fix addOne/subOne for SVInt

Signed-off-by: adream307 <[email protected]>
MikePopoloski · Mar 12, 2023 · 89cebd0 · 89cebd0
1 parent d9c8300
commit 89cebd0
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diff --git a/source/numeric/SVIntHelpers.h b/source/numeric/SVIntHelpers.h
@@ -217,6 +217,8 @@ static bool addOne(uint64_t* dst, uint64_t* src, uint32_t len, uint64_t value) {
 
         if (!carry)
             break;
+
+        value = 0;
     }
     return carry;
 }
@@ -231,6 +233,8 @@ static bool subOne(uint64_t* dst, uint64_t* src, uint32_t len, uint64_t value) {
 
         if (!borrow)
             break;
+
+        value = 0;
     }
     return borrow;
 }

diff --git a/tests/unittests/NumericTests.cpp b/tests/unittests/NumericTests.cpp
@@ -342,6 +342,14 @@ TEST_CASE("Arithmetic") {
     CHECK(v8 == 2);
 
     CHECK_THAT(-SVInt(logic_t::z), exactlyEquals(SVInt(logic_t::x)));
+
+    SVInt v9 = "193'hFFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF"_si;
+    v9++;
+    CHECK(v9 == "193'h1_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000"_si);
+
+    SVInt v10 = "193'h1_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000"_si;
+    v10--;
+    CHECK(v10 == "193'hFFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF"_si);
 }
 
 void testDiv(const SVInt& a, const SVInt& b, const SVInt& c) {