Add signed word iteration

src/private/as_signed_words.nim

@@ -0,0 +1,134 @@
+# Mpint
+# Copyright 2018 Status Research & Development GmbH
+# Licensed under either of
+#
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+#
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+import  ./datatypes, macros, as_words
+
+proc optimInt*(x: NimNode): NimNode =
+  let size = getSize(x)
+
+  if size > 64:
+    result = quote do:
+      # We represent as unsigned int. Signedness will be managed at a higher level.
+      array[`size` div 64, uint64]
+  elif size == 64:
+    result = quote do:
+      int64
+  elif size == 32:
+    result = quote do:
+      int32
+  elif size == 16:
+    result = quote do:
+      int16
+  elif size == 8:
+    result = quote do:
+      int8
+  else:
+    error "Unreachable path reached"
+
+proc isInt*(x: NimNode): static[bool] =
+  if eqIdent(x, "int64"):   true
+  elif eqIdent(x, "int32"): true
+  elif eqIdent(x, "int16"): true
+  elif eqIdent(x, "int8"):  true
+  else: false
+
+macro most_significant_word*(x: IntImpl): untyped =
+
+  let optim_type = optimInt(x)
+  if optim_type.isInt:
+    result = quote do:
+      cast[`optim_type`](`x`)
+  else:
+    when system.cpuEndian == littleEndian:
+      let size = getSize(x)
+      let msw_pos = size - 1
+    else:
+      let msw_pos = 0
+    result = quote do:
+      cast[`optim_type`](`x`)[`msw_pos`]
+
+macro asSignedWordsZip*[T](
+  x, y: IntImpl[T],
+  loopBody: untyped): untyped =
+  ## Iterates over x and y, as an array of words.
+  ## Input:
+  ##   - x, y: The multiprecision ints
+  ##   - loopBody: the operation you want to do.
+  ##               For the most significant word,
+  ##               the operation will be sign aware.
+  ##               for the next words it will ignore sign.
+  ## Iteration is always done from most significant to least significant
+  let
+    optim_type = optimInt(x)
+    idx = ident("idx_asSignedWordsRawZip")
+  var
+    first_x, first_y: NimNode
+    next_x, next_y: NimNode
+    to_replace = nnkBracket.newTree
+    replacing  = nnkBracket.newTree
+
+  to_replace.add x
+  to_replace.add y
+
+  # We directly cast the first x and y if the result fits in a word
+  # Otherwise we special case the most significant word
+  if optim_type.isInt:
+    first_x = quote do:
+      cast[`optim_type`](`x`)
+    first_y = quote do:
+      cast[`optim_type`](`y`)
+  else:
+    first_x = getAST(most_significant_word(x))
+    first_y = getAST(most_significant_word(y))
+
+  replacing.add first_x
+  replacing.add first_y
+
+  let firstReplacedAST = replaceNodes(loopBody, replacing, to_replace)
+
+  # Reset the replacement array
+  replacing = nnkBracket.newTree
+
+  # Setup the loop variables
+  next_x = ident("x_asSignedWordsRawZip")
+  next_y = ident("y_asSignedWordsRawZip")
+
+  # We replace the inner loop with the next_x[idx]
+  replacing.add quote do:
+    `next_x`[`idx`]
+  replacing.add quote do:
+    `next_y`[`idx`]
+
+  let nextReplacedAST = replaceNodes(loopBody, replacing, to_replace)
+
+  # Result:
+  result = newStmtList()
+  result.add firstReplacedAST
+
+  if not optim_type.isInt:
+    # if we have multiple iterations to do
+    if system.cpuEndian == bigEndian:
+      result = quote do:
+        {.pragma: restrict, codegenDecl: "$# __restrict__ $#".}
+        let
+          `next_x`{.restrict.} = cast[ptr `optim_type`](`x`.unsafeaddr)
+          `next_y`{.restrict.} = cast[ptr `optim_type`](`y`.unsafeaddr)
+        for `idx` in 1 ..< `next_x`[].len:
+          # We start from the second word
+          `nextReplacedAST`
+    else:
+      # Little-Endian, iteration in reverse
+      result = quote do:
+        {.pragma: restrict, codegenDecl: "$# __restrict__ $#".}
+        let
+          `next_x`{.restrict.} = cast[ptr `optim_type`](`x`.unsafeaddr)
+          `next_y`{.restrict.} = cast[ptr `optim_type`](`y`.unsafeaddr)
+        for `idx` in countdown(`next_x`[].len - 2, 0):
+          # We stop stop at the second to last word
+          `nextReplacedAST`

