Multiple fixes / improvements for LLVM backend

- Fix for #13904 -- stop "trashing" callee-saved registers, since it is
  not actually doing anything useful.

- Fix for #14251 -- fixes the calling convention for functions passing
  raw SSE-register values by adding padding as needed to get the values
  in the right registers. This problem cropped up when some args were
  unused an dropped from the live list.

- Fixed a typo in 'readnone' attribute

- Added 'lower-expect' pass to level 0 LLVM optimization passes to
  improve block layout in LLVM for stack checks, etc.

Test Plan: `make test WAYS=optllvm` and `make test WAYS=llvm`

Reviewers: bgamari, simonmar, angerman

Reviewed By: angerman

Subscribers: rwbarton, carter

GHC Trac Issues: #13904, #14251

Differential Revision: https://phabricator.haskell.org/D5190

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/llvmGen/Llvm/Types.hs b/compiler/llvmGen/Llvm/Types.hs
index bc7bbaab1b..a45004d3a8 100644
--- a/compiler/llvmGen/Llvm/Types.hs
+++ b/compiler/llvmGen/Llvm/Types.hs
@@ -564,7 +564,7 @@ instance Outputable LlvmFuncAttr where
   ppr OptSize            = text "optsize"
   ppr NoReturn           = text "noreturn"
   ppr NoUnwind           = text "nounwind"
-  ppr ReadNone           = text "readnon"
+  ppr ReadNone           = text "readnone"
   ppr ReadOnly           = text "readonly"
   ppr Ssp                = text "ssp"
   ppr SspReq             = text "ssqreq"