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-rw-r--r--erts/emulator/sys/unix/sys_float.c815
1 files changed, 815 insertions, 0 deletions
diff --git a/erts/emulator/sys/unix/sys_float.c b/erts/emulator/sys/unix/sys_float.c
new file mode 100644
index 0000000000..15da6ab45c
--- /dev/null
+++ b/erts/emulator/sys/unix/sys_float.c
@@ -0,0 +1,815 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2001-2009. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "sys.h"
+#include "global.h"
+#include "erl_process.h"
+
+
+#ifdef NO_FPE_SIGNALS
+
+void
+erts_sys_init_float(void)
+{
+# ifdef SIGFPE
+ sys_sigset(SIGFPE, SIG_IGN); /* Ignore so we can test for NaN and Inf */
+# endif
+}
+
+static ERTS_INLINE void set_current_fp_exception(unsigned long pc)
+{
+ /* nothing to do */
+}
+
+#else /* !NO_FPE_SIGNALS */
+
+#ifdef ERTS_SMP
+static erts_tsd_key_t fpe_key;
+
+/* once-only initialisation early in the main thread (via erts_sys_init_float()) */
+static void erts_init_fp_exception(void)
+{
+ /* XXX: the wrappers prevent using a pthread destructor to
+ deallocate the key's value; so when/where do we do that? */
+ erts_tsd_key_create(&fpe_key);
+}
+
+void erts_thread_init_fp_exception(void)
+{
+ unsigned long *fpe = erts_alloc(ERTS_ALC_T_FP_EXCEPTION, sizeof(*fpe));
+ *fpe = 0L;
+ erts_tsd_set(fpe_key, fpe);
+}
+
+static ERTS_INLINE volatile unsigned long *erts_thread_get_fp_exception(void)
+{
+ return (volatile unsigned long*)erts_tsd_get(fpe_key);
+}
+#else /* !SMP */
+#define erts_init_fp_exception() /*empty*/
+static volatile unsigned long fp_exception;
+#define erts_thread_get_fp_exception() (&fp_exception)
+#endif /* SMP */
+
+volatile unsigned long *erts_get_current_fp_exception(void)
+{
+ Process *c_p;
+
+ c_p = erts_get_current_process();
+ if (c_p)
+ return &c_p->fp_exception;
+ return erts_thread_get_fp_exception();
+}
+
+static void set_current_fp_exception(unsigned long pc)
+{
+ volatile unsigned long *fpexnp = erts_get_current_fp_exception();
+ ASSERT(fpexnp != NULL);
+ *fpexnp = pc;
+}
+
+void erts_fp_check_init_error(volatile unsigned long *fpexnp)
+{
+ char buf[64];
+ snprintf(buf, sizeof buf, "ERTS_FP_CHECK_INIT at %p: detected unhandled FPE at %p\r\n",
+ __builtin_return_address(0), (void*)*fpexnp);
+ write(2, buf, strlen(buf));
+ *fpexnp = 0;
+#if defined(__i386__) || defined(__x86_64__)
+ erts_restore_fpu();
+#endif
+}
+
+/* Is there no standard identifier for Darwin/MacOSX ? */
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+#define __DARWIN__ 1
+#endif
+
+#if (defined(__i386__) || defined(__x86_64__)) && defined(__GNUC__)
+
+static void unmask_x87(void)
+{
+ unsigned short cw;
+
+ __asm__ __volatile__("fstcw %0" : "=m"(cw));
+ cw &= ~(0x01|0x04|0x08); /* unmask IM, ZM, OM */
+ __asm__ __volatile__("fldcw %0" : : "m"(cw));
+}
+
+/* mask x87 FPE, return true if the previous state was unmasked */
+static int mask_x87(void)
+{
+ unsigned short cw;
+ int unmasked;
+
+ __asm__ __volatile__("fstcw %0" : "=m"(cw));
+ unmasked = (cw & (0x01|0x04|0x08)) == 0;
+ /* or just set cw = 0x37f */
+ cw |= (0x01|0x04|0x08); /* mask IM, ZM, OM */
+ __asm__ __volatile__("fldcw %0" : : "m"(cw));
+ return unmasked;
+}
+
+static void unmask_sse2(void)
+{
+ unsigned int mxcsr;
+
+ __asm__ __volatile__("stmxcsr %0" : "=m"(mxcsr));
+ mxcsr &= ~(0x003F|0x0680); /* clear exn flags, unmask OM, ZM, IM (not PM, UM, DM) */
+ __asm__ __volatile__("ldmxcsr %0" : : "m"(mxcsr));
+}
+
+/* mask SSE2 FPE, return true if the previous state was unmasked */
+static int mask_sse2(void)
+{
+ unsigned int mxcsr;
+ int unmasked;
+
+ __asm__ __volatile__("stmxcsr %0" : "=m"(mxcsr));
+ unmasked = (mxcsr & 0x0680) == 0;
+ /* or just set mxcsr = 0x1f80 */
+ mxcsr &= ~0x003F; /* clear exn flags */
+ mxcsr |= 0x0680; /* mask OM, ZM, IM (not PM, UM, DM) */
+ __asm__ __volatile__("ldmxcsr %0" : : "m"(mxcsr));
+ return unmasked;
+}
+
+#if defined(__x86_64__)
+
+static inline int cpu_has_sse2(void) { return 1; }
+
+#else /* !__x86_64__ */
+
+/*
+ * Check if an x86-32 processor has SSE2.
