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authorPaul Clarke <pc@us.ibm.com>2019-02-04 19:16:50 -0600
committerGabriel F. T. Gomes <gabriel@inconstante.eti.br>2019-02-11 12:03:23 -0200
commita51bc4fe9da9f2b97877beb6692f7043f6c14a16 (patch)
treea64960fa4e31858e5d96bc9d7e943cd105212c6e /sysdeps/powerpc/fpu/e_sqrtf.c
parentfb25b1356ae6a0b2d27a307091ad4f384814cc77 (diff)
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Use float in e_sqrt.c
The type used within e_sqrt.c(__slow_ieee754_sqrtf) was, unnecessarily and
likely inadvertently, double.  float is not only appropriate, but also
more efficient, avoiding the need for the compiler to emit a
round-to-single-precision instruction.

This is the difference in compiled code:
 0000000000000000 <__ieee754_sqrtf>:
    0:  2c 08 20 ec     fsqrts  f1,f1
-   4:  18 08 20 fc     frsp    f1,f1
-   8:  20 00 80 4e     blr
+   4:  20 00 80 4e     blr

(Found by Anton Blanchard.)
Diffstat (limited to 'sysdeps/powerpc/fpu/e_sqrtf.c')
-rw-r--r--sysdeps/powerpc/fpu/e_sqrtf.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/sysdeps/powerpc/fpu/e_sqrtf.c b/sysdeps/powerpc/fpu/e_sqrtf.c
index 65df94bb80..5d9e900005 100644
--- a/sysdeps/powerpc/fpu/e_sqrtf.c
+++ b/sysdeps/powerpc/fpu/e_sqrtf.c
@@ -138,7 +138,7 @@ __slow_ieee754_sqrtf (float x)
 float
 __ieee754_sqrtf (float x)
 {
-  double z;
+  float z;
 
 #ifdef _ARCH_PPCSQ
   asm ("fsqrts	%0,%1\n" :"=f" (z):"f" (x));