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authorRichard Henderson <rth@twiddle.net>2012-03-18 15:58:00 -0700
committerRichard Henderson <rth@twiddle.net>2012-03-19 06:51:39 -0700
commitbd37f2ee314147c69a39817d590149cf1181ef47 (patch)
tree453f01145f7e526a6f5fdd5f3a6c1dde93f59ce8 /sysdeps/i386
parentd0adc9223031b606c3c7781b4ec41462796ab313 (diff)
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Optimize private 387 fenv access; share code between i386 and x86_64.
Diffstat (limited to 'sysdeps/i386')
-rw-r--r--sysdeps/i386/fpu/fenv_private.h304
-rw-r--r--sysdeps/i386/fpu/math_private.h46
2 files changed, 306 insertions, 44 deletions
diff --git a/sysdeps/i386/fpu/fenv_private.h b/sysdeps/i386/fpu/fenv_private.h
new file mode 100644
index 0000000000..f33f57c39c
--- /dev/null
+++ b/sysdeps/i386/fpu/fenv_private.h
@@ -0,0 +1,304 @@
+#ifndef FENV_PRIVATE_H
+#define FENV_PRIVATE_H 1
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+#ifdef __SSE2_MATH__
+# define math_opt_barrier(x) \
+ ({ __typeof(x) __x; \
+ if (sizeof (x) <= sizeof (double)) \
+ __asm ("" : "=x" (__x) : "0" (x)); \
+ else \
+ __asm ("" : "=t" (__x) : "0" (x)); \
+ __x; })
+# define math_force_eval(x) \
+ do { \
+ if (sizeof (x) <= sizeof (double)) \
+ __asm __volatile ("" : : "x" (x)); \
+ else \
+ __asm __volatile ("" : : "f" (x)); \
+ } while (0)
+#else
+# define math_opt_barrier(x) \
+ ({ __typeof (x) __x; \
+ __asm ("" : "=t" (__x) : "0" (x)); \
+ __x; })
+# define math_force_eval(x) \
+ do { \
+ __typeof (x) __x = (x); \
+ if (sizeof (x) <= sizeof (double)) \
+ __asm __volatile ("" : : "m" (__x)); \
+ else \
+ __asm __volatile ("" : : "f" (__x)); \
+ } while (0)
+#endif
+
+/* This file is used by both the 32- and 64-bit ports. The 64-bit port
+ has a field in the fenv_t for the mxcsr; the 32-bit port does not.
+ Instead, we (ab)use the only 32-bit field extant in the struct. */
+#ifndef __x86_64__
+# define __mxcsr __eip
+#endif
+
+
+/* All of these functions are private to libm, and are all used in pairs
+ to save+change the fp state and restore the original state. Thus we
+ need not care for both the 387 and the sse unit, only the one we're
+ actually using. */
+
+#if defined __AVX__ || defined SSE2AVX
+# define STMXCSR "vstmxcsr"
+# define LDMXCSR "vldmxcsr"
+#else
+# define STMXCSR "stmxcsr"
+# define LDMXCSR "ldmxcsr"
+#endif
+
+static __always_inline void
+libc_feholdexcept_sse (fenv_t *e)
+{
+ unsigned int mxcsr;
+ asm (STMXCSR " %0" : "=m" (*&mxcsr));
+ e->__mxcsr = mxcsr;
+ mxcsr = (mxcsr | 0x1f80) & ~0x3f;
+ asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
+}
+
+static __always_inline void
+libc_feholdexcept_387 (fenv_t *e)
+{
+ /* Recall that fnstenv has a side-effect of masking exceptions.