+ */
+static unsigned int xor_eflags(unsigned int mask)
+{
+ unsigned int eax, edx;
+
+ eax = mask; /* eax = mask */
+ __asm__("pushfl\n\t"
+ "popl %0\n\t" /* edx = original EFLAGS */
+ "xorl %0, %1\n\t" /* eax = mask ^ EFLAGS */
+ "pushl %1\n\t"
+ "popfl\n\t" /* new EFLAGS = mask ^ original EFLAGS */
+ "pushfl\n\t"
+ "popl %1\n\t" /* eax = new EFLAGS */
+ "xorl %0, %1\n\t" /* eax = new EFLAGS ^ old EFLAGS */
+ "pushl %0\n\t"
+ "popfl" /* restore original EFLAGS */
+ : "=d"(edx), "=a"(eax)
+ : "1"(eax));
+ return eax;
+}
+
+static __inline__ unsigned int cpuid_eax(unsigned int op)
+{
+ unsigned int eax, save_ebx;
+
+ /* In PIC mode i386 reserves EBX. So we must save
+ and restore it ourselves to not upset gcc. */
+ __asm__(
+ "movl %%ebx, %1\n\t"
+ "cpuid\n\t"
+ "movl %1, %%ebx"
+ : "=a"(eax), "=m"(save_ebx)
+ : "0"(op)
+ : "cx", "dx");
+ return eax;
+}
+
+static __inline__ unsigned int cpuid_edx(unsigned int op)
+{
+ unsigned int eax, edx, save_ebx;
+
+ /* In PIC mode i386 reserves EBX. So we must save
+ and restore it ourselves to not upset gcc. */
+ __asm__(
+ "movl %%ebx, %2\n\t"
+ "cpuid\n\t"
+ "movl %2, %%ebx"
+ : "=a"(eax), "=d"(edx), "=m"(save_ebx)
+ : "0"(op)
+ : "cx");
+ return edx;
+}
+
+/* The AC bit, bit #18, is a new bit introduced in the EFLAGS
+ * register on the Intel486 processor to generate alignment
+ * faults. This bit cannot be set on the Intel386 processor.
+ */
+static __inline__ int is_386(void)
+{
+ return ((xor_eflags(1<<18) >> 18) & 1) == 0;
+}
+
+/* Newer x86 processors have a CPUID instruction, as indicated by
+ * the ID bit (#21) in EFLAGS being modifiable.
+ */
+static __inline__ int has_CPUID(void)
+{
+ return (xor_eflags(1<<21) >> 21) & 1;
+}
+
+static int cpu_has_sse2(void)
+{
+ unsigned int maxlev, features;
+ static int has_sse2 = -1;
+
+ if (has_sse2 >= 0)
+ return has_sse2;
+ has_sse2 = 0;
+
+ if (is_386())
+ return 0;
+ if (!has_CPUID())
+ return 0;
+ maxlev = cpuid_eax(0);
+ /* Intel A-step Pentium had a preliminary version of CPUID.
