On Sat, Jan 20, 2024 at 10:30 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> When an interrupt handler is implemented by an assembly stub which does:
>
> 1. Save all registers.
> 2. Call a C function.
> 3. Restore all registers.
> 4. Return from interrupt.
>
> it is completely unnecessary to save and restore any registers in the C
> function called by the assembly stub, even if they would normally be
> callee-saved.
>
> Add no_callee_saved_registers function attribute, which is complementary
> to no_caller_saved_registers function attribute, to mark a function which
> doesn't have any callee-saved registers. Such a function won't save and
> restore any registers. Classify function call-saved register handling
> type with:
>
> 1. Default call-saved registers.
> 2. No caller-saved registers with no_caller_saved_registers attribute.
> 3. No callee-saved registers with no_callee_saved_registers attribute.
>
> Disallow sibcall if callee is a no_callee_saved_registers function
> and caller isn't a no_callee_saved_registers function. Otherwise,
> callee-saved registers won't be preserved.
>
> After a no_callee_saved_registers function is called, all registers may
> be clobbered. If the calling function isn't a no_callee_saved_registers
> function, we need to preserve all registers which aren't used by function
> calls.
>
> gcc/
>
> PR target/103503
> PR target/113312
> * config/i386/i386-expand.cc (ix86_expand_call): Set
> call_no_callee_saved_registers to true when calling function
> with no_callee_saved_registers attribute. Replace
> no_caller_saved_registers check with call_saved_registers check.
> * config/i386/i386-options.cc (ix86_set_func_type): Set
> call_saved_registers to TYPE_NO_CALLEE_SAVED_REGISTERS for
> noreturn function. Disallow no_callee_saved_registers with
> interrupt or no_caller_saved_registers attributes together.
> (ix86_set_current_function): Replace no_caller_saved_registers
> check with call_saved_registers check.
> (ix86_handle_no_caller_saved_registers_attribute): Renamed to ...
> (ix86_handle_call_saved_registers_attribute): This.
> (ix86_gnu_attributes): Add
> ix86_handle_call_saved_registers_attribute.
> * config/i386/i386.cc (ix86_conditional_register_usage): Replace
> no_caller_saved_registers check with call_saved_registers check.
> (ix86_function_ok_for_sibcall): Don't allow callee with
> no_callee_saved_registers attribute when the calling function
> has callee-saved registers.
> (ix86_comp_type_attributes): Also check
> no_callee_saved_registers.
> (ix86_epilogue_uses): Replace no_caller_saved_registers check
> with call_saved_registers check.
> (ix86_hard_regno_scratch_ok): Likewise.
> (ix86_save_reg): Replace no_caller_saved_registers check with
> call_saved_registers check. Don't save any registers for
> TYPE_NO_CALLEE_SAVED_REGISTERS. Save all registers with
> TYPE_DEFAULT_CALL_SAVED_REGISTERS if function with
> no_callee_saved_registers attribute is called.
> (find_drap_reg): Replace no_caller_saved_registers check with
> call_saved_registers check.
> * config/i386/i386.h (call_saved_registers_type): New enum.
> (machine_function): Replace no_caller_saved_registers with
> call_saved_registers. Add call_no_callee_saved_registers.
> * doc/extend.texi: Document no_callee_saved_registers attribute.
>
> gcc/testsuite/
>
> PR target/103503
> PR target/113312
> * gcc.dg/torture/no-callee-saved-run-1a.c: New file.
> * gcc.dg/torture/no-callee-saved-run-1b.c: Likewise.
> * gcc.target/i386/no-callee-saved-1.c: Likewise.
> * gcc.target/i386/no-callee-saved-2.c: Likewise.
> * gcc.target/i386/no-callee-saved-3.c: Likewise.
> * gcc.target/i386/no-callee-saved-4.c: Likewise.
> * gcc.target/i386/no-callee-saved-5.c: Likewise.
> * gcc.target/i386/no-callee-saved-6.c: Likewise.
> * gcc.target/i386/no-callee-saved-7.c: Likewise.
> * gcc.target/i386/no-callee-saved-8.c: Likewise.
> * gcc.target/i386/no-callee-saved-9.c: Likewise.
> * gcc.target/i386/no-callee-saved-10.c: Likewise.
> * gcc.target/i386/no-callee-saved-11.c: Likewise.
> * gcc.target/i386/no-callee-saved-12.c: Likewise.
