allocateRegsAndSpill: disable a panic for the time being (see comment)

diff --git a/compiler/nativeGen/RegAlloc/Linear/Main.hs b/compiler/nativeGen/RegAlloc/Linear/Main.hs
index c181f0e..473b549 100644 (file)
--- a/compiler/nativeGen/RegAlloc/Linear/Main.hs
+++ b/compiler/nativeGen/RegAlloc/Linear/Main.hs
@@ -621,7 +621,14 @@ allocateRegsAndSpill reading keep spills alloc (r:rs)
                -- Not already in a register, so we need to find a free one...
                Just (InMem slot) | reading   -> doSpill (ReadMem slot)
                                  | otherwise -> doSpill WriteMem
-               Nothing | reading   -> panic "allocateRegsAndSpill: Cannot read from uninitialized register"
+                Nothing | reading   ->
+                   -- pprPanic "allocateRegsAndSpill: Cannot read from uninitialized register" (ppr r)
+                   -- ToDo: This case should be a panic, but we
+                   -- sometimes see an unreachable basic block which
+                   -- triggers this because the register allocator
+                   -- will start with an empty assignment.
+                   doSpill WriteNew
+
                        | otherwise -> doSpill WriteNew