Assign more accurate code sizes to primops, so that the inlining

heuristics work better.  Also removed the old unused "needs_wrapper"
predicate for primops.  This helps with #4978.

9 files changed, 111 insertions, 79 deletions

diff --git a/compiler/coreSyn/CoreUnfold.lhs b/compiler/coreSyn/CoreUnfold.lhs
index da703efafe..6a737161d3 100644
--- a/compiler/coreSyn/CoreUnfold.lhs
+++ b/compiler/coreSyn/CoreUnfold.lhs
@@ -585,19 +585,11 @@ didn't adopt the idea.
 \begin{code}
 primOpSize :: PrimOp -> Int -> ExprSize
 primOpSize op n_val_args
- | not (primOpIsDupable op) = sizeN opt_UF_DearOp
- | not (primOpOutOfLine op) = sizeN 1
-	-- Be very keen to inline simple primops.
-	-- We give a discount of 1 for each arg so that (op# x y z) costs 2.
-	-- We can't make it cost 1, else we'll inline let v = (op# x y z) 
-	-- at every use of v, which is excessive.
-	--
-	-- A good example is:
-	--	let x = +# p q in C {x}
-	-- Even though x get's an occurrence of 'many', its RHS looks cheap,
-	-- and there's a good chance it'll get inlined back into C's RHS. Urgh!
-
- | otherwise = sizeN n_val_args
+ = if primOpOutOfLine op
+      then sizeN (op_size + n_val_args)
+      else sizeN op_size
+ where
+   op_size = primOpCodeSize op
 
 
 buildSize :: ExprSize
diff --git a/compiler/ghc.mk b/compiler/ghc.mk
index 2254332eb7..8ed34c3136 100644
--- a/compiler/ghc.mk
+++ b/compiler/ghc.mk
@@ -252,7 +252,7 @@ PRIMOP_BITS = compiler/primop-data-decl.hs-incl        \
               compiler/primop-has-side-effects.hs-incl \
               compiler/primop-out-of-line.hs-incl      \
               compiler/primop-commutable.hs-incl       \
-              compiler/primop-needs-wrapper.hs-incl    \
+              compiler/primop-code-size.hs-incl        \
               compiler/primop-can-fail.hs-incl         \
               compiler/primop-strictness.hs-incl       \
               compiler/primop-primop-info.hs-incl
@@ -278,8 +278,8 @@ compiler/primop-out-of-line.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
 	"$(GENPRIMOP_INPLACE)" --out-of-line        < $< > $@
 compiler/primop-commutable.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
 	"$(GENPRIMOP_INPLACE)" --commutable         < $< > $@
-compiler/primop-needs-wrapper.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
-	"$(GENPRIMOP_INPLACE)" --needs-wrapper      < $< > $@
+compiler/primop-code-size.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
+	"$(GENPRIMOP_INPLACE)" --code-size          < $< > $@
 compiler/primop-can-fail.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
 	"$(GENPRIMOP_INPLACE)" --can-fail           < $< > $@
 compiler/primop-strictness.hs-incl: $(PRIMOPS_TXT) $(GENPRIMOP_INPLACE)
diff --git a/compiler/prelude/PrimOp.lhs b/compiler/prelude/PrimOp.lhs
index 8c532ffc86..29c5644346 100644
--- a/compiler/prelude/PrimOp.lhs
+++ b/compiler/prelude/PrimOp.lhs
@@ -18,8 +18,8 @@ module PrimOp (
 
 	tagToEnumKey,
 
-	primOpOutOfLine, primOpNeedsWrapper, 
-	primOpOkForSpeculation, primOpIsCheap, primOpIsDupable,
+        primOpOutOfLine, primOpCodeSize,
+        primOpOkForSpeculation, primOpIsCheap,
 
 	getPrimOpResultInfo,  PrimOpResultInfo(..),
 
@@ -363,18 +363,23 @@ primOpIsCheap op = primOpOkForSpeculation op
 -- even if primOpIsCheap sometimes says 'True'.
 \end{code}
 