+ It also didn't have SSE2. */
+ if ((maxlev & 0xFFFFFF00) == 0x0500)
+ return 0;
+ /* If max level is zero then CPUID cannot report any features. */
+ if (maxlev == 0)
+ return 0;
+ features = cpuid_edx(1);
+ has_sse2 = (features & (1 << 26)) != 0;
+
+ return has_sse2;
+}
+#endif /* !__x86_64__ */
+
+static void unmask_fpe(void)
+{
+ __asm__ __volatile__("fnclex");
+ unmask_x87();
+ if (cpu_has_sse2())
+ unmask_sse2();
+}
+
+static void unmask_fpe_conditional(int unmasked)
+{
+ if (unmasked)
+ unmask_fpe();
+}
+
+/* mask x86 FPE, return true if the previous state was unmasked */
+static int mask_fpe(void)
+{
+ int unmasked;
+
+ unmasked = mask_x87();
+ if (cpu_has_sse2())
+ unmasked |= mask_sse2();
+ return unmasked;
+}
+
+void erts_restore_fpu(void)
+{
+ __asm__ __volatile__("fninit");
+ unmask_x87();
+ if (cpu_has_sse2())
+ unmask_sse2();
+}
+
+#elif defined(__sparc__) && defined(__linux__)
+
+#if defined(__arch64__)
+#define LDX "ldx"
+#define STX "stx"
+#else
+#define LDX "ld"
+#define STX "st"
+#endif
+
+static void unmask_fpe(void)
+{
+ unsigned long fsr;
+
+ __asm__(STX " %%fsr, %0" : "=m"(fsr));
+ fsr &= ~(0x1FUL << 23); /* clear FSR[TEM] field */
+ fsr |= (0x1AUL << 23); /* enable NV, OF, DZ exceptions */
+ __asm__ __volatile__(LDX " %0, %%fsr" : : "m"(fsr));
+}
+
+static void unmask_fpe_conditional(int unmasked)
+{
+ if (unmasked)
+ unmask_fpe();
+}
+
+/* mask SPARC FPE, return true if the previous state was unmasked */
+static int mask_fpe(void)
+{
+ unsigned long fsr;
+ int unmasked;
+
+ __asm__(STX " %%fsr, %0" : "=m"(fsr));
+ unmasked = ((fsr >> 23) & 0x1A) == 0x1A;
+ fsr &= ~(0x1FUL << 23); /* clear FSR[TEM] field */
+ __asm__ __volatile__(LDX " %0, %%fsr" : : "m"(fsr));
+ return unmasked;
+}
+
+#elif (defined(__powerpc__) && defined(__linux__)) || (defined(__ppc__) && defined(__DARWIN__))
+
+#if defined(__linux__)
+#include <sys/prctl.h>
+
+static void set_fpexc_precise(void)
+{
+ if (prctl(PR_SET_FPEXC, PR_FP_EXC_PRECISE) < 0) {
+ perror("PR_SET_FPEXC");
+ exit(1);
+ }
+}
+
+#elif defined(__DARWIN__)
+
+#include <mach/mach.h>
+#include <pthread.h>
+
+/*
+ * FE0 FE1 MSR bits
+ * 0 0 floating-point exceptions disabled
+ * 0 1 floating-point imprecise nonrecoverable
+ * 1 0 floating-point imprecise recoverable
+ * 1 1 floating-point precise mode
+ *
+ * Apparently:
+ * - Darwin 5.5 (MacOS X <= 10.1) starts with FE0 == FE1 == 0,
+ * and resets FE0 and FE1 to 0 after each SIGFPE.
+ * - Darwin 6.0 (MacOS X 10.2) starts with FE0 == FE1 == 1,
+ * and does not reset FE0 or FE1 after a SIGFPE.
