diff --git a/lib/std/crypto/sha2.zig b/lib/std/crypto/sha2.zig
index fd7ad532a3..f004bceac3 100644
--- a/lib/std/crypto/sha2.zig
+++ b/lib/std/crypto/sha2.zig
@@ -167,8 +167,7 @@ fn Sha2_32(comptime params: Sha2Params32) type {
             const rr = d.s[0 .. params.out_len / 32];
 
             for (rr) |s, j| {
-                // TODO https://github.com/ziglang/zig/issues/863
-                mem.writeIntSliceBig(u32, out[4 * j .. 4 * j + 4], s);
+                mem.writeIntBig(u32, out[4 * j ..][0..4], s);
             }
         }
 
@@ -509,8 +508,7 @@ fn Sha2_64(comptime params: Sha2Params64) type {
             const rr = d.s[0 .. params.out_len / 64];
 
             for (rr) |s, j| {
-                // TODO https://github.com/ziglang/zig/issues/863
-                mem.writeIntSliceBig(u64, out[8 * j .. 8 * j + 8], s);
+                mem.writeIntBig(u64, out[8 * j ..][0..8], s);
             }
         }
 
diff --git a/src/all_types.hpp b/src/all_types.hpp
index 5025ff7cb5..6719d78a92 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -3711,6 +3711,7 @@ struct IrInstGenSlice {
     IrInstGen *start;
     IrInstGen *end;
     IrInstGen *result_loc;
+    ZigValue *sentinel;
     bool safety_check_on;
 };
 
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 21e74ba609..8fae16e551 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -5425,17 +5425,9 @@ static LLVMValueRef ir_render_slice(CodeGen *g, IrExecutableGen *executable, IrI
         return nullptr;
     }
 
-    ZigValue *sentinel = nullptr;
-    if (result_type->id == ZigTypeIdPointer) {
-        ZigType *result_array_type = result_type->data.pointer.child_type;
-        ir_assert(result_array_type->id == ZigTypeIdArray, &instruction->base);
-        sentinel = result_array_type->data.array.sentinel;
-    } else if (result_type->id == ZigTypeIdStruct) {
-        ZigType *res_slice_ptr_type = result_type->data.structure.fields[slice_ptr_index]->type_entry;
-        sentinel = res_slice_ptr_type->data.pointer.sentinel;
-    } else {
-        zig_unreachable();
-    }
+    // This is not whether the result type has a sentinel, but whether there should be a sentinel check,
+    // e.g. if they used [a..b :s] syntax.
+    ZigValue *sentinel = instruction->sentinel;
 
     if (array_type->id == ZigTypeIdArray ||
         (array_type->id == ZigTypeIdPointer && array_type->data.pointer.ptr_len == PtrLenSingle))
diff --git a/src/ir.cpp b/src/ir.cpp
index e20111e21f..8cd780e46d 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -3732,7 +3732,8 @@ static IrInstSrc *ir_build_slice_src(IrBuilderSrc *irb, Scope *scope, AstNode *s
 }
 
 static IrInstGen *ir_build_slice_gen(IrAnalyze *ira, IrInst *source_instruction, ZigType *slice_type,
-    IrInstGen *ptr, IrInstGen *start, IrInstGen *end, bool safety_check_on, IrInstGen *result_loc)
+    IrInstGen *ptr, IrInstGen *start, IrInstGen *end, bool safety_check_on, IrInstGen *result_loc,
+    ZigValue *sentinel)
 {
     IrInstGenSlice *instruction = ir_build_inst_gen<IrInstGenSlice>(
             &ira->new_irb, source_instruction->scope, source_instruction->source_node);
@@ -3742,6 +3743,7 @@ static IrInstGen *ir_build_slice_gen(IrAnalyze *ira, IrInst *source_instruction,
     instruction->end = end;
     instruction->safety_check_on = safety_check_on;
     instruction->result_loc = result_loc;
+    instruction->sentinel = sentinel;
 
     ir_ref_inst_gen(ptr, ira->new_irb.current_basic_block);
     ir_ref_inst_gen(start, ira->new_irb.current_basic_block);
@@ -26667,7 +26669,7 @@ done_with_return_type:
     }
 
     return ir_build_slice_gen(ira, &instruction->base.base, return_type, ptr_ptr,
-            casted_start, end, instruction->safety_check_on, result_loc);
+            casted_start, end, instruction->safety_check_on, result_loc, sentinel_val);
 }
 
 static IrInstGen *ir_analyze_instruction_has_field(IrAnalyze *ira, IrInstSrcHasField *instruction) {