-primOpIsDupable
-~~~~~~~~~~~~~~~
-primOpIsDupable means that the use of the primop is small enough to
-duplicate into different case branches.  See CoreUtils.exprIsDupable.
+primOpCodeSize
+~~~~~~~~~~~~~~
+Gives an indication of the code size of a primop, for the purposes of
+calculating unfolding sizes; see CoreUnfold.sizeExpr.
 
 \begin{code}
-primOpIsDupable :: PrimOp -> Bool
-	-- See comments with CoreUtils.exprIsDupable
-	-- We say it's dupable it isn't implemented by a C call with a wrapper
-primOpIsDupable op = not (primOpNeedsWrapper op)
-\end{code}
+primOpCodeSize :: PrimOp -> Int
+#include "primop-code-size.hs-incl"
+
+primOpCodeSizeDefault :: Int
+primOpCodeSizeDefault = 1
+  -- CoreUnfold.primOpSize already takes into account primOpOutOfLine
+  -- and adds some further costs for the args in that case.
 
+primOpCodeSizeForeignCall :: Int
+primOpCodeSizeForeignCall = 4
+\end{code}
 
 \begin{code}
 primOpCanFail :: PrimOp -> Bool
@@ -421,14 +426,6 @@ primOpHasSideEffects :: PrimOp -> Bool
 #include "primop-has-side-effects.hs-incl"
 \end{code}
 
-Inline primitive operations that perform calls need wrappers to save
-any live variables that are stored in caller-saves registers.
-
-\begin{code}
-primOpNeedsWrapper :: PrimOp -> Bool
-#include "primop-needs-wrapper.hs-incl"
-\end{code}
-
 \begin{code}
 primOpType :: PrimOp -> Type  -- you may want to use primOpSig instead
 primOpType op
diff --git a/compiler/prelude/primops.txt.pp b/compiler/prelude/primops.txt.pp
index 69a12745fb..4dfe0195a9 100644
--- a/compiler/prelude/primops.txt.pp
+++ b/compiler/prelude/primops.txt.pp
@@ -43,7 +43,7 @@ defaults
    has_side_effects = False
    out_of_line      = False
    commutable       = False
-   needs_wrapper    = False
+   code_size        = { primOpCodeSizeDefault }
    can_fail         = False
    strictness       = { \ arity -> mkStrictSig (mkTopDmdType (replicate arity lazyDmd) TopRes) }
 
@@ -155,6 +155,7 @@ primop   CharLtOp  "ltChar#"   Compare   Char# -> Char# -> Bool
 primop   CharLeOp  "leChar#"   Compare   Char# -> Char# -> Bool
 
 primop   OrdOp   "ord#"  GenPrimOp   Char# -> Int#
+   with code_size = 0
 
 ------------------------------------------------------------------------
 section "Int#"
@@ -212,9 +213,12 @@ primop   IntNegOp    "negateInt#"    Monadic   Int# -> Int#
 primop   IntAddCOp   "addIntC#"    GenPrimOp   Int# -> Int# -> (# Int#, Int# #)
 	 {Add with carry.  First member of result is (wrapped) sum; 
           second member is 0 iff no overflow occured.}
+   with code_size = 2
+
 primop   IntSubCOp   "subIntC#"    GenPrimOp   Int# -> Int# -> (# Int#, Int# #)
 	 {Subtract with carry.  First member of result is (wrapped) difference; 
           second member is 0 iff no overflow occured.}
+   with code_size = 2
 
 primop   IntGtOp  ">#"   Compare   Int# -> Int# -> Bool
 primop   IntGeOp  ">=#"   Compare   Int# -> Int# -> Bool
@@ -231,8 +235,11 @@ primop   IntLtOp  "<#"   Compare   Int# -> Int# -> Bool
 primop   IntLeOp  "<=#"   Compare   Int# -> Int# -> Bool
 
 primop   ChrOp   "chr#"   GenPrimOp   Int# -> Char#
+   with code_size = 0
 
 primop   Int2WordOp "int2Word#" GenPrimOp Int# -> Word#
+   with code_size = 0
+
 primop   Int2FloatOp   "int2Float#"      GenPrimOp  Int# -> Float#
 primop   Int2DoubleOp   "int2Double#"          GenPrimOp  Int# -> Double#
 
