Fixed misc issues to make tr64 tests pass

-> Made API and tests use `transmute` for f64/u64 instead of `as`
-> Changed relevant logical shifts to (correctly) be arithmetic shifts
-> Fixed small typo in tests
-> (misc) Made STORE correctly handle arbitrary (< 64) sized ints

src/compiler/backend/arch/aarch64/mod.rs

@@ -22,6 +22,8 @@
 // TODO: Move architecture independent codes in here, inst_sel and asm_backend to somewhere else...
 pub mod inst_sel;
 
+use utils::bit_utils::bits_ones;
+
 mod codegen;
 pub use compiler::backend::aarch64::codegen::CodeGenerator;
 
@@ -1179,12 +1181,6 @@ fn hfa_length(t : P<MuType>) -> usize
     }
 }
 
-#[inline(always)]
-// Returns the number that has 'n' 1's in a row (i.e. 2^n-1)
-pub fn bits_ones(n: usize) -> u64 {
-    if n == 64 { (-(1 as i64)) as u64 }
-        else { (1 << n) - 1 }
-}
 // val is an unsigned multiple of n and val/n fits in 12 bits
 #[inline(always)]
 pub fn is_valid_immediate_offset(val: i64, n : usize) -> bool {
@@ -2555,4 +2551,4 @@ fn is_int_ex_reg(val: &P<Value>) -> bool
 fn is_fp_reg(val: &P<Value>) -> bool
 {
     RegGroup::get_from_value(&val) == RegGroup::FPR && (val.is_reg() || val.is_const())
-}
\ No newline at end of file
+}

src/utils/src/bit_utils.rs

@@ -26,6 +26,20 @@ pub fn lower_bits_u8(value: u8, len: usize) -> u8 {
 
 // u64
 
+#[inline(always)]
+// Returns the number that has 'n' 1's in a row (i.e. 2^n-1)
+pub fn bits_ones(n: usize) -> u64 {
+    if n == 64 { (-(1 as i64)) as u64 }
+        else { (1 << n) - 1 }
+}
+
+#[inline(always)]
+pub fn u64_asr(val: u64, shift: u32) -> u64 {
+    let _val: i64 = val as i64;
+    let res: i64 = _val >> shift;
+    res as u64
+}
+
 #[inline(always)]
 pub fn set_nth_bit_u64 (value: u64, index: usize, set_value: u8) -> u64 {
     value ^ (((-(set_value as i64) as u64) ^ value) & (1 << index))

src/vm/vm.rs

@@ -41,6 +41,9 @@ use std::sync::RwLock;
 use std::sync::RwLockWriteGuard;
 use std::sync::atomic::{AtomicUsize, AtomicBool, ATOMIC_BOOL_INIT, ATOMIC_USIZE_INIT, Ordering};
 
+use std;
+use utils::bit_utils::{bits_ones, u64_asr};
+
 // FIXME:
 // besides fields in VM, there are some 'globals' we need to persist
 // such as STRUCT_TAG_MAP
@@ -1410,14 +1413,12 @@ impl <'a> VM {
         unsafe {
             match val.v {
                 APIHandleValue::Int(ival, bits) => {
+                    let trunc: u64 = ival & bits_ones(bits);
                     match bits {
-                        1  => addr.store::<u8>((ival as u8) & 0b1u8),
-                        6  => addr.store::<u8>((ival as u8) & 0b111111u8),
-                        8  => addr.store::<u8>(ival as u8),
-                        16 => addr.store::<u16>(ival as u16),
-                        32 => addr.store::<u32>(ival as u32),
-                        52 => addr.store::<u64>(ival & ((1 << 51)-1)),
-                        64 => addr.store::<u64>(ival),
+                        1  ... 8   => addr.store::<u8>(trunc as u8),
+                        9  ... 16  => addr.store::<u16>(trunc as u16),
+                        17 ... 32  => addr.store::<u32>(trunc as u32),
+                        33 ... 64  => addr.store::<u64>(trunc as u64),
                         _  => panic!("unimplemented int length")
                     }
                 },
@@ -1653,7 +1654,7 @@ impl <'a> VM {
         self.new_handle(APIHandle {
             id: handle_id,
             v : APIHandleValue::Double(
-                value.v.as_tr64() as f64
+                unsafe { std::mem::transmute(value.v.as_tr64()) }
             )
         })
     }
@@ -1680,7 +1681,7 @@ impl <'a> VM {
             v : APIHandleValue::Ref(types::REF_VOID_TYPE.clone(),
                 unsafe { Address::from_usize(
                     ((opnd & 0x7ffffffffff8u64) |
-                        ((opnd & 0x8000000000000000u64) >> 16)) as usize
+                        u64_asr((opnd & 0x8000000000000000u64), 16)) as usize
                 ) })
         })
     }
@@ -1692,7 +1693,7 @@ impl <'a> VM {
         self.new_handle(APIHandle {
             id: handle_id,
             v : APIHandleValue::Int(
-                    (((opnd & 0x000f800000000000u64) >> 46) | ((opnd & 0x4) >> 2)),
+                    (u64_asr((opnd & 0x000f800000000000u64), 46) | (u64_asr((opnd & 0x4), 2))),
                 6
             )
         })
@@ -1701,7 +1702,7 @@ impl <'a> VM {
     // See: `fpToTr64`
     pub fn handle_tr64_from_fp(&self, value: APIHandleArg) -> APIHandleResult {
         let handle_id = self.next_id();
-        let double_bits = value.v.as_double() as u64;
+        let double_bits = unsafe { std::mem::transmute(value.v.as_double()) };
         
