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6708714: Optimize long LShift on 32-bits x86

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For small (1-3 bits) left long shifts in 32-bits VM use sets of add+addc instructions instead of shld+shl on new AMD cpus.

Reviewed-by: never
This commit is contained in:
Shrinivas Joshi 2008-06-23 14:11:12 -07:00 • committed by Vladimir Kozlov
parent d69fdc9d5b
commit 5106cf17a3
3 changed files with 91 additions and 0 deletions
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3
hotspot/src/share/vm/runtime/globals.hpp
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@ -946,6 +946,9 @@ class CommandLineFlags {
diagnostic(bool, UseIncDec, true, \
"Use INC, DEC instructions on x86") \
\
product(bool, UseNewLongLShift, false, \
"Use optimized bitwise shift left") \
\
product(bool, UseStoreImmI16, true, \
"Use store immediate 16-bits value instruction on x86") \
\