Revert "Batch merge"

This reverts commit 76c8fd674435a652c75a96c85abbf26f1f221876.

1 files changed, 28 insertions, 55 deletions

diff --git a/compiler/nativeGen/X86/CodeGen.hs b/compiler/nativeGen/X86/CodeGen.hs
index 9591c42ede..37080b990e 100644
--- a/compiler/nativeGen/X86/CodeGen.hs
+++ b/compiler/nativeGen/X86/CodeGen.hs
@@ -2045,37 +2045,25 @@ genCCall dflags is32Bit (PrimTarget (MO_Clz width)) dest_regs@[dst] args@[src] b
 
   | otherwise = do
     code_src <- getAnyReg src
+    src_r <- getNewRegNat format
+    tmp_r <- getNewRegNat format
     let dst_r = getRegisterReg platform False (CmmLocal dst)
-    if isBmi2Enabled dflags
-        then do
-            src_r <- getNewRegNat (intFormat width)
-            return $ appOL (code_src src_r) $ case width of
-                W8 -> toOL
-                    [ MOVZxL II8  (OpReg src_r)       (OpReg src_r) -- zero-extend to 32 bit
-                    , LZCNT  II32 (OpReg src_r)       dst_r         -- lzcnt with extra 24 zeros
-                    , SUB    II32 (OpImm (ImmInt 24)) (OpReg dst_r) -- compensate for extra zeros
-                    ]
-                W16 -> toOL
-                    [ LZCNT  II16 (OpReg src_r) dst_r
-                    , MOVZxL II16 (OpReg dst_r) (OpReg dst_r) -- zero-extend from 16 bit
-                    ]
-                _ -> unitOL (LZCNT (intFormat width) (OpReg src_r) dst_r)
-        else do
-            let format = if width == W8 then II16 else intFormat width
-            src_r <- getNewRegNat format
-            tmp_r <- getNewRegNat format
-            return $ code_src src_r `appOL` toOL
-                     ([ MOVZxL  II8    (OpReg src_r) (OpReg src_r) | width == W8 ] ++
-                      [ BSR     format (OpReg src_r) tmp_r
-                      , MOV     II32   (OpImm (ImmInt (2*bw-1))) (OpReg dst_r)
-                      , CMOV NE format (OpReg tmp_r) dst_r
-                      , XOR     format (OpImm (ImmInt (bw-1))) (OpReg dst_r)
-                      ]) -- NB: We don't need to zero-extend the result for the
-                         -- W8/W16 cases because the 'MOV' insn already
-                         -- took care of implicitly clearing the upper bits
+
+    -- The following insn sequence makes sure 'clz 0' has a defined value.
+    -- starting with Haswell, one could use the LZCNT insn instead.
+    return $ code_src src_r `appOL` toOL
+             ([ MOVZxL  II8    (OpReg src_r) (OpReg src_r) | width == W8 ] ++
+              [ BSR     format (OpReg src_r) tmp_r
+              , MOV     II32   (OpImm (ImmInt (2*bw-1))) (OpReg dst_r)
+              , CMOV NE format (OpReg tmp_r) dst_r
+              , XOR     format (OpImm (ImmInt (bw-1))) (OpReg dst_r)
+              ]) -- NB: We don't need to zero-extend the result for the
+                 -- W8/W16 cases because the 'MOV' insn already
+                 -- took care of implicitly clearing the upper bits
   where
     bw = widthInBits width
     platform = targetPlatform dflags
+    format = if width == W8 then II16 else intFormat width
     lbl = mkCmmCodeLabel primUnitId (fsLit (clzLabel width))
 
 genCCall dflags is32Bit (PrimTarget (MO_Ctz width)) [dst] [src] bid
@@ -2085,7 +2073,6 @@ genCCall dflags is32Bit (PrimTarget (MO_Ctz width)) [dst] [src] bid
           dst_r   = getRegisterReg platform False (CmmLocal dst)
       lbl1 <- getBlockIdNat
       lbl2 <- getBlockIdNat
-      let format = if width == W8 then II16 else intFormat width
       tmp_r <- getNewRegNat format
 
       -- New CFG Edges:
@@ -2122,38 +2109,24 @@ genCCall dflags is32Bit (PrimTarget (MO_Ctz width)) [dst] [src] bid
 
   | otherwise = do
     code_src <- getAnyReg src
+    src_r <- getNewRegNat format
+    tmp_r <- getNewRegNat format
     let dst_r = getRegisterReg platform False (CmmLocal dst)
 
-    if isBmi2Enabled dflags
-    then do
-        src_r <- getNewRegNat (intFormat width)
-        return $ appOL (code_src src_r) $ case width of
-            W8 -> toOL
-                [ OR    II32 (OpImm (ImmInt 0xFFFFFF00)) (OpReg src_r)
-                , TZCNT II32 (OpReg src_r)        dst_r
-                ]
-            W16 -> toOL
-                [ TZCNT  II16 (OpReg src_r) dst_r
-                , MOVZxL II16 (OpReg dst_r) (OpReg dst_r)
-                ]
-            _ -> unitOL $ TZCNT (intFormat width) (OpReg src_r) dst_r
-    else do
-        -- The following insn sequence makes sure 'ctz 0' has a defined value.
-        -- starting with Haswell, one could use the TZCNT insn instead.
-        let format = if width == W8 then II16 else intFormat width
-        src_r <- getNewRegNat format
-        tmp_r <- getNewRegNat format
-        return $ code_src src_r `appOL` toOL
-                 ([ MOVZxL  II8    (OpReg src_r) (OpReg src_r) | width == W8 ] ++
-                  [ BSF     format (OpReg src_r) tmp_r
-                  , MOV     II32   (OpImm (ImmInt bw)) (OpReg dst_r)
-                  , CMOV NE format (OpReg tmp_r) dst_r
-                  ]) -- NB: We don't need to zero-extend the result for the
-                     -- W8/W16 cases because the 'MOV' insn already
-                     -- took care of implicitly clearing the upper bits
+    -- The following insn sequence makes sure 'ctz 0' has a defined value.
+    -- starting with Haswell, one could use the TZCNT insn instead.
+    return $ code_src src_r `appOL` toOL
+             ([ MOVZxL  II8    (OpReg src_r) (OpReg src_r) | width == W8 ] ++
+              [ BSF     format (OpReg src_r) tmp_r
+              , MOV     II32   (OpImm (ImmInt bw)) (OpReg dst_r)
+              , CMOV NE format (OpReg tmp_r) dst_r
+              ]) -- NB: We don't need to zero-extend the result for the
+                 -- W8/W16 cases because the 'MOV' insn already
+                 -- took care of implicitly clearing the upper bits
   where
     bw = widthInBits width
     platform = targetPlatform dflags
+    format = if width == W8 then II16 else intFormat width
 
 genCCall dflags is32Bit (PrimTarget (MO_UF_Conv width)) dest_regs args bid = do
     targetExpr <- cmmMakeDynamicReference dflags