Implement and fix rotate intrinsic

Author: antoyo

gcc-test-backend/src/main.rs

@@ -1,17 +1,54 @@
-#![feature(is_sorted)]
-
 fn main() {
-    let b: u16 = 42;
-    assert_eq!(b, 42);
-    let empty: [i32; 0] = [];
-
-    assert!([1, 2, 2, 9].is_sorted());
-    assert!(![1, 3, 2].is_sorted());
-    assert!([42].is_sorted());
-    assert!(empty.is_sorted());
-    assert!(![0.0, 1.0, f32::NAN].is_sorted());
-    assert!([-2, -1, 0, 3].is_sorted());
-    assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));
-    assert!(!["c", "bb", "aaa"].is_sorted());
-    assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));
+    const A: i8 = 0b0101100;
+    const B: i8 = 0b0100001;
+    const C: i8 = 0b1111001;
+
+    const _0: i8 = 0;
+    const _1: i8 = !0;
+
+    assert_eq!(A.rotate_left(6).rotate_right(2).rotate_right(4), A);
+    assert_eq!(B.rotate_left(3).rotate_left(2).rotate_right(5), B);
+    assert_eq!(C.rotate_left(6).rotate_right(2).rotate_right(4), C);
+
+    /*fn rotate_left(x: u32, mut n: u32) -> u32 {
+        //(x << n) | (x >> (-(n as i32) & 31))
+        //println!("{}", 0 << 32);
+        let second_shift = 32 - (n % 32);
+        n %= 32;
+        (x << n) | (x >> second_shift)
+    }
+
+    fn irotate_left(x: i32, mut n: u32) -> i32 {
+        let x = x as u32;
+        let second_shift = 32 - (n % 32);
+        n %= 32;
+        ((x << n) | (x >> second_shift)) as i32
+    }
+
+    assert_eq!(rotate_left(2, 48), 131072);
+    assert_eq!(irotate_left(2, 48), 131072);
+    assert_eq!(irotate_left(-2, 48), -65537);
+    assert_eq!(irotate_left(_1, 124), _1);*/
+
+    /*const _2: u32 = 0;
+    assert_eq!(rotate_left(_2, 16), _2);
+    assert_eq!(rotate_left(_2, 32), _2);
+    assert_eq!(_2.rotate_left(32), _2);*/
+
+    // Rotating these should make no difference
+    //
+    // We test using 124 bits because to ensure that overlong bit shifts do
+    // not cause undefined behaviour. See #10183.
+    assert_eq!(_0.rotate_left(124), _0);
+    println!("{:b}", _1);
+    assert_eq!(_1.rotate_left(124), _1);
+
+    // Rotating by 0 should have no effect
+    assert_eq!(A.rotate_left(0), A);
+    assert_eq!(B.rotate_left(0), B);
+    assert_eq!(C.rotate_left(0), C);
+    // Rotating by a multiple of word size should also have no effect
+    assert_eq!(A.rotate_left(128), A);
+    assert_eq!(B.rotate_left(128), B);
+    assert_eq!(C.rotate_left(128), C);
 }

patches/0022-core-Disable-not-compiling-tests.patch

@@ -39,46 +39,6 @@ index a35897e..f0bf645 100644
 
  pub fn decode_finite<T: DecodableFloat>(v: T) -> Decoded {
      match decode(v).1 {
-diff --git a/library/core/tests/num/int_macros.rs b/library/core/tests/num/int_macros.rs
-index 0475aeb..9558198 100644
---- a/library/core/tests/num/int_macros.rs
-+++ b/library/core/tests/num/int_macros.rs
-@@ -88,6 +88,7 @@ mod tests {
-                 assert_eq!(x.trailing_ones(), 0);
-             }
- 
-+            /*
-             #[test]
-             fn test_rotate() {
-                 assert_eq!(A.rotate_left(6).rotate_right(2).rotate_right(4), A);
-@@ -112,6 +113,7 @@ mod tests {
-                 assert_eq!(B.rotate_left(128), B);
-                 assert_eq!(C.rotate_left(128), C);
-             }
-+            */
- 
-             #[test]
-             fn test_swap_bytes() {
-diff --git a/library/core/tests/num/uint_macros.rs b/library/core/tests/num/uint_macros.rs
-index 04ed14f..a6e372e 100644
---- a/library/core/tests/num/uint_macros.rs
-+++ b/library/core/tests/num/uint_macros.rs
-@@ -52,6 +52,7 @@ mod tests {
-                 assert_eq!(x.trailing_ones(), 0);
-             }
- 
-+            /*
-             #[test]
-             fn test_rotate() {
-                 assert_eq!(A.rotate_left(6).rotate_right(2).rotate_right(4), A);
-@@ -76,6 +77,7 @@ mod tests {
-                 assert_eq!(B.rotate_left(128), B);
-                 assert_eq!(C.rotate_left(128), C);
-             }
-+            */
- 
-             #[test]
-             fn test_swap_bytes() {
 diff --git a/library/core/tests/slice.rs b/library/core/tests/slice.rs
 index 6609bc3..241b497 100644
 --- a/library/core/tests/slice.rs

src/intrinsic.rs

@@ -296,14 +296,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                                         self.rotate_left(val, raw_shift, width)
                                     }
                                     else {
-                                        // TODO: implement now to enable more tests.
-                                        match width {
-                                            8 => unimplemented!(),
-                                            16 => unimplemented!(),
-                                            32 => unimplemented!(),
-                                            64 => unimplemented!(),
-                                            _ => unimplemented!("rotate for integer of size {}", width),
-                                        }
+                                        self.rotate_right(val, raw_shift, width)
                                     }
                                 },
                                 sym::saturating_add => {
@@ -935,13 +928,29 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
     // Algorithm from: https://blog.regehr.org/archives/1063
     fn rotate_left(&mut self, value: RValue<'gcc>, shift: RValue<'gcc>, width: u64) -> RValue<'gcc> {
+        let max = self.context.new_rvalue_from_long(shift.get_type(), width as i64);
+        let shift = shift % max;
         let lhs = self.shl(value, shift);
         let result_and =
             self.and(
                 self.context.new_unary_op(None, UnaryOp::Minus, shift.get_type(), shift),
                 self.context.new_rvalue_from_long(shift.get_type(), width as i64 - 1),
             );
-        let rhs = self.lshr(shift, result_and);
+        let rhs = self.lshr(value, result_and);
+        self.or(lhs, rhs)
+    }
+
+    // Algorithm from: https://blog.regehr.org/archives/1063
+    fn rotate_right(&mut self, value: RValue<'gcc>, shift: RValue<'gcc>, width: u64) -> RValue<'gcc> {
+        let max = self.context.new_rvalue_from_long(shift.get_type(), width as i64);
+        let shift = shift % max;
+        let lhs = self.lshr(value, shift);
+        let result_and =
+            self.and(
+                self.context.new_unary_op(None, UnaryOp::Minus, shift.get_type(), shift),
+                self.context.new_rvalue_from_long(shift.get_type(), width as i64 - 1),
+            );
+        let rhs = self.shl(value, result_and);
         self.or(lhs, rhs)
     }