+ */
+#define FE0_MASK (1<<11)
+#define FE1_MASK (1<<8)
+
+/* a thread cannot get or set its own MSR bits */
+static void *fpu_fpe_enable(void *arg)
+{
+ thread_t t = *(thread_t*)arg;
+ struct ppc_thread_state state;
+ unsigned int state_size = PPC_THREAD_STATE_COUNT;
+
+ if (thread_get_state(t, PPC_THREAD_STATE, (natural_t*)&state, &state_size) != KERN_SUCCESS) {
+ perror("thread_get_state");
+ exit(1);
+ }
+ if ((state.srr1 & (FE1_MASK|FE0_MASK)) != (FE1_MASK|FE0_MASK)) {
+#if 1
+ /* This would also have to be performed in the SIGFPE handler
+ to work around the MSR reset older Darwin releases do. */
+ state.srr1 |= (FE1_MASK|FE0_MASK);
+ thread_set_state(t, PPC_THREAD_STATE, (natural_t*)&state, state_size);
+#else
+ fprintf(stderr, "srr1 == 0x%08x, your Darwin is too old\n", state.srr1);
+ exit(1);
+#endif
+ }
+ return NULL; /* Ok, we appear to be on Darwin 6.0 or later */
+}
+
+static void set_fpexc_precise(void)
+{
+ thread_t self = mach_thread_self();
+ pthread_t enabler;
+
+ if (pthread_create(&enabler, NULL, fpu_fpe_enable, &self)) {
+ perror("pthread_create");
+ } else if (pthread_join(enabler, NULL)) {
+ perror("pthread_join");
+ }
+}
+
+#endif
+
+static void set_fpscr(unsigned int fpscr)
+{
+ union {
+ double d;
+ unsigned int fpscr[2];
+ } u;
+
+ u.fpscr[0] = 0xFFF80000;
+ u.fpscr[1] = fpscr;
+ __asm__ __volatile__("mtfsf 255,%0" : : "f"(u.d));
+}
+
+static unsigned int get_fpscr(void)
+{
+ union {
+ double d;
+ unsigned int fpscr[2];
+ } u;
+
+ __asm__("mffs %0" : "=f"(u.d));
+ return u.fpscr[1];
+}
+
+static void unmask_fpe(void)
+{
+ set_fpexc_precise();
+ set_fpscr(0x80|0x40|0x10); /* VE, OE, ZE; not UE or XE */
+}
+
+static void unmask_fpe_conditional(int unmasked)
+{
+ if (unmasked)
+ unmask_fpe();
+}
+
+/* mask PowerPC FPE, return true if the previous state was unmasked */
+static int mask_fpe(void)
+{
+ int unmasked;
+
+ unmasked = (get_fpscr() & (0x80|0x40|0x10)) == (0x80|0x40|0x10);
+ set_fpscr(0x00);
+ return unmasked;
+}
+
+#else
+
+static void unmask_fpe(void)
+{
+ fpsetmask(FP_X_INV | FP_X_OFL | FP_X_DZ);
+}
+
+static void unmask_fpe_conditional(int unmasked)
+{
+ if (unmasked)
+ unmask_fpe();
+}
+
+/* mask IEEE FPE, return true if previous state was unmasked */
+static int mask_fpe(void)
+{
+ const fp_except unmasked_mask = FP_X_INV | FP_X_OFL | FP_X_DZ;
+ fp_except old_mask;
+
+ old_mask = fpsetmask(0);
+ return (old_mask & unmasked_mask) == unmasked_mask;
+}
+
+#endif
+
+#if (defined(__linux__) && (defined(__i386__) || defined(__x86_64__) || defined(__sparc__) || defined(__powerpc__))) || (defined(__DARWIN__) && (defined(__i386__) || defined(__x86_64__) || defined(__ppc__))) || (defined(__FreeBSD__) && (defined(__x86_64__) || defined(__i386__))) || (defined(__OpenBSD__) && defined(__x86_64__)) || (defined(__sun__) && defined(__x86_64__))
+
+#if defined(__linux__) && defined(__i386__)
+#if !defined(X86_FXSR_MAGIC)
+#define X86_FXSR_MAGIC 0x0000
+#endif
+#elif defined(__FreeBSD__) && defined(__x86_64__)
+#include <sys/types.h>
+#include <machine/fpu.h>
+#elif defined(__FreeBSD__) && defined(__i386__)
+#include <sys/types.h>
+#include <machine/npx.h>
+#elif defined(__DARWIN__)
+#include <machine/signal.h>
