MSP430: Simplify and extend shift instruction patterns

The implementation of define_expand and define_insn patterns to handle
shifts in the MSP430 backend is inconsistent, resulting in missed
opportunities to make best use of the architecture's features.

There's now a single define_expand used as the entry point for all valid
shifts, and the decision to either use a helper function to perform the
shift (often required for the 430 ISA), or fall through to the
define_insn patterns can be made from that expander function.

Shifts by a constant amount have been grouped into one define_insn for
each type of shift, instead of having different define_insn patterns for
shifts by different amounts.

A new target option "-mmax-inline-shift=" has been added to allow tuning
of the number of shift instructions to emit inline, instead of using
a library helper function.

gcc/ChangeLog:

	* config/msp430/constraints.md (K): Change unused constraint to
	constraint to a const_int between 1 and 19.
	(P): New constraint.
	* config/msp430/msp430-protos.h (msp430x_logical_shift_right): Remove.
	(msp430_expand_shift): New.
	(msp430_output_asm_shift_insns): New.
	* config/msp430/msp430.c (msp430_rtx_costs): Remove shift costs.
	(CSH): Remove.
	(msp430_expand_helper): Remove hard-coded generation of some inline
	shift insns.
	(use_helper_for_const_shift): New.
	(msp430_expand_shift): New.
	(msp430_output_asm_shift_insns): New.
	(msp430_print_operand): Add new 'W' operand selector.
	(msp430x_logical_shift_right): Remove.
	* config/msp430/msp430.md (HPSI): New define_mode_iterator.
	(HDI): Likewise.
	(any_shift): New define_code_iterator.
	(shift_insn): New define_code_attr.
	Adjust unnamed insn patterns searched for by combine.
	(ashlhi3): Remove.
	(slli_1): Remove.
	(430x_shift_left): Remove.
	(slll_1): Remove.
	(slll_2): Remove.
	(ashlsi3): Remove.
	(ashldi3): Remove.
	(ashrhi3): Remove.
	(srai_1): Remove.
	(430x_arithmetic_shift_right): Remove.
	(srap_1): Remove.
	(srap_2): Remove.
	(sral_1): Remove.
	(sral_2): Remove.
	(ashrsi3): Remove.
	(ashrdi3): Remove.
	(lshrhi3): Remove.
	(srli_1): Remove.
	(430x_logical_shift_right): Remove.
	(srlp_1): Remove.
	(srll_1): Remove.
	(srll_2x): Remove.
	(lshrsi3): Remove.
	(lshrdi3): Remove.
	(<shift_insn><mode>3): New define_expand.
	(<shift_insn>hi3_430): New define_insn.
	(<shift_insn>si3_const): Likewise.
	(ashl<mode>3_430x): Likewise.
	(ashr<mode>3_430x): Likewise.
	(lshr<mode>3_430x): Likewise.
	(*bitbranch<mode>4_z): Replace renamed predicate msp430_bitpos with
	const_0_to_15_operand.
	* config/msp430/msp430.opt: New option -mmax-inline-shift=.
	* config/msp430/predicates.md (const_1_to_8_operand): New predicate.
	(const_0_to_15_operand): Rename msp430_bitpos predicate.
	(const_1_to_19_operand): New predicate.
	* doc/invoke.texi: Document -mmax-inline-shift=.

libgcc/ChangeLog:

	* config/msp430/slli.S (__gnu_mspabi_sllp): New.
	* config/msp430/srai.S (__gnu_mspabi_srap): New.
	* config/msp430/srli.S (__gnu_mspabi_srlp): New.

gcc/testsuite/ChangeLog:

	* gcc.target/msp430/emulate-srli.c: Fix expected assembler text.
	* gcc.target/msp430/max-inline-shift-430-no-opt.c: New test.
	* gcc.target/msp430/max-inline-shift-430.c: New test.
	* gcc.target/msp430/max-inline-shift-430x.c: New test.

3 files changed, 46 insertions, 0 deletions

diff --git a/libgcc/config/msp430/slli.S b/libgcc/config/msp430/slli.S
index c31e2d5..b22622e 100644
--- a/libgcc/config/msp430/slli.S
+++ b/libgcc/config/msp430/slli.S
@@ -65,6 +65,21 @@ __mspabi_slli:
 	RET
 #endif
 
+#ifdef __MSP430X__
+	.section	.text.__gnu_mspabi_sllp
+1:	ADDA	#-1,R13
+	ADDA	R12,R12
+	.global	__gnu_mspabi_sllp
+__gnu_mspabi_sllp:
+	CMP	#0,R13
+	JNZ	1b
+#ifdef __MSP430X_LARGE__
+	RETA
+#else
+	RET
+#endif /* __MSP430X_LARGE__ */
+#endif /* __MSP430X__ */
+
 /* Logical Left Shift - R12:R13 -> R12:R13.  */
 
 	.section	.text.__mspabi_slll_n
diff --git a/libgcc/config/msp430/srai.S b/libgcc/config/msp430/srai.S
index d4a47fa..0100a36 100644
--- a/libgcc/config/msp430/srai.S
+++ b/libgcc/config/msp430/srai.S
@@ -64,6 +64,21 @@ __mspabi_srai:
 	RET
 #endif
 
+#ifdef __MSP430X__
+	.section	.text.__gnu_mspabi_srap
+1:	ADDA	#-1,R13
+	RRAX.A	R12,R12
+	.global	__gnu_mspabi_srap
+__gnu_mspabi_srap:
+	CMP	#0,R13
+	JNZ	1b
+#ifdef __MSP430X_LARGE__
+	RETA
+#else
+	RET
+#endif /* __MSP430X_LARGE__ */
+#endif /* __MSP430X__ */
+
 /* Arithmetic Right Shift - R12:R13 -> R12:R13.  */
 
 	.section	.text.__mspabi_sral_n
diff --git a/libgcc/config/msp430/srli.S b/libgcc/config/msp430/srli.S
index 838c4bc..50db47c 100644
--- a/libgcc/config/msp430/srli.S
+++ b/libgcc/config/msp430/srli.S
@@ -66,6 +66,22 @@ __mspabi_srli:
 	RET
 #endif
 
+#ifdef __MSP430X__
+	.section	.text.__gnu_mspabi_srlp
+1:	ADDA	#-1,R13
+	CLRC
+	RRCX.A	R12,R12
+	.global	__gnu_mspabi_srlp
+__gnu_mspabi_srlp:
+	CMP	#0,R13
+	JNZ	1b
+#ifdef __MSP430X_LARGE__
+	RETA
+#else
+	RET
+#endif /* __MSP430X_LARGE__ */
+#endif /* __MSP430X__ */
+
 /* Logical Right Shift - R12:R13 -> R12:R13.  */
 
 	.section	.text.__mspabi_srll_n