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| author | Simon Marlow <marlowsd@gmail.com> | 2012-07-18 13:33:45 +0100 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2012-07-30 11:42:14 +0100 |
| commit | 6c2c07c5c98adac365cc3da912ceb209bee41a61 (patch) | |
| tree | 6045e1123894132d2b1029b3cbe70aa6e12a0d63 /compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs | |
| parent | 93c03f84c4bfebea5faeb60d75d708a578413e4a (diff) | |
| download | haskell-6c2c07c5c98adac365cc3da912ceb209bee41a61.tar.gz | |
bugfix: cope when a source reg is dead at a join point
We didn't trip over this one until I started generating code without
proc-point splitting, which has more join points and loops.
Diffstat (limited to 'compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs')
| -rw-r--r-- | compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs b/compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs index 3bf49a31f2..c17b65d6e2 100644 --- a/compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs +++ b/compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs @@ -235,16 +235,10 @@ joinToTargets_again -- makeRegMovementGraph :: RegMap Loc -> RegMap Loc -> [(Unique, Loc, [Loc])] makeRegMovementGraph adjusted_assig dest_assig - = let - mkNodes src vreg - = expandNode vreg src - $ lookupWithDefaultUFM_Directly - dest_assig - (panic "RegAllocLinear.makeRegMovementGraph") - vreg - - in [ node | (vreg, src) <- ufmToList adjusted_assig - , node <- mkNodes src vreg ] + = [ node | (vreg, src) <- ufmToList adjusted_assig + -- source reg might not be needed at the dest: + , Just loc <- [lookupUFM_Directly dest_assig vreg] + , node <- expandNode vreg src loc ] -- | Expand out the destination, so InBoth destinations turn into |