+#elif defined(__OpenBSD__) && defined(__x86_64__)
+#include <sys/types.h>
+#include <machine/fpu.h>
+#endif
+#if !(defined(__OpenBSD__) && defined(__x86_64__))
+#include <ucontext.h>
+#endif
+#include <string.h>
+
+#if defined(__linux__) && defined(__x86_64__)
+#define mc_pc(mc) ((mc)->gregs[REG_RIP])
+#elif defined(__linux__) && defined(__i386__)
+#define mc_pc(mc) ((mc)->gregs[REG_EIP])
+#elif defined(__DARWIN__) && defined(__i386__)
+#ifdef DARWIN_MODERN_MCONTEXT
+#define mc_pc(mc) ((mc)->__ss.__eip)
+#else
+#define mc_pc(mc) ((mc)->ss.eip)
+#endif
+#elif defined(__DARWIN__) && defined(__x86_64__)
+#ifdef DARWIN_MODERN_MCONTEXT
+#define mc_pc(mc) ((mc)->__ss.__rip)
+#else
+#define mc_pc(mc) ((mc)->ss.rip)
+#endif
+#elif defined(__FreeBSD__) && defined(__x86_64__)
+#define mc_pc(mc) ((mc)->mc_rip)
+#elif defined(__FreeBSD__) && defined(__i386__)
+#define mc_pc(mc) ((mc)->mc_eip)
+#elif defined(__OpenBSD__) && defined(__x86_64__)
+#define mc_pc(mc) ((mc)->sc_rip)
+#elif defined(__sun__) && defined(__x86_64__)
+#define mc_pc(mc) ((mc)->gregs[REG_RIP])
+#endif
+
+static void fpe_sig_action(int sig, siginfo_t *si, void *puc)
+{
+ ucontext_t *uc = puc;
+ unsigned long pc;
+
+#if defined(__linux__)
+#if defined(__x86_64__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ fpregset_t fpstate = mc->fpregs;
+ pc = mc_pc(mc);
+ /* A failed SSE2 instruction will restart. To avoid
+ looping we mask SSE2 exceptions now and unmask them
+ again later in erts_check_fpe()/erts_restore_fpu().
+ On RISCs we update PC to skip the failed instruction,
+ but the ever increasing complexity of the x86 instruction
+ set encoding makes that a poor solution here. */
+ fpstate->mxcsr = 0x1F80;
+ fpstate->swd &= ~0xFF;
+#elif defined(__i386__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ fpregset_t fpstate = mc->fpregs;
+ pc = mc_pc(mc);
+ if ((fpstate->status >> 16) == X86_FXSR_MAGIC)
+ ((struct _fpstate*)fpstate)->mxcsr = 0x1F80;
+ fpstate->sw &= ~0xFF;
+#elif defined(__sparc__) && defined(__arch64__)
+ /* on SPARC the 3rd parameter points to a sigcontext not a ucontext */
+ struct sigcontext *sc = (struct sigcontext*)puc;
+ pc = sc->sigc_regs.tpc;
+ sc->sigc_regs.tpc = sc->sigc_regs.tnpc;
+ sc->sigc_regs.tnpc += 4;
+#elif defined(__sparc__)
+ /* on SPARC the 3rd parameter points to a sigcontext not a ucontext */
+ struct sigcontext *sc = (struct sigcontext*)puc;
+ pc = sc->si_regs.pc;
+ sc->si_regs.pc = sc->si_regs.npc;
+ sc->si_regs.npc = (unsigned long)sc->si_regs.npc + 4;
+#elif defined(__powerpc__)
+#if defined(__powerpc64__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ unsigned long *regs = &mc->gp_regs[0];
+#else
+ mcontext_t *mc = uc->uc_mcontext.uc_regs;
+ unsigned long *regs = &mc->gregs[0];
+#endif
+ pc = regs[PT_NIP];
+ regs[PT_NIP] += 4;
+ regs[PT_FPSCR] = 0x80|0x40|0x10; /* VE, OE, ZE; not UE or XE */
+#endif
+#elif defined(__DARWIN__) && (defined(__i386__) || defined(__x86_64__))
+#ifdef DARWIN_MODERN_MCONTEXT
+ mcontext_t mc = uc->uc_mcontext;
+ pc = mc_pc(mc);
+ mc->__fs.__fpu_mxcsr = 0x1F80;
+ *(unsigned short *)&mc->__fs.__fpu_fsw &= ~0xFF;
+#else
+ mcontext_t mc = uc->uc_mcontext;
+ pc = mc_pc(mc);
