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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 /runtime/c/i64.h | |
| 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 'runtime/c/i64.h')
| -rw-r--r-- | runtime/c/i64.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/runtime/c/i64.h b/runtime/c/i64.h index dd584533..a75214fe 100644 --- a/runtime/c/i64.h +++ b/runtime/c/i64.h @@ -41,3 +41,5 @@ extern signed long long __i64_sar(signed long long x, int amount); extern unsigned long long __i64_udivmod(unsigned long long n, unsigned long long d, unsigned long long * rp); +extern unsigned long long __i64_umulh(unsigned long long u, + unsigned long long v); |