> * gcc.target/i386/no-callee-saved-13.c: Likewise.
> * gcc.target/i386/no-callee-saved-14.c: Likewise.
> * gcc.target/i386/no-callee-saved-15.c: Likewise.
> * gcc.target/i386/no-callee-saved-16.c: Likewise.
> * gcc.target/i386/no-callee-saved-17.c: Likewise.
> * gcc.target/i386/no-callee-saved-18.c: Likewise.
> ---
> gcc/config/i386/i386-expand.cc | 72 ++++++++++++++++---
> gcc/config/i386/i386-options.cc | 49 +++++++++----
> gcc/config/i386/i386.cc | 70 ++++++++++++++----
> gcc/config/i386/i386.h | 20 +++++-
> gcc/doc/extend.texi | 8 +++
> .../gcc.dg/torture/no-callee-saved-run-1a.c | 23 ++++++
> .../gcc.dg/torture/no-callee-saved-run-1b.c | 59 +++++++++++++++
> .../gcc.target/i386/no-callee-saved-1.c | 30 ++++++++
> .../gcc.target/i386/no-callee-saved-10.c | 46 ++++++++++++
> .../gcc.target/i386/no-callee-saved-11.c | 11 +++
> .../gcc.target/i386/no-callee-saved-12.c | 10 +++
> .../gcc.target/i386/no-callee-saved-13.c | 16 +++++
> .../gcc.target/i386/no-callee-saved-14.c | 16 +++++
> .../gcc.target/i386/no-callee-saved-15.c | 17 +++++
> .../gcc.target/i386/no-callee-saved-16.c | 16 +++++
> .../gcc.target/i386/no-callee-saved-17.c | 16 +++++
> .../gcc.target/i386/no-callee-saved-18.c | 51 +++++++++++++
> .../gcc.target/i386/no-callee-saved-2.c | 30 ++++++++
> .../gcc.target/i386/no-callee-saved-3.c | 8 +++
> .../gcc.target/i386/no-callee-saved-4.c | 8 +++
> .../gcc.target/i386/no-callee-saved-5.c | 11 +++
> .../gcc.target/i386/no-callee-saved-6.c | 12 ++++
> .../gcc.target/i386/no-callee-saved-7.c | 49 +++++++++++++
> .../gcc.target/i386/no-callee-saved-8.c | 50 +++++++++++++
> .../gcc.target/i386/no-callee-saved-9.c | 49 +++++++++++++
> 25 files changed, 709 insertions(+), 38 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
> create mode 100644 gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
> create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
>
> diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
> index 52754e114f4..c0c7c697440 100644
> --- a/gcc/config/i386/i386-expand.cc
> +++ b/gcc/config/i386/i386-expand.cc
> @@ -9739,17 +9739,41 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx
> callarg1,
> rtx use = NULL, call;
> unsigned int vec_len = 0.
> tree fndecl;
> + bool call_no_callee_saved_registers = false;
>
> if (GET_CODE (XEXP (fnaddr, 0)) == SYMBOL_REF)
> {
> fndecl = SYMBOL_REF_DECL (XEXP (fnaddr, 0));
> - if (fndecl
> - && (lookup_attribute ("interrupt",
> - TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))))
> - error ("interrupt service routine cannot be called directly");
> + if (fndecl)
> + {
> + if (lookup_attribute ("interrupt",
> + TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
> + error ("interrupt service routine cannot be called directly");
> + else if (lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
> + {
> + cfun->machine->call_no_callee_saved_registers = true;
> + call_no_callee_saved_registers = true;
> + }
> + }
> }
> else
> - fndecl = NULL_TREE;
> + {
> + if (MEM_P (fnaddr))
> + {
> + tree mem_expr = MEM_EXPR (fnaddr);
> + if (mem_expr != nullptr
> + && TREE_CODE (mem_expr) == MEM_REF
> + && lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (TREE_TYPE (mem_expr))))
> + {
> + cfun->machine->call_no_callee_saved_registers = true;
> + call_no_callee_saved_registers = true;
> + }
> + }
> +
> + fndecl = NULL_TREE;
> + }
>
> if (pop == const0_rtx)
> pop = NULL;
> @@ -9884,13 +9908,18 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx
> callarg1,
> vec[vec_len++] = pop;
> }
>
> - if (cfun->machine->no_caller_saved_registers
> + static const char ix86_call_used_regs[] = CALL_USED_REGISTERS;
> +
> + char clobbered_registers[FIRST_PSEUDO_REGISTER];
> + memset (clobbered_registers, 0, sizeof (clobbered_registers));
> +
> + if ((cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> && (!fndecl
> || (!TREE_THIS_VOLATILE (fndecl)
> && !lookup_attribute ("no_caller_saved_registers",
> TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))))
> {
> - static const char ix86_call_used_regs[] = CALL_USED_REGISTERS;
> bool is_64bit_ms_abi = (TARGET_64BIT
> && ix86_function_abi (fndecl) == MS_ABI);
