about summary refs log tree commit diff
path: root/sysdeps/libm-ieee754
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>1998-05-06 14:43:15 +0000
committerUlrich Drepper <drepper@redhat.com>1998-05-06 14:43:15 +0000
commit6600049466b586e3decaf24bd70c06b21382cf98 (patch)
tree536fc5c8efe78035527223283bcd5a48ac259576 /sysdeps/libm-ieee754
parentb22fc5f5651706304ac09305ac3ee5bf84516378 (diff)
downloadglibc-6600049466b586e3decaf24bd70c06b21382cf98.tar.gz
glibc-6600049466b586e3decaf24bd70c06b21382cf98.tar.xz
glibc-6600049466b586e3decaf24bd70c06b21382cf98.zip
Update.
1998-04-16 07:42  Geoff Keating  <geoffk@ozemail.com.au>

	* Makeconfig [!build-static]: Link `static' binaries with libc_pic.a.
	Still need *FLAGS-.o because we still sometimes build .o files.
	* db2/Makefile: Don't build libndbm.a if !build-static.

1998-04-16 07:42  Geoff Keating  <geoffk@ozemail.com.au>

	* configure.in: New test for broken gcc on PowerPC.
	* sysdeps/powerpc/atomicity.h: Use result of test.
	* linuxthreads/sysdeps/powerpc/pt-machine.h: Use result of test.

	* math/libm-test.c: Update many of the epsilon to match actual
	performance.

	* sysdeps/libm-ieee754/e_exp.c: Reduce the number of branches.
	* sysdeps/libm-ieee754/e_expf.c: Likewise.
	* sysdeps/libm-ieee754/s_exp2.c: Likewise.
	* sysdeps/libm-ieee754/s_exp2f.c: Likewise.

	* sysdeps/libm-ieee754/e_pow.c: Correct typo.

	* sysdeps/powerpc/elf/libc-start.c: New file.
	* sysdeps/powerpc/elf/start.S: New file, use libc-start.
	* sysdeps/powerpc/elf/start.c: Delete.

	* sysdeps/unix/sysv/linux/powerpc/Dist: Remove syscall.h
	* sysdeps/unix/sysv/linux/powerpc/syscall.h: Delete.  It was unused.

	* sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c: Correct previous
	few patches.
Diffstat (limited to 'sysdeps/libm-ieee754')
-rw-r--r--sysdeps/libm-ieee754/e_exp.c48
-rw-r--r--sysdeps/libm-ieee754/e_expf.c48
-rw-r--r--sysdeps/libm-ieee754/s_exp2.c14
-rw-r--r--sysdeps/libm-ieee754/s_exp2f.c14
4 files changed, 36 insertions, 88 deletions
diff --git a/sysdeps/libm-ieee754/e_exp.c b/sysdeps/libm-ieee754/e_exp.c
index 660c5bc88d..5eae12a19c 100644
--- a/sysdeps/libm-ieee754/e_exp.c
+++ b/sysdeps/libm-ieee754/e_exp.c
@@ -76,8 +76,8 @@ __ieee754_exp (double x)
   /* Check for usual case.  */
   if (isless (x, himark) && isgreater (x, lomark))
     {
-      static const double TWO43 = 8796093022208.0;
-      static const double TWO52 = 4503599627370496.0;
+      static const double THREEp42 = 13194139533312.0;
+      static const double THREEp51 = 6755399441055744.0;
       /* 1/ln(2).  */
       static const double M_1_LN2 = 1.442695040888963387;
       /* ln(2), part 1 */
@@ -94,40 +94,22 @@ __ieee754_exp (double x)
       fesetround (FE_TONEAREST);
 
       /* Calculate n.  */
-      if (x >= 0)
-	{
-	  n = x * M_1_LN2 + TWO52;
-	  n -= TWO52;
-	}
-      else
-	{
-	  n = x * M_1_LN2 - TWO52;
-	  n += TWO52;
-	}
+      n = x * M_1_LN2 + THREEp51;
+      n -= THREEp51;
       x = x - n*M_LN2_0;
-      if (x >= 0)
-	{
-	  /* Calculate t/512.  */
-	  t = x + TWO43;
-	  t -= TWO43;
-	  x -= t;
-
-	  /* Compute tval = t.  */
-	  tval = (int) (t * 512.0);
-
-	  x -= __exp_deltatable[tval];
-	}
-      else
-	{
-	  /* As above, but x is negative.  */
-	  t = x - TWO43;
-	  t += TWO43;
-	  x -= t;
 
-	  tval = (int) (t * 512.0);
+      /* Calculate t/512.  */
+      t = x + THREEp42;
+      t -= THREEp42;
+      x -= t;
 
-	  x += __exp_deltatable[-tval];
-	}
+      /* Compute tval = t.  */
+      tval = (int) (t * 512.0);
+
+      if (t >= 0)
+	x -= __exp_deltatable[tval];
+      else
+	x += __exp_deltatable[-tval];
 
