Add -mno-r11 support to PowerPC 64

From-SVN: r175943

gcc/ChangeLog

+2011-07-06  Michael Meissner  <meissner@linux.vnet.ibm.com>
+
+	* config/rs6000/rs6000-protos.h (rs6000_call_indirect_aix): New
+	declaration.
+	(rs6000_save_toc_in_prologue_p): Ditto.
+
+	* config/rs6000/rs6000.opt (-mr11): New switch to disable loading
+	up the static chain (r11) during indirect function calls.
+	(-msave-toc-indirect): New undocumented debug switch.
+
+	* config/rs6000/rs6000.c (struct machine_function): Add
+	save_toc_in_prologue field to note whether the prologue needs to
+	save the TOC value in the reserved stack location.
+	(rs6000_emit_prologue): Use TOC_REGNUM instead of 2.  If we need
+	to save the TOC in the prologue, do so.
+	(rs6000_trampoline_init): Don't allow creating AIX style
+	trampolines if -mno-r11 is in effect.
+	(rs6000_call_indirect_aix): New function to create AIX style
+	indirect calls, adding support for -mno-r11 to suppress loading
+	the static chain, and saving the TOC in the prologue instead of
+	the call body.
+	(rs6000_save_toc_in_prologue_p): Return true if we are saving the
+	TOC in the prologue.
+
+	* config/rs6000/rs6000.md (STACK_POINTER_REGNUM): Add more fixed
+	register numbers.
+	(TOC_REGNUM): Ditto.
+	(STATIC_CHAIN_REGNUM): Ditto.
+	(ARG_POINTER_REGNUM): Ditto.
+	(SFP_REGNO): Delete, unused.
+	(TOC_SAVE_OFFSET_32BIT): Add constants for AIX TOC save and
+	function descriptor offsets.
+	(TOC_SAVE_OFFSET_64BIT): Ditto.
+	(AIX_FUNC_DESC_TOC_32BIT): Ditto.
+	(AIX_FUNC_DESC_TOC_64BIT): Ditto.
+	(AIX_FUNC_DESC_SC_32BIT): Ditto.
+	(AIX_FUNC_DESC_SC_64BIT): Ditto.
+	(ptrload): New mode attribute for the appropriate load of a
+	pointer.
+	(call_indirect_aix32): Delete, rewrite AIX indirect function
+	calls.
+	(call_indirect_aix64): Ditto.
+	(call_value_indirect_aix32): Ditto.
+	(call_value_indirect_aix64): Ditto.
+	(call_indirect_nonlocal_aix32_internal): Ditto.
+	(call_indirect_nonlocal_aix32): Ditto.
+	(call_indirect_nonlocal_aix64_internal): Ditto.
+	(call_indirect_nonlocal_aix64): Ditto.
+	(call): Rewrite AIX indirect function calls.  Add support for
+	eliminating the static chain, and for moving the save of the TOC
+	to the function prologue.
+	(call_value): Ditto.
+	(call_indirect_aix<ptrsize>): Ditto.
+	(call_indirect_aix<ptrsize>_internal): Ditto.
+	(call_indirect_aix<ptrsize>_internal2): Ditto.
+	(call_indirect_aix<ptrsize>_nor11): Ditto.
+	(call_value_indirect_aix<ptrsize>): Ditto.
+	(call_value_indirect_aix<ptrsize>_internal): Ditto.
+	(call_value_indirect_aix<ptrsize>_internal2): Ditto.
+	(call_value_indirect_aix<ptrsize>_nor11): Ditto.
+	(call_nonlocal_aix32): Relocate in the rs6000.md file.
+	(call_nonlocal_aix64): Ditto.
+
+	* doc/invoke.texi (RS/6000 and PowerPC Options): Add -mr11 and
+	-mno-r11 documentation.
+
 2011-07-06  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
 	PR other/49658