+ Clobber all of the fp registers so that the TOS field is 0. */
+ asm volatile ("fnstenv %0; fnclex"
+ : "=m"(*e)
+ : : "st", "st(1)", "st(2)", "st(3)",
+ "st(4)", "st(5)", "st(6)", "st(7)");
+}
+
+static __always_inline void
+libc_feholdexcept_setround_sse (fenv_t *e, int r)
+{
+ unsigned int mxcsr;
+ asm (STMXCSR " %0" : "=m" (*&mxcsr));
+ e->__mxcsr = mxcsr;
+ mxcsr = ((mxcsr | 0x1f80) & ~0x603f) | (r << 3);
+ asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
+}
+
+/* Set both rounding mode and precision. A convenience function for use
+ by libc_feholdexcept_setround and libc_feholdexcept_setround_53bit. */
+static __always_inline void
+libc_feholdexcept_setround_387_prec (fenv_t *e, int r)
+{
+ libc_feholdexcept_387 (e);
+
+ fpu_control_t cw = e->__control_word;
+ cw &= ~(_FPU_RC_ZERO | _FPU_EXTENDED);
+ cw |= r | 0x3f;
+ _FPU_SETCW (cw);
+}
+
+static __always_inline void
+libc_feholdexcept_setround_387 (fenv_t *e, int r)
+{
+ libc_feholdexcept_setround_387_prec (e, r | _FPU_EXTENDED);
+}
+
+static __always_inline void
+libc_feholdexcept_setround_387_53bit (fenv_t *e, int r)
+{
+ libc_feholdexcept_setround_387_prec (e, r | _FPU_DOUBLE);
+}
+
+static __always_inline int
+libc_fetestexcept_sse (int e)
+{
+ unsigned int mxcsr;
+ asm volatile (STMXCSR " %0" : "=m" (*&mxcsr));
+ return mxcsr & e & FE_ALL_EXCEPT;
+}
+
+static __always_inline int
+libc_fetestexcept_387 (int ex)
+{
+ fexcept_t temp;
+ asm volatile ("fnstsw %0" : "=a" (temp));
+ return temp & ex & FE_ALL_EXCEPT;
+}
+
+static __always_inline void
+libc_fesetenv_sse (fenv_t *e)
+{
+ asm volatile (LDMXCSR " %0" : : "m" (e->__mxcsr));
+}
+
+static __always_inline void
+libc_fesetenv_387 (fenv_t *e)
+{
+ /* Clobber all fp registers so that the TOS value we saved earlier is
+ compatible with the current state of the compiler. */
+ asm volatile ("fldenv %0"
+ : : "m" (*e)
+ : "st", "st(1)", "st(2)", "st(3)",
+ "st(4)", "st(5)", "st(6)", "st(7)");
+}
+
+static __always_inline int
+libc_feupdateenv_test_sse (fenv_t *e, int ex)
+{
+ unsigned int mxcsr, old_mxcsr, cur_ex;
+ asm volatile (STMXCSR " %0" : "=m" (*&mxcsr));
+ cur_ex = mxcsr & FE_ALL_EXCEPT;
+
+ /* Merge current exceptions with the old environment. */
+ old_mxcsr = e->__mxcsr;
+ mxcsr = old_mxcsr | cur_ex;
+ asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
+
+ /* Raise SIGFPE for any new exceptions since the hold. Expect that
+ the normal environment has all exceptions masked. */
+ if (__builtin_expect ((old_mxcsr >> 7) & cur_ex, 0))
+ __feraiseexcept (cur_ex);
+
+ /* Test for exceptions raised since the hold. */
+ return cur_ex & ex;
+}
+
+static __always_inline int
+libc_feupdateenv_test_387 (fenv_t *e, int ex)
+{
+ fexcept_t cur_ex;
+
+ /* Save current exceptions. */
+ asm volatile ("fnstsw %0" : "=a" (cur_ex));
+ cur_ex &= FE_ALL_EXCEPT;
+
+ /* Reload original environment. */
+ libc_fesetenv_387 (e);
+
+ /* Merge current exceptions. */
+ __feraiseexcept (cur_ex);
+
+ /* Test for exceptions raised since the hold. */
+ return cur_ex & ex;
+}
+
+static __always_inline void
+libc_feupdateenv_sse (fenv_t *e)
+{
+ libc_feupdateenv_test_sse (e, 0);
+}
+
+static __always_inline void
+libc_feupdateenv_387 (fenv_t *e)
+{
+ libc_feupdateenv_test_387 (e, 0);
+}
+
+static __always_inline void
+libc_feholdsetround_sse (fenv_t *e, int r)
+{
+ unsigned int mxcsr;
+ asm (STMXCSR " %0" : "=m" (*&mxcsr));
+ e->__mxcsr = mxcsr;
+ mxcsr = (mxcsr & ~0x6000) | (r << 3);
+ asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
+}
+
+static __always_inline void
+libc_feholdsetround_387_prec (fenv_t *e, int r)
+{
+ fpu_control_t cw;
+
+ _FPU_GETCW (cw);
+ e->__control_word = cw;
+ cw &= ~(_FPU_RC_ZERO | _FPU_EXTENDED);
+ cw |= r;
+ _FPU_SETCW (cw);
+}
+
+static __always_inline void
+libc_feholdsetround_387 (fenv_t *e, int r)
+{
+ libc_feholdsetround_387_prec (e, r | _FPU_EXTENDED);
+}
+
+static __always_inline void
+libc_feholdsetround_387_53bit (fenv_t *e, int r)
+{
+ libc_feholdsetround_387_prec (e, r | _FPU_DOUBLE);
+}
+
+static __always_inline void
+libc_feresetround_sse (fenv_t *e)
+{
