+-- We map STG registers onto appropriate CmmExprs. Either they map
+-- to real machine registers or stored as offsets from BaseReg. Given
+-- a GlobalReg, get_GlobalReg_reg_or_addr produces either the real
+-- register it is in, on this platform, or a CmmExpr denoting the
+-- address in the register table holding it.
+-- (See also get_GlobalReg_addr in CgUtils.)
+
+get_GlobalReg_reg_or_addr :: GlobalReg -> Either Reg CmmExpr
+get_GlobalReg_reg_or_addr mid
+ = case globalRegMaybe mid of
+ Just rr -> Left rr
+ Nothing -> Right (get_GlobalReg_addr mid)
+
+
+-- allocatableRegs is allMachRegNos with the fixed-use regs removed.
+-- i.e., these are the regs for which we are prepared to allow the
+-- register allocator to attempt to map VRegs to.
+allocatableRegs :: [RegNo]
+allocatableRegs
+ = let isFree i = isFastTrue (freeReg i)
+ in filter isFree allMachRegNos
+