fixes nim-lang#12783 [backport] (nim-lang#12810)

* fixes nim-lang#12783 * Trigger build
narimiran · Dec 5, 2019 · 9b0e874 · 9b0e874
1 parent 26074f5
commit 9b0e874
Showing 1 changed file with 3 additions and 6 deletions.
diff --git a/compiler/int128.nim b/compiler/int128.nim
@@ -335,7 +335,6 @@ proc `*`(a: Int128, b: uint32): Int128 =
   result.udata[3] = cast[uint32](tmp3) + cast[uint32](tmp2 shr 32)
 
 proc `*`*(a: Int128, b: int32): Int128 =
-  let isNegative = isNegative(a) xor isNegative(b)
   result = a * cast[uint32](abs(b))
   if b < 0:
     result = -result
@@ -356,8 +355,6 @@ proc low64(a: Int128): uint64 =
   bitconcat(a.udata[1], a.udata[0])
 
 proc `*`*(lhs,rhs: Int128): Int128 =
-  let isNegative = isNegative(lhs) xor isNegative(rhs)
-
   let
     a = cast[uint64](lhs.udata[0])
     b = cast[uint64](lhs.udata[1])
@@ -379,9 +376,6 @@ proc `*`*(lhs,rhs: Int128): Int128 =
   result = result + toInt128(a32 * b00) shl 32
   result = result + toInt128(a00 * b32) shl 32
 
-  if isNegative != isNegative(result):
-    assert(false, "overflow")
-
 proc `*=`*(a: var Int128, b: Int128) =
   a = a * b
 
@@ -684,6 +678,9 @@ when isMainModule:
   var ma = 100'i64
   var mb = 13
 
+  doAssert toInt128(ma) * toInt128(0) == toInt128(0)
+  doAssert toInt128(-ma) * toInt128(0) == toInt128(0)
+
   # sign correctness
   doAssert divMod(toInt128( ma),toInt128( mb)) == (toInt128( ma div  mb), toInt128( ma mod  mb))
   doAssert divMod(toInt128(-ma),toInt128( mb)) == (toInt128(-ma div  mb), toInt128(-ma mod  mb))