Turn `compareByteArrays#` out-of-line primop into inline primop

Depends on D4090

Reviewers: austin, bgamari, erikd, simonmar, alexbiehl

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D4091

compiler/cmm/CmmMachOp.hs

@@ -584,6 +584,7 @@ data CallishMachOp
   | MO_Memcpy Int
   | MO_Memset Int
   | MO_Memmove Int
+  | MO_Memcmp Int
 
   | MO_PopCnt Width
   | MO_Clz Width
@@ -616,6 +617,7 @@ callishMachOpHints op = case op of
   MO_Memcpy _  -> ([], [AddrHint,AddrHint,NoHint])
   MO_Memset _  -> ([], [AddrHint,NoHint,NoHint])
   MO_Memmove _ -> ([], [AddrHint,AddrHint,NoHint])
+  MO_Memcmp _  -> ([], [AddrHint, AddrHint, NoHint])
   _            -> ([],[])
   -- empty lists indicate NoHint
 
@@ -625,4 +627,5 @@ machOpMemcpyishAlign op = case op of
   MO_Memcpy  align -> Just align
   MO_Memset  align -> Just align
   MO_Memmove align -> Just align
+  MO_Memcmp  align -> Just align
   _                -> Nothing

compiler/cmm/CmmParse.y

@@ -994,6 +994,7 @@ callishMachOps = listToUFM $
         ( "memcpy", memcpyLikeTweakArgs MO_Memcpy ),
         ( "memset", memcpyLikeTweakArgs MO_Memset ),
         ( "memmove", memcpyLikeTweakArgs MO_Memmove ),
+        ( "memcmp", memcpyLikeTweakArgs MO_Memcmp ),
 
         ("prefetch0", (,) $ MO_Prefetch_Data 0),
         ("prefetch1", (,) $ MO_Prefetch_Data 1),

compiler/cmm/PprC.hs

@@ -786,6 +786,7 @@ pprCallishMachOp_for_C mop
         MO_Memcpy _     -> text "memcpy"
         MO_Memset _     -> text "memset"
         MO_Memmove _    -> text "memmove"
+        MO_Memcmp _     -> text "memcmp"
         (MO_BSwap w)    -> ptext (sLit $ bSwapLabel w)
         (MO_PopCnt w)   -> ptext (sLit $ popCntLabel w)
         (MO_Clz w)      -> ptext (sLit $ clzLabel w)

compiler/codeGen/StgCmmPrim.hs

@@ -47,7 +47,7 @@ import Outputable
 import Util
 
 import Data.Bits ((.&.), bit)
-import Control.Monad (liftM, when)
+import Control.Monad (liftM, when, unless)
 
 ------------------------------------------------------------------------
 --      Primitive operations and foreign calls
@@ -568,6 +568,10 @@ emitPrimOp _      [] CopyAddrToByteArrayOp [src,dst,dst_off,n] =
 emitPrimOp _      [] SetByteArrayOp [ba,off,len,c] =
     doSetByteArrayOp ba off len c
 
+-- Comparing byte arrays
+emitPrimOp _      [res] CompareByteArraysOp [ba1,ba1_off,ba2,ba2_off,n] =
+    doCompareByteArraysOp res ba1 ba1_off ba2 ba2_off n
+
 emitPrimOp _      [res] BSwap16Op [w] = emitBSwapCall res w W16
 emitPrimOp _      [res] BSwap32Op [w] = emitBSwapCall res w W32
 emitPrimOp _      [res] BSwap64Op [w] = emitBSwapCall res w W64
@@ -1719,6 +1723,17 @@ doNewByteArrayOp res_r n = do
 
     emit $ mkAssign (CmmLocal res_r) base
 
+-- ----------------------------------------------------------------------------
+-- Comparing byte arrays
+
+doCompareByteArraysOp :: LocalReg -> CmmExpr -> CmmExpr -> CmmExpr -> CmmExpr -> CmmExpr
+                     -> FCode ()
+doCompareByteArraysOp res ba1 ba1_off ba2 ba2_off n = do
+    dflags <- getDynFlags
+    ba1_p <- assignTempE $ cmmOffsetExpr dflags (cmmOffsetB dflags ba1 (arrWordsHdrSize dflags)) ba1_off
+    ba2_p <- assignTempE $ cmmOffsetExpr dflags (cmmOffsetB dflags ba2 (arrWordsHdrSize dflags)) ba2_off
+    emitMemcmpCall res ba1_p ba2_p n 1
+
 -- ----------------------------------------------------------------------------
 -- Copying byte arrays
 