       /* Now, the variable x contains x + n*ln(2)_1.  */
       dely = n*M_LN2_1;
diff --git a/sysdeps/libm-ieee754/e_expf.c b/sysdeps/libm-ieee754/e_expf.c
index c4a7b644fd..ff6357bd1d 100644
--- a/sysdeps/libm-ieee754/e_expf.c
+++ b/sysdeps/libm-ieee754/e_expf.c
@@ -71,8 +71,8 @@ __ieee754_expf (float x)
   /* Check for usual case.  */
   if (isless (x, himark) && isgreater (x, lomark))
     {
-      static const float TWO43 = 8796093022208.0;
-      static const float TWO23 = 8388608.0;
+      static const float THREEp42 = 13194139533312.0;
+      static const float THREEp22 = 12582912.0;
       /* 1/ln(2).  */
 #undef M_1_LN2
       static const float M_1_LN2 = 1.44269502163f;
@@ -90,40 +90,22 @@ __ieee754_expf (float x)
       fesetround (FE_TONEAREST);
 
       /* Calculate n.  */
-      if (x >= 0)
-	{
-	  n = x * M_1_LN2 + TWO23;
-	  n -= TWO23;
-	}
-      else
-	{
-	  n = x * M_1_LN2 - TWO23;
-	  n += TWO23;
-	}
+      n = x * M_1_LN2 + THREEp22;
+      n -= THREEp22;
       dx = x - n*M_LN2;
-      if (dx >= 0)
-	{
-	  /* Calculate t/512.  */
-	  t = dx + TWO43;
-	  t -= TWO43;
-	  dx -= t;
-
-	  /* Compute tval = t.  */
-	  tval = (int) (t * 512.0);
-
-	  delta = - __exp_deltatable[tval];
-	}
-      else
-	{
-	  /* As above, but x is negative.  */
-	  t = dx - TWO43;
-	  t += TWO43;
-	  dx -= t;
 
-	  tval = (int) (t * 512.0);
+      /* Calculate t/512.  */
+      t = dx + THREEp42;
+      t -= THREEp42;
+      dx -= t;
 
-	  delta = __exp_deltatable[-tval];
-	}
+      /* Compute tval = t.  */
+      tval = (int) (t * 512.0);
+
+      if (t >= 0)
+	delta = - __exp_deltatable[tval];
+      else
+	delta = __exp_deltatable[-tval];
 
       /* Compute ex2 = 2^n e^(t/512+delta[t]).  */
       ex2_u.d = __exp_atable[tval+177];
diff --git a/sysdeps/libm-ieee754/s_exp2.c b/sysdeps/libm-ieee754/s_exp2.c
index ead1ce89eb..875d4d6f2c 100644
--- a/sysdeps/libm-ieee754/s_exp2.c
+++ b/sysdeps/libm-ieee754/s_exp2.c
@@ -48,7 +48,7 @@ __ieee754_exp2 (double x)
   /* Check for usual case.  */
   if (isless (x, himark) && isgreater (x, lomark))
     {
-      static const double TWO43 = 8796093022208.0;
+      static const double THREEp42 = 13194139533312.0;
       int tval, unsafe;
       double rx, x22, result;
       union ieee754_double ex2_u, scale_u;
@@ -66,16 +66,8 @@ __ieee754_exp2 (double x)
 	 x = ex + t/512 + x1.
 
 	 First, calculate rx = ex + t/512.  */
-      if (x >= 0)
-	{
-	  rx = x + TWO43;
-	  rx -= TWO43;
-	}
-      else
-	{
-	  rx = x - TWO43;
-	  rx += TWO43;
-	}
+      rx = x + THREEp42;
+      rx -= THREEp42;
       x -= rx;  /* Compute x=x1. */
       /* Compute tval = (ex*512 + t)+256.
 	 Now, t = (tval mod 512)-256 and ex=tval/512  [that's mod, NOT %; and
diff --git a/sysdeps/libm-ieee754/s_exp2f.c b/sysdeps/libm-ieee754/s_exp2f.c
index 641b7548f1..8229885453 100644
--- a/sysdeps/libm-ieee754/s_exp2f.c
+++ b/sysdeps/libm-ieee754/s_exp2f.c
@@ -49,7 +49,7 @@ __ieee754_exp2f (float x)
   /* Check for usual case.  */
   if (isless (x, himark) && isgreater (x, lomark))
     {
-      static const float TWO15 = 32768.0;
+      static const float THREEp14 = 49152.0;
       int tval, unsafe;
       float rx, x22, result;
       union ieee754_float ex2_u, scale_u;
@@ -67,16 +67,8 @@ __ieee754_exp2f (float x)
 	 x = ex + t/512 + x1.
 
 	 First, calculate rx = ex + t/256.  */
-      if (x >= 0)
-	{
-	  rx = x + TWO15;
-	  rx -= TWO15;
-	}
-      else
-	{
-	  rx = x - TWO15;
-	  rx += TWO15;
-	}
+      rx = x + THREEp14;
+      rx -= THREEp14;
       x -= rx;  /* Compute x=x1. */
       /* Compute tval = (ex*256 + t)+128.
 	 Now, t = (tval mod 256)-128 and ex=tval/256  [that's mod, NOT %; and