Don't do ARM FoldShiftLdrStr peephole optimization if there's an offset in the reference.

Use UXTH+UXTB instructions instead of two shifts on processors that supports that.
Eliminate internalerror when constant pointers are typecast as arrays.

git-svn-id: trunk@26647 -

compiler/arm/aoptcpu.pas

@@ -1376,7 +1376,8 @@ Implementation
                            )
                          )
                        ) and
-                       { Only fold if there isn't another shifterop already. }
+                       { Only fold if there isn't another shifterop already, and offset is zero. }
+                       (taicpu(hp1).oper[1]^.ref^.offset = 0) and
                        (taicpu(hp1).oper[1]^.ref^.shiftmode = SM_None) and
                        not(RegModifiedBetween(taicpu(p).oper[1]^.reg,p,hp1)) and
                        RegEndOfLife(taicpu(p).oper[0]^.reg, taicpu(hp1)) then

compiler/arm/cgcpu.pas

@@ -1022,7 +1022,15 @@ unit cgcpu;
                     ((lsb = 0) or ((lsb + width) = 32)) then
               begin
                 shifterop_reset(so);
-                if lsb = 0 then
+                if (width = 16) and
+                   (lsb = 0) and
+                   (current_settings.cputype >= cpu_armv6) then
+                  list.concat(taicpu.op_reg_reg(A_UXTH,dst,src))
+                else if (width = 8) and
+                   (lsb = 0) and
+                   (current_settings.cputype >= cpu_armv6) then
+                  list.concat(taicpu.op_reg_reg(A_UXTB,dst,src))
+                else if lsb = 0 then
                   begin
                     so.shiftmode:=SM_LSL;
                     so.shiftimm:=32-width;

compiler/ncgcnv.pas

@@ -378,6 +378,10 @@ interface
               if left.location.loc in [LOC_REFERENCE,LOC_CREFERENCE] then
                 location_freetemp(current_asmdata.CurrAsmList,left.location);
             end;
+          LOC_CONSTANT:
+            begin
+              location.reference.offset:=left.location.value;
+            end
           else
             internalerror(2002032216);
         end;