cmm: Use LocalBlockLabel instead of AsmTempLabel to represent blocks

blockLbl was originally changed in 8b007abbeb3045900a11529d907a835080129176 to
use mkTempAsmLabel to fix an inconsistency resulting in #14221. However, this
breaks the C code generator, which doesn't support AsmTempLabels (#14454).

Instead let's try going the other direction: use a new CLabel variety,
LocalBlockLabel. Then we can teach the C code generator to deal with
these as well.

5 files changed, 13 insertions, 14 deletions

diff --git a/compiler/nativeGen/NCGMonad.hs b/compiler/nativeGen/NCGMonad.hs
index f4d02dae3c..b9532e17b5 100644
--- a/compiler/nativeGen/NCGMonad.hs
+++ b/compiler/nativeGen/NCGMonad.hs
@@ -46,7 +46,7 @@ import TargetReg
 import BlockId
 import Hoopl.Collections
 import Hoopl.Label
-import CLabel           ( CLabel, mkAsmTempLabel )
+import CLabel           ( CLabel )
 import Debug
 import FastString       ( FastString )
 import UniqFM
@@ -160,8 +160,7 @@ getBlockIdNat
 
 getNewLabelNat :: NatM CLabel
 getNewLabelNat
- = do   u <- getUniqueNat
-        return (mkAsmTempLabel u)
+ = blockLbl <$> getBlockIdNat
 
 
 getNewRegNat :: Format -> NatM Reg
diff --git a/compiler/nativeGen/PPC/Ppr.hs b/compiler/nativeGen/PPC/Ppr.hs
index 101628e3a3..2f64d82ee5 100644
--- a/compiler/nativeGen/PPC/Ppr.hs
+++ b/compiler/nativeGen/PPC/Ppr.hs
@@ -603,7 +603,7 @@ pprInstr (BCC cond blockid prediction) = hcat [
         char '\t',
         ppr lbl
     ]
-    where lbl = mkAsmTempLabel (getUnique blockid)
+    where lbl = mkLocalBlockLabel (getUnique blockid)
           pprPrediction p = case p of
             Nothing    -> empty
             Just True  -> char '+'
@@ -621,7 +621,7 @@ pprInstr (BCCFAR cond blockid prediction) = vcat [
             ppr lbl
         ]
     ]
-    where lbl = mkAsmTempLabel (getUnique blockid)
+    where lbl = mkLocalBlockLabel (getUnique blockid)
           neg_prediction = case prediction of
             Nothing    -> empty
             Just True  -> char '-'
diff --git a/compiler/nativeGen/PPC/RegInfo.hs b/compiler/nativeGen/PPC/RegInfo.hs
index bf894fd42f..1015ed661d 100644
--- a/compiler/nativeGen/PPC/RegInfo.hs
+++ b/compiler/nativeGen/PPC/RegInfo.hs
@@ -51,8 +51,8 @@ shortcutStatics fn (Statics lbl statics)
 
 shortcutLabel :: (BlockId -> Maybe JumpDest) -> CLabel -> CLabel
 shortcutLabel fn lab
-  | Just uq <- maybeAsmTemp lab = shortBlockId fn (mkBlockId uq)
-  | otherwise                   = lab
+  | Just blkId <- maybeLocalBlockLabel lab = shortBlockId fn blkId
+  | otherwise                              = lab
 
 shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
 shortcutStatic fn (CmmStaticLit (CmmLabel lab))
@@ -71,6 +71,6 @@ shortBlockId
 
 shortBlockId fn blockid =
    case fn blockid of
-      Nothing -> mkAsmTempLabel uq
+      Nothing -> mkLocalBlockLabel uq
       Just (DestBlockId blockid')  -> shortBlockId fn blockid'
    where uq = getUnique blockid
diff --git a/compiler/nativeGen/SPARC/ShortcutJump.hs b/compiler/nativeGen/SPARC/ShortcutJump.hs
index 0df280095b..86c28138f1 100644
--- a/compiler/nativeGen/SPARC/ShortcutJump.hs
+++ b/compiler/nativeGen/SPARC/ShortcutJump.hs
@@ -46,8 +46,8 @@ shortcutStatics fn (Statics lbl statics)
 
 shortcutLabel :: (BlockId -> Maybe JumpDest) -> CLabel -> CLabel
 shortcutLabel fn lab
-  | Just uq <- maybeAsmTemp lab = shortBlockId fn (mkBlockId uq)
-  | otherwise                   = lab
+  | Just blkId <- maybeLocalBlockLabel lab = shortBlockId fn blkId
+  | otherwise                              = lab
 
 shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
 shortcutStatic fn (CmmStaticLit (CmmLabel lab))
diff --git a/compiler/nativeGen/X86/Instr.hs b/compiler/nativeGen/X86/Instr.hs
index 1bb682ad87..c937d4dba0 100644
--- a/compiler/nativeGen/X86/Instr.hs
+++ b/compiler/nativeGen/X86/Instr.hs
@@ -1035,8 +1035,8 @@ shortcutStatics fn (align, Statics lbl statics)
 
 shortcutLabel :: (BlockId -> Maybe JumpDest) -> CLabel -> CLabel
 shortcutLabel fn lab
-  | Just uq <- maybeAsmTemp lab = shortBlockId fn emptyUniqSet (mkBlockId uq)
-  | otherwise                   = lab
+  | Just blkId <- maybeLocalBlockLabel lab = shortBlockId fn emptyUniqSet blkId
+  | otherwise                              = lab
 
 shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
 shortcutStatic fn (CmmStaticLit (CmmLabel lab))
@@ -1056,8 +1056,8 @@ shortBlockId
 
 shortBlockId fn seen blockid =
   case (elementOfUniqSet uq seen, fn blockid) of
-    (True, _)    -> mkAsmTempLabel uq
-    (_, Nothing) -> mkAsmTempLabel uq
+    (True, _)    -> blockLbl blockid
+    (_, Nothing) -> blockLbl blockid
     (_, Just (DestBlockId blockid'))  -> shortBlockId fn (addOneToUniqSet seen uq) blockid'
     (_, Just (DestImm (ImmCLbl lbl))) -> lbl
     (_, _other) -> panic "shortBlockId"