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. --- backend/Selection.v | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'backend/Selection.v') diff --git a/backend/Selection.v b/backend/Selection.v index 5cb5d119..abda1d95 100644 --- a/backend/Selection.v +++ b/backend/Selection.v @@ -389,10 +389,13 @@ Definition get_helpers (defmap: PTree.t globdef) : res helper_functions := do i64_shl <- lookup_helper globs "__i64_shl" sig_li_l ; do i64_shr <- lookup_helper globs "__i64_shr" sig_li_l ; do i64_sar <- lookup_helper globs "__i64_sar" sig_li_l ; + do i64_umulh <- lookup_helper globs "__i64_umulh" sig_ll_l ; + do i64_smulh <- lookup_helper globs "__i64_smulh" sig_ll_l ; OK (mk_helper_functions i64_dtos i64_dtou i64_stod i64_utod i64_stof i64_utof i64_sdiv i64_udiv i64_smod i64_umod - i64_shl i64_shr i64_sar). + i64_shl i64_shr i64_sar + i64_umulh i64_smulh). (** Conversion of programs. *) -- cgit