> char c_mask = CALL_USED_REGISTERS_MASK (is_64bit_ms_abi);
> @@ -9903,8 +9932,11 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
> || (ix86_call_used_regs[i] & c_mask))
> && !STACK_REGNO_P (i)
> && !MMX_REGNO_P (i))
> - clobber_reg (&use,
> - gen_rtx_REG (GET_MODE (regno_reg_rtx[i]), i));
> + {
> + clobber_reg (&use,
> + gen_rtx_REG (GET_MODE (regno_reg_rtx[i]), i));
> + clobbered_registers[i] = 1;
> + }
> }
> else if (TARGET_64BIT_MS_ABI
> && (!callarg2 || INTVAL (callarg2) != -2))
> @@ -9917,6 +9949,7 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
> machine_mode mode = SSE_REGNO_P (regno) ? TImode : DImode;
>
> clobber_reg (&use, gen_rtx_REG (mode, regno));
> + clobbered_registers[i] = 1;
> }
>
> /* Set here, but it may get cleared later. */
> @@ -9953,6 +9986,27 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
> resolver could be used which clobbers R11 and R10. */
> clobber_reg (&use, gen_rtx_REG (DImode, R11_REG));
> clobber_reg (&use, gen_rtx_REG (DImode, R10_REG));
> + clobbered_registers[R11_REG] = 1;
> + clobbered_registers[R10_REG] = 1;
> + }
> +
> + if (call_no_callee_saved_registers)
> + {
> + /* After calling a no_callee_saved_registers function, all
> + registers may be clobbered. Clobber all registers that are
> + not clobbered yet and not used by the callee. */
> + bool is_64bit_ms_abi = (TARGET_64BIT
> + && ix86_function_abi (fndecl) == MS_ABI);
> + char c_mask = CALL_USED_REGISTERS_MASK (is_64bit_ms_abi);
> + for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
> + if (!fixed_regs[i]
> + && !clobbered_registers[i]
It seems to me clobbered_registers is only used here which seems
redundant, remove !clobbered_registers[i] should also be fine?
> + && !(ix86_call_used_regs[i] == 1
> + || (ix86_call_used_regs[i] & c_mask))
> + && !STACK_REGNO_P (i)
> + && !MMX_REGNO_P (i))
> + clobber_reg (&use,
> + gen_rtx_REG (GET_MODE (regno_reg_rtx[i]), i));
> }
>
> if (vec_len > 1)
> diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
> index b6f634e9a32..0cdea30599e 100644
> --- a/gcc/config/i386/i386-options.cc
> +++ b/gcc/config/i386/i386-options.cc
> @@ -3371,6 +3371,10 @@ ix86_simd_clone_adjust (struct cgraph_node *node)
> static void
> ix86_set_func_type (tree fndecl)
> {
> + bool has_no_callee_saved_registers
> + = lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (TREE_TYPE (fndecl)));
> +
> if (cfun->machine->func_type == TYPE_UNKNOWN)
> {
> if (lookup_attribute ("interrupt",
> @@ -3380,12 +3384,18 @@ ix86_set_func_type (tree fndecl)
> error_at (DECL_SOURCE_LOCATION (fndecl),
> "interrupt and naked attributes are not compatible");
>
> + if (has_no_callee_saved_registers)
> + error_at (DECL_SOURCE_LOCATION (fndecl),
> + "%qs and %qs attributes are not compatible",
> + "interrupt", "no_callee_saved_registers");
> +
> int nargs = 0;
> for (tree arg = DECL_ARGUMENTS (fndecl);
> arg;
> arg = TREE_CHAIN (arg))
> nargs++;
> - cfun->machine->no_caller_saved_registers = true;
> + cfun->machine->call_saved_registers
> + = TYPE_NO_CALLER_SAVED_REGISTERS;
> cfun->machine->func_type
> = nargs == 2 ? TYPE_EXCEPTION : TYPE_INTERRUPT;
>
> @@ -3401,7 +3411,19 @@ ix86_set_func_type (tree fndecl)
> cfun->machine->func_type = TYPE_NORMAL;
> if (lookup_attribute ("no_caller_saved_registers",
> TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
> - cfun->machine->no_caller_saved_registers = true;
> + cfun->machine->call_saved_registers
> + = TYPE_NO_CALLER_SAVED_REGISTERS;
> + if (has_no_callee_saved_registers)
> + {
> + if (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> + error_at (DECL_SOURCE_LOCATION (fndecl),
> + "%qs and %qs attributes are not compatible",
> + "no_caller_saved_registers",
> + "no_callee_saved_registers");
> + cfun->machine->call_saved_registers
> + = TYPE_NO_CALLEE_SAVED_REGISTERS;
> + }
> }
> }
> }
> @@ -3571,7 +3593,7 @@ ix86_set_current_function (tree fndecl)
> }
> ix86_previous_fndecl = fndecl;
>
> - static bool prev_no_caller_saved_registers;
> + static call_saved_registers_type prev_call_saved_registers;
>
> /* 64-bit MS and SYSV ABI have different set of call used registers.
