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authorAurelien Jarno <aurelien@aurel32.net>2016-08-02 09:18:59 +0200
committerMike Frysinger <vapier@gentoo.org>2016-12-08 00:38:41 -0500
commitb099b9c11b003927010b18fe7adf66b5f1c1817c (patch)
tree92300c6afd897492aa1b4f908fb726ae30ed53d2
parent201fca8584b5aca30e807890b607064f16ef38ef (diff)
downloadglibc-gentoo/2.23.zip
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alpha: fix trunc for big input valuesgentoo/2.23
The alpha specific version of trunc and truncf always add and subtract 0x1.0p23 or 0x1.0p52 even for big values. This causes this kind of errors in the testsuite: Failure: Test: trunc_towardzero (0x1p107) Result: is: 1.6225927682921334e+32 0x1.fffffffffffffp+106 should be: 1.6225927682921336e+32 0x1.0000000000000p+107 difference: 1.8014398509481984e+16 0x1.0000000000000p+54 ulp : 0.5000 max.ulp : 0.0000 Change this by returning the input value when its absolute value is greater than 0x1.0p23 or 0x1.0p52. NaN have to go through the add and subtract operations to get possibly silenced. Finally remove the code to handle inexact exception, trunc should never generate such an exception. Changelog: * sysdeps/alpha/fpu/s_trunc.c (__trunc): Return the input value when its absolute value is greater than 0x1.0p52. [_IEEE_FP_INEXACT] Remove. * sysdeps/alpha/fpu/s_truncf.c (__truncf): Return the input value when its absolute value is greater than 0x1.0p23. [_IEEE_FP_INEXACT] Remove. (cherry picked from commit b74d259fe793499134eb743222cd8dd7c74a31ce) (cherry picked from commit 3a5aa2ee4ffc515c8e7e615ea38d6b3b20ed0a30)
-rw-r--r--sysdeps/alpha/fpu/s_trunc.c7
-rw-r--r--sysdeps/alpha/fpu/s_truncf.c7
2 files changed, 6 insertions, 8 deletions
diff --git a/sysdeps/alpha/fpu/s_trunc.c b/sysdeps/alpha/fpu/s_trunc.c
index 16cb114..4b986a6 100644
--- a/sysdeps/alpha/fpu/s_trunc.c
+++ b/sysdeps/alpha/fpu/s_trunc.c
@@ -28,12 +28,11 @@ __trunc (double x)
double two52 = copysign (0x1.0p52, x);
double r, tmp;
+ if (isgreaterequal (fabs (x), 0x1.0p52))
+ return x;
+
__asm (
-#ifdef _IEEE_FP_INEXACT
- "addt/suic %2, %3, %1\n\tsubt/suic %1, %3, %0"
-#else
"addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0"
-#endif
: "=&f"(r), "=&f"(tmp)
: "f"(x), "f"(two52));
diff --git a/sysdeps/alpha/fpu/s_truncf.c b/sysdeps/alpha/fpu/s_truncf.c
index 2290f28..3e93356 100644
--- a/sysdeps/alpha/fpu/s_truncf.c
+++ b/sysdeps/alpha/fpu/s_truncf.c
@@ -27,12 +27,11 @@ __truncf (float x)
float two23 = copysignf (0x1.0p23, x);
float r, tmp;
+ if (isgreaterequal (fabsf (x), 0x1.0p23))
+ return x;
+
__asm (
-#ifdef _IEEE_FP_INEXACT
- "adds/suic %2, %3, %1\n\tsubs/suic %1, %3, %0"
-#else
"adds/suc %2, %3, %1\n\tsubs/suc %1, %3, %0"
-#endif
: "=&f"(r), "=&f"(tmp)
: "f"(x), "f"(two23));