From f5f24c7a5c9d975c5edc16d19ae613853ff3f4e7 Mon Sep 17 00:00:00 2001
From: bjorn3 <bjorn3@users.noreply.github.com>
Date: Fri, 1 May 2020 17:28:45 +0200
Subject: [PATCH] Implement a few volatile intrinsics

---
 src/intrinsics/mod.rs | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/intrinsics/mod.rs b/src/intrinsics/mod.rs
index a9954aff6d1..98509847b83 100644
--- a/src/intrinsics/mod.rs
+++ b/src/intrinsics/mod.rs
@@ -471,7 +471,26 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
             assert_eq!(args.len(), 3);
             let byte_amount = fx.bcx.ins().imul(count, elem_size);
 
-            if intrinsic.ends_with("_nonoverlapping") {
+            if intrinsic.contains("nonoverlapping") {
+                // FIXME emit_small_memcpy
+                fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
+            } else {
+                // FIXME emit_small_memmove
+                fx.bcx.call_memmove(fx.module.target_config(), dst, src, byte_amount);
+            }
+        };
+        // NOTE: the volatile variants have src and dst swapped
+        volatile_copy_memory | volatile_copy_nonoverlapping_memory, <elem_ty> (v dst, v src, v count) {
+            let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
+            let elem_size = fx
+                .bcx
+                .ins()
+                .iconst(fx.pointer_type, elem_size as i64);
+            assert_eq!(args.len(), 3);
+            let byte_amount = fx.bcx.ins().imul(count, elem_size);
+
+            // FIXME make the copy actually volatile when using emit_small_mem{cpy,move}
+            if intrinsic.contains("nonoverlapping") {
                 // FIXME emit_small_memcpy
                 fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
             } else {
@@ -633,11 +652,13 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
         transmute, (c from) {
             ret.write_cvalue_transmute(fx, from);
         };
-        write_bytes, (c dst, v val, v count) {
+        write_bytes | volatile_set_memory, (c dst, v val, v count) {
             let pointee_ty = dst.layout().ty.builtin_deref(true).unwrap().ty;
             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
             let count = fx.bcx.ins().imul_imm(count, pointee_size as i64);
             let dst_ptr = dst.load_scalar(fx);
+            // FIXME make the memset actually volatile when switching to emit_small_memset
+            // FIXME use emit_small_memset
             fx.bcx.call_memset(fx.module.target_config(), dst_ptr, val, count);
         };
         ctlz | ctlz_nonzero, <T> (v arg) {