@@ -286,6 +293,7 @@ primop   SrlOp   "uncheckedShiftRL#"   GenPrimOp   Word# -> Int# -> Word#
           in the range 0 to word size - 1 inclusive.}
 
 primop   Word2IntOp   "word2Int#"   GenPrimOp   Word# -> Int#
+   with code_size = 0
 
 primop   WordGtOp   "gtWord#"   Compare   Word# -> Word# -> Bool
 primop   WordGeOp   "geWord#"   Compare   Word# -> Word# -> Bool
@@ -396,63 +404,72 @@ primop   Double2FloatOp   "double2Float#" GenPrimOp Double# -> Float#
 
 primop   DoubleExpOp   "expDouble#"      Monadic
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleLogOp   "logDouble#"      Monadic         
    Double# -> Double#
    with
-   needs_wrapper = True
+   code_size = { primOpCodeSizeForeignCall }
    can_fail = True
 
 primop   DoubleSqrtOp   "sqrtDouble#"      Monadic  
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleSinOp   "sinDouble#"      Monadic          
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleCosOp   "cosDouble#"      Monadic          
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleTanOp   "tanDouble#"      Monadic          
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleAsinOp   "asinDouble#"      Monadic 
    Double# -> Double#
    with
-   needs_wrapper = True
+   code_size = { primOpCodeSizeForeignCall }
    can_fail = True
 
 primop   DoubleAcosOp   "acosDouble#"      Monadic  
    Double# -> Double#
    with
-   needs_wrapper = True
+   code_size = { primOpCodeSizeForeignCall }
    can_fail = True
 
 primop   DoubleAtanOp   "atanDouble#"      Monadic  
    Double# -> Double#
    with
-   needs_wrapper = True
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleSinhOp   "sinhDouble#"      Monadic  
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleCoshOp   "coshDouble#"      Monadic  
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleTanhOp   "tanhDouble#"      Monadic  
    Double# -> Double#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoublePowerOp   "**##" Dyadic  
    Double# -> Double# -> Double#
    {Exponentiation.}
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   DoubleDecode_2IntOp   "decodeDouble_2Int#" GenPrimOp    
    Double# -> (# Int#, Word#, Word#, Int# #)
@@ -506,58 +523,71 @@ primop   Float2IntOp   "float2Int#"      GenPrimOp  Float# -> Int#
 
 primop   FloatExpOp   "expFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatLogOp   "logFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
-        can_fail = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
+   can_fail = True
 
 primop   FloatSqrtOp   "sqrtFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatSinOp   "sinFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatCosOp   "cosFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatTanOp   "tanFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatAsinOp   "asinFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
-        can_fail = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
+   can_fail = True
 
 primop   FloatAcosOp   "acosFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
-        can_fail = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
+   can_fail = True
 
 primop   FloatAtanOp   "atanFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatSinhOp   "sinhFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatCoshOp   "coshFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatTanhOp   "tanhFloat#"      Monadic          
    Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   FloatPowerOp   "powerFloat#"      Dyadic   
    Float# -> Float# -> Float#
-   with needs_wrapper = True
+   with
+   code_size = { primOpCodeSizeForeignCall }
 
 primop   Float2DoubleOp   "float2Double#" GenPrimOp  Float# -> Double#
 
@@ -599,6 +629,7 @@ primop  WriteArrayOp "writeArray#" GenPrimOp
    {Write to specified index of mutable array.}
    with
    has_side_effects = True
+   code_size = 2 -- card update too
 
