diff options
Diffstat (limited to 'gas/doc')
| -rw-r--r-- | gas/doc/c-i386.texi | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi index 6c63560..7e5f5c2 100644 --- a/gas/doc/c-i386.texi +++ b/gas/doc/c-i386.texi @@ -453,10 +453,12 @@ Intel64 ISA in 64-bit mode. The default is to accept both. Optimize instruction encoding with smaller instruction size. @samp{-O} and @samp{-O1} encode 64-bit register load instructions with 64-bit immediate as 32-bit register load instructions with 31-bit or 32-bits -immediates and encode 64-bit register clearing instructions with 32-bit -register clearing instructions. @samp{-O2} includes @samp{-O1} -optimization plus encodes 256-bit and 512-bit vector register clearing -instructions with 128-bit vector register clearing instructions. +immediates, encode 64-bit register clearing instructions with 32-bit +register clearing instructions and encode 256-bit/512-bit VEX/EVEX +vector register clearing instructions with 128-bit VEX vector register +clearing instructions. @samp{-O2} includes @samp{-O1} optimization plus +encodes 256-bit/512-bit EVEX vector register clearing instructions with +128-bit EVEX vector register clearing instructions. @samp{-Os} includes @samp{-O2} optimization plus encodes 16-bit, 32-bit and 64-bit register tests with immediate as 8-bit register test with immediate. @samp{-O0} turns off this optimization. |