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| author | matz <matz@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-11-05 14:11:26 +0000 |
|---|---|---|
| committer | matz <matz@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-11-05 14:11:26 +0000 |
| commit | 4472d56a7b3b0c0fc0170756b24b61bf8ebc001f (patch) | |
| tree | 072cc0b7f17624b605c0faacb8c6cb7a931d9219 /gcc/doc | |
| parent | 1bf7a84d9d07d5c3dbc40fd202c25fedae926451 (diff) | |
| download | gcc-4472d56a7b3b0c0fc0170756b24b61bf8ebc001f.tar.gz | |
* config/i386/i386.c (ix86_builtin_reciprocal): Remove dependency
on TARGET_RECIP.
* doc/invoke.texi (-mrecip): Clarify that we don't need -mrecip
for 1/sqrtf.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@153940 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/invoke.texi | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 0a8911b6a56..20a9395f0b7 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -12096,6 +12096,10 @@ Note that while the throughput of the sequence is higher than the throughput of the non-reciprocal instruction, the precision of the sequence can be decreased by up to 2 ulp (i.e. the inverse of 1.0 equals 0.99999994). +Note that GCC implements 1.0f/sqrtf(x) in terms of RSQRTSS (or RSQRTPS) +already with @option{-ffast-math} (or the above option combination), and +doesn't need @option{-mrecip}. + @item -mveclibabi=@var{type} @opindex mveclibabi Specifies the ABI type to use for vectorizing intrinsics using an |