mcode: improve support of Win64 (allocate stack for home registers)

3 files changed, 22 insertions, 6 deletions

diff --git a/src/ortho/mcode/ortho_code-x86-abi.adb b/src/ortho/mcode/ortho_code-x86-abi.adb
index 0bba430a0..69eb8d26e 100644
--- a/src/ortho/mcode/ortho_code-x86-abi.adb
+++ b/src/ortho/mcode/ortho_code-x86-abi.adb
@@ -44,8 +44,8 @@ package body Ortho_Code.X86.Abi is
 
    type Regs_List is array (Boolean range <>, Natural range <>) of O_Reg;
    Int_Regs : constant Regs_List :=
-     (False => (R_Di, R_Si, R_Dx, R_Cx, R_R8, R_R9),
-      True  => (R_Cx, R_Dx, R_R8, R_R9, R_None, R_None));
+     (False => (R_Di, R_Si, R_Dx, R_Cx, R_R8, R_R9),       --  SysV x86-64
+      True  => (R_Cx, R_Dx, R_R8, R_R9, R_None, R_None));  --  Win X64
    Sse_Regs : constant Regs_List :=
      (False => (R_Xmm0, R_Xmm1, R_Xmm2, R_Xmm3,
                 R_Xmm4, R_Xmm5, R_Xmm6, R_Xmm7),
diff --git a/src/ortho/mcode/ortho_code-x86-emits.adb b/src/ortho/mcode/ortho_code-x86-emits.adb
index 48aa745e6..70b1fb584 100644
--- a/src/ortho/mcode/ortho_code-x86-emits.adb
+++ b/src/ortho/mcode/ortho_code-x86-emits.adb
@@ -1641,9 +1641,13 @@ package body Ortho_Code.X86.Emits is
       Gen_8 (Opc2_Grp1_And or 2#11_000_000# or To_Reg32 (Reg));
       Gen_32 (not (X86.Flags.Stack_Boundary - 1));
       End_Insn;
+      --  Call chkstk if needed.
+      --  On windows x32, chkstk probes the stack and allocate stack.
+      --  On windows x64, chkstk only probes the stack.
       if X86.Flags.Flag_Alloca_Call then
          Gen_Call (Chkstk_Symbol);
-      else
+      end if;
+      if (not X86.Flags.Flag_Alloca_Call) or X86.Flags.Win64 then
          --  subl esp, reg
          Start_Insn;
          Gen_Rex_B (Reg, Sz_Ptr);
diff --git a/src/ortho/mcode/ortho_code-x86-insns.adb b/src/ortho/mcode/ortho_code-x86-insns.adb
index 94b16754d..0264e952a 100644
--- a/src/ortho/mcode/ortho_code-x86-insns.adb
+++ b/src/ortho/mcode/ortho_code-x86-insns.adb
@@ -1231,12 +1231,16 @@ package body Ortho_Code.X86.Insns is
       use Interfaces;
       Subprg : constant O_Dnode := Get_Call_Subprg (Stmt);
       Push_Size : constant Uns32 := Uns32 (Get_Subprg_Stack (Subprg));
+      Push_Home : Uns32;
       Reg_Res : O_Reg;
       Pad : Uns32;
       Res_Stmt : O_Enode;
    begin
+      --  Note: Push_Offset may not be 0 if an argument contains a call.
+      --  In that case, the stack may not be aligned.
+
       --  Emit Setup_Frame (to align stack).
-      --  Pad the stack if necessary (this may be a nested call).
+      --  Pad the stack if necessary.
       Pad := (Push_Size + Push_Offset) and Uns32 (Flags.Stack_Boundary - 1);
       if Pad /= 0 then
          Pad := Uns32 (Flags.Stack_Boundary) - Pad;
@@ -1256,14 +1260,22 @@ package body Ortho_Code.X86.Insns is
          Clobber_Caller_Saved_Registers_32;
       end if;
 
+      if Flags.M64 and Flags.Win64 then
+         --  Need to reserve 4*8 bytes to home registers
+         Push_Home := 4*8;
+         Gen_Stack_Adjust (Int32 (Push_Home));
+      else
+         Push_Home := 0;
+      end if;
+
       --  Add the call.
       Reg_Res := Get_Return_Register (Get_Expr_Mode (Stmt));
       Set_Expr_Reg (Stmt, Reg_Res);
       Link_Stmt (Stmt);
       Res_Stmt := Stmt;
 
-      if Push_Size + Pad /= 0 then
-         Gen_Stack_Adjust (-Int32 (Push_Size + Pad));
+      if Push_Size + Push_Home + Pad /= 0 then
+         Gen_Stack_Adjust (-Int32 (Push_Size + Push_Home + Pad));
 
          --  The stack has been restored (just after the call).
          Push_Offset := Push_Offset - (Push_Size + Pad);