src/private/as_words.nim

@@ -9,7 +9,7 @@
 
 import  ./datatypes, macros
 
-proc optim(x: NimNode): NimNode =
+proc optimUint(x: NimNode): NimNode =
   let size = getSize(x)
 
   if size > 64:
@@ -37,22 +37,7 @@ proc isUint(x: NimNode): static[bool] =
   elif eqIdent(x, "uint8"):  true
   else: false
 
-macro most_significant_word*(x: IntImpl): untyped =
-
-  let optim_type = optim(x)
-  if optim_type.isUint:
-    result = quote do:
-      cast[`optim_type`](`x`)
-  else:
-    when system.cpuEndian == littleEndian:
-      let size = getSize(x)
-      let msw_pos = size - 1
-    else:
-      let msw_pos = 0
-    result = quote do:
-      cast[`optim_type`](`x`)[`msw_pos`]
-
-proc replaceNodes(ast: NimNode, replacing: NimNode, to_replace: NimNode): NimNode =
+proc replaceNodes*(ast: NimNode, replacing: NimNode, to_replace: NimNode): NimNode =
   # Args:
   #   - The full syntax tree
   #   - an array of replacement value
@@ -75,14 +60,16 @@ proc replaceNodes(ast: NimNode, replacing: NimNode, to_replace: NimNode): NimNod
       return rTree
   result = inspect(ast)
 
-macro asWords*[T](n: UintImpl[T], ignoreEndianness: static[bool], loopBody: untyped): untyped =
+macro asWords*(n: UintImpl or IntImpl, ignoreEndianness: static[bool], loopBody: untyped): untyped =
   ## Iterates over n, as an array of words.
   ## Input:
   ##   - n: The Multiprecision int
-  ##   - body: the operation you want to do on each word of n
-  ## If iteration is needed, it is done from low to high, not taking endianness in account
+  ##   - If endianness should be taken into account for iteratio order.
+  ##     If yes, iteration is done from most significant word to least significant.
+  ##     Otherwise it is done in memory layout order.
+  ##   - loopBody: the operation you want to do on each word of n
   let
-    optim_type = optim(n)
+    optim_type = optimUint(n)
   var
     inner_n: NimNode
     to_replace = nnkBracket.newTree
@@ -111,13 +98,16 @@ macro asWords*[T](n: UintImpl[T], ignoreEndianness: static[bool], loopBody: unty
     else:
       assert false, "Not implemented"
 
-macro asWordsZip*[T](x, y: UintImpl[T], ignoreEndianness: static[bool], loopBody: untyped): untyped =
+macro asWordsZip*(x, y: UintImpl or IntImpl, ignoreEndianness: static[bool], loopBody: untyped): untyped =
   ## Iterates over x and y, as an array of words.
   ## Input:
   ##   - x, y: The multiprecision ints
-  ## If iteration is needed, it is done from low to high, not taking endianness in account
+  ##   - If endianness should be taken into account for iteratio order.
+  ##     If yes, iteration is done from most significant word to least significant.
+  ##     Otherwise it is done in memory layout order.
+  ##   - loopBody: the operation you want to do on each word of n
   let
-    optim_type = optim(x)
+    optim_type = optimUint(x)
     idx = ident("idx_asWordsRawZip")
   var
     inner_x, inner_y: NimNode
@@ -170,15 +160,19 @@ macro asWordsZip*[T](x, y: UintImpl[T], ignoreEndianness: static[bool], loopBody
         for `idx` in countdown(`inner_x`[].len - 1, 0):
           `replacedAST`
 