 primop  SizeofArrayOp "sizeofArray#" GenPrimOp
    Array# a -> Int#
@@ -633,6 +664,7 @@ primop  CopyArrayOp "copyArray#" GenPrimOp
    The two arrays must not be the same array in different states, but this is not checked either.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 primop  CopyMutableArrayOp "copyMutableArray#" GenPrimOp
   MutableArray# s a -> Int# -> MutableArray# s a -> Int# -> Int# -> State# s -> State# s
@@ -640,6 +672,7 @@ primop  CopyMutableArrayOp "copyMutableArray#" GenPrimOp
    Both arrays must fully contain the specified ranges, but this is not checked.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 primop  CloneArrayOp "cloneArray#" GenPrimOp
   Array# a -> Int# -> Int# -> Array# a
@@ -647,6 +680,7 @@ primop  CloneArrayOp "cloneArray#" GenPrimOp
    The provided Array# should contain the full subrange specified by the two Int#s, but this is not checked.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 primop  CloneMutableArrayOp "cloneMutableArray#" GenPrimOp
   MutableArray# s a -> Int# -> Int# -> State# s -> (# State# s, MutableArray# s a #)
@@ -654,6 +688,7 @@ primop  CloneMutableArrayOp "cloneMutableArray#" GenPrimOp
    The provided MutableArray# should contain the full subrange specified by the two Int#s, but this is not checked.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 primop  FreezeArrayOp "freezeArray#" GenPrimOp
   MutableArray# s a -> Int# -> Int# -> State# s -> (# State# s, Array# a #)
@@ -661,6 +696,7 @@ primop  FreezeArrayOp "freezeArray#" GenPrimOp
    The provided MutableArray# should contain the full subrange specified by the two Int#s, but this is not checked.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 primop  ThawArrayOp "thawArray#" GenPrimOp
   Array# a -> Int# -> Int# -> State# s -> (# State# s, MutableArray# s a #)
@@ -668,6 +704,7 @@ primop  ThawArrayOp "thawArray#" GenPrimOp
    The provided Array# should contain the full subrange specified by the two Int#s, but this is not checked.}
   with
   has_side_effects = True
+  code_size = { primOpCodeSizeForeignCall + 4 }
 
 ------------------------------------------------------------------------
 section "Byte Arrays"
@@ -931,8 +968,10 @@ primop	 AddrRemOp "remAddr#" GenPrimOp Addr# -> Int# -> Int#
 #if (WORD_SIZE_IN_BITS == 32 || WORD_SIZE_IN_BITS == 64)
 primop   Addr2IntOp  "addr2Int#"     GenPrimOp   Addr# -> Int#
 	{Coerce directly from address to int. Strongly deprecated.}
+   with code_size = 0
 primop   Int2AddrOp   "int2Addr#"    GenPrimOp  Int# -> Addr#
 	{Coerce directly from int to address. Strongly deprecated.}
+   with code_size = 0
 #endif
 
 primop   AddrGtOp  "gtAddr#"   Compare   Addr# -> Addr# -> Bool
@@ -1149,6 +1188,7 @@ primop  WriteMutVarOp "writeMutVar#"  GenPrimOp
    {Write contents of {\tt MutVar\#}.}
    with
    has_side_effects = True
+   code_size = { primOpCodeSizeForeignCall } -- for the write barrier
 