gcc/config/rs6000/rs6000-protos.h

@@ -171,6 +171,8 @@ extern unsigned int rs6000_dbx_register_number (unsigned int);
 extern void rs6000_emit_epilogue (int);
 extern void rs6000_emit_eh_reg_restore (rtx, rtx);
 extern const char * output_isel (rtx *);
+extern void rs6000_call_indirect_aix (rtx, rtx, rtx);
+extern bool rs6000_save_toc_in_prologue_p (void);
 
 extern void rs6000_aix_asm_output_dwarf_table_ref (char *);
 

gcc/config/rs6000/rs6000.c

@@ -130,6 +130,9 @@ typedef struct GTY(()) machine_function
   int ra_need_lr;
   /* Cache lr_save_p after expansion of builtin_eh_return.  */
   int lr_save_state;
+  /* Whether we need to save the TOC to the reserved stack location in the
+     function prologue.  */
+  bool save_toc_in_prologue;
   /* Offset from virtual_stack_vars_rtx to the start of the ABI_V4
      varargs save area.  */
   HOST_WIDE_INT varargs_save_offset;
@@ -20325,7 +20328,7 @@ rs6000_emit_prologue (void)
       JUMP_LABEL (jump) = toc_save_done;
       LABEL_NUSES (toc_save_done) += 1;
 
-      emit_frame_save (frame_reg_rtx, frame_ptr_rtx, reg_mode, 2,
+      emit_frame_save (frame_reg_rtx, frame_ptr_rtx, reg_mode, TOC_REGNUM,
 		       sp_offset + 5 * reg_size, info->total_size);
       emit_label (toc_save_done);
       if (using_static_chain_p)
@@ -20516,6 +20519,11 @@ rs6000_emit_prologue (void)
 	emit_move_insn (lr, gen_rtx_REG (Pmode, 0));
     }
 #endif
+
+  /* If we need to, save the TOC register after doing the stack setup.  */
+  if (rs6000_save_toc_in_prologue_p ())
+    emit_frame_save (sp_reg_rtx, sp_reg_rtx, reg_mode, TOC_REGNUM,
+		     5 * reg_size, info->total_size);
 }
 
 /* Write function prologue.  */
@@ -24469,9 +24477,14 @@ rs6000_trampoline_init (rtx m_tramp, tree fndecl, rtx cxt)
     /* Under AIX, just build the 3 word function descriptor */
     case ABI_AIX:
       {
-	rtx fnmem = gen_const_mem (Pmode, force_reg (Pmode, fnaddr));
-	rtx fn_reg = gen_reg_rtx (Pmode);
-	rtx toc_reg = gen_reg_rtx (Pmode);
+	rtx fnmem, fn_reg, toc_reg;
+
+	if (!TARGET_R11)
+	  error ("-mno-r11 must not be used if you have trampolines");
+
+	fnmem = gen_const_mem (Pmode, force_reg (Pmode, fnaddr));
+	fn_reg = gen_reg_rtx (Pmode);
+	toc_reg = gen_reg_rtx (Pmode);
 
   /* Macro to shorten the code expansions below.  */
 # define MEM_PLUS(MEM, OFFSET) adjust_address (MEM, Pmode, OFFSET)
@@ -27760,4 +27773,132 @@ rs6000_legitimate_constant_p (enum machine_mode mode, rtx x)
 	  || easy_vector_constant (x, mode));
 }
 
