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. --- ia32/Asmgen.v | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'ia32/Asmgen.v') diff --git a/ia32/Asmgen.v b/ia32/Asmgen.v index ccf2e6fd..bb26d507 100644 --- a/ia32/Asmgen.v +++ b/ia32/Asmgen.v @@ -453,6 +453,14 @@ Definition transl_op | Omullimm n, a1 :: nil => assertion (mreg_eq a1 res); do r <- ireg_of res; OK (Pimulq_ri r n :: k) + | Omullhs, a1 :: a2 :: nil => + assertion (mreg_eq a1 AX); + assertion (mreg_eq res DX); + do r2 <- ireg_of a2; OK (Pimulq_r r2 :: k) + | Omullhu, a1 :: a2 :: nil => + assertion (mreg_eq a1 AX); + assertion (mreg_eq res DX); + do r2 <- ireg_of a2; OK (Pmulq_r r2 :: k) | Odivl, a1 :: a2 :: nil => assertion (mreg_eq a1 AX); assertion (mreg_eq a2 CX); -- cgit