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authorSimon Marlow <marlowsd@gmail.com>2014-07-31 11:47:35 +0100
committerSimon Marlow <marlowsd@gmail.com>2014-08-01 12:45:41 +0100
commitaab5937405d379ee2e9ac0a54f145ca4005cf283 (patch)
tree46ee105d6e1f98fd9279bc235db4324baf86237b /compiler
parent028630ab2153d4a6eb473fef6e18130388a68636 (diff)
downloadhaskell-aab5937405d379ee2e9ac0a54f145ca4005cf283.tar.gz
update comment
Diffstat (limited to 'compiler')
-rw-r--r--compiler/cmm/CmmPipeline.hs7
1 files changed, 3 insertions, 4 deletions
diff --git a/compiler/cmm/CmmPipeline.hs b/compiler/cmm/CmmPipeline.hs
index 4314695201..af4f62a4a8 100644
--- a/compiler/cmm/CmmPipeline.hs
+++ b/compiler/cmm/CmmPipeline.hs
@@ -326,10 +326,9 @@ _GLOBAL_OFFSET_TABLE_, regardless of which entry point we arrived via.
{- Note [unreachable blocks]
The control-flow optimiser sometimes leaves unreachable blocks behind
-containing junk code. If these blocks make it into the native code
-generator then they trigger a register allocator panic because they
-refer to undefined LocalRegs, so we must eliminate any unreachable
-blocks before passing the code onwards.
+containing junk code. These aren't necessarily a problem, but
+removing them is good because it might save time in the native code
+generator later.
-}