+
+/* A function pointer under AIX is a pointer to a data area whose first word
+   contains the actual address of the function, whose second word contains a
+   pointer to its TOC, and whose third word contains a value to place in the
+   static chain register (r11).  Note that if we load the static chain, our
+   "trampoline" need not have any executable code.  */
+
+void
+rs6000_call_indirect_aix (rtx value, rtx func_desc, rtx flag)
+{
+  rtx func_addr;
+  rtx toc_reg;
+  rtx sc_reg;
+  rtx stack_ptr;
+  rtx stack_toc_offset;
+  rtx stack_toc_mem;
+  rtx func_toc_offset;
+  rtx func_toc_mem;
+  rtx func_sc_offset;
+  rtx func_sc_mem;
+  rtx insn;
+  rtx (*call_func) (rtx, rtx, rtx, rtx);
+  rtx (*call_value_func) (rtx, rtx, rtx, rtx, rtx);
+
+  stack_ptr = gen_rtx_REG (Pmode, STACK_POINTER_REGNUM);
+  toc_reg = gen_rtx_REG (Pmode, TOC_REGNUM);
+
+  /* Load up address of the actual function.  */
+  func_desc = force_reg (Pmode, func_desc);
+  func_addr = gen_reg_rtx (Pmode);
+  emit_move_insn (func_addr, gen_rtx_MEM (Pmode, func_desc));
+
+  if (TARGET_32BIT)
+    {
+
+      stack_toc_offset = GEN_INT (TOC_SAVE_OFFSET_32BIT);
+      func_toc_offset = GEN_INT (AIX_FUNC_DESC_TOC_32BIT);
+      func_sc_offset = GEN_INT (AIX_FUNC_DESC_SC_32BIT);
+      if (TARGET_R11)
+	{
+	  call_func = gen_call_indirect_aix32bit;
+	  call_value_func = gen_call_value_indirect_aix32bit;
+	}
+      else
+	{
+	  call_func = gen_call_indirect_aix32bit_nor11;
+	  call_value_func = gen_call_value_indirect_aix32bit_nor11;
+	}
+    }
+  else
+    {
+      stack_toc_offset = GEN_INT (TOC_SAVE_OFFSET_64BIT);
+      func_toc_offset = GEN_INT (AIX_FUNC_DESC_TOC_64BIT);
+      func_sc_offset = GEN_INT (AIX_FUNC_DESC_SC_64BIT);
+      if (TARGET_R11)
+	{
+	  call_func = gen_call_indirect_aix64bit;
+	  call_value_func = gen_call_value_indirect_aix64bit;
+	}
+      else
+	{
+	  call_func = gen_call_indirect_aix64bit_nor11;
+	  call_value_func = gen_call_value_indirect_aix64bit_nor11;
+	}
+    }
+
+  /* Reserved spot to store the TOC.  */
+  stack_toc_mem = gen_frame_mem (Pmode,
+				 gen_rtx_PLUS (Pmode,
+					       stack_ptr,
+					       stack_toc_offset));
+
+  gcc_assert (cfun);
+  gcc_assert (cfun->machine);
+
+  /* Can we optimize saving the TOC in the prologue or do we need to do it at
+     every call?  */
+  if (TARGET_SAVE_TOC_INDIRECT && !cfun->calls_alloca
+      && !cfun->calls_setjmp && !cfun->has_nonlocal_label
+      && !cfun->can_throw_non_call_exceptions
+      && ((flags_from_decl_or_type (cfun->decl) & ECF_NOTHROW) == ECF_NOTHROW))
+    cfun->machine->save_toc_in_prologue = true;
+
+  else
+    {
+      MEM_VOLATILE_P (stack_toc_mem) = 1;
+      emit_move_insn (stack_toc_mem, toc_reg);
+    }
+
+  /* Calculate the address to load the TOC of the called function.  We don't
+     actually load this until the split after reload.  */
+  func_toc_mem = gen_rtx_MEM (Pmode,
+			      gen_rtx_PLUS (Pmode,
+					    func_desc,
+					    func_toc_offset));
+
+  /* If we have a static chain, load it up.  */
+  if (TARGET_R11)
+    {
+      func_sc_mem = gen_rtx_MEM (Pmode,
+				 gen_rtx_PLUS (Pmode,
+					       func_desc,
+					       func_sc_offset));
+
+      sc_reg = gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
+      emit_move_insn (sc_reg, func_sc_mem);
+    }
+
+  /* Create the call.  */
+  if (value)
+    insn = call_value_func (value, func_addr, flag, func_toc_mem,
+			    stack_toc_mem);
+  else
+    insn = call_func (func_addr, flag, func_toc_mem, stack_toc_mem);
+
+  emit_call_insn (insn);
+  return;
+}
+
+/* Return whether we need to always update the saved TOC pointer when we update
+   the stack pointer.  */
+
+bool
+rs6000_save_toc_in_prologue_p (void)
+{
+  return (cfun && cfun->machine && cfun->machine->save_toc_in_prologue);
+}
+
 #include "gt-rs6000.h"

gcc/config/rs6000/rs6000.opt

@@ -521,4 +521,10 @@ mxilinx-fpu
 Target Var(rs6000_xilinx_fpu) Save
 Specify Xilinx FPU.
 