> Avoid expensive re-initialization of init_regs each time we switch
> @@ -3582,12 +3604,13 @@ ix86_set_current_function (tree fndecl)
> reinit_regs ();
> /* Need to re-initialize init_regs if caller-saved registers are
> changed. */
> - else if (prev_no_caller_saved_registers
> - != cfun->machine->no_caller_saved_registers)
> + else if (prev_call_saved_registers
> + != cfun->machine->call_saved_registers)
> reinit_regs ();
>
> if (cfun->machine->func_type != TYPE_NORMAL
> - || cfun->machine->no_caller_saved_registers)
> + || (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS))
> {
> /* Don't allow SSE, MMX nor x87 instructions since they
> may change processor state. */
> @@ -3614,12 +3637,12 @@ ix86_set_current_function (tree fndecl)
> "the %<no_caller_saved_registers%> attribute", isa);
> /* Don't issue the same error twice. */
> cfun->machine->func_type = TYPE_NORMAL;
> - cfun->machine->no_caller_saved_registers = false;
> + cfun->machine->call_saved_registers
> + = TYPE_DEFAULT_CALL_SAVED_REGISTERS;
> }
> }
>
> - prev_no_caller_saved_registers
> - = cfun->machine->no_caller_saved_registers;
> + prev_call_saved_registers = cfun->machine->call_saved_registers;
> }
>
> /* Implement the TARGET_OFFLOAD_OPTIONS hook. */
> @@ -4018,8 +4041,8 @@ ix86_handle_fndecl_attribute (tree *node, tree name,
> tree args, int,
> }
>
> static tree
> -ix86_handle_no_caller_saved_registers_attribute (tree *, tree, tree,
> - int, bool *)
> +ix86_handle_call_saved_registers_attribute (tree *, tree, tree,
> + int, bool *)
> {
> return NULL_TREE;
> }
> @@ -4181,7 +4204,9 @@ static const attribute_spec ix86_gnu_attributes[] =
> { "interrupt", 0, 0, false, true, true, false,
> ix86_handle_interrupt_attribute, NULL },
> { "no_caller_saved_registers", 0, 0, false, true, true, false,
> - ix86_handle_no_caller_saved_registers_attribute, NULL },
> + ix86_handle_call_saved_registers_attribute, NULL },
> + { "no_callee_saved_registers", 0, 0, false, true, true, true,
> + ix86_handle_call_saved_registers_attribute, NULL },
> { "naked", 0, 0, true, false, false, false,
> ix86_handle_fndecl_attribute, NULL },
> { "indirect_branch", 1, 1, true, false, false, false,
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index c5eaeedc7e0..f10e745fb40 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -475,7 +475,9 @@ ix86_conditional_register_usage (void)
> except fixed_regs and registers used for function return value
> since aggregate_value_p checks call_used_regs[regno] on return
> value. */
> - if (cfun && cfun->machine->no_caller_saved_registers)
> + if (cfun
> + && (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS))
> for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
> if (!fixed_regs[i] && !ix86_function_value_regno_p (i))
> call_used_regs[i] = 0;
> @@ -944,7 +946,8 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>
> /* Sibling call isn't OK if there are no caller-saved registers
> since all registers must be preserved before return. */
> - if (cfun->machine->no_caller_saved_registers)
> + if (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> return false;
>
> /* If we are generating position-independent code, we cannot sibcall