+ mc->fs.fpu_mxcsr = 0x1F80;
+ *(unsigned short *)&mc->fs.fpu_fsw &= ~0xFF;
+#endif /* DARWIN_MODERN_MCONTEXT */
+#elif defined(__DARWIN__) && defined(__ppc__)
+ mcontext_t mc = uc->uc_mcontext;
+ pc = mc->ss.srr0;
+ mc->ss.srr0 += 4;
+ mc->fs.fpscr = 0x80|0x40|0x10;
+#elif defined(__FreeBSD__) && defined(__x86_64__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ struct savefpu *savefpu = (struct savefpu*)&mc->mc_fpstate;
+ struct envxmm *envxmm = &savefpu->sv_env;
+ pc = mc_pc(mc);
+ envxmm->en_mxcsr = 0x1F80;
+ envxmm->en_sw &= ~0xFF;
+#elif defined(__FreeBSD__) && defined(__i386__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ union savefpu *savefpu = (union savefpu*)&mc->mc_fpstate;
+ pc = mc_pc(mc);
+ if (mc->mc_fpformat == _MC_FPFMT_XMM) {
+ struct envxmm *envxmm = &savefpu->sv_xmm.sv_env;
+ envxmm->en_mxcsr = 0x1F80;
+ envxmm->en_sw &= ~0xFF;
+ } else {
+ struct env87 *env87 = &savefpu->sv_87.sv_env;
+ env87->en_sw &= ~0xFF;
+ }
+#elif defined(__OpenBSD__) && defined(__x86_64__)
+ struct fxsave64 *fxsave = uc->sc_fpstate;
+ pc = mc_pc(uc);
+ fxsave->fx_mxcsr = 0x1F80;
+ fxsave->fx_fsw &= ~0xFF;
+#elif defined(__sun__) && defined(__x86_64__)
+ mcontext_t *mc = &uc->uc_mcontext;
+ struct fpchip_state *fpstate = &mc->fpregs.fp_reg_set.fpchip_state;
+ pc = mc_pc(mc);
+ fpstate->mxcsr = 0x1F80;
+ fpstate->sw &= ~0xFF;
+#endif
+#if 0
+ {
+ char buf[64];
+ snprintf(buf, sizeof buf, "%s: FPE at %p\r\n", __FUNCTION__, (void*)pc);
+ write(2, buf, strlen(buf));
+ }
+#endif
+ set_current_fp_exception(pc);
+}
+
+static void erts_thread_catch_fp_exceptions(void)
+{
+ struct sigaction act;
+ memset(&act, 0, sizeof act);
+ act.sa_sigaction = fpe_sig_action;
+ act.sa_flags = SA_SIGINFO;
+ sigaction(SIGFPE, &act, NULL);
+ unmask_fpe();
+}
+
+#else /* !((__linux__ && (__i386__ || __x86_64__ || __powerpc__)) || (__DARWIN__ && (__i386__ || __x86_64__ || __ppc__))) */
+
+static void fpe_sig_handler(int sig)
+{
+ set_current_fp_exception(1); /* XXX: convert to sigaction so we can get the trap PC */
+}
+
+static void erts_thread_catch_fp_exceptions(void)
+{
+ sys_sigset(SIGFPE, fpe_sig_handler);
+ unmask_fpe();
+}
+
+#endif /* (__linux__ && (__i386__ || __x86_64__ || __powerpc__)) || (__DARWIN__ && (__i386__ || __x86_64__ || __ppc__))) */
+
+/* once-only initialisation early in the main thread */
+void erts_sys_init_float(void)
+{
+ erts_init_fp_exception();
+ erts_thread_catch_fp_exceptions();
+ erts_printf_block_fpe = erts_sys_block_fpe;
+ erts_printf_unblock_fpe = erts_sys_unblock_fpe;
+}
+
+#endif /* NO_FPE_SIGNALS */
+
+void erts_thread_init_float(void)
+{
+#ifdef ERTS_SMP
+ /* This allows Erlang schedulers to leave Erlang-process context
+ and still have working FP exceptions. XXX: is this needed? */
+ erts_thread_init_fp_exception();
+#endif
+
+#ifndef NO_FPE_SIGNALS
+ /* NOTE:
+ * erts_thread_disable_fpe() is called in all threads at
+ * creation. We at least need to call unmask_fpe()
+ */
+#if defined(__DARWIN__) || defined(__FreeBSD__)
+ /* Darwin (7.9.0) does not appear to propagate FP exception settings
+ to a new thread from its parent. So if we want FP exceptions, we
+ must manually re-enable them in each new thread.