 primop  SameMutVarOp "sameMutVar#" GenPrimOp
    MutVar# s a -> MutVar# s a -> Bool
@@ -1381,7 +1421,6 @@ primop  DelayOp "delay#" GenPrimOp
    Int# -> State# s -> State# s
    {Sleep specified number of microseconds.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1389,7 +1428,6 @@ primop  WaitReadOp "waitRead#" GenPrimOp
    Int# -> State# s -> State# s
    {Block until input is available on specified file descriptor.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1397,7 +1435,6 @@ primop  WaitWriteOp "waitWrite#" GenPrimOp
    Int# -> State# s -> State# s
    {Block until output is possible on specified file descriptor.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1406,7 +1443,6 @@ primop  AsyncReadOp "asyncRead#" GenPrimOp
    Int# -> Int# -> Int# -> Addr# -> State# RealWorld-> (# State# RealWorld, Int#, Int# #)
    {Asynchronously read bytes from specified file descriptor.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1414,7 +1450,6 @@ primop  AsyncWriteOp "asyncWrite#" GenPrimOp
    Int# -> Int# -> Int# -> Addr# -> State# RealWorld-> (# State# RealWorld, Int#, Int# #)
    {Asynchronously write bytes from specified file descriptor.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1422,7 +1457,6 @@ primop  AsyncDoProcOp "asyncDoProc#" GenPrimOp
    Addr# -> Addr# -> State# RealWorld-> (# State# RealWorld, Int#, Int# #)
    {Asynchronously perform procedure (first arg), passing it 2nd arg.}
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1539,6 +1573,7 @@ primop  FinalizeWeakOp "finalizeWeak#" GenPrimOp
 primop TouchOp "touch#" GenPrimOp
    o -> State# RealWorld -> State# RealWorld
    with
+   code_size = { 0 }
    has_side_effects = True
 
 ------------------------------------------------------------------------
@@ -1558,7 +1593,6 @@ primop  MakeStablePtrOp "makeStablePtr#" GenPrimOp
 primop  DeRefStablePtrOp "deRefStablePtr#" GenPrimOp
    StablePtr# a -> State# RealWorld -> (# State# RealWorld, a #)
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1570,7 +1604,6 @@ primop  EqStablePtrOp "eqStablePtr#" GenPrimOp
 primop  MakeStableNameOp "makeStableName#" GenPrimOp
    a -> State# RealWorld -> (# State# RealWorld, StableName# a #)
    with
-   needs_wrapper    = True
    has_side_effects = True
    out_of_line      = True
 
@@ -1598,6 +1631,7 @@ primop  ParOp "par#" GenPrimOp
       -- Note that Par is lazy to avoid that the sparked thing
       -- gets evaluted strictly, which it should *not* be
    has_side_effects = True
+   code_size = { primOpCodeSizeForeignCall }
 
 primop GetSparkOp "getSpark#" GenPrimOp
    State# s -> (# State# s, Int#, a #)
@@ -1687,6 +1721,8 @@ primtype BCO#
 primop   AddrToHValueOp "addrToHValue#" GenPrimOp
    Addr# -> (# a #)
    {Convert an {\tt Addr\#} to a followable type.}
+   with
+   code_size = 0
 
 primop   MkApUpd0_Op "mkApUpd0#" GenPrimOp
    BCO# -> (# a #)
diff --git a/utils/genprimopcode/Lexer.x b/utils/genprimopcode/Lexer.x
index df710d72b3..6f48c02f8f 100644
--- a/utils/genprimopcode/Lexer.x
+++ b/utils/genprimopcode/Lexer.x
@@ -54,6 +54,7 @@ words :-
     <0>         "thats_all_folks"   { mkT TThatsAllFolks }
     <0>         [a-z][a-zA-Z0-9\#_]* { mkTv TLowerName }
     <0>         [A-Z][a-zA-Z0-9\#_]* { mkTv TUpperName }
+    <0>         [0-9][0-9]*         { mkTv (TInteger . read) }
     <0>         \" [^\"]* \"        { mkTv (TString . tail . init) }
     <in_braces> [^\{\}]+            { mkTv TNoBraces }
     <in_braces> \n                  { mkTv TNoBraces }
diff --git a/utils/genprimopcode/Main.hs b/utils/genprimopcode/Main.hs
index 5b802bccd7..d9bfd21fde 100644
--- a/utils/genprimopcode/Main.hs
+++ b/utils/genprimopcode/Main.hs
@@ -46,13 +46,13 @@ main = getArgs >>= \args ->
                                        "commutable" 
                                        "commutableOp" p_o_specs)
 
