Remove the intrinsic for align_offset

Keep only the language item. This removes some indirection and makes
codegen worse for debug builds, but simplifies code significantly, which
is a good tradeoff to make, in my opinion.

Besides, the codegen can be improved even further with some constant
evaluation improvements that we expect to happen in the future.

1 files changed, 0 insertions, 26 deletions

diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs
index 93351651db9..cffe7f79e97 100644
--- a/src/librustc_codegen_llvm/intrinsic.rs
+++ b/src/librustc_codegen_llvm/intrinsic.rs
@@ -25,7 +25,6 @@ use type_of::LayoutLlvmExt;
 use rustc::ty::{self, Ty};
 use rustc::ty::layout::{HasDataLayout, LayoutOf};
 use rustc::hir;
-use rustc::middle::lang_items::AlignOffsetLangItem;
 use syntax::ast;
 use syntax::symbol::Symbol;
 use builder::Builder;
@@ -390,31 +389,6 @@ pub fn codegen_intrinsic_call<'a, 'tcx>(bx: &Builder<'a, 'tcx>,
             args[0].deref(bx.cx).codegen_get_discr(bx, ret_ty)
         }
 
-        "align_offset" => {
-            let (ptr, align) = (args[0].immediate(), args[1].immediate());
-            let stride_of_t = bx.cx.layout_of(substs.type_at(0)).size_and_align().0.bytes();
-            let stride = C_usize(bx.cx, stride_of_t);
-            let zero = C_null(bx.cx.isize_ty);
-            let max = C_int(cx.isize_ty, -1); // -1isize (wherein I cheat horribly to make !0usize)
-
-            if stride_of_t <= 1 {
-                // offset = ptr as usize % align => offset = ptr as usize & (align - 1)
-                let modmask = bx.sub(align, C_usize(bx.cx, 1));
-                let offset = bx.and(bx.ptrtoint(ptr, bx.cx.isize_ty), modmask);
-                let is_zero = bx.icmp(llvm::IntPredicate::IntEQ, offset, zero);
-                // if offset == 0 { 0 } else { if stride_of_t == 1 { align - offset } else { !0 } }
-                bx.select(is_zero, zero, if stride_of_t == 1 {
-                    bx.sub(align, offset)
-                } else {
-                    max
-                })
-            } else {
-                let did = ::common::langcall(bx.tcx(), Some(span), "", AlignOffsetLangItem);
-                let instance = ty::Instance::mono(bx.tcx(), did);
-                let llfn = ::callee::get_fn(bx.cx, instance);
-                bx.call(llfn, &[ptr, align, stride], None)
-            }
-        }
         name if name.starts_with("simd_") => {
             match generic_simd_intrinsic(bx, name,
                                          callee_ty,