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Do not raise "inexact" from x86_64 SSE4.1 ceil, floor (bug 15479).

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Continuing fixes for ceil and floor functions not to raise the
"inexact" exception, this patch fixes the x86_64 SSE4.1 versions.  The
roundss / roundsd instructions take an immediate operand that
determines the rounding mode and whether to raise "inexact"; this just
needs bit 3 set to disable "inexact", which this patch does.

Remark: we don't have an SSE4.1 version of trunc / truncf (using this
instruction with operand 11); I'd expect one to make sense, but of
course it should be benchmarked against the existing C code.  I'll
file a bug in Bugzilla for the lack of such a version.

Tested for x86_64.

	[BZ #15479]
	* sysdeps/x86_64/fpu/multiarch/s_ceil.S (__ceil_sse41): Set bit 3
	of immediate operand to rounding instruction.
	* sysdeps/x86_64/fpu/multiarch/s_ceilf.S (__ceilf_sse41):
	Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_floor.S (__floor_sse41):
	Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_floorf.S (__floorf_sse41):
	Likewise.
This commit is contained in:
Joseph Myers 2016-05-24 21:11:18 +00:00
parent 7cfcb778c9
commit 5ff81530dd
5 changed files with 16 additions and 4 deletions
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12
ChangeLog
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@ -1,3 +1,15 @@
2016-05-24 Joseph Myers <joseph@codesourcery.com>
[BZ #15479]
* sysdeps/x86_64/fpu/multiarch/s_ceil.S (__ceil_sse41): Set bit 3
of immediate operand to rounding instruction.
* sysdeps/x86_64/fpu/multiarch/s_ceilf.S (__ceilf_sse41):
Likewise.
* sysdeps/x86_64/fpu/multiarch/s_floor.S (__floor_sse41):
Likewise.
* sysdeps/x86_64/fpu/multiarch/s_floorf.S (__floorf_sse41):
Likewise.
2016-05-24 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
* math/libm-test.inc (MIN_EXP): Directly define as

2
sysdeps/x86_64/fpu/multiarch/s_ceil.S
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@ -33,6 +33,6 @@ weak_alias (__ceil, ceil)
ENTRY(__ceil_sse41)
roundsd $2, %xmm0, %xmm0
roundsd $10, %xmm0, %xmm0
ret
END(__ceil_sse41)

2
sysdeps/x86_64/fpu/multiarch/s_ceilf.S
View File

@ -33,6 +33,6 @@ weak_alias (__ceilf, ceilf)
ENTRY(__ceilf_sse41)
roundss $2, %xmm0, %xmm0
roundss $10, %xmm0, %xmm0
ret
END(__ceilf_sse41)

2
sysdeps/x86_64/fpu/multiarch/s_floor.S
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@ -33,6 +33,6 @@ weak_alias (__floor, floor)
ENTRY(__floor_sse41)
roundsd $1, %xmm0, %xmm0
roundsd $9, %xmm0, %xmm0
ret
END(__floor_sse41)

2
sysdeps/x86_64/fpu/multiarch/s_floorf.S
View File

@ -33,6 +33,6 @@ weak_alias (__floorf, floorf)
ENTRY(__floorf_sse41)
roundss $1, %xmm0, %xmm0
roundss $9, %xmm0, %xmm0
ret
END(__floorf_sse41)