Replace (ptext .. sLit) with `text`

1. `text` is as efficient as `ptext . sLit` thanks to the rewrite rules

2. `text` is visually nicer than `ptext . sLit`

3. `ptext . sLit` encourages using one `ptext` for several `sLit` as in:

    ptext $ case xy of
      ... -> sLit ...
      ... -> sLit ...

  which may allocate SDoc's TextBeside constructors at runtime instead
  of sharing them into CAFs.

3 files changed, 45 insertions, 50 deletions

diff --git a/compiler/GHC/Cmm/CLabel.hs b/compiler/GHC/Cmm/CLabel.hs
index 4d6c66066c..02d3f60ad6 100644
--- a/compiler/GHC/Cmm/CLabel.hs
+++ b/compiler/GHC/Cmm/CLabel.hs
@@ -1334,7 +1334,7 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
 
     tempLabelPrefixOrUnderscore :: Platform -> SDoc
     tempLabelPrefixOrUnderscore platform = case sty of
-      AsmStyle -> ptext (asmTempLabelPrefix platform)
+      AsmStyle -> asmTempLabelPrefix platform
       CStyle   -> char '_'
 
 
@@ -1347,7 +1347,7 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
       -> tempLabelPrefixOrUnderscore platform <> pprUniqueAlways u
 
    AsmTempDerivedLabel l suf
-      -> ptext (asmTempLabelPrefix platform)
+      -> asmTempLabelPrefix platform
          <> case l of AsmTempLabel u    -> pprUniqueAlways u
                       LocalBlockLabel u -> pprUniqueAlways u
                       _other            -> pprCLabel platform sty l
@@ -1370,7 +1370,7 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
       maybe_underscore $ text "dsp_" <> pprCLabel platform sty lbl <> text "_dsp"
 
    StringLitLabel u
-      -> maybe_underscore $ pprUniqueAlways u <> ptext (sLit "_str")
+      -> maybe_underscore $ pprUniqueAlways u <> text "_str"
 
    ForeignLabel fs (Just sz) _ _
       | AsmStyle <- sty
@@ -1389,7 +1389,7 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
                       isRandomGenerated = not (isExternalName name)
                       internalNamePrefix =
                          if isRandomGenerated
-                            then ptext (asmTempLabelPrefix platform)
+                            then asmTempLabelPrefix platform
                             else empty
       CStyle   -> ppr name <> ppIdFlavor flavor
 
@@ -1400,38 +1400,38 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
       -> maybe_underscore $ ftext str <> text "_fast"
 
    RtsLabel (RtsSelectorInfoTable upd_reqd offset)
-      -> maybe_underscore $ hcat [text "stg_sel_", text (show offset),
-                                  ptext (if upd_reqd
-                                         then (sLit "_upd_info")
-                                         else (sLit "_noupd_info"))
+      -> maybe_underscore $ hcat [ text "stg_sel_", text (show offset)
+                                 , if upd_reqd
+                                    then text "_upd_info"
+                                    else text "_noupd_info"
                                  ]
 
    RtsLabel (RtsSelectorEntry upd_reqd offset)
-      -> maybe_underscore $ hcat [text "stg_sel_", text (show offset),
-                                        ptext (if upd_reqd
-                                                then (sLit "_upd_entry")
-                                                else (sLit "_noupd_entry"))
+      -> maybe_underscore $ hcat [ text "stg_sel_", text (show offset)
+                                 , if upd_reqd
+                                    then text "_upd_entry"
+                                    else text "_noupd_entry"
                                  ]
 
    RtsLabel (RtsApInfoTable upd_reqd arity)
-      -> maybe_underscore $ hcat [text "stg_ap_", text (show arity),
-                                        ptext (if upd_reqd
-                                                then (sLit "_upd_info")
-                                                else (sLit "_noupd_info"))
+      -> maybe_underscore $ hcat [ text "stg_ap_", text (show arity)
+                                 , if upd_reqd
+                                    then text "_upd_info"
+                                    else text "_noupd_info"
                                  ]
 
    RtsLabel (RtsApEntry upd_reqd arity)
-      -> maybe_underscore $ hcat [text "stg_ap_", text (show arity),
-                                        ptext (if upd_reqd
-                                                then (sLit "_upd_entry")
-                                                else (sLit "_noupd_entry"))
+      -> maybe_underscore $ hcat [ text "stg_ap_", text (show arity)
+                                 , if upd_reqd
+                                    then text "_upd_entry"
+                                    else text "_noupd_entry"
                                  ]
 
    RtsLabel (RtsPrimOp primop)
       -> maybe_underscore $ text "stg_" <> ppr primop
 
    RtsLabel (RtsSlowFastTickyCtr pat)
-      -> maybe_underscore $ text "SLOW_CALL_fast_" <> text pat <> ptext (sLit "_ctr")
+      -> maybe_underscore $ text "SLOW_CALL_fast_" <> text pat <> text "_ctr"
 
    LargeBitmapLabel u
       -> maybe_underscore $ tempLabelPrefixOrUnderscore platform
@@ -1441,7 +1441,7 @@ pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
                             -- with a letter so the label will be legal assembly code.
 