> @@ -977,6 +980,14 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
> decl_or_type = type;
> }
>
> + /* Sibling call isn't OK if callee has no callee-saved registers
> + and the calling function has callee-saved registers. */
> + if ((cfun->machine->call_saved_registers
> + != TYPE_NO_CALLEE_SAVED_REGISTERS)
> + && lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (type)))
> + return false;
> +
> /* If outgoing reg parm stack space changes, we cannot do sibcall. */
> if ((OUTGOING_REG_PARM_STACK_SPACE (type)
> != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
> @@ -1139,6 +1150,12 @@ ix86_comp_type_attributes (const_tree type1,
> const_tree type2)
> != ix86_function_regparm (type2, NULL))
> return 0;
>
> + if (lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (type1))
> + != lookup_attribute ("no_callee_saved_registers",
> + TYPE_ATTRIBUTES (type2)))
> + return 0;
> +
> return 1;
> }
>
> @@ -6569,7 +6586,8 @@ ix86_epilogue_uses (int regno)
> and restoring registers. Don't explicitly save SP register since
> it is always preserved. */
> return (epilogue_completed
> - && cfun->machine->no_caller_saved_registers
> + && (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> && !fixed_regs[regno]
> && !STACK_REGNO_P (regno)
> && !MMX_REGNO_P (regno));
> @@ -6585,7 +6603,8 @@ ix86_hard_regno_scratch_ok (unsigned int regno)
> as a scratch register after epilogue and use REGNO as scratch
> register only if it has been used before to avoid saving and
> restoring it. */
> - return (!cfun->machine->no_caller_saved_registers
> + return ((cfun->machine->call_saved_registers
> + != TYPE_NO_CALLER_SAVED_REGISTERS)
> || (!epilogue_completed
> && df_regs_ever_live_p (regno)));
> }
> @@ -6595,14 +6614,32 @@ ix86_hard_regno_scratch_ok (unsigned int regno)
> bool
> ix86_save_reg (unsigned int regno, bool maybe_eh_return, bool
> ignore_outlined)
> {
> - /* If there are no caller-saved registers, we preserve all registers,
> - except for MMX and x87 registers which aren't supported when saving
> - and restoring registers. Don't explicitly save SP register since
> - it is always preserved. */
> - if (cfun->machine->no_caller_saved_registers)
> - {
> - /* Don't preserve registers used for function return value. */
> - rtx reg = crtl->return_rtx;
> + rtx reg;
> +
> + switch (cfun->machine->call_saved_registers)
> + {
> + case TYPE_DEFAULT_CALL_SAVED_REGISTERS:
> + /* If any no_callee_saved_registers functions are called and this
> + is not a no_callee_saved_registers function, we preserve all
> + registers which aren't used by function calls, except for MMX
> + and x87 registers which aren't supported when saving and
> + restoring registers. Don't explicitly save SP register since
> + it is always preserved. */
> + if (cfun->machine->call_no_callee_saved_registers)
> + return (!fixed_regs[regno]
> + && !call_used_regs[regno]
> + && !STACK_REGNO_P (regno)
> + && !MMX_REGNO_P (regno));
> + break;
> +
> + case TYPE_NO_CALLER_SAVED_REGISTERS:
> + /* If there are no caller-saved registers, we preserve all
> + registers, except for MMX and x87 registers which aren't
> + supported when saving and restoring registers. Don't
> + explicitly save SP register since it is always preserved.
