+ added new compiler debug ifdef DEBUG_INSTRUCTIONREGISTERDEPENDENCIES, which

  adds instruction register usage info to the assembly output (only register
  reads for now, but register writes will also be added later). Useful for
  debugging InstructionLoadsFromReg and other similar functions.

git-svn-id: trunk@35967 -

compiler/aopt.pas

@@ -26,6 +26,7 @@ Unit aopt;
 {$i fpcdefs.inc}
 
 { $define DEBUG_OPTALLOC}
+{ $define DEBUG_INSTRUCTIONREGISTERDEPENDENCIES}
 
   Interface
 
@@ -381,6 +382,9 @@ Unit aopt;
       begin
         p:=casmoptimizer.Create(AsmL);
         p.Optimize;
+{$ifdef DEBUG_INSTRUCTIONREGISTERDEPENDENCIES}
+        p.Debug_InsertInstrRegisterDependencyInfo;
+{$endif DEBUG_INSTRUCTIONREGISTERDEPENDENCIES}
         p.free
       end;
 

compiler/aoptobj.pas

@@ -350,6 +350,11 @@ Unit AoptObj;
         function PeepHoleOptPass1Cpu(var p: tai): boolean; virtual;
         function PeepHoleOptPass2Cpu(var p: tai): boolean; virtual;
         function PostPeepHoleOptsCpu(var p: tai): boolean; virtual;
+
+        { insert debug comments about which registers are read and written by
+          each instruction. Useful for debugging the InstructionLoadsFromReg and
+          other similar functions. }
+        procedure Debug_InsertInstrRegisterDependencyInfo; virtual;
       End;
 
        Function ArrayRefsEq(const r1, r2: TReference): Boolean;
@@ -1572,4 +1577,30 @@ Unit AoptObj;
         result := false;
       end;
 
+
+    procedure TAOptObj.Debug_InsertInstrRegisterDependencyInfo;
+      var
+        p: tai;
+        ri: tregisterindex;
+        reg: TRegister;
+        commentstr: AnsiString;
+      begin
+        p:=tai(AsmL.First);
+        while (p<>AsmL.Last) Do
+          begin
+            if p.typ=ait_instruction then
+              begin
+                commentstr:='Instruction reads';
+                for ri in tregisterindex do
+                  begin
+                    reg:=regnumber_table[ri];
+                    if (reg<>NR_NO) and InstructionLoadsFromReg(reg,p) then
+                      commentstr:=commentstr+' '+std_regname(reg);
+                  end;
+                AsmL.InsertAfter(tai_comment.Create(strpnew(commentstr)),p);
+              end;
+            p:=tai(p.next);
+          end;
+      end;
+
 End.