[commit: ghc] master: [LlvmCodeGen] Fixes for Int8#/Word8# (f424515)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/f424515fd8cbc2b7380cdf8427f972d062940bd5/ghc

>---------------------------------------------------------------

commit f424515fd8cbc2b7380cdf8427f972d062940bd5
Author: Michal Terepeta <michal.terepeta at gmail.com>
Date:   Wed Nov 7 08:03:16 2018 -0500

    [LlvmCodeGen] Fixes for Int8#/Word8#
    
    This fixes two isssues:
    
    - Using bitcast for MO_XX_Conv
      Arguments to a bitcast must be of the same size. We should be using
      `trunc` and `zext` instead.
    
    - Using unsupported MO_*_QuotRem for LLVM
      The two primops `MO_*_QuotRem` are not supported by the LLVM backend,
    so
      we shouldn't use them for `Int8#`/`Word8#` (just as we do not use
    them for
      `Int#`/`Word#`).
    
    Signed-off-by: Michal Terepeta <michal.terepeta at gmail.com>
    
    Test Plan: manually run tests with WAY=llvm
    
    Reviewers: bgamari, simonmar
    
    Reviewed By: bgamari
    
    Subscribers: rwbarton, carter
    
    GHC Trac Issues: #15864
    
    Differential Revision: https://phabricator.haskell.org/D5304


>---------------------------------------------------------------

f424515fd8cbc2b7380cdf8427f972d062940bd5
 compiler/codeGen/StgCmmPrim.hs          | 6 +++---
 compiler/llvmGen/LlvmCodeGen/CodeGen.hs | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs
index 9da472e..75d46b5 100644
--- a/compiler/codeGen/StgCmmPrim.hs
+++ b/compiler/codeGen/StgCmmPrim.hs
@@ -881,7 +881,7 @@ callishPrimOpSupported dflags op
                          Right (genericIntQuotRemOp (wordWidth dflags))
 
       Int8QuotRemOp  | (ncg && x86ish)
-                        || llvm      -> Left (MO_S_QuotRem W8)
+                                     -> Left (MO_S_QuotRem W8)
                      | otherwise     -> Right (genericIntQuotRemOp W8)
 
       WordQuotRemOp  | ncg && (x86ish || ppc) ->
@@ -895,8 +895,8 @@ callishPrimOpSupported dflags op
                      | otherwise      -> Right (genericWordQuotRem2Op dflags)
 
       Word8QuotRemOp | (ncg && x86ish)
-                        || llvm      -> Left (MO_U_QuotRem W8)
-                     | otherwise     -> Right (genericWordQuotRemOp W8)
+                                      -> Left (MO_U_QuotRem W8)
+                     | otherwise      -> Right (genericWordQuotRemOp W8)
 
       WordAdd2Op     | (ncg && (x86ish
                                 || ppc))
diff --git a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
index efc8709..d24075e 100644
--- a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
+++ b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
@@ -1194,7 +1194,7 @@ genMachOp _ op [x] = case op of
         -> sameConv from (widthToLlvmInt to) LM_Trunc LM_Zext
 
     MO_XX_Conv from to
-        -> sameConv from (widthToLlvmInt to) LM_Bitcast LM_Bitcast
+        -> sameConv from (widthToLlvmInt to) LM_Trunc LM_Zext
 
     MO_FF_Conv from to
         -> sameConv from (widthToLlvmFloat to) LM_Fptrunc LM_Fpext