From d245228ba69f50d2d2b3e3e42a5f9a112fd966f7 Mon Sep 17 00:00:00 2001
From: Jonas Maebe <jonas@freepascal.org>
Date: Mon, 11 Nov 2013 11:15:20 +0000
Subject: [PATCH]   + tcgllvm.a_label() and tcgllvm.a_jmp_always(). Special for
 llvm: every     basic block must end with a terminator instruciton (such as a
 branch) ->     when emitting a label, check whether the previous instruction
 is a     terminator instruction and if not, add an unconditional branch to
 the     label we are adding.    o Implemented at the tcg instead of at the
 thlcgobj level because     a) these methods don't need any high level type
 information     b) implementing them in thlcgobj would require making
 thlcg.a_label()        virtual and ensuring that no-one ever calls
 cg.a_label() in any        generic code

git-svn-id: branches/hlcgllvm@26038 -
---
 compiler/llvm/cgllvm.pas   | 24 +++++++++++++++++++++++-
 compiler/llvm/llvmbase.pas |  5 +++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/compiler/llvm/cgllvm.pas b/compiler/llvm/cgllvm.pas
index 5f40b1c4ea..4ac40f55f4 100644
--- a/compiler/llvm/cgllvm.pas
+++ b/compiler/llvm/cgllvm.pas
@@ -28,11 +28,13 @@ interface
     uses
        globtype,parabase,
        cgbase,cgutils,cgobj,cghlcpu,
-       llvmbase,llvminfo,aasmtai,aasmdata,aasmllvm;
+       llvmbase,llvminfo,aasmbase,aasmtai,aasmdata,aasmllvm;
 
     type
       tcgllvm=class(thlbasecgcpu)
      public
+        procedure a_label(list : TAsmList;l : tasmlabel);override;
+        procedure a_jmp_always(list: TAsmList; l: tasmlabel); override;
         procedure init_register_allocators;override;
         procedure done_register_allocators;override;
         function  getintregister(list:TAsmList;size:Tcgsize):Tregister;override;
@@ -54,6 +56,26 @@ implementation
                               Assembler code
 ****************************************************************************}
 
+    procedure tcgllvm.a_label(list: TAsmList; l: tasmlabel);
+      begin
+        { in llvm, every block must end with a terminator instruction, such as
+          a branch -> if the previous instruction is not a terminator instruction,
+          add an unconditional branch to the next block (= the one starting with
+          this label) }
+        if not assigned(list.last) or
+           (tai(list.Last).typ<>ait_llvmins) or
+           not(taillvm(list.Last).llvmopcode in llvmterminatoropcodes) then
+          a_jmp_always(list,l);
+        inherited;
+      end;
+
+
+    procedure tcgllvm.a_jmp_always(list: TAsmList; l: tasmlabel);
+      begin
+        list.concat(taillvm.op_lab(la_br,l));
+      end;
+
+
     procedure tcgllvm.init_register_allocators;
       begin
         inherited init_register_allocators;
diff --git a/compiler/llvm/llvmbase.pas b/compiler/llvm/llvmbase.pas
index 0792c341e9..5fd652b1ef 100644
--- a/compiler/llvm/llvmbase.pas
+++ b/compiler/llvm/llvmbase.pas
@@ -69,6 +69,11 @@ interface
       la_type { type definition }
     );
 
+  const
+    llvmterminatoropcodes = [la_ret, la_br, la_switch, la_indirectbr,
+      la_invoke, la_resume,
+      la_unreachable];
+
   type
     tllvmfpcmp = (
       lfc_false,