Cheri-research/cheri-cap-lib
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Move getLength to address length (not address length + 1), as we're explicitly saturating in order to express as a normal address.

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This commit is contained in:
Jonathan Woodruff
2025-02-04 16:31:01 +00:00
parent 3926b793bf
commit b3896e4e50
3 changed files with 6 additions and 6 deletions
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6
CHERICC_Fat.bsv
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@@ -346,7 +346,7 @@ function BoundsInfo#(CapAddrW) getBoundsInfoFat (CapFat cap, TempFields tf)
Bit #(TAdd #(MW, 2)) correctTop = {pack (tf.topCorrection), topBits};
// Get the length by subtracting base from top and shifting appropriately, and
// saturate in case of big exponent
CapAddrPlus1 length =
CapAddr length =
(exp >= resetExp) ? ~0 : zeroExtend (correctTop - correctBase) << exp;
// compute repBase
@@ -437,12 +437,12 @@ function CapAddrPlus1 getTopFat(CapFat cap, TempFields tf);
ret[valueOf(CapAddrW)] = ~ret[valueOf(CapAddrW)];
return ret;
endfunction
function CapAddrPlus1 getLengthFat(CapFat cap, TempFields tf);
function CapAddr getLengthFat(CapFat cap, TempFields tf);
// Get the top and base bits with the 2 correction bits prepended
Bit#(TAdd#(MW,2)) top = {pack(tf.topCorrection),cap.bounds.topBits};
Bit#(TAdd#(MW,2)) base = {pack(tf.baseCorrection),cap.bounds.baseBits};
// Get the length by substracting base from top and shifting appropriately
CapAddrPlus1 length = zeroExtend(top - base) << cap.bounds.exp;
CapAddr length = zeroExtend(top - base) << cap.bounds.exp;
// Return a saturated length in case of big exponent
// TODO: The saturation behaviour here is short of being correct
return (cap.bounds.exp >= resetExp) ? ~0 : length;