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| -rw-r--r-- | lib/Target/X86/README.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 91bdb538e9..58a864e01c 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -542,6 +542,13 @@ Currently the load folding imull has a higher complexity than the LEA32 pattern. //===---------------------------------------------------------------------===// +We are currently lowering large (1MB+) memmove/memcpy to rep/stosl and rep/movsl +We should leave these as libcalls for everything over a much lower threshold, +since libc is hand tuned for medium and large mem ops (avoiding RFO for large +stores, TLB preheating, etc) + +//===---------------------------------------------------------------------===// + Lower memcpy / memset to a series of SSE 128 bit move instructions when it's feasible. |