From d2af79a77ed2936ff0ed90cadf8e48637d774d4c Mon Sep 17 00:00:00 2001 From: Xavier Leroy Date: Tue, 4 Oct 2016 15:52:16 +0200 Subject: 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. --- runtime/c/i64.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'runtime/c/i64.h') 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); -- cgit