+ FreeBSD 6.1 appears to suffer from a similar issue. */
+ erts_thread_catch_fp_exceptions();
+#else
+ unmask_fpe();
+#endif
+
+#endif
+}
+
+void erts_thread_disable_fpe(void)
+{
+#if !defined(NO_FPE_SIGNALS)
+ (void)mask_fpe();
+#endif
+}
+
+#if !defined(NO_FPE_SIGNALS)
+int erts_sys_block_fpe(void)
+{
+ return mask_fpe();
+}
+
+void erts_sys_unblock_fpe(int unmasked)
+{
+ unmask_fpe_conditional(unmasked);
+}
+#endif
+
+/* The following check is incorporated from the Vee machine */
+
+#define ISDIGIT(d) ((d) >= '0' && (d) <= '9')
+
+/*
+ ** Convert a double to ascii format 0.dddde[+|-]ddd
+ ** return number of characters converted
+ **
+ ** These two functions should maybe use localeconv() to pick up
+ ** the current radix character, but since it is uncertain how
+ ** expensive such a system call is, and since no-one has heard
+ ** of other radix characters than '.' and ',' an ad-hoc
+ ** low execution time solution is used instead.
+ */
+
+int
+sys_double_to_chars(double fp, char *buf)
+{
+ char *s = buf;
+
+ (void) sprintf(buf, "%.20e", fp);
+ /* Search upto decimal point */
+ if (*s == '+' || *s == '-') s++;
+ while (ISDIGIT(*s)) s++;
+ if (*s == ',') *s++ = '.'; /* Replace ',' with '.' */
+ /* Scan to end of string */
+ while (*s) s++;
+ return s-buf; /* i.e strlen(buf) */
+}
+
+/* Float conversion */
+
+int
+sys_chars_to_double(char* buf, double* fp)
+{
+#ifndef NO_FPE_SIGNALS
+ volatile unsigned long *fpexnp = erts_get_current_fp_exception();
+#endif
+ char *s = buf, *t, *dp;
+
+ /* Robert says that something like this is what he really wanted:
+ * (The [.,] radix test is NOT what Robert wanted - it was added later)
+ *
+ * 7 == sscanf(Tbuf, "%[+-]%[0-9][.,]%[0-9]%[eE]%[+-]%[0-9]%s", ....);
+ * if (*s2 == 0 || *s3 == 0 || *s4 == 0 || *s6 == 0 || *s7)
+ * break;
+ */
+
+ /* Scan string to check syntax. */
+ if (*s == '+' || *s == '-') s++;
+ if (!ISDIGIT(*s)) /* Leading digits. */
+ return -1;
+ while (ISDIGIT(*s)) s++;
+ if (*s != '.' && *s != ',') /* Decimal part. */
+ return -1;
+ dp = s++; /* Remember decimal point pos just in case */
+ if (!ISDIGIT(*s))
+ return -1;
+ while (ISDIGIT(*s)) s++;
+ if (*s == 'e' || *s == 'E') {
+ /* There is an exponent. */
+ s++;
+ if (*s == '+' || *s == '-') s++;
+ if (!ISDIGIT(*s))
+ return -1;
+ while (ISDIGIT(*s)) s++;
+ }
+ if (*s) /* That should be it */
+ return -1;
+
+#ifdef NO_FPE_SIGNALS
+ errno = 0;
+#endif
+ __ERTS_FP_CHECK_INIT(fpexnp);
+ *fp = strtod(buf, &t);
+ __ERTS_FP_ERROR_THOROUGH(fpexnp, *fp, return -1);
+ if (t != s) { /* Whole string not scanned */
+ /* Try again with other radix char */
+ *dp = (*dp == '.') ? ',' : '.';
+ errno = 0;
+ __ERTS_FP_CHECK_INIT(fpexnp);
+ *fp = strtod(buf, &t);
+ __ERTS_FP_ERROR_THOROUGH(fpexnp, *fp, return -1);
+ }
+
+#ifdef NO_FPE_SIGNALS
+ if (errno == ERANGE && (*fp == 0.0 || *fp == HUGE_VAL || *fp == -HUGE_VAL)) {
+ return -1;
+ }
+#endif
+ return 0;
+}
+
+int
+matherr(struct exception *exc)
+{
+#if !defined(NO_FPE_SIGNALS)
+ set_current_fp_exception((unsigned long)__builtin_return_address(0));
+#endif
+ return 1;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 23:45:03 +0000