From d2af79a77ed2936ff0ed90cadf8e48637d774d4c Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@inria.fr>
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.
---
 cfrontend/C2C.ml | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'cfrontend/C2C.ml')

diff --git a/cfrontend/C2C.ml b/cfrontend/C2C.ml
index b68887c5..38ef45e7 100644
--- a/cfrontend/C2C.ml
+++ b/cfrontend/C2C.ml
@@ -251,6 +251,14 @@ let builtins_generic = {
     "__i64_sar",
         (TInt(ILongLong, []),
          [TInt(ILongLong, []); TInt(IInt, [])],
+         false);
+    "__i64_smulh",
+        (TInt(ILongLong, []),
+         [TInt(ILongLong, []); TInt(ILongLong, [])],
+         false);
+    "__i64_umulh",
+        (TInt(IULongLong, []),
+         [TInt(IULongLong, []); TInt(IULongLong, [])],
          false)
   ]
 }
-- 
cgit