> +
> + Don't preserve registers used for function return value. */
> + reg = crtl->return_rtx;
> if (reg)
> {
> unsigned int i = REGNO (reg);
> @@ -6618,6 +6655,9 @@ ix86_save_reg (unsigned int regno, bool
> maybe_eh_return, bool ignore_outlined)
> && !MMX_REGNO_P (regno)
> && (regno != HARD_FRAME_POINTER_REGNUM
> || !frame_pointer_needed));
> +
> + case TYPE_NO_CALLEE_SAVED_REGISTERS:
> + return false;
> }
>
> if (regno == REAL_PIC_OFFSET_TABLE_REGNUM
> @@ -7717,7 +7757,8 @@ find_drap_reg (void)
> registers in epilogue, DRAP must not use caller-saved
> register in such case. */
> if (DECL_STATIC_CHAIN (decl)
> - || cfun->machine->no_caller_saved_registers
> + || (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> || crtl->tail_call_emit)
> return R13_REG;
>
> @@ -7730,7 +7771,8 @@ find_drap_reg (void)
> registers in epilogue, DRAP must not use caller-saved
> register in such case. */
> if (DECL_STATIC_CHAIN (decl)
> - || cfun->machine->no_caller_saved_registers
> + || (cfun->machine->call_saved_registers
> + == TYPE_NO_CALLER_SAVED_REGISTERS)
> || crtl->tail_call_emit
> || crtl->calls_eh_return)
> return DI_REG;
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> index b9c574e62e1..bf1ca6014f5 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -2724,6 +2724,17 @@ enum function_type
> TYPE_EXCEPTION
> };
>
> +enum call_saved_registers_type
> +{
> + TYPE_DEFAULT_CALL_SAVED_REGISTERS = 0,
> + /* The current function is a function specified with the "interrupt"
> + or "no_caller_saved_registers" attribute. */
> + TYPE_NO_CALLER_SAVED_REGISTERS,
> + /* The current function is a function specified with the "noreturn"
> + or "no_callee_saved_registers" attribute. */
> + TYPE_NO_CALLEE_SAVED_REGISTERS
> +};
> +
> enum queued_insn_type
> {
> TYPE_NONE = 0,
> @@ -2793,9 +2804,12 @@ struct GTY(()) machine_function {
> /* How to generate function return. */
> ENUM_BITFIELD(indirect_branch) function_return_type : 3;
>
> - /* If true, the current function is a function specified with
> - the "interrupt" or "no_caller_saved_registers" attribute. */
> - BOOL_BITFIELD no_caller_saved_registers : 1;
> + /* Call saved registers type. */
> + ENUM_BITFIELD(call_saved_registers_type) call_saved_registers : 2;
> +
> + /* If true, the current function calls no_callee_saved_registers
> + functions. */
> + BOOL_BITFIELD call_no_callee_saved_registers : 1;
>
> /* If true, there is register available for argument passing. This
> is used only in ix86_function_ok_for_sibcall by 32-bit to determine
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index 0bc586d120e..4cafa6d416b 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -6767,6 +6767,14 @@ On x86-32 targets, the @code{stdcall} attribute causes
> the compiler to
> assume that the called function pops off the stack space used to
> pass arguments, unless it takes a variable number of arguments.
>
> +@cindex @code{no_callee_saved_registers} function attribute, x86
> +@item no_callee_saved_registers
> +Use this attribute to indicate that the specified function has no
> +callee-saved registers. That is, all registers can be used as scratch
> +registers. For example, this attribute can be used for a function
> +called from the interrupt handler assembly stub which will preserve
> +all registers and return from interrupt.
> +
> @cindex @code{no_caller_saved_registers} function attribute, x86
> @item no_caller_saved_registers
> Use this attribute to indicate that the specified function has no
> diff --git a/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
> b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
> new file mode 100644
> index 00000000000..8c48ec0c79a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
> @@ -0,0 +1,23 @@
> +/* { dg-do run { target i?86-*-* x86_64-*-* } } */
> +/* { dg-additional-sources no-callee-saved-run-1b.c } */
> +
> +extern void bar0 (int, int, int, int, int, int, int, int, int)
> + __attribute__ ((no_callee_saved_registers));
> +
> +void
> +foo (void)
> +{
> + bar0 (0, 1, 2, 3, 4, 5, 6, 7, 8);
> +}
> +
> +int
> +bar (int x)
> +{
> + return x;
> +}
> +
> +void
> +bad (void)
> +{
> + __builtin_abort ();
> +}
> diff --git a/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
> b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
> new file mode 100644
> index 00000000000..b3ce7e72e85
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
> @@ -0,0 +1,59 @@
> +/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
> +
> +extern void foo (void);
> +extern void bad (void);
> +extern int bar (int);
> +
> +void
> +__attribute__ ((no_callee_saved_registers))
> +bar0 (int i0, int i1, int i2, int i3, int i4, int i5, int i6,
> + int i7, int i8)
> +{
> + if (i0 != 0)
> + bad ();
> +
> + if (i1 != 1)
> + bad ();
> +
> + if (i2 != 2)
> + bad ();
> +
> + if (i3 != 3)
> + bad ();
> +
> + if (i4 != 4)
> + bad ();
> +
> + if (i5 != 5)
> + bad ();
> +
> + if (i6 != 6)
> + bad ();
> +
> + if (i7 != 7)
> + bad ();
> +
> + if (i8 != 8)
> + bad ();
> +
> + int a,b,c,d,e,f,i;
> + a = bar (5);
> + b = bar (a);
> + c = bar (b);
> + d = bar (c);
> + e = bar (d);
> + f = bar (e);
> + for (i = 1; i < 10; i++)
> + {
> + a += bar (a + i) + bar (b + i) +
> + bar (c + i) + bar (d + i) +
> + bar (e + i) + bar (f + i);
> + }
> +}
> +
> +int
> +main ()
> +{
> + foo ();
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
> new file mode 100644
> index 00000000000..8fe36eb5198