+ unsigned int mxcsr;
+ asm (STMXCSR " %0" : "=m" (*&mxcsr));
+ mxcsr = (mxcsr & ~0x6000) | (e->__mxcsr & 0x6000);
+ asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
+}
+
+static __always_inline void
+libc_feresetround_387 (fenv_t *e)
+{
+ _FPU_SETCW (e->__control_word);
+}
+
+#ifdef __SSE_MATH__
+# define libc_feholdexceptf libc_feholdexcept_sse
+# define libc_feholdexcept_setroundf libc_feholdexcept_setround_sse
+# define libc_fetestexceptf libc_fetestexcept_sse
+# define libc_fesetenvf libc_fesetenv_sse
+# define libc_feupdateenv_testf libc_feupdateenv_test_sse
+# define libc_feupdateenvf libc_feupdateenv_sse
+# define libc_feholdsetroundf libc_feholdsetround_sse
+# define libc_feresetroundf libc_feresetround_sse
+#else
+# define libc_feholdexceptf libc_feholdexcept_387
+# define libc_feholdexcept_setroundf libc_feholdexcept_setround_387
+# define libc_fetestexceptf libc_fetestexcept_387
+# define libc_fesetenvf libc_fesetenv_387
+# define libc_feupdateenv_testf libc_feupdateenv_test_387
+# define libc_feupdateenvf libc_feupdateenv_387
+# define libc_feholdsetroundf libc_feholdsetround_387
+# define libc_feresetroundf libc_feresetround_387
+#endif /* __SSE_MATH__ */
+
+#ifdef __SSE2_MATH__
+# define libc_feholdexcept libc_feholdexcept_sse
+# define libc_feholdexcept_setround libc_feholdexcept_setround_sse
+# define libc_fetestexcept libc_fetestexcept_sse
+# define libc_fesetenv libc_fesetenv_sse
+# define libc_feupdateenv_test libc_feupdateenv_test_sse
+# define libc_feupdateenv libc_feupdateenv_sse
+# define libc_feholdsetround libc_feholdsetround_sse
+# define libc_feresetround libc_feresetround_sse
+#else
+# define libc_feholdexcept libc_feholdexcept_387
+# define libc_feholdexcept_setround libc_feholdexcept_setround_387
+# define libc_fetestexcept libc_fetestexcept_387
+# define libc_fesetenv libc_fesetenv_387
+# define libc_feupdateenv_test libc_feupdateenv_test_387
+# define libc_feupdateenv libc_feupdateenv_387
+# define libc_feholdsetround libc_feholdsetround_387
+# define libc_feresetround libc_feresetround_387
+#endif /* __SSE2_MATH__ */
+
+#define libc_feholdexceptl libc_feholdexcept_387
+#define libc_feholdexcept_setroundl libc_feholdexcept_setround_387
+#define libc_fetestexceptl libc_fetestexcept_387
+#define libc_fesetenvl libc_fesetenv_387
+#define libc_feupdateenv_testl libc_feupdateenv_test_387
+#define libc_feupdateenvl libc_feupdateenv_387
+#define libc_feholdsetroundl libc_feholdsetround_387
+#define libc_feresetroundl libc_feresetround_387
+
+#ifndef __SSE2_MATH__
+# define libc_feholdexcept_setround_53bit libc_feholdexcept_setround_387_53bit
+# define libc_feholdsetround_53bit libc_feholdsetround_387_53bit
+#endif
+
+#undef __mxcsr
+
+#endif /* FENV_PRIVATE_H */
diff --git a/sysdeps/i386/fpu/math_private.h b/sysdeps/i386/fpu/math_private.h
index 9236448978..541a7f8d93 100644
--- a/sysdeps/i386/fpu/math_private.h
+++ b/sysdeps/i386/fpu/math_private.h
@@ -1,48 +1,6 @@
#ifndef _MATH_PRIVATE_H
-#include <fenv.h>
-#include <fpu_control.h>
-
-#define math_opt_barrier(x) \
-({ __typeof (x) __x; \
- __asm ("" : "=t" (__x) : "0" (x)); \
- __x; })
-#define math_force_eval(x) \
-do \
- { \
- __typeof (x) __x = (x); \
- if (sizeof (x) <= sizeof (double)) \
- __asm __volatile ("" : : "m" (__x)); \
- else \
- __asm __volatile ("" : : "f" (__x)); \
- } \
-while (0)
-
-static __always_inline void
-libc_feholdexcept_setround_53bit (fenv_t *e, int r)
-{
- feholdexcept (e);
- fesetround (r);
-
- fpu_control_t cw;
- _FPU_GETCW (cw);
- cw &= ~(fpu_control_t) _FPU_EXTENDED;
- cw |= _FPU_DOUBLE;
- _FPU_SETCW (cw);
-}
-#define libc_feholdexcept_setround_53bit libc_feholdexcept_setround_53bit
-
-static __always_inline void
-libc_feupdateenv_53bit (fenv_t *e)
-{
- feupdateenv (e);
-
- /* Unfortunately, feupdateenv fails to affect the rounding precision.
- We can get that back by restoring the exact control word we saved. */
- _FPU_SETCW (e->__control_word);
-}
-#define libc_feupdateenv_53bit libc_feupdateenv_53bit
-
+#include "fenv_private.h"
#include_next <math_private.h>
-#endif /* _MATH_PRIVATE_H */
+#endif