new shift ops for Nim; based on #4743

1 files changed, 48 insertions, 27 deletions

diff --git a/lib/system.nim b/lib/system.nim
index 564117573..405d93f50 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -868,29 +868,43 @@ when defined(nimnomagic64):
 else:
   proc `mod` *(x, y: int64): int64 {.magic: "ModI64", noSideEffect.}
 
-proc `shr` *(x, y: int): int {.magic: "ShrI", noSideEffect.}
-proc `shr` *(x, y: int8): int8 {.magic: "ShrI", noSideEffect.}
-proc `shr` *(x, y: int16): int16 {.magic: "ShrI", noSideEffect.}
-proc `shr` *(x, y: int32): int32 {.magic: "ShrI", noSideEffect.}
-proc `shr` *(x, y: int64): int64 {.magic: "ShrI", noSideEffect.}
-  ## computes the `shift right` operation of `x` and `y`, filling
-  ## vacant bit positions with zeros.
-  ##
-  ## .. code-block:: Nim
-  ##   0b0001_0000'i8 shr 2 == 0b0000_0100'i8
-  ##   0b1000_0000'i8 shr 8 == 0b0000_0000'i8
-  ##   0b0000_0001'i8 shr 1 == 0b0000_0000'i8
-
-proc `shl` *(x, y: int): int {.magic: "ShlI", noSideEffect.}
-proc `shl` *(x, y: int8): int8 {.magic: "ShlI", noSideEffect.}
-proc `shl` *(x, y: int16): int16 {.magic: "ShlI", noSideEffect.}
-proc `shl` *(x, y: int32): int32 {.magic: "ShlI", noSideEffect.}
-proc `shl` *(x, y: int64): int64 {.magic: "ShlI", noSideEffect.}
-  ## computes the `shift left` operation of `x` and `y`.
-  ##
-  ## .. code-block:: Nim
-  ##  1'i32 shl 4 == 0x0000_0010
-  ##  1'i64 shl 4 == 0x0000_0000_0000_0010
+when defined(nimNewShiftOps):
+  proc `shr` *(x: int, y: SomeInteger): int {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x: int8, y: SomeInteger): int8 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x: int16, y: SomeInteger): int16 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x: int32, y: SomeInteger): int32 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x: int64, y: SomeInteger): int64 {.magic: "ShrI", noSideEffect.}
+    ## computes the `shift right` operation of `x` and `y`, filling
+    ## vacant bit positions with zeros.
+    ##
+    ## .. code-block:: Nim
+    ##   0b0001_0000'i8 shr 2 == 0b0000_0100'i8
+    ##   0b1000_0000'i8 shr 8 == 0b0000_0000'i8
+    ##   0b0000_0001'i8 shr 1 == 0b0000_0000'i8
+
+
+  proc `shl` *(x: int, y: SomeInteger): int {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x: int8, y: SomeInteger): int8 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x: int16, y: SomeInteger): int16 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x: int32, y: SomeInteger): int32 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x: int64, y: SomeInteger): int64 {.magic: "ShlI", noSideEffect.}
+    ## computes the `shift left` operation of `x` and `y`.
+    ##
+    ## .. code-block:: Nim
+    ##  1'i32 shl 4 == 0x0000_0010
+    ##  1'i64 shl 4 == 0x0000_0000_0000_0010
+else:
+  proc `shr` *(x, y: int): int {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x, y: int8): int8 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x, y: int16): int16 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x, y: int32): int32 {.magic: "ShrI", noSideEffect.}
+  proc `shr` *(x, y: int64): int64 {.magic: "ShrI", noSideEffect.}
+
+  proc `shl` *(x, y: int): int {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x, y: int8): int8 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x, y: int16): int16 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x, y: int32): int32 {.magic: "ShlI", noSideEffect.}
+  proc `shl` *(x, y: int64): int64 {.magic: "ShlI", noSideEffect.}
 
 proc `and` *(x, y: int): int {.magic: "BitandI", noSideEffect.}
 proc `and` *(x, y: int8): int8 {.magic: "BitandI", noSideEffect.}
@@ -991,11 +1005,18 @@ proc `<%` *(x, y: int64): bool {.magic: "LtU64", noSideEffect.}
 proc `not`*[T: SomeUnsignedInt](x: T): T {.magic: "BitnotI", noSideEffect.}
   ## computes the `bitwise complement` of the integer `x`.
 
-proc `shr`*[T: SomeUnsignedInt](x, y: T): T {.magic: "ShrI", noSideEffect.}
-  ## computes the `shift right` operation of `x` and `y`.
+when defined(nimNewShiftOps):
+  proc `shr`*[T: SomeUnsignedInt](x: T, y: SomeInteger): T {.magic: "ShrI", noSideEffect.}
+    ## computes the `shift right` operation of `x` and `y`.
+
+  proc `shl`*[T: SomeUnsignedInt](x: T, y: SomeInteger): T {.magic: "ShlI", noSideEffect.}
+    ## computes the `shift left` operation of `x` and `y`.
+else:
+  proc `shr`*[T: SomeUnsignedInt](x, y: T): T {.magic: "ShrI", noSideEffect.}
+    ## computes the `shift right` operation of `x` and `y`.
 
-proc `shl`*[T: SomeUnsignedInt](x, y: T): T {.magic: "ShlI", noSideEffect.}
-  ## computes the `shift left` operation of `x` and `y`.
+  proc `shl`*[T: SomeUnsignedInt](x, y: T): T {.magic: "ShlI", noSideEffect.}
+    ## computes the `shift left` operation of `x` and `y`.
 
 proc `and`*[T: SomeUnsignedInt](x, y: T): T {.magic: "BitandI", noSideEffect.}
   ## computes the `bitwise and` of numbers `x` and `y`.