X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fprelude%2Fprimops.txt.pp;h=adb2e110ff8ced4fc4348f767daa93185a37c4bf;hb=9d03becc597e5b1ab6c8466209a1263bf8ba6f29;hp=57abb7d3c76826eef26794388fa3ff08c03ccb14;hpb=493d09b47e4d4faec4f0696d071e3b7f4e7b84ea;p=ghc-hetmet.git

diff --git a/compiler/prelude/primops.txt.pp b/compiler/prelude/primops.txt.pp
index 57abb7d..adb2e11 100644
--- a/compiler/prelude/primops.txt.pp
+++ b/compiler/prelude/primops.txt.pp
@@ -618,6 +618,13 @@ primop   DoubleDecodeOp   "decodeDouble#" GenPrimOp
     represent an {\tt Integer\#} holding the mantissa.}
    with out_of_line = True
 
+primop   DoubleDecode_2IntOp   "decodeDouble_2Int#" GenPrimOp    
+   Double# -> (# Int#, Int#, Int# #)
+   {Convert to arbitrary-precision integer.
+    First {\tt Int\#} in result is the high 32 bits of the mantissa, and the
+    second is the low 32. The third is the exponent.}
+   with out_of_line = True
+
 ------------------------------------------------------------------------
 section "Float#" 
 	{Operations on single-precision (32-bit) floating-point numbers.}
@@ -724,6 +731,12 @@ primop   FloatDecodeOp   "decodeFloat#" GenPrimOp
     represent an {\tt Integer\#} holding the mantissa.}
    with out_of_line = True
 
+primop   FloatDecode_IntOp   "decodeFloat_Int#" GenPrimOp
+   Float# -> (# Int#, Int# #)
+   {Convert to arbitrary-precision integer.
+    First {\tt Int\#} in result is the mantissa; second is the exponent.}
+   with out_of_line = True
+
 ------------------------------------------------------------------------
 section "Arrays"
 	{Operations on {\tt Array\#}.}
@@ -1795,7 +1808,14 @@ pseudoop   "unsafeCoerce#"
            known to be empty.  Also, a {\tt newtype} of a type {\tt T} has the same representation
            at runtime as {\tt T}.
 
-        Other uses of {\tt unsafeCoerce\#} are undefined.
+        Other uses of {\tt unsafeCoerce\#} are undefined.  In particular, you should not use
+	{\tt unsafeCoerce\#} to cast a T to an algebraic data type D, unless T is also
+	an algebraic data type.  For example, do not cast {\tt Int->Int} to {\tt Bool}, even if
+        you later cast that {\tt Bool} back to {\tt Int->Int} before applying it.  The reasons
+        have to do with GHC's internal representation details (for the congnoscenti, data values
+	can be entered but function closures cannot).  If you want a safe type to cast things
+	to, use {\tt Any}, which is not an algebraic data type.
+	
         }
 
 -- NB. It is tempting to think that casting a value to a type that it doesn't have is safe