@@ -2213,6 +2228,30 @@ emitMemsetCall dst c n align = do
         (MO_Memset align)
         [ dst, c, n ]
 
+emitMemcmpCall :: LocalReg -> CmmExpr -> CmmExpr -> CmmExpr -> Int -> FCode ()
+emitMemcmpCall res ptr1 ptr2 n align = do
+    -- 'MO_Memcmp' is assumed to return an 32bit 'CInt' because all
+    -- code-gens currently call out to the @memcmp(3)@ C function.
+    -- This was easier than moving the sign-extensions into
+    -- all the code-gens.
+    dflags <- getDynFlags
+    let is32Bit = typeWidth (localRegType res) == W32
+
+    cres <- if is32Bit
+              then return res
+              else newTemp b32
+
+    emitPrimCall
+        [ cres ]
+        (MO_Memcmp align)
+        [ ptr1, ptr2, n ]
+
+    unless is32Bit $ do
+      emit $ mkAssign (CmmLocal res)
+                      (CmmMachOp
+                         (mo_s_32ToWord dflags)
+                         [(CmmReg (CmmLocal cres))])
+
 emitBSwapCall :: LocalReg -> CmmExpr -> Width -> FCode ()
 emitBSwapCall res x width = do
     emitPrimCall

compiler/llvmGen/LlvmCodeGen/CodeGen.hs

@@ -728,6 +728,7 @@ cmmPrimOpFunctions mop = do
     MO_Memcpy _   -> fsLit $ "llvm.memcpy."  ++ intrinTy1
     MO_Memmove _  -> fsLit $ "llvm.memmove." ++ intrinTy1
     MO_Memset _   -> fsLit $ "llvm.memset."  ++ intrinTy2
+    MO_Memcmp _   -> fsLit $ "memcmp"
 
     (MO_PopCnt w) -> fsLit $ "llvm.ctpop."  ++ showSDoc dflags (ppr $ widthToLlvmInt w)
     (MO_BSwap w)  -> fsLit $ "llvm.bswap."  ++ showSDoc dflags (ppr $ widthToLlvmInt w)

compiler/nativeGen/PPC/CodeGen.hs

@@ -1905,6 +1905,7 @@ genCCall' dflags gcp target dest_regs args
                     MO_Memcpy _  -> (fsLit "memcpy", False)
                     MO_Memset _  -> (fsLit "memset", False)
                     MO_Memmove _ -> (fsLit "memmove", False)
+                    MO_Memcmp _  -> (fsLit "memcmp", False)
 
                     MO_BSwap w   -> (fsLit $ bSwapLabel w, False)
                     MO_PopCnt w  -> (fsLit $ popCntLabel w, False)

compiler/nativeGen/SPARC/CodeGen.hs

@@ -650,6 +650,7 @@ outOfLineMachOp_table mop
         MO_Memcpy _  -> fsLit "memcpy"
         MO_Memset _  -> fsLit "memset"
         MO_Memmove _ -> fsLit "memmove"
+        MO_Memcmp _  -> fsLit "memcmp"
 
         MO_BSwap w   -> fsLit $ bSwapLabel w
         MO_PopCnt w  -> fsLit $ popCntLabel w

compiler/nativeGen/X86/CodeGen.hs

@@ -2682,6 +2682,7 @@ outOfLineCmmOp mop res args
               MO_Memcpy _  -> fsLit "memcpy"
               MO_Memset _  -> fsLit "memset"
               MO_Memmove _ -> fsLit "memmove"
+              MO_Memcmp _  -> fsLit "memcmp"
 
               MO_PopCnt _  -> fsLit "popcnt"
               MO_BSwap _   -> fsLit "bswap"

compiler/prelude/primops.txt.pp

@@ -1410,7 +1410,6 @@ primop  CompareByteArraysOp "compareByteArrays#" GenPrimOp
     respectively, to be byte-wise lexicographically less than, to
     match, or be greater than the second range.}
    with
-   out_of_line = True
    can_fail = True
 
 primop  CopyByteArrayOp "copyByteArray#" GenPrimOp