-                      "--needs-wrapper" 
+                      "--code-size"
                          -> putStr (gen_switch_from_attribs 
-                                       "needs_wrapper" 
-                                       "primOpNeedsWrapper" p_o_specs)
+                                       "code_size"
+                                       "primOpCodeSize" p_o_specs)
 
-                      "--can-fail" 
-                         -> putStr (gen_switch_from_attribs 
+                      "--can-fail"
+                         -> putStr (gen_switch_from_attribs
                                        "can_fail" 
                                        "primOpCanFail" p_o_specs)
 
@@ -91,7 +91,7 @@ known_args
        "--has-side-effects",
        "--out-of-line",
        "--commutable",
-       "--needs-wrapper",
+       "--code-size",
        "--can-fail",
        "--strictness",
        "--primop-primop-info",
@@ -550,6 +550,7 @@ gen_switch_from_attribs attrib_name fn_name (Info defaults entries)
 
          getAltRhs (OptionFalse _)    = "False"
          getAltRhs (OptionTrue _)     = "True"
+         getAltRhs (OptionInteger _ i) = show i
          getAltRhs (OptionString _ s) = s
 
          mkAlt po
diff --git a/utils/genprimopcode/Parser.y b/utils/genprimopcode/Parser.y
index b20414d7d2..5773abb4fe 100644
--- a/utils/genprimopcode/Parser.y
+++ b/utils/genprimopcode/Parser.y
@@ -48,6 +48,7 @@ import Syntax
     lowerName       { TLowerName $$ }
     upperName       { TUpperName $$ }
     string          { TString $$ }
+    integer         { TInteger $$ }
     noBraces        { TNoBraces $$ }
 
 %%
@@ -66,6 +67,7 @@ pOption :: { Option }
 pOption : lowerName '=' false               { OptionFalse  $1 }
         | lowerName '=' true                { OptionTrue   $1 }
         | lowerName '=' pStuffBetweenBraces { OptionString $1 $3 }
+        | lowerName '=' integer             { OptionInteger $1 $3 }
 
 pEntries :: { [Entry] }
 pEntries : pEntry pEntries { $1 : $2 }
diff --git a/utils/genprimopcode/ParserM.hs b/utils/genprimopcode/ParserM.hs
index edc300d6cc..a2b39d7a21 100644
--- a/utils/genprimopcode/ParserM.hs
+++ b/utils/genprimopcode/ParserM.hs
@@ -81,6 +81,7 @@ data Token = TEOF
            | TUpperName String
            | TString String
            | TNoBraces String
+           | TInteger Int
     deriving Show
 
 -- Actions
diff --git a/utils/genprimopcode/Syntax.hs b/utils/genprimopcode/Syntax.hs
index 809467020f..5fe4e0b23e 100644
--- a/utils/genprimopcode/Syntax.hs
+++ b/utils/genprimopcode/Syntax.hs
@@ -40,6 +40,7 @@ data Option
    = OptionFalse  String          -- name = False
    | OptionTrue   String          -- name = True
    | OptionString String String   -- name = { ... unparsed stuff ... }
+   | OptionInteger String Int     -- name = <int>
      deriving Show
 
 -- categorises primops
@@ -120,6 +121,7 @@ get_attrib_name :: Option -> String
 get_attrib_name (OptionFalse nm) = nm
 get_attrib_name (OptionTrue nm)  = nm
 get_attrib_name (OptionString nm _) = nm
+get_attrib_name (OptionInteger nm _) = nm
 
 lookup_attrib :: String -> [Option] -> Maybe Option
 lookup_attrib _ [] = Nothing