-macro m_asWordsZip*[T](m: var UintImpl[T], x: UintImpl[T], ignoreEndianness: static[bool], loopBody: untyped): untyped =
+macro m_asWordsZip*[T: UintImpl or IntImpl](m: var T, x: T,
+  ignoreEndianness: static[bool], loopBody: untyped): untyped =
   ## Iterates over a mutable int m and x as an array of words.
   ## returning a !! Pointer !! of the proper type to m.
   ## Input:
   ##   - m: A mutable array
   ##   - x: The multiprecision ints
-  ## Iteration is done from low to high, not taking endianness in account
+  ##   - If endianness should be taken into account for iteratio order.
+  ##     If yes, iteration is done from most significant word to least significant.
+  ##     Otherwise it is done in memory layout order.
+  ##   - loopBody: the operation you want to do on each word of n
   let
-    optim_type = optim(x)
+    optim_type = optimUint(x)
     idx = ident("idx_asWordsRawZip")
   var
     inner_m, inner_x: NimNode
@@ -232,15 +226,19 @@ macro m_asWordsZip*[T](m: var UintImpl[T], x: UintImpl[T], ignoreEndianness: sta
           `replacedAST`
 
 
-macro m_asWordsZip*[T](m: var UintImpl[T], x, y: UintImpl[T], ignoreEndianness: static[bool], loopBody: untyped): untyped =
+macro m_asWordsZip*[T: UintImpl or IntImpl](m: var T, x, y: T,
+  ignoreEndianness: static[bool], loopBody: untyped): untyped =
   ## Iterates over a mutable int m and x as an array of words.
   ## returning a !! Pointer !! of the proper type to m.
   ## Input:
   ##   - m: A mutable array
   ##   - x: The multiprecision ints
-  ## Iteration is done from low to high, not taking endianness in account
+  ##   - If endianness should be taken into account for iteratio order.
+  ##     If yes, iteration is done from most significant word to least significant.
+  ##     Otherwise it is done in memory layout order.
+  ##   - loopBody: the operation you want to do on each word of n
   let
-    optim_type = optim(x)
+    optim_type = optimUint(x)
     idx = ident("idx_asWordsRawZip")
   var
     inner_m, inner_x, inner_y: NimNode

src/private/bithacks.nim

@@ -7,7 +7,7 @@
 #
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-import  ./datatypes, stdlib_bitops, as_words
+import  ./datatypes, stdlib_bitops, as_signed_words
 export stdlib_bitops
 
 # We reuse bitops from Nim standard lib, and expand it for multi-precision int.

src/private/int_comparison.nim

@@ -7,7 +7,7 @@
 #
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-import  ./datatypes, ./bithacks, ./as_words,
+import  ./datatypes, ./bithacks, ./as_words, ./as_signed_words,
         ./bithacks
 
 func isZero*(n: SomeSignedInt): bool {.inline.} =
@@ -22,3 +22,24 @@ func isZero*(n: IntImpl): bool {.inline.} =
 func isNegative*(n: IntImpl): bool {.inline.} =
   ## Returns true if a number is negative:
   n.msb.bool
+
+func `<`*(x, y: IntImpl): bool {.inline.}=
+  # Lower comparison for multi-precision integers
+  asSignedWordsZip(x, y):
+    if x != y:
+      return x < y
+  return false # they're equal
+
+func `==`*(x, y: UintImpl): bool {.inline.}=
+  # Equal comparison for multi-precision integers
+  asWordsZip(x, y, ignoreEndianness = true):
+    if x != y:
+      return false
+  return true # they're equal
+
+func `<=`*(x, y: UintImpl): bool {.inline.}=
+  # Lower or equal comparison for multi-precision integers
+  asSignedWordsZip(x, y):
+    if x != y:
+      return x < y
+  return true # they're equal

tests/all_tests.nim

@@ -7,8 +7,8 @@
 #
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-import  test_endianness,
-        test_comparison,
-        test_bitwise,
-        test_addsub,
-        test_muldiv
+import  test_uint_endianness,
+        test_uint_comparison,
+        test_uint_bitwise,
+        test_uint_addsub,
+        test_uint_muldiv