         let result_bits = if value.v.as_double().is_nan() {
             double_bits & 0xfff8000000000000u64 | 0x0000000000000008u64

tests/test_api/test_tr64.rs

@@ -18,6 +18,7 @@ use mu::ast::types::*;
 use mu::utils::Address;
 
 use std::f64;
+use std::mem::transmute;
 
 /**
  * Helper functions to test VM:: methods with literal values
@@ -97,7 +98,7 @@ fn test_other_bit_pattern_is_double() {
     assert!(vm.handle_tr64_is_fp(&tr64(0x123456789abcdef0u64)));
     assert!(vm.handle_tr64_is_fp(&tr64(0x7ff123456789abccu64)));
     assert!(vm.handle_tr64_is_fp(&tr64(0xfffffffffffffffcu64)));
-    assert!(vm.handle_tr64_is_fp(&tr64(3.1415927f64 as u64)));
+    unsafe { assert!(vm.handle_tr64_is_fp(&tr64(transmute(3.1415927f64)))); }
 }
 
 #[test]
@@ -114,11 +115,13 @@ fn test_encode_int() {
 fn test_encode_double() {
     let vm = VM::new();
     
-    assert_eq!(vm.handle_tr64_from_fp(&double(3.14_f64)).v.as_tr64(), 3.14_f64 as u64);
-    assert_eq!(vm.handle_tr64_from_fp(&double(-3.14_f64)).v.as_tr64(), -3.14_f64 as u64);
-    assert_eq!(vm.handle_tr64_from_fp(&double(f64::INFINITY)).v.as_tr64(), 0x7ff0000000000000u64);
-    assert_eq!(vm.handle_tr64_from_fp(&double(0x7ff123456789abcdu64 as f64)).v.as_tr64(), 0x7ff0000000000008u64);
-    assert!((vm.handle_tr64_from_fp(&double(0x7ff123456789abcdu64 as f64)).v.as_tr64() as f64).is_nan());
+    unsafe {
+        assert_eq!(vm.handle_tr64_from_fp(&double(3.14_f64)).v.as_tr64(), transmute(3.14_f64));
+        assert_eq!(vm.handle_tr64_from_fp(&double(-3.14_f64)).v.as_tr64(), transmute(-3.14_f64));
+        assert_eq!(vm.handle_tr64_from_fp(&double(f64::INFINITY)).v.as_tr64(), 0x7ff0000000000000u64);
+        assert_eq!(vm.handle_tr64_from_fp(&double(transmute(0x7ff123456789abcdu64))).v.as_tr64(), 0x7ff0000000000008u64);
+        assert!(transmute::<u64, f64>((vm.handle_tr64_from_fp(&double(transmute(0x7ff123456789abcdu64))).v.as_tr64())).is_nan());
+    }
 }
 
 #[test]
@@ -156,7 +159,7 @@ fn test_decode_tagref() {
     let vm = VM::new();
 
     assert_eq!(vm.handle_tr64_to_ref(&tr64(0x7ff0555555555552u64)).v.as_ref().1.as_usize() as u64, 0x555555555550u64);
-    assert_eq!(vm.handle_tr64_to_ref(&tr64(0xfff02aaaaaaaaaaau64)).v.as_ref().1.as_usize() as u64, 0x555555555550u64);
+    assert_eq!(vm.handle_tr64_to_ref(&tr64(0xfff02aaaaaaaaaaau64)).v.as_ref().1.as_usize() as u64, 0xffffaaaaaaaaaaa8u64);
     assert_eq!(vm.handle_tr64_to_tag(&tr64(0x7ff0555555555552u64)).v.as_int(), 0u64);
     assert_eq!(vm.handle_tr64_to_tag(&tr64(0x7fff800000000006u64)).v.as_int(), 0x3fu64);
     assert_eq!(vm.handle_tr64_to_tag(&tr64(0x7ffa800000000002u64)).v.as_int(), 0x2au64);