMB_DISPATCH_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/macros.h>
+
+/*----- Macros ------------------------------------------------------------*/
+
+/* --- Atomic data access machinery --- *
+ *
+ * If they're available, use GCC's `__atomic_*' intrinsics. If that doesn't
+ * work and we're using one of a small number of processors I'm sure won't
+ * mind, then just stick with simple memory access. Otherwise turn
+ * dispatching off, because it probably isn't thread-safe.
+ */
+
+#if GCC_VERSION_P(4, 7)
+# define CPU_DISPATCH_P 1
+# define DISPATCH_LOAD(g, v) \
+ ((v) = __atomic_load_n(&(g), __ATOMIC_RELAXED))
+# define DISPATCH_STORE(g, v) \
+ (__atomic_store_n(&(g), (v), __ATOMIC_RELAXED))
+#elif defined(__i386__) || defined(__amd64__) || \
+ defined(__arm__) || defined(__aarch64__) || \
+ defined(__mips__)
+# define CPU_DISPATCH_P 1
+# define DISPATCH_LOAD(g, v) ((v) = (g))
+# define DISPATCH_STORE(g, v) ((g) = (v))
+#endif
+
+/* --- A simple hack --- */
+
+#ifndef EMPTY
+# define EMPTY
+#endif
+
+/* --- @CPU_DISPATCH@ --- *
+ *
+ * Arguments: @stcls@ = storage class for the main @ext@ function
+ * (typically either @static@ or @EMPTY@)
+ * @rtn@ = prefix for tail-calling a function of the appropriate
+ * type (either @(void)@ or @return@)
+ * @ret@ = return type for the function
+ * @ext@ = name for the main function (other named are derived
+ * from this)
+ * @argdecls@ = parenthesis-enclosed list of argument types
+ * @args@ = parenthesis-enclosed list of argument names only
+ * @pick@ = function to select appropriate implementation
+ * @dflt@ = fallback implementation
+ *
+ * Use: Main machinery for CPU-specfic dispatching.
+ *
+ * The macro defines a function
+ *
+ * @stcls ret ext argdcls@
+ *
+ * The first time @ext@ is called, it will invoke @pick@ to
+ * select and a return a pointer to an appropriate
+ * implementation for the runtime environment. Subsequent calls
+ * to @ext@ will (usually) call this preferred implementation
+ * directly.
+ *
+ * Some target platforms may not be able to establish the
+ * necessary function pointer in a threadsafe way. On such
+ * platforms, the dispatch machinery is disabled and @ext@ will
+ * simply call @dflt@.
+ *
+ * Some additional declarations are made. As a convenience,
+ * @ext__functype@ is the function type of @ext@. Declarations
+ * are made for @pick@ and @dflt@, as @static@ functions.
+ */
+
+#ifdef CPU_DISPATCH_P
+
+#define CPU_DISPATCH(stcls, rtn, ret, ext, argdecls, args, pick, dflt) \
+ \
+typedef ret ext##__functype argdecls; \
+static ret dflt argdecls; \
+static ret ext##__dispatch argdecls; \
+static ext##__functype *pick(void); \
+static ext##__functype *ext##__ptr = ext##__dispatch; \
+ \
+static ret ext##__dispatch argdecls \
+{ \
+ ext##__functype *f = pick(); \
+ DISPATCH_STORE(ext##__ptr, f); \
+ rtn f args; \
+} \
+ \
+stcls ret ext argdecls \
+{ \
+ ext##__functype *f; \
+ DISPATCH_LOAD(ext##__ptr, f); \
+ rtn f args; \
+}
+
+#else
+
+#define CPU_DISPATCH(stcls, rtn, ret, ext, argdecls, args, pick, dflt) \
+ \
+typedef ret ext##__functype argdecls; \
+static ret dflt argdecls; \
+static ext##__functype *pick(void) IGNORABLE; \
+ \
+stcls ret ext argdecls { rtn dflt args; }
+
+#endif
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @cpu_feature_p@ --- *
+ *
+ * Arguments: @unsigned feat@ = a @CPUFEAT_...@ code
+ *
+ * Returns: Nonzero if the feature is available.
+ */
+
+enum {
+ CPUFEAT_X86_SSE2 /* Streaming SIMD Extensions 2 */
+};
+
+extern int cpu_feature_p(int /*feat*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
AC_CONFIG_SRCDIR([catacomb.pc.in])
AC_CONFIG_AUX_DIR([config])
AM_INIT_AUTOMAKE([foreign parallel-tests])
+AC_CANONICAL_HOST
mdw_SILENT_RULES
AC_PROG_CC
AC_SUBST(AM_CFLAGS)
dnl--------------------------------------------------------------------------
+dnl Host-specific configuration.
+
+AC_DEFUN([catacomb_CPU_FAMILIES],
+ [$1([i[[3-6]]86], [X86])])
+
+case $host_cpu in
+ m4_define([catacomb_CPU_CASE],
+ [$1)
+ AC_DEFINE([CPUFAM_$2], [1], [Define if host CPU family is $2.])
+ cpufam=$2
+ ;;
+])
+ catacomb_CPU_FAMILIES([catacomb_CPU_CASE])
+ *) cpufam=nil ;;
+esac
+m4_define([catacomb_CPU_DEFS],
+ [AM_CONDITIONAL([CPUFAM_$2], [test x$cpufam = x$2])])
+catacomb_CPU_FAMILIES([catacomb_CPU_DEFS])
+
+dnl--------------------------------------------------------------------------
dnl C programming environment.
dnl Find out if we're cross-compiling.
~mdw / catacomb / commitdiff