+mr11
+Target Report Var(TARGET_R11) Init(1) Save
+Use/do not use r11 to hold the static link in calls.
 
+msave-toc-indirect
+Target Undocumented Var(TARGET_SAVE_TOC_INDIRECT) Save Init(1)
+; Control whether we save the TOC in the prologue for indirect calls or generate the save inline

gcc/doc/invoke.texi

@@ -807,7 +807,7 @@ See RS/6000 and PowerPC Options.
 -msdata=@var{opt}  -mvxworks  -G @var{num}  -pthread @gol
 -mrecip -mrecip=@var{opt} -mno-recip -mrecip-precision @gol
 -mno-recip-precision @gol
--mveclibabi=@var{type} -mfriz -mno-friz}
+-mveclibabi=@var{type} -mfriz -mno-friz -mr11 -mno-r11}
 
 @emph{RX Options}
 @gccoptlist{-m64bit-doubles  -m32bit-doubles  -fpu  -nofpu@gol
@@ -16325,6 +16325,19 @@ Generate (do not generate) the @code{friz} instruction when the
 rounding a floating point value to 64-bit integer and back to floating
 point.  The @code{friz} instruction does not return the same value if
 the floating point number is too large to fit in an integer.
+
+@item -mr11
+@itemx -mno-r11
+@opindex mr11
+Generate (do not generate) code to load up the static chain register
+(@var{r11}) when calling through a pointer on AIX and 64-bit Linux
+systems where a function pointer points to a 3 word descriptor giving
+the function address, TOC value to be loaded in register @var{r2}, and
+static chain value to be loaded in register @var{r11}.  The
+@option{-mr11} is on by default.  You will not be able to call through
+pointers to nested functions or pointers to functions compiled in
+other languages that use the static chain if you use the
+@option{-mno-r11}.
 @end table
 
 @node RX Options

gcc/testsuite/ChangeLog

+2011-07-06  Michael Meissner  <meissner@linux.vnet.ibm.com>
+
+	* gcc.target/powerpc/no-r11-1.c: New test for -mr11, -mno-r11.
+	* gcc.target/powerpc/no-r11-2.c: Ditto.
+	* gcc.target/powerpc/no-r11-3.c: Ditto.
+
 2011-07-06  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.dg/stack-layout-2.c: Cleanup expand rtl dump.

gcc/testsuite/gcc.target/powerpc/no-r11-1.c

+/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */
+/* { dg-skip-if "" { *-*-darwin* } { "*" } { "" } } */
+/* { dg-options "-O2 -mno-r11" } */
+
+int
+call_ptr (int (func) (void))
+{
+  return func () + 1;
+}
+
+/* { dg-final { scan-assembler-not "ld 11,16(3)" } } */

gcc/testsuite/gcc.target/powerpc/no-r11-2.c

+/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */
+/* { dg-skip-if "" { *-*-darwin* } { "*" } { "" } } */
+/* { dg-options "-O2 -mr11" } */
+
+int
+call_ptr (int (func) (void))
+{
+  return func () + 1;
+}
+
+/* { dg-final { scan-assembler "ld 11,16" } } */

gcc/testsuite/gcc.target/powerpc/no-r11-3.c

+/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */
+/* { dg-skip-if "" { *-*-darwin* } { "*" } { "" } } */
+/* { dg-options "-O2 -mno-r11" } */
+
+extern void ext_call (int (func) (void));
+
+int
+outer_func (int init)	/* { dg-error "-mno-r11 must not be used if you have trampolines" "" } */
+{
+  int value = init;
+
+  int inner (void)
+  {
+    return ++value;
+  }
+
+  ext_call (inner);
+  return value;
+}
+