diff options
Diffstat (limited to 'compiler/rustc_const_eval')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/intrinsics.rs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs index 123eb3125f0..f22cd919c36 100644 --- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs +++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs @@ -261,6 +261,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { sym::write_bytes => { self.write_bytes_intrinsic(&args[0], &args[1], &args[2])?; } + sym::compare_bytes => { + let result = self.compare_bytes_intrinsic(&args[0], &args[1], &args[2])?; + self.write_scalar(result, dest)?; + } sym::arith_offset => { let ptr = self.read_pointer(&args[0])?; let offset_count = self.read_target_isize(&args[1])?; @@ -643,6 +647,24 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { self.write_bytes_ptr(dst, bytes) } + pub(crate) fn compare_bytes_intrinsic( + &mut self, + left: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>, + right: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>, + byte_count: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>, + ) -> InterpResult<'tcx, Scalar<M::Provenance>> { + let left = self.read_pointer(left)?; + let right = self.read_pointer(right)?; + let n = Size::from_bytes(self.read_target_usize(byte_count)?); + + let left_bytes = self.read_bytes_ptr_strip_provenance(left, n)?; + let right_bytes = self.read_bytes_ptr_strip_provenance(right, n)?; + + // `Ordering`'s discriminants are -1/0/+1, so casting does the right thing. + let result = Ord::cmp(left_bytes, right_bytes) as i32; + Ok(Scalar::from_i32(result)) + } + pub(crate) fn raw_eq_intrinsic( &mut self, lhs: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>, |