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authorUlrich Drepper <drepper@gmail.com>2011-10-18 09:59:04 -0400
committerUlrich Drepper <drepper@gmail.com>2011-10-18 09:59:04 -0400
commit4855e3ddf5061dd8ddcefafc7185f6f70937434b (patch)
tree7e29eb6e22a1dda9a7133e577787ac9f9b6c17e7
parent23ce5627803ad1e6686355965cd68bb23d05fb28 (diff)
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Provide combined internal feholdexcept/fesetround interface
-rw-r--r--ChangeLog6
-rw-r--r--math/math_private.h7
-rw-r--r--sysdeps/ieee754/dbl-64/e_exp2.c6
-rw-r--r--sysdeps/x86_64/fpu/math_private.h14
4 files changed, 27 insertions, 6 deletions
diff --git a/ChangeLog b/ChangeLog
index 3802f857fa..de8b2c3b98 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2011-10-18  Ulrich Drepper  <drepper@gmail.com>
 
+	* math/math_private.h: Define defaults for libc_feholdexcept_setround,
+	libc_feholdexcept_setroundf, libc_feholdexcept_setroundl.
+	* sysdeps/ieee754/dbl-64/e_exp2.c: Use libc_feholdexcept_setround.
+	* sysdeps/x86_64/fpu/math_private.h: Define special version of
+	libc_feholdexcept_setround.
+
 	* sysdeps/x86_64/fpu/multiarch/Makefile [math] (libm-sysdep-routines):
 	Add s_nearbyint-c and s_nearbyintf-c.
 	* sysdeps/x86_64/fpu/bits/mathinline.h: Define nearbyint and
diff --git a/math/math_private.h b/math/math_private.h
index a1ce0142b1..38ff09e7e0 100644
--- a/math/math_private.h
+++ b/math/math_private.h
@@ -376,6 +376,13 @@ extern void __docos (double __x, double __dx, double __v[]);
 #define libc_feholdexceptf(e) (void) feholdexcept (e)
 #define libc_feholdexceptl(e) (void) feholdexcept (e)
 
+#define libc_feholdexcept_setround(e, r) \
+  do { feholdexcept (e); fesetround (r); } while (0)
+#define libc_feholdexcept_setroundf(e, r) \
+  do { feholdexcept (e); fesetround (r); } while (0)
+#define libc_feholdexcept_setroundl(e, r) \
+  do { feholdexcept (e); fesetround (r); } while (0)
+
 #define libc_fesetenv(e) (void) fesetenv (e)
 #define libc_fesetenvf(e) (void) fesetenv (e)
 #define libc_fesetenvl(e) (void) fesetenv (e)
diff --git a/sysdeps/ieee754/dbl-64/e_exp2.c b/sysdeps/ieee754/dbl-64/e_exp2.c
index 734e476ce5..0b7330aace 100644
--- a/sysdeps/ieee754/dbl-64/e_exp2.c
+++ b/sysdeps/ieee754/dbl-64/e_exp2.c
@@ -64,11 +64,7 @@ __ieee754_exp2 (double x)
       union ieee754_double ex2_u, scale_u;
       fenv_t oldenv;
 
-      libc_feholdexcept (&oldenv);
-#ifdef FE_TONEAREST
-      /* If we don't have this, it's too bad.  */
-      libc_fesetround (FE_TONEAREST);
-#endif
+      libc_feholdexcept_setround (&oldenv, FE_TONEAREST);
 
       /* 1. Argument reduction.
 	 Choose integers ex, -256 <= t < 256, and some real
diff --git a/sysdeps/x86_64/fpu/math_private.h b/sysdeps/x86_64/fpu/math_private.h
index 4886c64dc3..28bd9cee2d 100644
--- a/sysdeps/x86_64/fpu/math_private.h
+++ b/sysdeps/x86_64/fpu/math_private.h
@@ -145,7 +145,7 @@ do {								\
 
 #undef libc_feholdexcept
 #define libc_feholdexcept(e) \
-  do {			     \
+  do {									      \
      unsigned int mxcsr;						      \
      asm ("stmxcsr %0" : "=m" (*&mxcsr));				      \
      (e)->__mxcsr = mxcsr;						      \
@@ -155,6 +155,18 @@ do {								\
 // #define libc_feholdexceptf(e) (void) feholdexcept (e)
 // #define libc_feholdexceptl(e) (void) feholdexcept (e)
 
+#undef libc_feholdexcept_setround
+#define libc_feholdexcept_setround(e, r) \
+  do {									      \
+     unsigned int mxcsr;						      \
+     asm ("stmxcsr %0" : "=m" (*&mxcsr));				      \
+     (e)->__mxcsr = mxcsr;						      \
+     mxcsr = ((mxcsr | 0x1f80) & ~0x603f) | ((r) << 3);			      \
+     asm volatile ("ldmxcsr %0" : : "m" (*&mxcsr));			      \
+  } while (0)
+// #define libc_feholdexcept_setroundf(e, r) ...
+// #define libc_feholdexcept_setroundl(e, r) ...
+
 #undef libc_fesetenv
 #define libc_fesetenv(e) \
   asm volatile ("ldmxcsr %0" : : "m" ((e)->__mxcsr))