Don't adjust hp up when the case scrutinee won't allocate

[ghc-hetmet.git] / compiler / codeGen / StgCmmExpr.hs

diff --git a/compiler/codeGen/StgCmmExpr.hs b/compiler/codeGen/StgCmmExpr.hs
index 379f1cd..dac7d67 100644 (file)
--- a/compiler/codeGen/StgCmmExpr.hs
+++ b/compiler/codeGen/StgCmmExpr.hs
@@ -273,15 +273,15 @@ cgCase scrut bndr srt alt_type alts
        ; let ret_bndrs = chooseReturnBndrs bndr alt_type alts
              alt_regs  = map idToReg ret_bndrs
              simple_scrut = isSimpleScrut scrut alt_type
-             gc_plan | not simple_scrut = GcInAlts alt_regs srt
-                     | isSingleton alts = NoGcInAlts
-                     | up_hp_usg > 0    = NoGcInAlts
-                     | otherwise        = GcInAlts alt_regs srt
+             gcInAlts | not simple_scrut = True
+                      | isSingleton alts = False
+                      | up_hp_usg > 0    = False
+                      | otherwise        = True
+              gc_plan = if gcInAlts then GcInAlts alt_regs srt else NoGcInAlts
 
        ; mb_cc <- maybeSaveCostCentre simple_scrut
        ; c_srt <- getSRTInfo srt
-       ; withSequel (AssignTo alt_regs c_srt)
-                    (cgExpr scrut)
+       ; withSequel (AssignTo alt_regs gcInAlts) (cgExpr scrut)
        ; restoreCurrentCostCentre mb_cc
 
        ; bindArgsToRegs ret_bndrs