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
> @@ -0,0 +1,30 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern int bar (int)
> +#ifndef __x86_64__
> +__attribute__ ((regparm(3)))
> +#endif
> +;
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void *frame)
> +{
> + int a,b,c,d,e,f,i;
> + a = bar (5);
> + b = bar (a);
> + c = bar (b);
> + d = bar (c);
> + e = bar (d);
> + f = bar (e);
> + for (i = 1; i < 10; i++)
> + {
> + a += bar (a + i) + bar (b + i) +
> + bar (c + i) + bar (d + i) +
> + bar (e + i) + bar (f + i);
> + }
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
> new file mode 100644
> index 00000000000..87766c6cd88
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
> @@ -0,0 +1,46 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -mgeneral-regs-only
> -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
> +
> +extern void bar (void) __attribute__ ((no_callee_saved_registers));
> +
> +__attribute__ ((no_caller_saved_registers))
> +void
> +foo (void)
> +{
> + bar ();
> +}
> +
> +/* foo must save and restore all caller saved registers since bar won't
> + preserve any. */
> +/* { dg-final { scan-assembler-not "jmp\[\\t \]+_?bar" } } */
> +/* { dg-final { scan-assembler "call\[\\t \]+_?bar" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)ax" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)cx" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)dx" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)si" 1 } }
> */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)di" 1 } }
> */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r8" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r9" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r10" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r11" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)ax" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)cx" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)dx" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)si" 1 } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)di" 1 } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r8" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r9" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r10" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r11" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32
> } } } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
> new file mode 100644
> index 00000000000..902a764489e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +extern void foo (void); /* { dg-note "previous declaration" } */
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void) /* { dg-error "conflicting types" } */
> +{
> +}
> +
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
> new file mode 100644
> index 00000000000..5524a4af29c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +extern void foo (void) __attribute__ ((no_callee_saved_registers)); /* {
> dg-note "previous declaration" } */
> +
> +void
> +foo (void) /* { dg-error "conflicting types" } */
> +{
> +}
> +
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
> new file mode 100644
> index 00000000000..6757e72d848
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern void foo (void);
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +bar (void)
> +{
> + foo ();
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> +/* { dg-final { scan-assembler-not "call\[\\t \]+_?foo" } } */
> +/* { dg-final { scan-assembler "jmp\[\\t \]+_?foo" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
> new file mode 100644
> index 00000000000..2239e286e6a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern void bar (void) __attribute__ ((no_callee_saved_registers));
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void)
> +{
> + bar ();
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> +/* { dg-final { scan-assembler "jmp\[\\t \]+_?bar" } } */
> +/* { dg-final { scan-assembler-not "call\[\\t \]+_?bar" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
> new file mode 100644
> index 00000000000..10135fec9c1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
> @@ -0,0 +1,17 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
> +extern fn_t bar;
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void)
> +{
> + bar ();
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> +/* { dg-final { scan-assembler "jmp" } } */
> +/* { dg-final { scan-assembler-not "call\[\\t \]+" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
> new file mode 100644
> index 00000000000..112d1764f3e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (fn_t bar)
> +{
> + bar ();
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> +/* { dg-final { scan-assembler "jmp" } } */
> +/* { dg-final { scan-assembler-not "call\[\\t \]+" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
> new file mode 100644
> index 00000000000..1fd5daadf08
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern void foo (void) __attribute__ ((no_caller_saved_registers));
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +bar (void)
> +{
> + foo ();
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> +/* { dg-final { scan-assembler-not "call\[\\t \]+_?foo" } } */
> +/* { dg-final { scan-assembler "jmp\[\\t \]+_?foo" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
> new file mode 100644
> index 00000000000..e7101009be4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
