Constant folding for ctz/clz/popCnt (#20376)

3 files changed, 97 insertions, 0 deletions

diff --git a/testsuite/tests/numeric/should_compile/T20376.hs b/testsuite/tests/numeric/should_compile/T20376.hs
new file mode 100644
index 0000000000..5290503708
--- /dev/null
+++ b/testsuite/tests/numeric/should_compile/T20376.hs
@@ -0,0 +1,39 @@
+{-# LANGUAGE UnboxedTuples #-}
+{-# LANGUAGE MagicHash #-}
+
+module T20376 where
+
+import GHC.Exts
+import GHC.Word
+import Data.Bits
+
+foo0 (# #) = popCnt#   123456789##
+foo1 (# #) = popCnt8#         89##
+foo2 (# #) = popCnt16#     56789##
+foo3 (# #) = popCnt32# 123456789##
+
+foo0' = popCount (123456789 :: Word)
+foo1' = popCount (       89 :: Word8)
+foo2' = popCount (    56789 :: Word16)
+foo3' = popCount (123456789 :: Word32)
+foo4' = popCount (123456789123456789 :: Word64)
+
+ctz0 (# #) = ctz#   0xC0000000##
+ctz1 (# #) = ctz8#        0xC0##
+ctz2 (# #) = ctz16#     0xC000##
+ctz3 (# #) = ctz32# 0xC0000000##
+
+ctz0' = countTrailingZeros (0xC0000000 :: Word)
+ctz1' = countTrailingZeros (      0xC0 :: Word8)
+ctz2' = countTrailingZeros (    0xC000 :: Word16)
+ctz3' = countTrailingZeros (0xC0000000 :: Word32)
+ctz4' = countTrailingZeros (0xC000000000000000 :: Word64)
+
+clz1 (# #) = clz8#        0x04##
+clz2 (# #) = clz16#     0x0004##
+clz3 (# #) = clz32# 0x00000004##
+
+clz1' = countLeadingZeros (      0x04 :: Word8)
+clz2' = countLeadingZeros (    0x0004 :: Word16)
+clz3' = countLeadingZeros (0x00000004 :: Word32)
+clz4' = countLeadingZeros (0x0000000000000004 :: Word64)
diff --git a/testsuite/tests/numeric/should_compile/T20376.stderr b/testsuite/tests/numeric/should_compile/T20376.stderr
new file mode 100644
index 0000000000..0bcf76151d
--- /dev/null
+++ b/testsuite/tests/numeric/should_compile/T20376.stderr
@@ -0,0 +1,57 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+  = {terms: 71, types: 45, coercions: 0, joins: 0/0}
+
+foo0 = \ _ -> 16##
+
+foo1 = \ _ -> 4##
+
+foo2 = \ _ -> 11##
+
+foo3 = foo0
+
+foo0' = I# 16#
+
+foo1' = I# 4#
+
+foo2' = I# 11#
+
+foo3' = foo0'
+
+foo4' = I# 31#
+
+ctz0 = \ _ -> 30##
+
+ctz1 = \ _ -> 6##
+
+ctz2 = \ _ -> 14##
+
+ctz3 = ctz0
+
+ctz0' = I# 30#
+
+ctz1' = I# 6#
+
+ctz2' = I# 14#
+
+ctz3' = ctz0'
+
+ctz4' = I# 62#
+
+clz1 = \ _ -> 5##
+
+clz2 = \ _ -> 13##
+
+clz3 = \ _ -> 29##
+
+clz1' = I# 5#
+
+clz2' = I# 13#
+
+clz3' = I# 29#
+
+clz4' = I# 61#
+
+
+
diff --git a/testsuite/tests/numeric/should_compile/all.T b/testsuite/tests/numeric/should_compile/all.T
index c95296fcde..5a0f9efae3 100644
--- a/testsuite/tests/numeric/should_compile/all.T
+++ b/testsuite/tests/numeric/should_compile/all.T
@@ -12,3 +12,4 @@ test('T16402', [ grep_errmsg(r'and'), when(wordsize(32), expect_broken(19024)) ]
 test('T19892', normal, compile, ['-O -ddump-rule-firings'])
 test('T20062', [ grep_errmsg(r'integer') ], compile, ['-ddump-simpl -O -dsuppress-all'])
 test('T20245', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-binds'])
+test('T20376', normal, compile, ['-ddump-simpl -O -dsuppress-all -dsuppress-uniques -dno-typeable-binds'])