    HpcTicksLabel mod
-      -> maybe_underscore $ text "_hpc_tickboxes_"  <> ppr mod <> ptext (sLit "_hpc")
+      -> maybe_underscore $ text "_hpc_tickboxes_"  <> ppr mod <> text "_hpc"
 
    CC_Label cc   -> maybe_underscore $ ppr cc
    CCS_Label ccs -> maybe_underscore $ ppr ccs
@@ -1528,11 +1528,11 @@ instance Outputable ForeignLabelSource where
 -- -----------------------------------------------------------------------------
 -- Machine-dependent knowledge about labels.
 
-asmTempLabelPrefix :: Platform -> PtrString  -- for formatting labels
+asmTempLabelPrefix :: Platform -> SDoc  -- for formatting labels
 asmTempLabelPrefix !platform = case platformOS platform of
-    OSDarwin -> sLit "L"
-    OSAIX    -> sLit "__L" -- follow IBM XL C's convention
-    _        -> sLit ".L"
+    OSDarwin -> text "L"
+    OSAIX    -> text "__L" -- follow IBM XL C's convention
+    _        -> text ".L"
 
 pprDynamicLinkerAsmLabel :: Platform -> DynamicLinkerLabelInfo -> SDoc -> SDoc
 pprDynamicLinkerAsmLabel !platform dllInfo ppLbl =
diff --git a/compiler/GHC/Cmm/Ppr/Decl.hs b/compiler/GHC/Cmm/Ppr/Decl.hs
index 469ae66dbc..b6a2e1992e 100644
--- a/compiler/GHC/Cmm/Ppr/Decl.hs
+++ b/compiler/GHC/Cmm/Ppr/Decl.hs
@@ -51,7 +51,6 @@ import GHC.Cmm.Ppr.Expr
 import GHC.Cmm
 
 import GHC.Utils.Outputable
-import GHC.Data.FastString
 
 import Data.List (intersperse)
 
@@ -160,15 +159,12 @@ pprSection platform (Section t suffix) =
     section = text "section"
 
 pprSectionType :: SectionType -> SDoc
-pprSectionType s = doubleQuotes (ptext t)
- where
-  t = case s of
-    Text              -> sLit "text"
-    Data              -> sLit "data"
-    ReadOnlyData      -> sLit "readonly"
-    ReadOnlyData16    -> sLit "readonly16"
-    RelocatableReadOnlyData
-                      -> sLit "relreadonly"
-    UninitialisedData -> sLit "uninitialised"
-    CString           -> sLit "cstring"
-    OtherSection s'   -> sLit s' -- Not actually a literal though.
+pprSectionType s = doubleQuotes $ case s of
+  Text                    -> text "text"
+  Data                    -> text "data"
+  ReadOnlyData            -> text "readonly"
+  ReadOnlyData16          -> text "readonly16"
+  RelocatableReadOnlyData -> text "relreadonly"
+  UninitialisedData       -> text "uninitialised"
+  CString                 -> text "cstring"
+  OtherSection s'         -> text s'
diff --git a/compiler/GHC/Cmm/Type.hs b/compiler/GHC/Cmm/Type.hs
index 954fc5fe80..c7e2a4069b 100644
--- a/compiler/GHC/Cmm/Type.hs
+++ b/compiler/GHC/Cmm/Type.hs
@@ -33,7 +33,6 @@ where
 import GHC.Prelude
 
 import GHC.Platform
-import GHC.Data.FastString
 import GHC.Utils.Outputable
 import GHC.Utils.Panic
 
@@ -172,18 +171,18 @@ isFloat64 _other                 = False
 --              Width
 -----------------------------------------------------------------------------
 
-data Width   = W8 | W16 | W32 | W64
-             | W128
-             | W256
-             | W512
-             deriving (Eq, Ord, Show)
+data Width
+  = W8
+  | W16
+  | W32
+  | W64
+  | W128
+  | W256
+  | W512
+  deriving (Eq, Ord, Show)
 
 instance Outputable Width where
-   ppr rep = ptext (mrStr rep)
-
-mrStr :: Width -> PtrString
-mrStr = sLit . show
-
+   ppr rep = text (show rep)
 
 -------- Common Widths  ------------
 wordWidth :: Platform -> Width