base: Implement bit casts between word and float types

Test Plan: Test on x86 and x86_64

Reviewers: duncan, trofi, simonmar, tibbe, hvr, austin, rwbarton,
bgamari

Reviewed By: duncan

Subscribers: Phyx, DemiMarie, rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3358

3 files changed, 234 insertions, 0 deletions

diff --git a/testsuite/tests/codeGen/should_run/all.T b/testsuite/tests/codeGen/should_run/all.T
index 9f334cf298..6318341abb 100644
--- a/testsuite/tests/codeGen/should_run/all.T
+++ b/testsuite/tests/codeGen/should_run/all.T
@@ -155,4 +155,6 @@ test('T9577', [ unless(arch('x86_64') or arch('i386'),skip),
                 when(opsys('darwin'), expect_broken(12937)),
                 when(opsys('mingw32'), expect_broken(12965)),
                 only_ways(['normal']) ], compile_and_run, [''])
+
 test('T13425', normal, compile_and_run, ['-O'])
+test('castFloatWord', normal, compile_and_run, ['-dcmm-lint'])
diff --git a/testsuite/tests/codeGen/should_run/castFloatWord.hs b/testsuite/tests/codeGen/should_run/castFloatWord.hs
new file mode 100644
index 0000000000..9c10aa84fc
--- /dev/null
+++ b/testsuite/tests/codeGen/should_run/castFloatWord.hs
@@ -0,0 +1,28 @@
+import Data.Bits
+import GHC.Float
+import GHC.Word
+import Numeric
+
+main :: IO ()
+main = do
+    putStrLn "Float"
+    mapM_ print floats
+    putStrLn "\nDouble"
+    mapM_ print doubles
+    putStrLn "\nWord32"
+    mapM_ (printHex32 . castFloatToWord32) floats
+    putStrLn "\nWord64"
+    mapM_ (printHex64 . castDoubleToWord64) doubles
+    putStrLn "Done!"
+
+floats :: [Float]
+floats = map castWord32ToFloat $ 0 : map (2^) [ 0 .. 31 ]
+
+doubles :: [Double]
+doubles = map castWord64ToDouble $ 0 : map (2^) [ 0 .. 63 ]
+
+printHex32 :: Word32 -> IO ()
+printHex32 w = putStrLn $ "0x" ++ showHex (0xffffffff .&. w) ""
+
+printHex64 :: Word64 -> IO ()
+printHex64 w = putStrLn $ "0x" ++ showHex w ""
diff --git a/testsuite/tests/codeGen/should_run/castFloatWord.stdout b/testsuite/tests/codeGen/should_run/castFloatWord.stdout
new file mode 100644
index 0000000000..930f2fec02
--- /dev/null
+++ b/testsuite/tests/codeGen/should_run/castFloatWord.stdout
@@ -0,0 +1,204 @@
+Float
+0.0
+1.0e-45
+3.0e-45
+6.0e-45
+1.1e-44
+2.2e-44
+4.5e-44
+9.0e-44
+1.8e-43
+3.59e-43
+7.17e-43
+1.435e-42
+2.87e-42
+5.74e-42
+1.148e-41
+2.2959e-41
+4.5918e-41
+9.1835e-41
+1.83671e-40
+3.67342e-40
+7.34684e-40
+1.469368e-39
+2.938736e-39
+5.877472e-39
+1.1754944e-38
+2.3509887e-38
+9.403955e-38
+1.5046328e-36
+3.85186e-34
+2.524355e-29
+1.0842022e-19
+2.0
+-0.0
+
+Double
+0.0
+5.0e-324
+1.0e-323
+2.0e-323
+4.0e-323
+8.0e-323
+1.6e-322
+3.16e-322
+6.3e-322
+1.265e-321
+2.53e-321
+5.06e-321
+1.012e-320
+2.0237e-320
+4.0474e-320
+8.095e-320
+1.61895e-319
+3.2379e-319
+6.4758e-319
+1.295163e-318
+2.590327e-318
+5.180654e-318
+1.036131e-317
+2.0722615e-317
+4.144523e-317
+8.289046e-317
+1.6578092e-316
+3.3156184e-316
+6.63123685e-316
+1.32624737e-315
+2.65249474e-315
+5.304989477e-315
+1.0609978955e-314
+2.121995791e-314
+4.243991582e-314
+8.487983164e-314
+1.69759663277e-313
+3.39519326554e-313
+6.7903865311e-313
+1.35807730622e-312
+2.716154612436e-312
+5.43230922487e-312
+1.086461844974e-311
+2.1729236899484e-311
+4.345847379897e-311
+8.691694759794e-311
+1.73833895195875e-310
+3.4766779039175e-310
+6.953355807835e-310
+1.390671161567e-309
+2.781342323134e-309
+5.562684646268003e-309
+1.1125369292536007e-308
+2.2250738585072014e-308
+4.450147717014403e-308
+1.7800590868057611e-307
+2.848094538889218e-306
+7.291122019556398e-304
+4.778309726736481e-299
+2.0522684006491881e-289
+3.785766995733679e-270
+1.2882297539194267e-231
+1.4916681462400413e-154
+2.0
+-0.0
+
+Word32
+0x0
+0x1
+0x2
+0x4
+0x8
+0x10
+0x20
+0x40
+0x80
+0x100
+0x200
+0x400
+0x800
+0x1000
+0x2000
+0x4000
+0x8000
+0x10000
+0x20000
+0x40000
+0x80000
+0x100000
+0x200000
+0x400000
+0x800000
+0x1000000
+0x2000000
+0x4000000
+0x8000000
+0x10000000
+0x20000000
+0x40000000
+0x80000000
+
+Word64
+0x0
+0x1
+0x2
+0x4
+0x8
+0x10
+0x20
+0x40
+0x80
+0x100
+0x200
+0x400
+0x800
+0x1000
+0x2000
+0x4000
+0x8000
+0x10000
+0x20000
+0x40000
+0x80000
+0x100000
+0x200000
+0x400000
+0x800000
+0x1000000
+0x2000000
+0x4000000
+0x8000000
+0x10000000
+0x20000000
+0x40000000
+0x80000000
+0x100000000
+0x200000000
+0x400000000
+0x800000000
+0x1000000000
+0x2000000000
+0x4000000000
+0x8000000000
+0x10000000000
+0x20000000000
+0x40000000000
+0x80000000000
+0x100000000000
+0x200000000000
+0x400000000000
+0x800000000000
+0x1000000000000
+0x2000000000000
+0x4000000000000
+0x8000000000000
+0x10000000000000
+0x20000000000000
+0x40000000000000
+0x80000000000000
+0x100000000000000
+0x200000000000000
+0x400000000000000
+0x800000000000000
+0x1000000000000000
+0x2000000000000000
+0x4000000000000000
+0x8000000000000000
+Done!