1 files changed, 69 insertions, 0 deletions
diff --git a/lib/mono_rewrites.sail b/lib/mono_rewrites.sail
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+++ b/lib/mono_rewrites.sail
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+(* Definitions for use with the -mono_rewrites option *)
+
+(* External definitions not in the usual asl prelude *)
+
+val "shiftleft" : forall 'n 'o ('ord : Order).
+    (vector('o, 'n, 'ord, bit), int) -> vector('o, 'n, 'ord, bit) effect pure
+
+overload operator << = {shiftleft}
+
+val "shiftright" : forall 'n 'o ('ord : Order).
+    (vector('o, 'n, 'ord, bit), int) -> vector('o, 'n, 'ord, bit) effect pure
+
+overload operator >> = {shiftright}
+
+val "extz" : forall 'n 'm 'o 'p. (atom('p),atom('m),vector('o, 'n, dec, bit)) -> vector('p, 'm, dec, bit) effect pure
+val extzv : forall 'n 'm 'o 'p. vector('o, 'n, dec, bit) -> vector('p, 'm, dec, bit) effect pure
+function extzv(v) = extz(sizeof('p), sizeof('m),v)
+
+(* Definitions for the rewrites *)
+
+val slice_mask : forall 'n, 'n >= 0. (int, int) -> bits('n) effect pure
+function slice_mask(i,l) =
+  let one : bits('n) = extzv(0b1) in
+  ((one << l) - one) << i
+
+val is_zero_subrange : forall 'n, 'n >= 0.
+  (bits('n), int, int) -> bool effect pure
+
+function is_zero_subrange (xs, i, j) = {
+  (xs & slice_mask(j, i-j)) == extzv(0b0)
+}
+
+val is_ones_subrange : forall 'n, 'n >= 0.
+  (bits('n), int, int) -> bool effect pure
+
+function is_ones_subrange (xs, i, j) = {
+  let m : bits('n) = slice_mask(j,j-i) in
+  (xs & m) == m
+}
+
+val slice_slice_concat : forall 'n 'm 'p 'q 'r, 'r = 'p + 'q & 'n >= 0 & 'm >= 0 & 'p >= 0 & 'q >= 0.
+  (bits('n), int, atom('p), bits('m), int, atom('q)) -> bits('r) effect pure
+
+function slice_slice_concat (xs, i, l, ys, i', l') = {
+  let xs = (xs & slice_mask(i,l)) >> i in
+  let ys = (ys & slice_mask(i',l')) >> i' in
+  extzv(xs) << l' | extzv(ys)
+}
+
+(* Assumes initial vectors are of equal size *)
+
+val subrange_subrange_eq : forall 'n, 'n >= 0.
+  (bits('n), int, int, bits('n), int, int) -> bool effect pure
+
+function subrange_subrange_eq (xs, i, j, ys, i', j') = {
+  let xs = (xs & slice_mask(j,i-j)) >> j in
+  let ys = (ys & slice_mask(j',i'-j')) >> j' in
+  xs == ys
+}
+
+val subrange_subrange_concat : forall 'n 'o 'p 'm 'q 'r 's, 's = 'o - ('p - 1) + 'q - ('r - 1) & 'n >= 0 & 'm >= 0.
+  (bits('n), atom('o), atom('p), bits('m), atom('q), atom('r)) -> bits('s) effect pure
+
+function subrange_subrange_concat (xs, i, j, ys, i', j') = {
+  let xs = (xs & slice_mask(j,i-j)) >> j in
+  let ys = (ys & slice_mask(j',i'-j')) >> j' in
+  extzv(xs) << i' - (j' - 1) | extzv(ys)
+}
+