Support MO_{Add,Sub}IntC and MO_Add2 in the LLVM backend

This includes:

- Adding new LlvmType called LMStructP that represents an unpacked
  struct (this is necessary since LLVM's instructions the
  llvm.sadd.with.overflow.* return an unpacked struct).

- Modifications to LlvmCodeGen.CodeGen to generate the LLVM
  instructions for the primops.

- Modifications to StgCmmPrim to actually use those three instructions
  if we use the LLVM backend (so far they were only used for NCG).

Test Plan: validate

Reviewers: austin, rwbarton, bgamari

Reviewed By: bgamari

Subscribers: thomie, bgamari

Differential Revision: https://phabricator.haskell.org/D991

GHC Trac Issues: #9430

2 files changed, 77 insertions, 1 deletions

diff --git a/testsuite/tests/primops/should_run/T9430.hs b/testsuite/tests/primops/should_run/T9430.hs
new file mode 100644
index 0000000000..571b6db37d
--- /dev/null
+++ b/testsuite/tests/primops/should_run/T9430.hs
@@ -0,0 +1,75 @@
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE UnboxedTuples #-}
+
+module Main where
+
+import GHC.Exts
+
+checkI
+    :: (Int, Int)                          -- ^ expected results
+    -> (Int# -> Int# -> (# Int#, Int# #))  -- ^ primop
+    -> Int                                 -- ^ first argument
+    -> Int                                 -- ^ second argument
+    -> Maybe String                        -- ^ maybe error
+checkI (expX, expY) op (I# a) (I# b) =
+  case op a b of
+      (# x, y #)
+          | I# x == expX && I# y == expY -> Nothing
+          | otherwise ->
+              Just $
+                  "Expected " ++ show expX ++ " and " ++ show expY
+                      ++ " but got " ++ show (I# x) ++ " and " ++ show (I# y)
+checkW
+    :: (Word, Word)                            -- ^ expected results
+    -> (Word# -> Word# -> (# Word#, Word# #))  -- ^ primop
+    -> Word                                    -- ^ first argument
+    -> Word                                    -- ^ second argument
+    -> Maybe String                            -- ^ maybe error
+checkW (expX, expY) op (W# a) (W# b) =
+    case op a b of
+        (# x, y #)
+            | W# x == expX && W# y == expY -> Nothing
+            | otherwise ->
+                Just $
+                    "Expected " ++ show expX ++ " and " ++ show expY
+                        ++ " but got " ++ show (W# x) ++ " and " ++ show (W# y)
+
+check :: String -> Maybe String -> IO ()
+check s (Just err) = error $ "Error for " ++ s ++ ": " ++ err
+check _ Nothing    = return ()
+
+main :: IO ()
+main = do
+    -- First something trivial
+    check "addIntC# maxBound 0" $ checkI (maxBound, 0) addIntC# maxBound 0
+    check "addIntC# 0 maxBound" $ checkI (maxBound, 0) addIntC# 0 maxBound
+    -- Overflows
+    check "addIntC# maxBound 1" $ checkI (minBound, 1) addIntC# maxBound 1
+    check "addIntC# 1 maxBound" $ checkI (minBound, 1) addIntC# 1 maxBound
+    check "addIntC# maxBound 2" $ checkI (minBound + 1, 1) addIntC# maxBound 2
+    check "addIntC# 2 maxBound" $ checkI (minBound + 1, 1) addIntC# 2 maxBound
+    check "addIntC# minBound minBound" $
+      checkI (0, 1) addIntC# minBound minBound
+
+    -- First something trivial
+    check "subIntC# minBound 0" $ checkI (minBound, 0) subIntC# minBound 0
+    -- Overflows
+    check "subIntC# minBound 1" $ checkI (maxBound, 1) subIntC# minBound 1
+    check "subIntC# minBound 1" $ checkI (maxBound - 1, 1) subIntC# minBound 2
+    check "subIntC# 0 minBound" $ checkI (minBound, 1) subIntC# 0 minBound
+    check "subIntC# -1 minBound" $ checkI (maxBound, 0) subIntC# (-1) minBound
+    check "subIntC# minBound -1" $
+      checkI (minBound + 1, 0) subIntC# minBound (-1)
+
+    -- First something trivial (note that the order of results is different!)
+    check "plusWord2# maxBound 0" $ checkW (0, maxBound) plusWord2# maxBound 0
+    check "plusWord2# 0 maxBound" $ checkW (0, maxBound) plusWord2# 0 maxBound
+    -- Overflows
+    check "plusWord2# maxBound 1" $
+      checkW (1, minBound) plusWord2# maxBound 1
+    check "plusWord2# 1 maxBound" $
+      checkW (1, minBound) plusWord2# 1 maxBound
+    check "plusWord2# maxBound 2" $
+      checkW (1, minBound + 1) plusWord2# maxBound 2
+    check "plusWord2# 2 maxBound" $
+      checkW (1, minBound + 1) plusWord2# 2 maxBound
diff --git a/testsuite/tests/primops/should_run/all.T b/testsuite/tests/primops/should_run/all.T
index a2c48fe19a..12f94913d3 100644
--- a/testsuite/tests/primops/should_run/all.T
+++ b/testsuite/tests/primops/should_run/all.T
@@ -1,3 +1,4 @@
 test('T6135', normal, compile_and_run, [''])
-
 test('T7689', normal, compile_and_run, [''])
+# The test is using unboxed tuples, so omit ghci
+test('T9430', omit_ways(['ghci']), compile_and_run, [''])