diff options
| -rw-r--r-- | src/intrinsics/mod.rs | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/intrinsics/mod.rs b/src/intrinsics/mod.rs index d76dfca7960..b254ca3bec8 100644 --- a/src/intrinsics/mod.rs +++ b/src/intrinsics/mod.rs @@ -713,14 +713,21 @@ fn codegen_regular_intrinsic_call<'tcx>( ret.write_cvalue(fx, val); }; - ptr_offset_from, (v ptr, v base) { + ptr_offset_from | ptr_offset_from_unsigned, (v ptr, v base) { let ty = substs.type_at(0); let isize_layout = fx.layout_of(fx.tcx.types.isize); let pointee_size: u64 = fx.layout_of(ty).size.bytes(); - let diff = fx.bcx.ins().isub(ptr, base); + let diff_bytes = fx.bcx.ins().isub(ptr, base); // FIXME this can be an exact division. - let val = CValue::by_val(fx.bcx.ins().sdiv_imm(diff, pointee_size as i64), isize_layout); + let diff = if intrinsic == sym::ptr_offset_from_unsigned { + // Because diff_bytes ULT isize::MAX, this would be fine as signed, + // but unsigned is slightly easier to codegen, so might as well. + fx.bcx.ins().udiv_imm(diff_bytes, pointee_size as i64) + } else { + fx.bcx.ins().sdiv_imm(diff_bytes, pointee_size as i64) + }; + let val = CValue::by_val(diff, isize_layout); ret.write_cvalue(fx, val); }; |