msp430-protos.h: Add prototypes for new functions.

	* config/msp430/msp430-protos.h: Add prototypes for new functions.
	* config/msp430/msp430.c (msp430_preserve_reg_p): Add support for
	interrupt handlers.
	(is_attr_func): New function.
	(msp430_is_interrupt_func): New function.
	(is_naked_func): New function.
	(is_reentrant_func): New function.
	(is_critical_func): New function.
	(msp430_start_function): Add annotations for function attributes.
	(msp430_attr): New function.
	(msp430_attribute_table): New.
	(msp430_function_section): New function.
	(TARGET_ASM_FUNCTION_SECTION): Define.
	(msp430_builtin): New enum.
	(msp430_init_builtins): New function.
	(msp430_builtin_devl): New function.
	(msp430_expand_builtin): New function.
	(TARGET_INIT_BUILTINS): Define.
	(TARGET_EXPAND_BUILTINS): Define.
	(TARGET_BUILTIN_DECL): Define.
	(msp430_expand_prologue): Add support for naked, interrupt,
	critical and reentrant functions.
	(msp430_expand_epilogue): Likewise.
	(msp430_print_operand): Handle 'O' character.
	* config/msp430/msp430.h (TARGET_CPU_CPP_BUILTINS): Define
	NO_TRAMPOLINES.
	* config/msp430/msp430.md (unspec): Add UNS_DINT, UNS_EINT,
	UNS_PUSH_INTR, UNS_POP_INTR, UNS_BIC_SR, UNS_BIS_SR.
	(pushm): Use a 'n' rather than an 'i' constraint.
	(msp_return): Add generation of the interrupt return instruction.
	(disable_interrupts): New pattern.
	(enable_interrupts): New pattern.
	(push_intr_state): New pattern.
	(pop_intr_state): New pattern.
	(bic_SR): New pattern.
	(bis_SR): New pattern.
	* doc/extend.texi: Document MSP430 function attributes and builtin
	functions.

From-SVN: r202645

1 files changed, 53 insertions, 3 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index cb48220..cb0306b 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -30,7 +30,7 @@ extensions, accepted by GCC in C90 mode and in C++.
 * Constructing Calls::  Dispatching a call to another function.
 * Typeof::              @code{typeof}: referring to the type of an expression.
 * Conditionals::        Omitting the middle operand of a @samp{?:} expression.
-* __int128::			128-bit integers---@code{__int128}.
+* __int128::		128-bit integers---@code{__int128}.
 * Long Long::           Double-word integers---@code{long long int}.
 * Complex::             Data types for complex numbers.
 * Floating Types::      Additional Floating Types.
@@ -2813,7 +2813,7 @@ least version 2.20.1), and GNU C library (at least version 2.11.1).
 @item interrupt
 @cindex interrupt handler functions
 Use this attribute on the ARM, AVR, CR16, Epiphany, M32C, M32R/D, m68k, MeP, MIPS,
-RL78, RX and Xstormy16 ports to indicate that the specified function is an
+MSP430, RL78, RX and Xstormy16 ports to indicate that the specified function is an
 interrupt handler.  The compiler generates function entry and exit
 sequences suitable for use in an interrupt handler when this attribute
 is present.  With Epiphany targets it may also generate a special section with
@@ -2844,6 +2844,35 @@ Permissible values for this parameter are: @code{IRQ}, @code{FIQ},
 On ARMv7-M the interrupt type is ignored, and the attribute means the function
 may be called with a word-aligned stack pointer.
 
+Note, for the MSP430 you can provide an argument to the interrupt
+attribute which specifies a name or number.  If the argument is a
+number it indicates the slot in the interrupt vector table (0 - 31) to
+which this handler should be assigned.  If the argument is a name it
+is treated as a symbolic name for the vector slot.  These names should
+match up with appropriate entries in the linker script.  By default
+the names @code{watchdog} for vector 26, @code{nmi} for vector 30 and
+@code{reset} for vector 31 are recognised.
+
+You can also use the following function attributes to modify how
+normal functions interact with interrupt functions:
+
+@table @code
+@item critical
+@cindex @code{critical} attribute
+Critical functions disable interrupts upon entry and restore the
+previous interrupt state upon exit.  Critical functions cannot also
+have the @code{naked} or @code{reentrant} attributes.  They can have
+the @code{interrupt} attribute.
+
+@item reentrant
+@cindex @code{reentrant} attribute
+Reentrant functions disable interrupts upon entry and enable them
+upon exit.  Reentrant functions cannot also have the @code{naked}
+or @code{critical} attributes.  They can have the @code{interrupt}
+attribute.
+
+@end table
+
 On Epiphany targets one or more optional parameters can be added like this:
 
 @smallexample
@@ -3143,7 +3172,7 @@ and newer.
 
 @item naked
 @cindex function without a prologue/epilogue code
-Use this attribute on the ARM, AVR, MCORE, RL78, RX and SPU ports to indicate that
+Use this attribute on the ARM, AVR, MCORE, MSP430, RL78, RX and SPU ports to indicate that
 the specified function does not need prologue/epilogue sequences generated by
 the compiler.  It is up to the programmer to provide these sequences. The
 only statements that can be safely included in naked functions are
@@ -8844,6 +8873,7 @@ instructions, but allow the compiler to schedule those calls.
 * MIPS Paired-Single Support::
 * MIPS Loongson Built-in Functions::
 * Other MIPS Built-in Functions::
+* MSP430 Built-in Functions::
 * picoChip Built-in Functions::
 * PowerPC Built-in Functions::
 * PowerPC AltiVec/VSX Built-in Functions::
@@ -11853,6 +11883,26 @@ GCC defines the preprocessor macro @code{___GCC_HAVE_BUILTIN_MIPS_CACHE}
 when this function is available.
 @end table
 
+@node MSP430 Built-in Functions
+@subsection MSP430 Built-in Functions
+
+GCC provides a couple of special builtin functions to aid in the
+writing of interrupt handlers in C.
+
+@table @code
+@item __bic_SR_register_on_exit (int @var{mask})
+This clears the indicated bits in the saved copy of the status register
+currently residing on the stack.  This only works inside interrupt
+handlers and the changes to the status register will only take affect
+once the handler returns.
+
+@item __bis_SR_register_on_exit (int @var{mask})
+This sets the indicated bits in the saved copy of the status register
+currently residing on the stack.  This only works inside interrupt
+handlers and the changes to the status register will only take affect
+once the handler returns.
+@end table
+
 @node picoChip Built-in Functions
 @subsection picoChip Built-in Functions