> @@ -0,0 +1,51 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +#include <stdint.h>
> +
> +typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
> +
> +void
> +foo (uintptr_t p)
> +{
> + ((fn_t) p) ();
> +}
> +
> +/* foo must save and restore all caller saved registers since bar won't
> + preserve any. */
> +/* { dg-final { scan-assembler-not "jmp" } } */
> +/* { dg-final { scan-assembler "call\[\\t \]+" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } }
> */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } }
> */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32
> } } } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
> new file mode 100644
> index 00000000000..ce4ab3b1799
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
> @@ -0,0 +1,30 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern int bar (int) __attribute__ ((no_caller_saved_registers))
> +#ifndef __x86_64__
> +__attribute__ ((regparm(3)))
> +#endif
> +;
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void *frame)
> +{
> + int a,b,c,d,e,f,i;
> + a = bar (5);
> + b = bar (a);
> + c = bar (b);
> + d = bar (c);
> + e = bar (d);
> + f = bar (e);
> + for (i = 1; i < 10; i++)
> + {
> + a += bar (a + i) + bar (b + i) +
> + bar (c + i) + bar (d + i) +
> + bar (e + i) + bar (f + i);
> + }
> +}
> +
> +/* { dg-final { scan-assembler-not "push" } } */
> +/* { dg-final { scan-assembler-not "pop" } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
> new file mode 100644
> index 00000000000..453272e11c0
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +__attribute__ ((no_callee_saved_registers, no_caller_saved_registers))
> +void
> +foo (void) /* { dg-error "attributes are not compatible" } */
> +{
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
> new file mode 100644
> index 00000000000..ec566aaf09f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mgeneral-regs-only" } */
> +
> +__attribute__ ((no_callee_saved_registers, interrupt))
> +void
> +foo (void *frame) /* { dg-error "attributes are not compatible" } */
> +{
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
> new file mode 100644
> index 00000000000..b28b211986a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +typedef void (*fn_t) (void *) __attribute__ ((no_callee_saved_registers));
> +
> +void
> +foo (void *frame)
> +{
> +}
> +
> +fn_t func = foo; /* { dg-error "incompatible pointer type" } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
> new file mode 100644
> index 00000000000..a7b3bdabf43
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +typedef void (*fn_t) (void *) __attribute__ ((no_callee_saved_registers));
> +
> +__attribute__ ((no_callee_saved_registers))
> +void
> +foo (void *frame)
> +{
> +}
> +
> +fn_t func = foo;
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
> new file mode 100644
> index 00000000000..a1837fdfd4b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
> @@ -0,0 +1,49 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +extern void bar (void) __attribute__ ((no_callee_saved_registers));
> +
> +void
> +foo (void)
> +{
> + bar ();
> +}
> +
> +/* foo must save and restore all caller saved registers since bar won't
> + preserve any. */
> +/* { dg-final { scan-assembler-not "jmp\[\\t \]+_?bar" } } */
> +/* { dg-final { scan-assembler "call\[\\t \]+_?bar" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } }
> */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } }
> */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32
> } } } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
> new file mode 100644
> index 00000000000..90b98a21aef
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
> @@ -0,0 +1,50 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
> +extern fn_t bar;
> +
> +void
> +foo (void)
> +{
> + bar ();
> +}
> +
> +/* foo must save and restore all caller saved registers since bar won't
> + preserve any. */
> +/* { dg-final { scan-assembler-not "jmp" } } */
> +/* { dg-final { scan-assembler "call\[\\t \]+" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } }
> */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } }
> */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32
> } } } } */
> diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
> b/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
> new file mode 100644
> index 00000000000..e261100ac1a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
> @@ -0,0 +1,49 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move"
> } */
> +
> +typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
> +
> +void
> +foo (fn_t bar)
> +{
> + bar ();
> +}
> +
> +/* foo must save and restore all caller saved registers since bar won't
> + preserve any. */
> +/* { dg-final { scan-assembler-not "jmp" } } */
> +/* { dg-final { scan-assembler "call\[\\t \]+" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } }
> */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } }
> */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 }
> } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
> +/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
> +/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } }
> } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } }
> } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32
> } } } } */
> +/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32
> } } } } */
> --
> 2.43.0
>
--
BR,
Hongtao
