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| author | Xavier Leroy <xavier.leroy@inria.fr> | 2016-10-04 15:52:16 +0200 |
|---|---|---|
| committer | Xavier Leroy <xavier.leroy@inria.fr> | 2016-10-04 15:52:16 +0200 |
| commit | d2af79a77ed2936ff0ed90cadf8e48637d774d4c (patch) | |
| tree | 09300943e12a98ae80598c79d455b31725271ead /ia32/SelectLong.vp | |
| parent | a44893028eb1dd434c68001234ad56d030205a8e (diff) | |
| download | compcert-d2af79a77ed2936ff0ed90cadf8e48637d774d4c.tar.gz compcert-d2af79a77ed2936ff0ed90cadf8e48637d774d4c.zip | |
Turn 64-bit integer division and modulus by constants into multiply-high
This trick was already implemented for 32-bit integer division and modulus. Here we extend it to the 64-bit case.
For 32-bit target processors, the runtime library must implement 64-bit multiply-high (signed and unsigned). Tentative implementations are provided for IA32 and PowerPC, but need testing.
Diffstat (limited to 'ia32/SelectLong.vp')
| -rw-r--r-- | ia32/SelectLong.vp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/ia32/SelectLong.vp b/ia32/SelectLong.vp index 77fc4071..2869f823 100644 --- a/ia32/SelectLong.vp +++ b/ia32/SelectLong.vp @@ -285,6 +285,14 @@ Nondetfunction mull (e1: expr) (e2: expr) := | _, _ => Eop Omull (e1:::e2:::Enil) end. +Definition mullhu (e1: expr) (n2: int64) := + if Archi.splitlong then SplitLong.mullhu e1 n2 else + Eop Omullhu (e1 ::: longconst n2 ::: Enil). + +Definition mullhs (e1: expr) (n2: int64) := + if Archi.splitlong then SplitLong.mullhs e1 n2 else + Eop Omullhs (e1 ::: longconst n2 ::: Enil). + Definition shrxlimm (e: expr) (n: int) := if Archi.splitlong then SplitLong.shrxlimm e n else if Int.eq n Int.zero then e else Eop (Oshrxlimm n) (e ::: Enil). |